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FIELD  COLUMBIAN  MUSEUM. 

PUBLICATION  No.   127. 
ZOOLOGICAL  SERIES.  VOL.  VII,  No.  6. 


THE  ZOOLOGY  OF  LAKES 
AMATITLAN  AND  ATITLAN, 

GUATEMALA,  WITH 

SPECIAL  REFERENCE  TO 

ICHTHYOLOGY 


BY 


SETH  EUGENE  MEEK, 
Assistant  Curator  of  Department. 


CHARLES  B.  CORY, 
Curator  of  Department  of  Zoology. 


CHICAGO,  U.  S.  A. 

April,  1908. 


The  Zoology  of  Lakes  Amatitlan  and  Atitlan,  Guatemala, 
with  Special  Reference  to  Ichthyology. 


By  SETH  EUGENE  MEEK. 


The  following  paper  is  the  result  of  a  study,  under  the  patronage  of 
the  Government  of  Guatemala,  of  Lakes  Amatitlan  and  Atitlan  for 
the  purpose  of  determining  whether  and  how  the  quantity  and  quality 
of  the  useful  food  and  game  fishes  of  these  lakes  could  be  increased, 
and  to  determine  the  suitability  of  the  waters  for  the  introduction 
of  species  of  food-fishes  from  the  United  States  and  elsewhere,  and 
the  possibilities  of  fish-cultural  operations.  This  investigation  was 
undertaken  at  the  request  of  His  Excellency,  Sefior  Don  Manuel 
Estrada  Cabrera,  President  of  the  Republic  of  Guatemala.  Most 
attention  was  given  to  Lake  Amatitlan,  which  is  only  twenty  miles 
from  the  City  of  Guatemala,  and  easily  accessible  to  the  residents  of 
that  city.  The  field  work  was  done  during  the  months  of  January 
and  February,  1906.  In  this  I  received  considerable  assistance  from 
Dr.  Kellerman  and  Mr.  Smith,  of  the  Ohio  State  University,  who 
were  in  Guatemala  at  this  time  collecting  plants,  and  from  Dr.  N. 
Dearborn  and  Mr.  C.  M.  Barber,  who  were  then  in  Guatemala  col- 
lecting birds  and  mammals  for  this  Museum.  For  notes  and  other 
aids  concerning  the  plants  of  this  region,  I  am  indebted  to  Miss 
Josephine  E.  Tilden,*  of  the  University  of  Minnesota,  Dr.  J.  M.  Green- 
man,  of  this  Museum,  and  Mr.  H.  W.  Clark,f  of  the  U.  S.  Bureau  of 
Fisheries. 

In  the  study  of  the  collections  of  animals  made  during  this  time, 
I  received  the  assistance  of  specialists  to  whom  credit  is  given  in  the 
accounts  of  the  groups  studied  by  each.  I  also  received  many  cour- 
tesies from  Dr.  B.  W.  Evermann,  in  charge  of  the  Division  of  Scientific 
Enquiry  of  the  U.  S.  Bureau  of  Fisheries.  Mr.  J.  W.  Titcomb,  in  charge 
of  the  Division  of  Fish  Culture  U.  S.  Bureau  of  Fisheries,  kindly 
assisted  me  in  that  portion  of  this  paper  relating  to  the  recommenda- 
tions of  the  most  suitable  fishes  from  the  United  States  for  introduc- 
tion into  these  lakes.  I  wish  to  acknowledge  my  indebtedness  to 
Mr.  Combs,  U.  S.  Minister  to  Guatemala,  his  secretary,  Mr.  Brown, 


*  Proc.  Biol.  Soc.  Wash.  1908,  106-110. 
t  Proc.  Biol.  Soc  Wash.  1908,  92-105. 


159 


i6o 


FIELD  COLUMBIAN  MUSEUM  —  ZOOLOGY,  VOL.  VII. 


and  to  Mr.  Winslow,  U.  S.  Consul  General,  for  many  courtesies;  also 
to  Mr.  Hodgson  and  Mr.  Tisdal,  of  the  Guatemala  Central  Railroad, 
who  very  materially  aided  me  in  transportation.  I  am  especially 
indebted  to  Mr.  Carlos  Palma,  of  the  Consulate  of  Cuba,  who  very 
greatly  aided  me  in  my  business  relations  with  the  Government 
Officials  of  Guatemala. 

It  is,  perhaps,  not  out  of  place  here  to  state  that  this  investigation 
grew  out  of  a  desire  of  President  Cabrera  to  do  something  to  increase 
the  value  of  the  food  supply  of  Lake  Amatitlan.  He  therefore  asked 
Hon.  George  M.  Bowers,  U.  S.  Commissioner  of  Fish  and  Fisheries,  to 
recommend  some  person  who  was  properly  trained  to  make  the  neces- 
sary preliminary  investigation,  to  insure  the  best  possible  results. 

Very  little  has  been  done  towards  the  study  of  the  Zoology  of 
tropical  lakes,  which  makes  the  study  of  these  bodies  of  water  of 
some  scientific  value.  The  Government  of  Guatemala  has  already 
begun  to  establish  a  Fish  Cultural  station  on  Lake  Amatitlan,  the 
results  of  which  will  be  watched  with  considerable  interest. 

It  might  also  be  well  to  note  here  that  no  attempt  was  made  to 
collect  and  study  the  insects  in  or  about  the  lake.  The  species  of 
insects  most  important  in  an  investigation  of  this  kind  are  those  forms 
whose  larvae  live  for  a  time  in  the  water.  During  the  winter,  or  dry 
season,  these  insects  are  less  active  than  in  the  summer,  or  wet  season. 


VOLCAN   DE  AGUA  FROM    LAKE  AMATITLAN 


APRIL,  1908.       LAKES  AMATITLAN  AND  ATITLAN  —  MEEK. 


161 


LAKE  AMATITLAN. 

Lake  Amatitlan  is  situated  on  the  Pacific  slope  of  Guatemala  in 
lat.  90°  30'  N.,  long.  14°  25'  W.  Its  surface  is  about  4,000  feet  above 
sea  level,  and  about  1,000  feet  below  the  plateau  on  which  the  City  of 
Guatemala  is  built.  It  is  strictly  a  mountain  lake,  the  depression 
which  it  occupies  having  been  formed  when  the  surrounding  mountains 
took  their  present  form.  It  may,  therefore,  best  be  considered  as 


HOTEL  LAGUNA,  LAKE  AMATITLAN 

occupying  the  bottom  of  a  depression  in  the  plateau  above  mentioned. 
The  lake  and  its  small  valley  are  surrounded  by  mountains  whose 
average  altitude,  except  the  canon  and  a  few  low  hills  to  the  south- 
west, is  from  about  800  to  1,300  feet  above  its  surface.  It  occupies 
an  area  near  the  head  waters  of  the  Michatoya  River,  through  which 
its  waters  find  an  outlet  to  the  sea.  During  the  earliest  portion  of 
its  history  it  was  somewhat  oval  in  outline,  its  greatest  width  being 
about  3  miles,  its  length  about  8  miles.  The  long  diameter  of  the 
lake  is  nearly  in  a  northwest  and  southeast  direction.  To  the  north- 
east is  a  small  valley  which  is  drained  into  the  lake  by  the  Lobos 
River,  the  only  stream  which  flows  into  the  lake  during  the  entire 
year.  This  stream  has  the  appearance  of  having  shifted  its  position 


l62 


FIELD  COLUMBIAN  MUSEUM  —  ZOOLOGY,  VOL.  VII. 


many  times  during  the  past  centuries,  and  to  have  been  responsible 
for  transporting  much  of  the  material  which  has  filled  up  about  two- 
fifths  of  the  lake.  The  material  worn  from  the  mountains  by  rain  has 
been  transported  by  the  inlet  and  other  small  streams  to  the  lake,  form- 
ing that  portion  of  the  low  land  bordering  it  to  the  north  and  east. 


LAKE  AMATITLAN  FROM  ITS  UPPER  END 

This  land  has  so  encroached  on  the  lake  that  now  it  is  narrowest  near  its 
middle,  where  it  is  only  one-fourth  of  a  mile  wide.  The  bottom  at  this 
place  is  of  soft  mud,  apparently  to  a  considerable  depth.  This  is  evi- 
dent from  the  fact  that  much  trouble  was  experienced  in  making  a  fill 
across  this  narrow  portion  for  the  railroad.  This  fill  sank  out  of 
sight  as  soon  as  the  soft  material  of  which  the  bottom  of  the  lake  is 
composed  became  overloaded.  It  required  much  more  material  to 
make  the  railroad  fill  than  the  depth  of  the  water  indicated. 

To  the  northwest,  the  mountains  consist  of  hard  granite  rock  and 
basaltic  columns.  The  other  mountains  about  the  lake  are  mostly 
composed  of  loose  material,  much  of  it  being  volcanic  ashes,  pumice, 
and  other  soft  material,  which  is  easily  eroded.  The  hills  which  border 


APRIL,  1908.      LAKES  AMATITLAN  AND  ATITLAN  —  MEEK.  163 


SHORE  NEAR  OUTLET  OF  LAKE  AMATITLAN 


DELTA  AT  MOUTH  OF  LOBOS  RIVER   LAKE  AMATITLAN 


164 


FIELD  COLUMBIAN  MUSEUM  —  ZOOLOGY,  VOL.  VII. 


the  valley  to  the  north  are  composed  mostly  of  this  softer  material. 
Even  now,  in  low  water,  the  Lobos  River,  which  drains  this  valley, 
rolls  along  on  its  bottom  a  considerable  amount  of  this  material,  form- 
ing at  its  mouth  a  small  though  quite  typical  delta.  The  valley 
about  and  above  Moran  shows  evidence  of  considerable  erosion,  and 
the  material  carried  away  forms  a  large  portion  of  the  low  land  below 
this  city. 

Lake  Amatitlan  is  about  8  miles  long,  and  about  2%  miles  wide 
at  either  end,  and  %  mile  near  its  middle.     The  fill  on  which  the  rail- 


DELTA  AT  MOUTH  OF  LOBOS  RIVER,  LAKE  AMATITLAN 

road  is  built  divides  the  lake  into  two  parts,  or  two  quite  similar 
basins.  The  upper  is  the  smaller,  and  near  its  center  is  95  feet  in 
depth.  The  lower  and  larger  portion  is  no  feet  deep.  In  its  nar- 
rowest portion,  both  above  and  below  the  railroad,  the  lake  is  50  feet 
deep. 

The  bottom  of  the  lake  is  a  quite  uniform  basin ;  the  lake  is  deepest 
where  widest,  and  the  slope  from  shore  line  to  bottom  is  everywhere 
steep  and  quite  uniform.  The  bottom  is  covered  with  a  light  mud, 
mixed  with  the  remains  of  small  plant  life.  At  a  depth  of  about  three 
feet  this  mud  becomes  somewhat  firm,  and  is  a  clay-like  substance  of  a 
grayish-blue  color.  The  bottom  at  the  base  of  the  tules  is  quite  firm, 
being  covered  with  a  light  mud,  sand,  and  gravel. 


APRIL,  1908.     LAKES  AMATITLAN  AND  ATITLAN  —  MEEK. 


165 


i66  FIELD  COLUMBIAN  MUSEUM  —  ZOOLOGY,  VOL.  VII. 

The  temperature  of  the  water  in  the  lake  is  very  uniform.  During 
the  time  of  these  investigations,  the  surface  temperature  varied  from 
70°  F.  at  6:30  A.  M.  during  the  last  few  days  in  January,  to  76°  F.  at 
noon  to  4  p.  M.  about  the  middle  of  January.  The  heat  of  the  sun 
during  the  day  does  not  warm  the  water  at  the  surface  to  a  depth  of 
more  than  5  to  10  feet,  while  during  the  night  it  cools  off  quite 
rapidly.  From  January  22  to  February  i,  the  temperature  of  the 
air  at  6:30  A.  M.  was  from  53°  F.  to  60°  F.,  while  during  the  day  it 
seldom  rose  to  70°  F.  These  ten  days  of  cool  weather  did  not  cool 


HOT  SPRING,  LAGUNA,  LAKE  AMATITLAN 

the  water  in  the  lake  more  than  one  or  two  degrees.  From  my  obser- 
vation it  is  quite  evident  that  the  water  in  the  lake  never  becomes 
cooler  than  69°  F.,  and  that  it  is  never,  except  near  the  surface,  more 
than  two  or  three  degrees  warmer  than  this.  These  temperatures 
were  taken  with  a  Nigretti-Zamba  deep-sea  thermometer.  The  bottom 
temperatures  taken  were  not  always  recorded,  for  all  of  these  taken 
at  the  bottom  on  any  one  day  were  the  same. 

Along  the  south  and  east  ends  of  the  lake  are  a  number  of  warm 
or  hot  springs.  These  springs  discharge  their  waters  into  the  lake 
at  its  surface,  where  it  forms  only  a  thin  layer  of  hot  water  over  a 
small  area  near  the  spring,  and  soon  becomes  the  same  temperature  as 
the  air.  The  hot  springs  influence  the  temperature  of  the  water  in  the 


APRIL,  1908.     LAKES  AMATITLAN  AND  ATITLAN — MEEK.  167 

lake  only  a  few  feet  from  the  shore,  and  then  only  at  the  surface.  The 
many  bottom  temperatures  which  I  took  in  all  parts  of  the  lake  did 
not  indicate  any  local  sources  of  heat  in  the  bed  of  the  lake.  I  was 
unable  to  secure  a  thermometer  in  the  City  of  Guatemala  which  would 
register  over  110°  F.  and  so  I  was  unable  to  take  the  temperature  of 
the  water  as  it  came  from  these  hot  springs.  The  largest  and  hottest 
one,  near  the  station  of  Laguna,  was  hot  enough  to  boil  eggs  very  suc- 
cessfully. In  6  minutes  the  egg  would  be  soft  boiled,  at  10  to  12 
minutes  medium,  and  at  15  minutes  the  yolk  would  be  hard  but  the 
white  was  quite  soft. 

The  small  fishes  (Pcecilia  sphenops}  will  swim  nearly  up  to  these 
springs,  but  they  remain  in  the  cooler  layer  of  water  near  the  bottom. 
They  appear  to  be  swimming  in  water  hot  enough  to  scald  one's  hand, 
but  in  reality  are  in  water  not  warmer  than  90°  or  100°  F.  A  few  of 
these  fishes  were  placed  by  me  in  water  taken  directly  from  the  spring, 
and  these  died  almost  immediately.  These  small  fishes,  although  they 
come  very  close  to  the  spring,  do  so  in  the  lower  stratum  of  water. 
The  hot  springs  on  the  margin  of  Lake  Amatitlan  are  too  small  and 
too  near  the  surface  to  have  any  influence  on  the  general  temperature 
of  the  water  in  the  lake. 

The  water  is  only  moderately  clear.  A  white  disc  12  inches  in 
diameter  cannot  be  seen  at  a  depth  of  over  10  to  15  feet,  seldom  over 
12  feet.  The  same  disc  is  plainly  visible  in  Atitlan  at  a  depth  of 
45  feet.  The  lack  of  clearness  is  due  more  to  the  abundance  of  Plankton 
(microscopic  animals  and  plants)  in  the  water  than  to  the  fine,  silt-like 
material  held  in  suspension.  The  water  in  Lake  Amatitlan  is  slightly 
alkaline,  having  a  specific  gravity  of  about  1.002  (specific  gravity  of 
sea  water  is  1.027).  Compared  with  water  from  Lake  Michigan,  it 
contains  relatively  larger  quantities  of  soda,  potash,  lime,  magnesia, 
soluble  silica,  and  chlorine.  It  also  contains  a  small  quantity  of  iron 
and  aluminum.  The  following  table  gives  a  comparison  of  the  more 
common  mineral  substances  as  found  in  Lake  Amatitlan  and  Lake 
Michigan.  The  analysis  of  the  water  from  Lake  Michigan  was  made 
in  office  of  Chicago  Board  of  Health;  that  of  Lake  Amatitlan  by  Mr. 
R.  Gwirz,  in  charge  of  the  Government  Chemical  Laboratory  of 


i68          FIELD  COLUMBIAN  MUSEUM  —  ZOOLOGY,  VOL.  VII. 

Guatemala.     From  these  analyses,  the  following  table  was  prepared 
by  Mr.  Nichols,  of  this  Museum: 

Parts  per  million. 
L.  Michigan.     L.  Amatitlan. 

Silica 5  .00  40 .00 

Calcium  Carbonate 50 .00  140 .00 

Magnesium  Carbonate 16  .68  27  .30 

Calcium  Sulphate 22.77  trace 

Sod.  &  Pot.  Chloride r4-75  210.00 

Sod.  &  Pot.  Carbonates .      2.24  .... 

Ferric  Oxide  &  Alumina trace  6 .  oo 

Phosphates trace 

Potassium  Nitrate 2  .00 

Nitrates none 

Ammonia .02 

Oxygen  consumed  — 

in  acid  sol 4.6 

in  alkaline  sol 4.6 

Total  solids 1 1 1  . 40  42 1  . oo 

It  will  be  noticed  that  the  total  solids  in  the  water  of  Lake  Ama-- 
titlan  is  nearly  four  times  that  of  Lake  Michigan,  although  but  about 
i .  2  per  cent  of  that  of  sea  water.  The  water  of  Lake  Amatitlan, 
though  considerably  used  by  the  residents  for  drinking  purposes,  is 
not  a  good  potable  water.  It  is  slightly  salty  to  the  taste,  and  its 
oxygen  consuming  power  indicates  the  presence  of  considerable  de- 
composing organic  matter,  and  consequently  the  probable  presence  of 
bacteria.  It  is  probable  that  this  test  of  the  water  was  made  some 
time  after  the  water  was  taken  from  the  lake,  and  is  not  a  fair  indica- 
tion of  its  actual  condition.  By  the  residents  of  this  region  the  lake 
water  is  regarded  as  poor  for  drinking  purposes. 

The  amount  of  mineral  matter  in  the  lake  is  too  small  to  unfit  the 
water  for  fresh  water  fish  life.  The  volume  of  water  is  large,  and  the 
inflow  and  the  outflow  great  enough  to  prevent  the  lake  water  from 
ever  becoming  salty  to  any  harmful  extent. 

The  shore  vegetation  of  the  lake  may  be  characterized  as  only 
moderately  abundant.  A  few  large  trees,  as  the  Willow  (Salix 
Humboldtiana),  and  several  species  belonging  to  the  genus  Ficus 
(Rubber-trees)  grow  close  to  the  water's  edge,  their  low,  drooping 
branches  being  often  bathed  by  the  waves.  These  trees  afford  a  con- 
siderable amount  of  shade,  which  appears  to  be  a  favored  hiding  place 
for  fishes  in  the  lake.  This,  and  other  land  vegetation,  supports  a 
large  number  of  Fungi  and  Epiphytes  (Orchids  and  Bromeliads)  attrac- 
tive to  insects,  which  are  constantly  falling  into  the  lake  and  forming  a 
supply  of  food  for  fishes.  There  are  no  extensive  forest  areas  on  the 


APRIL,  1908.       LAKES  AMATITLAN  AND  ATITLAN  —  MEEK.  169 


WILLOWS  ON  UPPER  PORTION  OF  DELTA,  LAKE  AMATITLAN 


UPPER  END  OF  LAKE  AMATITLAN 


170          FIELD  COLUMBIAN  MUSEUM  —  ZOOLOGY,  VOL.  VII. 

sides  of  the  mountains  immediately  bordering  the  lake.  The  low 
flat  area  to  the  north  and  east  is  under  cultivation.  On  it  are  grown 
sugar  cane,  lemons,  oranges,  and  various  other  tropical  fruits.  The 
shrubs  which  grow  close  to  the  water's  edge  belong  mostly  to  the 
Compositae,  and  with  these  are  usually  associated  many  species  of 
Lichens,  Mosses,  Hepatics,  Ferns,  and  the  like. 

The  flowering  plants  of  the  marshes  are  only  moderately  abundant 
along  the  shores  of  Lake  Amatitlan,  for  there  is  very  little  low  wet 
land  along  the  margins,  and  very  small  areas  of  shallow  water.  The 
sudden  great  depth  makes  it  quite  impossible  for  the  higher  aquatic 
plants,  particularly  the  marsh  plants,  to  secure  a  foothold. 

The  most  conspicuous  of  these  marsh  plants  is  a  species  of  Cat-tail 
(Typha  angustifolia) ,  and  a  tall  Rush  (Scirpus  sp.).  These  two  species 
are  recognized  as  Tules  by  the  natives,  who  cut  and  dry  them  for 
weaving  into  mats.  They  usually  grow  together,  and  when  this  occurs 
one  is  generally  much  more  abundant  than  the  other.  The  Rush  is 
the  more  abundant  of  the  two  in  the  deeper  water.  Neither  of  these 
grows  where  the  water  is  more  than  five  or  six  feet  in  depth,  more  than 
half  of  the  plant  being  above  the  water.  A  small  Spike  Rush  (Eleo- 
charis  sp.)  is  quite  abundant  along  the  shore  next  the  lowland  where 
sandy.  It  grows  to  a  height  of  from  one  to  eight  inches,  and  is  usually 
entirely  submerged.  It  is  at  the  base  of  these  Cat-tails  and  Rushes 
that  the  larger  Moj arras  find  their  best  breeding  and  spawning 
grounds,  and  where  the  fishermen  find  the  capture  of  these  fishes  the 
easiest. 

There  are  two  species  of  grasses  growing  in  patches  along  the  shore 
of  the  lake.  The  larger  one  (Panicum  sp.)  is  more  common  on  the 
south  side  of  the  lake,  more  particularly  where  the  margin  is  rocky. 
In  general  appearance  it  resembles  sugar  cane  more  than  it  does  any 
other  plant  growing  in  the  water  of  the  lake,  the  other  grass  (Phrag- 
mites  sp.)  is  widely  distributed  here,  but  is  nowhere  abundant.  It 
occurs  mostly  on  the  side  adjacent  to  the  lowlands. 

There  are  two  floating  plants  which  occur  on  the  lake ;  the  smaller 
(Salvinia  natans)  is  the  more  widely  distributed,  being  found  in  most 
places  where  there  is  other  vegetation,  and  especially  so  in  the  neigh- 
borhood of  warm  springs.  The  larger  of  these  floating  plants  is  the 
Water  Lettuce  (Pistia  obcordata),  not  found  except  along  the  shore 
next  the  low  lands.  It  is  abundant  at  only  one  plant,  about  one  half 
mile  above  the  railroad.  The  inhabitants  call  this  plant  La  Chuga. 
It  is  easily  distinguished  from  all  other  floating  plants  by  its  broad 
leaves  growing  in  the  form  of  rosettes. 

There  are  several  species  of  Pickerel  weeds  growing  in  the  shallow 


APRIL,  1908.       LAKES  AMATITLAN  AND  ATITLAN  —  MEEK.  171 

water  where  they  can  get  a  foothold.  In  most  places,  especially  next  the 
low  lands,  these  plants  are  very  abundant,  usually  growing  to  a  depth 
of  20  feet  or  more.  They  are  usually  submerged,  though  occasionally 
the  upper  leaves  or  those  in  the  shallow  water  float  on  the  surface. 
Two  species  of  these  (Potamogeton  lucens  and  Potamogeton  sp.)  are 
very  abundant  where  found.  Associated  with  these  is  a  Hornwort 
(Ceratophyllum  demersum) ,  and  two  or  three  species  of  Char  a  are  abun- 
dant. These  submerged  plants  are  very  important  in  connection  with 
fish  food  supply,  since  the  absence  of  such  plants  means  absence  of  the 


WILD  LETTUCE,  LAKE  AMATITLAN 

small  animals  and  insect  larvae,  as  well  as  a  decrease  in  the  quantity 
of  algae.  The  tender  portions  of  these  plants  furnish  a  considerable 
supply  of  food  for  the  smaller  fishes  in  the  lake. 

There  is  in  Lake  Amatitlan  a  considerable  quantity  of  microscopic 
organism,  or  Plankton,  enough  to  prevent  the  water  from  being  suffi- 
ciently clear  to  see  a  white  object  a  foot  in  diameter  deeper  than  12  or 
15  feet.  The  Phytoplankton  here  much  exceeds  the  Zooplankton; 
in  Lake  Atitlan  the  reverse  is  true.  In  general  the  Zooplankton  is 
dependent  on  Phytoplankton  for  its  food  supply.  The  Phytoplankton 
of  Lake  Amatitlan  consists  chiefly  of  algae.  Closely  allied  to  but  not 
properly  included  in  Plankton  are  the  larger  forms  of  filamentous 
algae.  These  are  usually  associated  with  the  marsh  plants  and  are  often 


172          FIELD  COLUMBIAN  MUSEUM  —  ZOOLOGY,  VOL.  VII. 

attached  to  rocks,  pieces  of  dead  timber,  sticks,  and  to  the  branches  of 
trees  which  touch  the  water.  The  non-filamentous  forms,  or  the  blue- 
green  slimes,  are  very  abundant,  and  with  many  of  these  are  associated 
filamentous  forms.  Some  species  grow  in  considerable  quantities  in 
very  warm  water  near  the  warm  springs.  The  most  conspicuous  and 
by  far  the  most  abundant  of  these  blue-green  forms  is  a  species  of 
Clathrocystis.  It  is  exceedingly  abundant  near  the  surface  in  the  upper 
half  of  the  lake,  or  rather  that  portion  above  the  railroad,  but  is  not 
noticeable  to  the  naked  eye  on  that  portion  of  the  lake  below  the 
railroad.  Associated  with  this  form,  in  colonies,  are  several  species 
of  Anacystis  and  Anab&na.  Belonging  to  these  genera  are  the  char- 
acteristic "  Wasserbliite "  plants,  but  these  nowhere  on  the  lake  or 
near  its  margins  formed  a  scum  on  the  surface,  and  so,  in  the  strict 
sense,  "Wasserbliite"  cannot  be  said  to  exist  on  the  lake  in  January 
and  February,  especially  so  on  its  lower  half;  although,  in  a  broader 
use  of  the  term,  the  presence  of  Anabcena  and  Clathrocystis  in  such 
abundance  indicated  that  it  did  exist  to  a  limited  extent,  at  least,  on 
the  upper  half  of  the  lake.  "  Wasserbliite "  is  considered  by  some 
writers  to  be  injurious  to  fishes,  especially  so  in  small  stagnant  ponds. 
While  this  may  be  true  in  small  ponds,  it  certainly  is  not  in  such  large 
bodies  of  water  as  this  lake,  where  the  surface  is  frequently  agitated. 
These  forms  do  form  a  portion  of  the  food  supply  of  the  fishes  in 
this  lake,  and  no  doubt  furnish  the  important  food  supply  of  Ento- 
mostraca. 

The  fact  that  the  water  in  Lake  Amatitlan  has  about  the  same  tem- 
perature during  the  entire  year  would  indicate  that  Plankton  was 
quite  uniform  in  quantity  at  all  times;  a  condition  which  is  not  true, 
however,  of  our  northern  lakes. 

In  Lake  Amatitlan  the  Phytoplankton  is  much  more  abundant  in 
January  and  February  than  the  Zooplankton.  In  Lake  Atitlan  the 
reverse  is  true.  Lake  Atitlan,  the  larger  lake,  is  about  1,000  feet 
higher.  Its  water  will  average  from  one  to  two  degrees  cooler  than 
Lake  Amatitlan.  It  has  no  outlet,  and  its  drainage  area  is  very  small. 
That  portion  of  Lake  Amatitlan  which  is  the  least  disturbed  by  the 
inflow  and  the  outflow  of  water  contains  by  far  the  greatest  abundance 
of  Phytoplankton. 

The  abundance  of  the  blue-green  algae  previously  mentioned  on 
onte  portion  of  lake,  and  not  on  the  other,  is  not  well  understood. 
The  only  reason  I  am  able  to  suggest  why  they  are  so  much  more 
abundant  in  the  upper  part  of  the  lake  than  in  the  lower  is  that  the 
drainage  into  this  portion  of  the  lake  is  small  compared  to  that 
received  by  the  lower  portion.  The  upper  part  of  the  lake  becomes 


APRIL,  1908.       LAKES  AMATITLAN  AND  ATITLAN  —  MEEK.  173 

to  some  extent  a  body  of  partially  stagnant  water.  In  the  lower 
portion  there  is  a  constant  flowing  in  of  a  considerable  amount  of 
water  at  its  upper  portion,  and  a  constant  outflow  at  the  opposite 
end.  This  would  tend  to  decrease  the  quantity  of  any  floating  parti- 
cles in  the  water.  Much  of  the  algae  floats  on  or  near  the  surface. 
It  is  often  driven  together  by  the  wind,  forming  on  the  surface  of  the 
lake  large,  blue-green  patches.  The  alga?  to  which  these  species  are 
most  nearly  related  form  a  large  portion  of  the  food  supply  for  micro- 
scopic animal  life,  and  for  small  fishes  which  feed  on  vegetation.  The 
Algae  and  softer  portions  of  the  other  water  plants  furnish  a  large  part 
of  the  food  supply  for  the  young  fishes,  and  also  for  the  adult  of  the 
three  most  abundant  species  of  fishes  (Pescadito,  Serica,  and  Mojarra) 
in  the  lake. 

The  water  of  Lake  Atitlan  is  very  clear  as  compared  with  that  of 
Lake  Amatitlan  and,  as  noted  above,  the  amount  of  Plankton  material 
in  it  is  very  much  less. 

So  far  as  I  could  discover  there  are  no  diseases  among  the  fishes  of 
Lake  Amatitlan.  The  Mojarras  are  occasionally  infested  with  intes- 
tinal parasites,  but  the  fishes  appear  in  good  condition,  which  indicates 
that  these  do  no  harm.  Parasites  are  occasionally  noticed  in  the  other 
species  of  fishes  in  the  lake.  Intestinal  parasites  are  not  uncommon 
with  fishes  and  other  animals,  and  their  presence  is  not  to  be  regarded 
as  an  indication  of  ill  health  or  disease.  In  our  northern  waters  there 
are  occasionally  epidemics  among  fishes  during  which  many  dead  and 
dying  are  found  along  the  shore.  I  was  unable  to  learn  of  any  similar 
epidemic  among  the  fishes  of  Lake  Amatitlan.  If  such  ever  occur 
they  are  not  at  all  frequent  or  serious.  During  my  stay  at  the  lake  all 
animal  and  plant  life  in  the  lake  appeared  vigorous  and  healthy.  The 
uniform  temperature  of  the  water,  the  freedom  from  sewage,  and  the 
large  volume  of  water,  are  all  factors  which  induce  a  very  healthful 
condition  in  this  body  of  water.  An  over  supply  of  plant  life  contri- 
butes largely  to  eliminate  from  the  lake  the  noxious  gases  formed  from 
any  decomposition  of  animal  or  vegetable  life,  and  to  take  up  the 
waste  products  of  water  animals. 

The  conditions  of  Lake  Amatitlan,  its  fish  food  supply,  the  tem- 
perature and  purity  of  its  water,  etc.,  are  such  that  it  should  contain  a 
far  greater  number  of  large  fishes  than  it  does  at  present.  In  general, 
the  fishes  which  feed  on  animal  life  are  superior  as  food  for  man  to 
those  whose  food  consists  mostly  or  entirely  of  plants;  and  it  is  this 
class  of  the  larger  fishes  that  is  lacking  in  the  lake.  The  smaller 
fishes,  especially  the  Pescadito,  are  very  abundant,  and  it  seems  best 
to  introduce  a  few  large  species  into  the  lake  which  would  utilize  these 


174          FIELD  COLUMBIAN  MUSEUM  —  ZOOLOGY,  VOL.  VII. 

for  food.  In  this  way  a  species  of  fish  (the  Serica),  worthless  as  food 
for  man,  and  another  species  (the  Pescadito),  too  small  to  ever  become 
a  desirable  food  fish,  could  probably  be  converted  into  good  food 
fishes. 

In  the  Pacific  Slope  rivers  of  Guatemala  there  are  no  Mojarras 
which  strictly  feed  on  small  fishes,  and  none  larger  or  better  than  the 
one  now  found  in  the  lake.  The  largest  one  (Cichlasoma  trimacu- 
latum)  could  easily  be  introduced  into  the  lake.  Its  introduction 
would,  to  some  extent,  increase  the  food  fish  supply  of  the  lake  and 
its  presence  there  would  do  no  harm. 

In  the  Rio  Montagua  and  in  Lake  Isabel  is  a  large  Mojarra  (Cich- 
lasoma motaguense)  which  feeds  mostly  on  small  fishes.  After  the 
completion  of  the  Guatemala  Northern  Railroad  the  introduction  of 
this  fish  into  the  lake  could  be  easily  accomplished.  It  is  a  larger 
species  than  the  Mojarra  which  now  lives  in  the  lake. 

The  Robalo  (Centropomus  nigrescens]  and  the  Pepemechin  (Philyp- 
nus  dormitor)  are  food  fish  of  some  value.  These  are  both  found  in  the 
Pacific  Coast  streams  of  Guatemala.  Concerning  the  value  of  these 
fishes  as  food  or  game  fishes  I  know  almost  nothing.  The  Pepemechin 
is  quite  common  in  the  lakes  of  Nicaragua,  and  is  sold  in  the  markets 
there  for  about  the  same  price  as  is  the  Mojarra. 

The  Large-mouth  Black  Bass,  which  is  found  in  all  of  the  streams 
and  lakes  of  the  eastern  United  States,  from  Lake  Superior  to  Tampico, 
Mexico,  is  a  most  excellent  game  and  food  fish.  It  feeds  almost  alto- 
gether on  small  fishes.  Its  flesh  is  firm  and  better  flavored  than  that 
of  any  of  the  Mojarras  or  other  fishes  above  mentioned.  This  fish  is  a 
great  favorite  with  sportsmen,  who  fish  with  hook  and  line  for  pleasure. 
So  highly  prized  is  it  in  the  United  States,  that  it  has  been  introduced 
into  many  of  the  western  lakes  and  streams.  The  rate  of  growth  of 
the  Large-mouth  Black  Bass  varies  much  in  different  localities.  Indi- 
viduals in  some  of  our  United  States  hatching  stations  are  known  to 
reach  a  weight  of  two  to  eleven  pounds  when  two  or  three  years  of  age. 
In  lakes  and  streams  in  the  southern  United  States  this  fish  is  often 
taken  weighing  6  or  8  pounds,  while  individuals  are  not  uncommon 
weighing  20  pounds  or  more.  It  grows  larger  and  grows  more  rapidly 
in  the  waters  of  our  southern  states  than  farther  north.  In  these 
southern  waters  it  feeds  during  most  of  the  year.  During  the  winters 
in  the  northern  portion  of  the  United  States  the  lakes  and  rivers  become 
covered  with  ice,  and  the  water  in  them  under  the  ice  is  so  cold  that 
fishes  become  inactive  and  do  not  eat.  So  there  is  a  period  of  from 
2  to  4  months  that  fishes  have  no  chance  to  grow.  The  water  in 
Amatitlan  is  always  warm  enough  to  prevent  this  period  of  inactivity, 


APRIL,  1908.       LAKES  AMATITLAN  AND  ATITLAN  —  MEEK.  175 

and  so  fishes  will  grow  larger  in  a  given  time  there  than  in  the  United 
States.  In  this  respect  there  is  a  marked  difference  in  the  growth  of 
the  Large-mouth  Black  Bass  in  the  lakes  of  Wisconsin  and  of  Florida. 
The  Large-mouth  Black  Bass  spawns  in  the  spring.  It  deposits  its 
eggs  in  shallow  nests  which  it  makes  near  the  shore  in  shallow  water. 
Its  habits  in  this  respect  are  about  the  same  as  those  of  the  Mojarra 
found  in  Lake  Amatitlan. 

Closely  related  to  the  Large-mouth  Black  Bass  are  the  Rock  Bass 
(Ambloplites  rupestris),  the  Crappie  (Pomoxis  sparoides) ,  and  the  Blue- 
gill  (Lepomis  pallidus).  These  seldom  exceed  one  or  two  pounds  in 
weight.  They  feed  on  small  fishes  and  afford  much  pleasure  in  their 
capture  with  hook  and  line.  They  are  excellent  food  fishes.  These 
fishes  could  easily  be  introduced  with  the  Large-mouth  Black  Bass. 

In  the  lakes  of  Nicaragua  is  a  species  of  Mojarra  known  as  Guapote 
(Cichlasoma  managuense) .  In  shape  and  form  it  much  resembles  the 
Large-mouth  Black  Bass  of  the  United  States.  It  grows  to  a  length 
of  12  to  1 8  inches.  This  fish  feeds  upon  smaller  fishes.  It  is  the  best 
flavored  food  fish  found  in  the  lakes  in  Nicaragua.  It  will  live  out  of 
water  much  longer  than  any  of  the  fishes  I  have  so  far  mentioned, 
which  fact  will  greatly  assist  in  its  introduction  into  other  waters  than 
where  found.  Nothing  is  known  of  its  spawning  habits.  Considering 
the  temperature  of  the  water  (83°  F.)  in  which  it  lives,  its  flesh  is 
exceeding  firm  and  well  flavored.  In  the  future  stocking  of  tropical 
lakes  with  fishes,  I  am  sure  the  Guapote  should,  and  no  doubt  will, 
receive  favorable  consideration.  In  general,  the  fresh  water  fishes, 
when  taken  from  cold  water,  have  firmer  flesh  and  are  better  flavored 
than  those  taken  from  warm  water.  In  the  northern  lakes  of  the 
United  States  the  temperature  is  seldom  warmer  than  60°  F.  Lake 
Amatitlan  is  10°  F.  warmer.  Owing  to  the  fact  that  its  volume  of 
water  is  so  great  and  its  water  so  pure,  it  is  probable  that  the  Large- 
mouth  Black  Bass  would  not,  to  any  marked  degree,  lose  its  good  food 
qualities,  and  the  Guapote  would  probably  gain.  There  are  several 
species  of  Catfishes  which  could  easily  be  introduced  at  the  same  time. 

The  best  fishes  to  introduce  into  Lake  Amatitlan  are  the  Large- 
mouth  Black  Bass(Micropterus  salmoides),  the  Rock  Bass  (Ambloplites 
rupestris),  the  Crappie  (Pomoxis sparoides) ,  and  the  Bluegill  (Lepomis 
pallidus).  The  second  best  fish  seems  to  be  the  Guapote  (Cichlasoma 
managuense)  from  the  lakes  of  Nicaragua.  The  third  choice  would  be 
the  Mojarra  (Cichlasoma  motaguense)  from  Lake  Isabel  and  the 
Montagua  River.  There  could  be  no  objection  in  introducing  all  of 
these  fishes  at  the  same  time. 

The  habits  of  the  Moj arras"  dre  not  well-known,  and  their  recom- 


176          FIELD  COLUMBIAN  MUSEUM  —  ZOOLOGY,  VOL.  VII. 

mended  introduction  into  waters  other  than  those  in  which  they  are 
now  found  is  made  with  a  little  hesitancy.  I  am  very  sure  that  the 
introduction  of  those  that  I  have  named  will  do  no  harm,  and  the 
chances  are  that  to  introduce  any  or  all  of  them  will  considerably 
increase  the  supply  of  food  fish  in  the  lake. 

If  quantity  of  fishes  or  of  fish  food,  at  the  expense  of  quality,  is 
desired,  the  German  Carp  is  recommended.*  The  Carp  is  a  large, 
coarse  fish  which  grows  very  rapidly.  It  is  also  very  prolific.  A 
female  of  25  pounds'  weight,  brought  to  the  Museum  a  few  weeks  ago, 
contained  about  1,750,000  eggs.  This  fish  is  much  cultivated  in  small 
ponds  in  Germany,  Austria  and  other  European  countries,  and  for 
small  ponds  they  are  much  desired,  for  they  grow  more  rapidly  than 
do  most  of  our  better  food  fishes.  At  one  year  old,  they  weigh  about 
one  pound.  At  three  or  four  years  of  age,  they  grow  in  ponds  to  a 
weight  of  6  to  8  pounds.  In  large  bodies  of  water  they  grow  even 
more  rapidly.  In  the  Fox  River,  near  Chicago,  Carp  are  often  taken 
of  over  30  pounds  weight.  In  the  Illinois  River  more  pounds  of 
Carp  are  taken  by  commercial  fishermen  than  of  all  other  fishes  com- 
bined. The  Carp  feeds  upon  plants,  and  of  this  class  of  food  there  is 
an  abundance  in  Lake  Amatitlan. 

If  Carp  are  introduced  into  the  lake,  it  would  not  be  so  desirable 
to  put  into  it  the  Large-mouth  Black  Bass,  or  the  other  fishes  men- 
tioned. In  eating  vegetation  the  Carp  digs  up  the  bottom,  much  as 
do  hogs.  In  this  way  they  might  destroy  spawning  places  for  Mojarras, 
Large-mouth  Black  Bass,  and  other  fishes,  and  the  areas  suitable  for 
spawning  places  for  these  fish  are  small.  In  addition  to  this,  they  are 
sure  to  become  abundant  enough  to  stir  mud  and  sand  around  the 
shores  to  the  extent  of  making  the  water  very  muddy.  In  this  way, 
the  Carp  would  partially  destroy  some  of  the  beauty  of  the  lake. 

In  the  introduction  of  the  fishes  mentioned  the  important  thing 
to  decide  is  whether  first-class  fishes  are  desired  or  not.  If  they  are, 
the  Carp  should  not  be  introduced  into  the  lake.  It  is  not  nearly  so 
good  a  food  fish  as  is  the  Mojarra.  If  Carp  are  introduced,  the  supply 
of  fishes  for  food  will  be  many  times  as  great  as  it  is  now,  and  perhaps 
twice  as  much  as  if  the  other  species  mentioned  were  introduced.  The 
introduction  of  Carp  is  quite  sure  to  decrease  the  abundance  of  better 
fishes,  such  as  the  Large-mouth  Black  Bass,  the  Crappie,  the  Rock 
Bass  and  the  Guapote.  For  the  introduction  of  any  of  the  fishes 
mentioned,  the  food  supply  is  abundant.  The  water  is  clear  and  pure, 
and  the  temperature  is  such  that  they  would  feed  during  the  entire 
year,  and  thus  grow  rapidly. 

*  Mr.  J.  W.  Ticomb  strongly  believes  German  Carp  should  not  be  introduced  into  this  lake. 


APRIL,  1908.       LAKES  AMATITLAN  AND  ATITLAN  —  MEEK. 


177 


In  order  that  fishes  should  exist  in  at  least  fairly  large  numbers, 
they  should  not  be  disturbed  during  the  breeding  season.  The  supply 
of  fishes  in  Lake  Amatitlan  is  much  reduced  in  numbers  by  over  fishing 
during  the  breeding  season.  Especially  is  this  true  of  the  Mojarras. 
This  fish  deposits  its  eggs  in  nests  made  by  it  in  the  sand  at  the  base 
of  the  Tules.  When  depositing  their  eggs,  the  fishes  are  very  persistent 


FISHERMEN,  LAKE  AMATITLAN 

in  remaining  in  shallow  water  along  the  shore,  and  so  at  that  time  they 
are  more  easily  caught.  In  catching  them  by  the  methods  used  by 
the  lake  fishermen  many  of  the  nests  are  destroyed,  and  the  chances 
for  increase  are  much  reduced.  During  the  breeding  time  of  food 
fishes  a  portion  or  all  of  their  spawning  grounds  should  be  protected. 
The  fishes  at  the  breeding  time  are  not  so  good  to  eat  as  at  other  times 
of  the  year.  Another  bad  feature  in  the  taking  of  Mojarras  is  the 
capture  of  such  a  large  number  of  small  individuals.  The  smaller 


178  FIELD  COLUMBIAN  MUSEUM  —  ZOOLOGY,  VOL.  VII. 

ones  should  not  be  taken  from  the  lake.  In  one  or  two  years  they 
would  grow  into  large  fish  and  be  more  desirable.  The  German  Carp 
is  about  the  only  species  of  fish  that  will  increase  rapidly  no  matter 
when,  or  where,  or  how  caught.  All  other  species  should  be  protected 
and  cared  for  during  the  breeding  season ;  and  the  small  ones,  those  less 
than  X  or  %  grown,  should  not  be  taken  from  the  lake,  but  if  caught 
should  be  returned  immediately  to  the  water.  The  spawning  time  of 
the  Mojarras  and  the  Large-mouth  Black  Bass  is  in  the  spring  —  the 
most  of  it  during  April,  May,  and  June.  If  the  laws  regarding  fishing 
in  Lake  Amatitlan  were  as  strict  as  they  are  in  the  lakes  of  Illinois, 
Indiana,  and  others,  of  our  northern  states,  the  Mojarras  there  would 
greatly  increase  in  numbers.  The  Carp  need  no  protection,  and  where 
the  volume  of  water  is  as  great  as  it  is  in  Lake  Amatitlan,  they  are 
quite  sure,  if  introduced,  to  always  be  plentiful.  Personally,  I  should 
advise  that  Carp  be  not  introduced  into  the  lake. 

During  a  portion  of  January  and  February  a  maximum  and  mini- 
mum self-registering  thermometer  was  exposed  at  Laguna  with  the 
following  results.  The  coldest  time  of  the  day  was  between  3  and 
5  A.  M.  The  warmest  was  between  2  and  4  p.  M. 

January  17,  coldest  66°  F.  warmest  75°  F. 

18,  "       65°    "         "         76°  " 

19,  "        65°    "         "         76°  " 
"         so,        "        61°    "  74°  " 

21,  "  60°    "  "  74°  " 

22,  "  62°    "  "  79°  " 

23,  "  56°    "  "  70°  " 

24,  "  56°    "  "  67°  " 
"         25,  "  55°    "  "  66°" 

26,  55°    '  64°  " 

27,  "        56°    "          "         66°  " 

28,  "        53°    "          "         65°" 

30,  "        58°    "          "         69°  " 

31,  "        61°    "          "         69°  " 
February  i,        "        59°    "  72°  " 


LAKE  ATITLAN. 

Lake  Atitlan  is  a  mountain  lake,  whose  elevation  is  about  5,000 
feet  above  the  sea.  Except  for  the  narrow  pass  to  the  south,  through 
which  one  passes  on  the  road  between  San  Lucas  and  Patulul,  the 
lake  is  surrounded  by  mountains,  which  rise  directly  from  the  water's 
edge  to  an  elevation  of  about  2,500  feet  above  its  surface.  There  are 
several  small  streams  flowing  into  the  lake.  The  largest  one  empties 


APRIL,  1908.      LAKES  AMATITLAN  AND  ATITLAN  —  MEEK. 


179 


into  the  lake  near  the  village  of  Jairal;  the  next  largest  near  Pana- 
jachel.  The  valleys  drained  by  these  streams  are  each  about  one  mile 
wide  and  two  or  three  miles  in  length.  So  small  are  all  of  these  valleys 
that  the  shore  of  the  lake  has  been  but  very  slightly  changed  since  its 
formation.  The  lake  has  no  visible  outlet.  If  it  ever  had  one  it  was 
through  the  San  Lucas  pass.  On  the  south  shore  of  the  lake  are  two 
volcanoes,  Atitlan  and  San  Pedro,  whose  summits  are  7,000  feet  above 


LAKE  ATITLAN  SHOWING  DEPTH  WHERE  SOUNDINGS  WERE  TAKEN 

the  lake  and  12,000  feet  above  the  level  of  the  sea.  To  the  north  and 
back  of  the  mountains  bordering  this  side  of  the  lake,  is  the  plateau 
over  which  the  upland  road  between  Guatemala  City  and  Quezaltan- 
ango  passes.  This  plateau  is  about  5,000  feet  above  the  lake. 

Lake  Atitlan  is  about  12  miles  wide  and  about  24  miles  in  length. 
It  is  one  of  the  most  beautiful  of  our  American  lakes,  and  is  situated 
in  a  most  delightful  and  healthful  climate.  Its  elevation,  and  the 
scarcity  of  lowland  and  swampy  places,  unfit  it  as  a  habitation  for 
mosquitoes,  and  so  it  is  always  free  from  malarial  fevers. 


180           FIELD  COLUMBIAN  MUSEUM  —  ZOOLOGY,  VOL.  VII. 

Along  the  greater  part  of  the  shore  line  the  mountains  rise  perpen- 
dicularly out  of  the  water,  and  so  within  a  few  feet  of  the  water's  edge 
the  depth  is  very  great.  At  almost  any  point  along  the  shore  from 
San  Lucas  to  Santa  Cruz  (the  only  shore  where  soundings  were  made 
near  the  water's  edge)  the  lake  less  than  X  mile  from  shore  is  between 
400  and  700  feet  in  depth;  near  the  middle  of  the  eastern  half  of  the 
lake  its  depth  is  over  i  ,000  feet.  The  deepest  place  found  by  me  was 
1,055  feet,  which  is  probably  the  deepest  place  in  the  lake.  ' 

The  water  in  the  lake  is  exceedingly  clear.  A  white  disc  12  inches 
in  diameter  can  easily  be  seen  at  a  depth  of  45  feet.  The  shallow 
water  near  the  shore  is  confined  to  the  small  stretches  at  the  mouth 
of  the  few  small  inlets,  and  to  the  shore  to  the  north  of  Atitlan  and 
west  of  San  Lucas.  The  margins  of  these  areas  usually  support  a 
growth  of  Tules  such  as  are  found  in  Lake  Amatitlan.  In  these 
limited  areas,  water  plants,  as  Chara,  Potamogeton,  and  Algce,  are 
abundant. 

Of  microscopical  animal  and  plant  life  there  is  less  to  a  cubic  foot 
of  water  in  Lake  Atitlan  than  in  Amatitlan.  As  compared  with  its 
immense  volume  of  water  the  shore  vegetation  is  very  small  and 
the  spawning  and  feeding  grounds  for  fishes  are  very  much  re- 
duced. 

The  temperature  of  the  water  in  Atitlan  is  68  degrees.  The  surface 
during  warm  days  becomes  slightly  warmer  to  a  depth  of  about  5  feet. 
Below  5  or  10  feet  the  temperature  of  the  water  in  the  lake  is  68°  F. 
I  was  unable  to  take  the  temperature  deeper  than  750  feet,  but  wher- 
ever taken  the  temperature  was  the  same.  There  are  two  small 
streams  flowing  into  the  lake  near  Panajachel.  Between  3  130  and 
5:30  P.M.  on  February  19,  the  temperature  of  the  water  in  both  of 
these  streams  near  the  lake  was  64°  F. 

In  Lake  Atitlan  there  are  but  three  species  of  fishes,  all  of  which 
are  natives  of  Lake  Amatitlan.  The  largest  is  the  Serica  (Cichlasoma 
nigrofasciatum) ;  the  most  abundant  is  the  Pescadito  (Poecilia 
sphenops) ,  and  by  far  the  least  important  is  the  Gulumina  (Fundulus 
guatemalensis) .  These  fishes  are  much  used  for  food  by  the  natives, 
especially  by  those  people  living  in  Santa  Catalina.  These  fishes  are 
eaten  only  because  no  others  are  to  be  had.  An  effort  is  being  made 
to  introduce  into  this  lake  fishes  from  the  rivers  of  the  lowland. 
Already  two  or  three  species  of  Mojarra  and  the  Pepemechin  have 
been  brought  up  from  the  lowlands  and  placed  in  a  pond  near  San 
Lucas.  It  is  very  doubtful  if  much  benefit  will  be  derived  from  this 
effort  to  stock  the  lake,  but  certainly  no  harm  can  result  from  it. 
The  same  energy,  more  wisely  applied,  might  result  in  more  good. 


APRIL,  1908.      LAKES  AMATITLAN  AND  ATITLAN  —  MEEK.  181 

This  effort  is  an  experiment,  with  chances  in  favor  of  increasing  and 
improving,  to  a  very  limited  extent,  the  fishes  in  the  lake. 

The  conditions  for  introduction  of  fishes  into  Atitlan  are  much 
different  from  those  existing  in  Lake  Amatitlan.  Atitlan  is  very  deep, 
with  but  a  small  amount  of  shallow  water  for  spawning  and  feeding 
grounds.  It  is  very  certain  that  Lake  Atitlan  cannot  support  nearly 
so  many  fishes  per  cubic  meter  of  water  as  can  Lake  Amatitlan.  Its 
volume  of  water  being  many  times  greater,  the  capture  of  the  fishes 
would  be  much  more  difficult.  The  stocking  of  this  lake  for  strictly 
commercial  purposes  is  sure  to  result  in  disppointment. 


LAKE  ATITLAN  NEAR  PANAJACHEL 

The  fact  that  Lake  Atitlan  is  such  a  beautiful  sheet  of  water,  situ- 
ated at  an  altitude,  and  so  completely  surrounded  by  mountains  as  to 
insure  it  a  delightful  and  healthful  climate,  is  quite  sure  to  cause  it  to 
become  a  resort  for  many  people  living  in  the  cities  and  in  the  lowlands 
of  Guatemala.  There  is  nothing  that  would  add  more  to  the  attrac- 
tiveness of  this  place  than  to  have  in  the  lake  a  fair  supply  of  first-class 
game  fishes, —  that  is,  fishes  whose  capture  with  hook  and  line  would 
afford  recreation  and  pleasure.  Fishes  of  this  sort,  which  are  common- 
ly known  as  game  fishes,  are  the  only  ones  that  should  be  introduced  in- 
to this  lake.  Of  all  fishes  the  Carp  should  be  avoided.  The  vegetation 
about  the  lake  is  too  scant  to  ever  enable  this  fish  to  become  abundant 


182  FIELD  COLUMBIAN  MUSEUM  —  ZOOLOGY,  VOL.  VII. 

enough  to  be  of  commercial  value.  The  difficulty  of  taking  it,  or  any 
large  fishes,  from  the  lake  with  nets  would  be  so  great  as  to  make  fishing 
for  them  for  commercial  purposes  unprofitable. 

The  water  in  Lake  Atitlan  is  cool  enough  and  pure  enough  to 
justify  the  introduction  of  Rainbow  Trout  (Salmo  irideus).  This  is  a 
very  beautiful  fish,  a  very  excellent  food  fish,  and  one  very  popular 
with  the  professional  sportsman  who  fishes  for  pleasure  with  hook 
and  line.  It  is  one  of  the  very  best  American  game  fishes.  This  fish 
grows  to  a  weight  of  10  to  12  pounds  in  comparatively  warm  water, 
the  average  weight  being  from  3  to  6  pounds.  In  very  cool  water  the 
growth  is  slow,  and  the  fishes  may  never  exceed  one  or  two  pounds  in 
weight.  The  introduction  of  the  Rainbow  Trout  is  very  simple  and 
easy,  if  care  is  taken.  The  eggs  can  be  obtained  at  hatching  stations 
operated  by  the  United  States  Bureau  of  Fisheries,  packed  in  ice  and 
shipped  to  the  lake,  and  there  hatched.  After  trout  eggs  have  been 
hatched  until  the  eyes  appear  as  dark  spots,  their  development  can 
be  arrested  by  packing  them  in  moss  on  trays  which  are  surrounded 
by  ice.  Eggs  packed  in  this  way  have  been  sent  to  Europe,  Argen- 
tina, South  America,  and  to  New  Zealand,  and  they  could  easily  be 
taken  in  this  way  to  Lake  Atitlan.  The  small  streams  which  flow 
into  the  lake  would  furnish  a  limited  spawning  area,  but  the  supply  of 
fishes  could  easily  be  increased  by  the  addition  of  a  small  hatching  sta- 
tion on  one  of  the  streams.  The  artificial  propagation  of  trout 
presents  no  serious  difficulties.  Any  intelligent  person  who  is  careful 
can,  with  a  little  training,  successfully  operate  one  of  these  stations. 
The  Rainbow  Trout  is  a  fish  which  quite  readily  adapts  itself  to  sur- 
rounding conditions.  Its  natural  habitat  is  in  water  cooler  than  that 
found  in  Lake  Atitlan.  It  is  known  to  live  in  water  as  warm  as  75°  F. 
and  it  is  very  certain  that  it  will  do  well  in  a  large  body  of  pure  water, 
such  as  we  find  in  the  lake  in  question. 

In  addition  to  the  introduction  of  Rainbow  Trout,  the  Steelhead 
Trout  (Salmo  gairdneri)  and  the  Landlocked  Salmon  (Salmo 
sebago)  are  recommended.  These  fishes  grow  larger  than  do  the 
Rainbow  Trout,  and  their  eggs  can  be  transported  and  hatched  ,in 
the  same  way.  The  Trout  and  Salmon  are  much  more  easily  intro- 
duced into  the  lake  than  are  any  others,  and  they  are  far  more  de- 
sirable. 

The  next  desirable  fishes  to  introduce  into  Lake  Atitlan  are  the 
Large-mouth  Black  Bass,  the  Rock  Bass  and  the  Crappie.  These 
fishes  would  probably  do  well  in  the  lake,  but  they  should  not  be 
introduced  if  any  or  all  of  the  species  mentioned  above  are  put  into  the 
lake.  No  species  of  fishes  will  ever  become  abundant  in  this  body  of 


APRIL,  1908.        LAKES  AMATITLAN  AND  ATITLAN —  MEEK.  183 

water,  because  the  spawning  and  feeding  grounds  are  so  small,  when 
compared  with  the  immense  volume  of  water  in  the  lake. 

Lake  Atitlan  will  always  be  attractive  to  the  pleasure  seeker,  if 
it  contains  game  fishes  like  the  Rainbow  Trout  or  the  Large-mouth 
Black  Bass.  The  money  brought  to  its  shores  by  the  pleasure-seeker 
will,  no  doubt,  be  greater  than  could  be  realized  from  the  capture  and 
sale  of  German  Carp  if  introduced  there,  for  this  lake  is  not  suited  for 
Carp,  and  its  introduction  into  this  lake  should  not  be  considered. 
The  food  supply  is  not  at  all  large,  and  the  great  depth  of  the  water 
would  render  the  capture  of  the  Carp  very  difficult.  Carp  should 
never  be  introduced  into  Lake  Atitlan. 

The  Rainbow  Trout,  the  Steelhead,  and  the  Landlocked  Salmon 
are  the  most  favored  fish  for  this  lake.  If  these  fishes  are  not  selected, 
the  next  best  are  the  Large-mouth  Black  Bass,  the  Crappie,  the  Rock 
Bass,  and  the  Bluegill. 


THE  FISHES  OF  LAKES  AMATITLAN  AND  ATITLAN. 

The  fish  fauna  of  these  lakes  is  not  extensive.  In  Lake  Amatitlan 
occur  seven  species,  only  three  of  which,  the  smallest  ones,  are  found 
in  Lake  Atitlan.  Of  those  in  Lake  Amatitlan  only  three  exceed  a 
length  of  four  or  five  inches,  and  two  of  these  are  very  slender,  which 
really  leaves  but  one  species  which,  if  in  the  United  States,  would  be 
considered  of  sufficient  size  to  become  a  marketable  fish.  This  largest 
species  is  not  plentiful,  due  largely  no  doubt,  to  over  fishing.  For 
catching  the  smaller  species,  the  ordinary  cast  or  throw  net  is  used. 
These  nets  vary  in  size  from  about  four  feet  to  about  ten  feet  in  diam- 
eter. The  mesh  is  about  l/2  inch  stretch  measure.  The  larger 
Mojarras  are  taken  with  gill  nets,  which  are  usually  about  six  feet  in 
depth  and  about  100  to  300  feet  in  length,  with  a  mesh  of  about  1^4 
inches,  stretch  measure. 


Family  Siluridse.     CATFISHES;  B ACRES;  JUILINS. 

Rhamdia  cabrerae  Meek.  JUILIN. 

This  fish  inhabits  the  lake,  though  it  is  more  abundant  in  the 
outlet.  Its  food  consists  almost  entirely  of  insects  and  insect 
larvae.  The  stomachs  of  most  of  those  examined  by  me  con- 
tained almost  entirely  the  larvae  of  the  mosquito  and  the  damsel 
fly.  The  Juilin  seldom  reaches  a  length  of  over  200  mm.  It  is 


184  FIELD  COLUMBIAN  MUSEUM  —  ZOOLOGY,  VOL.  VII. 

very  slender,  and  so  one  that  is  full  grown  is  not  large.  As  a  fish 
for  food  for  man,  or  for  food  for  other  fishes,  it  is  of  very  little 
importance.  It  is  reported  to  spawn  during  the  months  of  March, 
April  and  May.  Lake  Amatitlan,  scarce. 


Family  <•>  ninot  i<la>.     EELS. 

Qymnotus  carapo  Linnaeus.     ANGUILLA. 

This  fish  reaches  a  length  of  about  210  mm.  It  is  very 
slender.  During  my  stay  at  the  lake  I  saw  but  three  specimens 
of  this  species,  and  was  unable  to  learn  much  about  its  habits. 
I  was  told  that  it  is  only  occasionally  taken  in  the  lake,  and  though 
it  is  much  prized  as  a  food  fish,  it  is  too  small,  and  found  in  too 
few  numbers,  to  be  of  any  economic  value.  This  fish  inhabits 
streams  from  Lake  Amatitlan  and  Rio  Motagua  to  the  Rio  de  la 
Plata  in  South  America.  Lake  Amatitlan,  scarce. 


Family  Characinidse.     CHARACINS. 

Astyanax  micropthalmus  Gunther.     PEPESCA. 

This  fish  reaches  a  length  of  about  140  mm.  It  is  a  deep  fish 
of  silvery  color,  with  a  dark  band  on  the  posterior  half  of  the  middle 
of  the  body.  The  food  of  this  fish  consists  almost  wholly  of 
insects  and  insect  larvae.  These  fishes  usually  go  to  deep  water 
in  the  daytime  and  so  seldom  are  fished  for  except  at  night.  They 
are  most  abundant  in  the  inlets  and  near  the  outlet  of  the  lake. 
The  Pepescas  are  sold  in  large  numbers  in  the  markets  at  Ama- 
titlan. They  spawn  about  May,  probably  April,  May  and 
June.  I  could  secure  no  information  in  regard  to  their  spawning 
habits.  This  fish  is  too  small,  and  is  found  in  quantities  not  large 
enough  to  be  of  much  economic  value.  Lake  Amatitlan,  common. 


Family  Pceciliidse.     KILLIFISHES. 

Fundulus  guatemalensis  Gunther.     GULUMINA. 

The  Gulumina  is  a  small,  nearly  cylindrical  fish  which  grows 
to  a  length  of  about  85  mm.  It  is  more  abundant  in  the  outlet 
of  the  lake  than  in  the  lake  itself.  This  fish  is  seldom  taken  in 
shallow  water  along  the  shores  where  the  Pescaditos  are  most 


APRIL,  1908.       LAKES  AMATITLAN  AND  ATITLAN  —  MEEK.  185 


FISH  TRAP   LAKE  AMATITLAN 


FISH  TRAP,  LAKE  AMATITLAN 


186  FIELD  COLUMBIAN  MUSEUM — ZOOLOGY,  VOL.  VII. 

abundant.  I  examined  many  large  catches  of  the  latter  and  did 
not  find  in  them  a  single  species  of  Gulumina.  I  observed  this 
small  fish  to  be  exceedingly  abundant  along  the  railroad  fill. 
During  warm  days,  when  the  sun  was  shining  brightly,  they  would 
rise  in  large  schools  near  the  surface  of  the  water.  On  coming 
near  the  water's  edge,  or  approaching  them  slowly  in  a  boat,  they 
would  sink  to  a  considerable  depth  and  hide  among  the  rocks.  The 
food  of  this  fish  consists  almost  entirely  of  insects  and  insect 
larvae.  It  is  said  to  spawn  about  March  and  April.  Lakes  Amati- 
tlan  and  Atitlan,  scarce. 

Pcecilia  sphenops  C.  &  V.     PESCADITO. 

There  are  probably  more  individuals  of  this  fish  in  Lake 
Amatitlan  than  of  all  other  fishes  combined.  It  is  a  small  fish, 
in  shape  and  size  much  like  the  Gulumina.  This  fish  is  vivi- 
parous; that  is,  it  brings  forth  its  young  alive.  Each  female  has 
a  brood  of  from  30  to  50  small  fishes.  The  young  are  born  in 
March  and  April  and  May.  This  fish  feeds  on  filamentous  alga?, 
the  larger  species  of  free  algae,  and  the  tender  parts  of  the  Char  a, 
Potamogeton  and  Ceratophyllum.  They  also  eat  mud  in  which 
microscopic  animal  and  plant  life  is  abundant,  and  also  insects  and 
insect  larvae  when  these  are  abundant.  This  species  comes  near 
shore  in  greater  numbers  during  the  night,  yet  they  seem  very 
plentiful  in  daytime  in  shallow  water.  They  are  caught  in  large 
quantities  by  the  residents  of  this  region.  Their  flesh  is  quite 
firm  and  well  flavored,  but  the  many  small  bones  and  their  small 
size  prevent  them  from  being  very  desirable  for  food.  The 
absence  of  better  fish,  or  the  presence  of  no  fish  at  all,  and  the 
ease  with  which  they  can  be  taken  in  large  numbers,  largely 
explains  why  so  many  are  used  for  food  by  residents  about  the 
lakes.  These  fishes  are  captured  by  the  small-mesh  throw-nets 
used  so  extensively  in  Spanish  American  countries.  In  order  to 
make  their  capture  more  certain  and  easy,  the  fishermen  build 
nearly  circular  basins  along  the  margins  of  the  lake.  These 
basins  are  formed  by  placing  rocks  around  the  margin,  enclosing 
areas  of  shallow  water  usually  about  one  or  two  feet  deep  and 
from  5  to  15  or  20  feet  in  diameter.  These  are  often  built  in  the 
shade  of  an  overhanging  bush,  or  they  may  or  may  not  be  covered 
with  brush.  On  the  side  towards  the  lake  a  narrow  opening  is 
left  through  which  these  small  fishes  enter  the  basin.  In  a  short 
time  the  Pescaditos  enter  these  basins  in  large  numbers.  After 


APRIL.  1908.       LAKES  AMATITLAN  AND  ATITLAN  —  MEEK.  187 


FISH  RUNWAYS,  SANTA  CATARINA.  LAKE  ATITLAN 


CATCHING  SERICAS   LAKE  ATITLAN 


i88  FIELD  COLUMBIAN  MUSEUM  —  ZOOLOGY.  VOL.  VII. 

they  have  become  accustomed  to  these  places,  the  fisherman 
removes  the  brush  and  the  fish  continue  to  enter  the  enclosure  the 
same  as  before.  When  the  net  is  thrown  into  the  center  of  the 
enclosure,  the  fish  become  frightened  and  swim  in  all  directions. 
By  the  time  the  net  strikes  the  water  they  have  gone  to  the  edges 
of  the  basin,  and  not  being  able  to  escape  swim  back  towards  the 
opposite  side  and  thus  many  are  caught  under  the  net.  A  few 
throws  take  most  of  the  fish  out  of  the  basin.  Soon,  however, 
others  come  in  and  are  captured  in  the  same  way.  The  Pesca- 
ditos  frequent  the  shore  and  these  basins  in  larger  numbers  at 
night  than  in  the  daytime,  and  so  fishing  for  them  is  done  mostly 
after  sundown.  In  rocky  places,  and  where  there  is  no  shallow 
water,  these  basins  are  made  by  digging  back  in  the  shore,  and  some 
have  been  made  at  the  expense  of  considerable  labor.  These 
small  fishes  are  usually  more  abundant  along  the  shores  where 
there  are  warm  springs.  On  Lake  Atitlan,  at  Santa  Catarina,  is 
a  stretch  of  shore  line  where  there  is  considerable  surface  of  warm 
water.  At  this  place  narrow  trenches  are  dug  back  some  dis- 
tance, which  this  species  frequents  in  large  numbers,  where  they 
are  easily  caught.  The  shore  of  this  lake  contains  only  small 
areas  of  shallow  water,  and  does  not  afford  opportunities  for  the 
construction  of  small  trap-like  basins  for  the  capture  of  this  fish, 
as  does  the  shore  at  Lake  Amatitlan.  Conical  traps,  made  of 
wickerwork,  are  also  used  here  to  capture  these  fishes.  The 
Serica  is,  however,  more  easily  taken  in  these  traps  than  is  this 
species.  In  these  lakes  and  neighboring  waters  there  are  evi- 
dently more  individuals  of  the  Pescadito  than  of  all  other  fishes 
combined.  This  is  especially  true  of  Lake  Atitlan.  This  species 
is  very  abundant  in  fresh  and  brackish  water  of  the  lowlands  of 
southern  Mexico,  south  to  Nicaragua.  In  Central  America  it  is 
the  small  fish  found  near  the  head  waters  of  rivers  on  both  sides 
of  the  divide.  It  is  the  small  fish  usually  seen  swimming  near 
the  hot  springs  in  Middle  America.  It  probably  never  goes  in 
water  warmer  than  100  to  110°  F.  It  certainly  does  not  at 
Amatitlan.  As  food  for  game  fishes,  it  will  serve  its  purpose  best. 
The  introduction  of  a  fish  which  lives  on  small  fishes  is  the  best 
means  of  converting  this  species  into  much  better  food  than 
it  at  present  makes.  Lakes  Amatitlan  and  Atitlan,  very 
abundant. 


APRIL,  1908.       LAKES  AMATITLAN  AND  ATITLAN  —  MEEK.  189 

Family  Cichlidse.     MOJARRAS. 

Cichlasoma  nigrofasciatum  Giinther.     SERICA. 

Next  to  the  Pescadito,  the  Serica  is  most  abundant  in  the 
lakes.  It  is  a  small  Mojarra  never  growing  longer  than  100  mm. 
As  a  food  fish  it  is  considered  of  little  value  by  the  people  who  live 
on  Lake  Amatitlan.  The  chief  objection  to  it  is  its  small  size  and 
the  numerous  small  bones  it  contains.  This  fish  is  not  seen  in  the 
markets  and  seldom  in  the  catch  of  any  of  the  fishermen  there. 
It  is  very  abundant  along  the  shores  where  there  is  much  vegeta- 
tion, as  it  feeds  almost  entirely  on  algae  and  the  tender  parts  of 
the  higher  water  plants  in  the  lakes.  It  is  a  handsome,  active 
fish,  but  of  no  important  commercial  value.  This  fish  in  Lake 
Atitlan  is  of  more  importance,  due  largely  to  the  absence  of  larger 
fishes.  It  is  easily  captured  by  use  of  conical  wickerwork  traps, 
which  are  set  in  the  water  where  vegetation  is  abundant.  The 
Serica  will  enter  fish  traps  of  this  style  in  Lake  Amatitlan  in  far 
greater  numbers  than  do  any  of  the  other  species  there.  Its  habits, 
so  far  as  known,  are  about  the  same  as  those  of  the  Mojarra.  They 
deposit  their  eggs  in  April,  May  and  June.  So  far  as  known,  this 
fish  is  found  only  in  the  mountain  lakes  of  western  Guatemala, 
but  it  is  not,  at  present,  recorded  from  any  of  the  rivers  of  the 
Republic.  Lakes  Amatitlan  and  Atitlan,  abundant. 

Cichlasoma  guttulatum  Giinther.     MOJARRA. 

This  is  the  largest  fish  in  Lake  Amatitlan.  The  largest  speci- 
men obtained  by  me  was  270  mm.  in  length.  It  is  a  very  hand- 
some fish ;  its  flesh  is  well  flavored  and  very  firm.  As  a  food  fish 
it  is  regarded  as  one  of  the  very  best  in  the  fresh  waters  of  the 
republic.  This  fish  feeds  to  some  extent  on  small  fishes,  but 
plants  formed  much  the  largest  supply  of  the  food  of  a  large 
number  of  specimens  examined  by  me.  The  Mojarra  deposits 
its  eggs  in  nests  made  in  the  sand  and  gravel  in  shallow  water  at 
the  base  of  the  Tules.  I  am  told  that  they  deposit  their  eggs  in 
April,  May  and  June.  This  fish  is  found  in  the  rivers  on  the  west 
slope  of  Guatemala.  Its  rather  small  size,  and  being  found  in 
rather  small  numbers,  prevent  its  becoming  a  food  fish  of  much 
importance.  Over  fishing,  especially  during  the  breeding  season, 
is  always  sure  to  keep  the  numbers  of  this  fish  much  reduced  in 
the  lake.  All  of  the  individuals  of  the  species  which  are  caught, 
whether  large  or  small,  are  used  for  food.  These  fishes  are 


igo  FIELD  COLUMBIAN  MUSEUM  —  ZOOLOGY,  VOL.  VII. 

usually  taken  in  gill  nets.  These  nets  are  about  one  to  300  feet 
in  length  and  about  6  feet  in  depth.  A  net  is  run  out  for  about 
^3  of  its  length  along  the  edge  of  the  Tules ;  the  ends  are  carried 
at  right  angles  into  the  Tules,  forming  three  sides  of  a  rectangular 
enclosure.  The  fishermen  then  get  between  the  shore  and  the 
net,  and  drive  the  fishes  with  considerable  vigor  towards  the  net. 
They  appear  to  be  easily  gilled.  The  net  is  then  taken  up  and 
put  out  as  a  seine  into  the  deeper  water  just  outside  the  line  of  the 
Tules,  in  the  form  of  a  circle.  The  boat  is  anchored  to  the  Tules, 


FISHING  FOR  MOJARRAS,  LAKE  AMATITLAN 

the  ends  of  the  net  are  drawn  to  the  boat,  and  the  circle  closed  by 
lapping  the  ends  of  the  net.  The  fishermen  slowly  pull  in  the  net 
by  the  cork  line,  permitting  it  to  gather  in  folds  at  each  end  of  the 
boat.  Usually  several  fishes  are  gilled  in  this  way,  and  are  taken 
out  as  the  net  is  pulled  in.  The  fishermen  then  move  to  another 
place  and  repeat  these  hauls  till  a  sufficient  number  of  fishes  are 
taken.  This  species  of  fish  is  usually  taken  in  daytime.  It  is  said 
that  at  night  they  go  into  deep  water.  The  largest  numbers  are 
taken  during  the  months  when  they  are  breeding,  for  during  this 
time  they  are  more  easily  caught.  The  practices  of  the  fishermen 
on  Lake  Amatitlan  in  taking  this  fish  at  all  times  of  the  year  are 
very  harmful  to  their  own  interests,  and  would  not  be  tolerated  on 


APRIL,  1908.      LAKES  AMATITLAN  AND  ATITLAN — MEEK.  191 

any  lake  or  stream  in  the  United  States.  These  fish  should  not  be 
disturbed  when  they  are  depositing  their  eggs,  and  at  other  times 
of  the  year  only  the  larger  ones  captured  should  be  retained,  and 
all  others  returned  to  the  lake.  Lake  Amatitlan,  common. 


AMPHIBIANS  OF  LAKES  AMATITLAN  AND  ATITLAN. 

One  toad  and  three  frogs  are  the  only  Amphibians  taken  at 
these  lakes.  During  the  winter  and  the  dry  season  these  animals 
are  not  abundant  in  the  tropics,  and  the  following  list  is  not  a  fair 
index  of  their  abundance  in  these  places.  The  larger  frog,  Rana 
pipiens,  is  the  only  one  used  for  food  by  the  natives.  It  occurs 
at  both  lakes.  For  assistance  in  the  identification  of  these  species 
I  am  indebted  to  Dr.  L.  Stejneger,  Smithsonian  Institution, 
Washington,  D.  C. 


Family  Bufonidae.    TOADS;    SAPOS. 

Bufo  marinus  Linnaeus.  TOAD;    SAPO. 

Several  toads  inhabit  Guatemala,  but  this  is  the  only  species 
I  found  on  the  shores  of  Lake  Amatitlan.  This  species  deposits 
its  eggs  in  shallow  water,  and  there  they  develop  into  the  larval 
or  tadpole  stage.  In  this  stage  they  feed  chiefly  on  algae.  Al- 
though many  of  them  are  eaten  by  fishes  they  are  not  abundant 
enough  to  furnish  any  large  supply  of  food  for  fishes.  This  toad 
is  very  abundant  in  the  West  Indies,  and  from  southern  Mexico 
to  Brazil.  It  is  one  of  the  largest  toads  in  Middle  America. 
Abundant  on  shores  of  Lake  Amatitlan,  but  it  does  not  occur  at 
Lake  Atitlan. 


Family  Ranicke.  FROGS;  RANAS. 

Rana  pipiens  Gmelin.     FROGS;  RANA. 

This  is  the  larger  of  the  two  frogs  found  in  this  region.  It  is 
found  in  wet  places  and  in  shallow  water,  along  the  shores  of 
both  lakes.  Its  feet  are  webbed,  a  character  which  distinguishes 
it  from  the  species  listed  below.  It  deposits  its  eggs  in  shallow 


192  FIELD  COLUMBIAN  MUSEUM  —  ZOOLOGY,  VOL.  VII. 

water,  and  these  develop  into  a  larval  or  tadpole  form,  which  much 
resembles  that  of  toads,  and  which  has  similar  habits.  The  tadpole 
or  larval  form  of  the  frog  is  larger  than  that  of  the  toad,  though 
the  adult  is  smaller.  Lakes  Amatitlan  and  Atitlan,  common. 


Family  Cystignathidse.  FROGS;  RANAS. 

Leptodactylus  microtis  Cope.     FROG;  RAN  A. 

This  small  frog  is  quite  abundant  in  wet  places  under  stones, 
pieces  of  wood  or  other  material,  which  easily  conceal  them. 
Its  breeding  habits  are  the  same  as  those  of  the  preceding  species. 
Though  quite  abundant  about  the  shores  of  the  lake  Amatitlan 
it  is  too  small  to  be  of  much  economic  importance.  The  adult 
frog  and  the  adult  toad  feed  mostly  on  insects.  This  species  was 
not  taken  at  Lake  Atitlan.  Common  at  Lake  Amatitlan. 


THE  REPTILES  OF  LAKES  AMATITLAN  AND  ATITLAN 

Reptiles  were  not  abundant  during  January  and  February  on 
or  about  the  shores  of  these  lakes,  and  none  of  those  found  there, 
except  one  turtle,  are  distinctively  water  animals.  The  following 
list  comprises  all  that  were  taken  or  were  common  near  the  water's 
edge.  No  water  snakes,  or  rather  snakes  frequenting  the  water, 
were  observed  during  my  stay  at  these  lakes. 


Family  Iguaiiidre.     IGUANAN. 

Basaliscus  vittatus  Gray. 

A  few  specimens  of  this  species  were  taken  along  the  more 
rocky  shores  of  Lake  Amatitlan.  It  is  not  nearly  so  abundant 
here  as  in  the  lower  lands. 

Iguana  rhinopla  Gray.     IGUANA. 

One  specimen  was  taken  during  my  stay  at  Lake  Amatitlan, 
the  only  one  I  saw. 

Ctenosaura  acanthura  Gray.     IGUANA. 

This  species  is  very  abundant  along  the  rocky  shores  of  the 
lake.  Its  eggs  and  flesh  are  eaten  by  the  natives.  This  species 


APRIL,  1908.       LAKES  AMATITLAN  AND  ATITLAN  —  MEEK.  193 

and  the  two  preceding  apparently  do  not  occur  on  the  shores  of 
Lake  Atitlan.  This  lizard  is  very  abundant  along  streams  in  the 
lower  lands  of  western  Guatemala. 


Family   Teiidse. 

Ameiva  undulata  Gray. 

This  small  lizard  is  quite  plentiful  on  the  shores  of  both  of 
these  lakes.  It  seldom,  if  ever,  enters  the  water,  and  is  too  small 
to  be  of  any  economic  value. 


Family    Cinosteridse.     TURTLES. 

Cinosternum  cruentatum  Dumeril.     TURTLE;  TORTUGA. 

The  only  turtle  I  saw  at  Lake  Amatitlan  was  an  individual  of 
this  species  which  I  purchased  of  a  native  at  Laguna.  So  far  as 
I  could  learn,  turtles  are  very  scarce  in  this  region.  The  specimen 
here  listed  agrees  well  with  the  accounts  of  the  species  as  given  by 
Dr.  Gtinther  and  Dr.  Boulenger.  Length  of  carapace  122  mm., 
width,  85  mm.,  depth,  62  mm. ;  length  of  anterior  lobe  of  plastron 
42  mm.,  of  middle  lobe  27  mm.,  of  posterior  lobe  45  mm.;  pos- 
terior margin  of  plastron  with  a  slight  notch. 

The  members  of  the  family  to  which  this  species  belongs  are 
regarded  as  inferior  for  food.  The  introduction  of  one  or  more 
turtles  would  increase  the  food  supply  of  the  lake,  and  in  no  way 
be  harmful  to  the  fishes  now  there,  or  to  the  fishes  introduced. 


THE  WATER  BIRDS  OF  LAKES   AMATITLAN  AND  ATITLAN. 

The  following  list  of  water  birds  includes  only  such  species  as 
were  collected,  by  Mr.  Barber  or  by  Dr.  Dearborn,  or  positively 
identified  by  other  means,  during  a  brief  visit  to  these  lakes  in 
March  and  April,  1906.  It  may  be  well  to  state  in  this  connection 
that  both  of  these  lakes  are  centers  for  all  bird  life,  at  least  during 
the  dry  season,  when  the  surrounding  mountains  are  without 
green  vegetation,  and  the  short  alluvial  valleys  alone  furnish 
green  foliage  and  food  for  all  classes  of  birds.  Most  of  the  species 
here  named  are  undoubtedly  to  be  found  in  this  region  only  in 


iQ4  FIELD  COLUMBIAN  MUSEUM — ZOOLOGY,  VOL.  VII. 

winter,  as  their  breeding  range  is  much  to  the  northward  of 
Guatemala.  This  account  of  the  water  birds  of  this  region  was 
kindly  furnished  me  by  Dr.  Ned  Dearborn*  of  this  museum. 


Family   Podieipedidse.     GREBES. 

Colymbus     dominicus    brachypterus    Chapman.     SHORT-WINGED 
GREBE. 

A  small  colony  of  Short-winged  Grebes  frequented  an  area  of 
surface  vegetation  in  a  small  bay  of  Atitlan  near  Panajachel, 
whence  several  specimens  were  collected  in  April. 

Colymbus    nigricollis    californicus   Heermann.     AMERICAN   EARED 
GREBE. 

American  Eared  Grebes  were  found  in  small  numbers  at  the 
western  end  of  Amatitlan,  and  more  common  and  generally  dis- 
tributed near  Panajachel  on  Atitlan.  At  this  latter  place,  the 
Indians,  by  dextrous  paddling  in  small  canoes,  tire  out  and 
capture  these  Grebes  after  a  short  but  lively  chase.  The  Grebes, 
as  well  as  all  the  other  species  of  water  birds,  remain  near  the 
shore  -when  undisturbed,  as  the  rapidly  declining  bottom  of  the 
lakes  allows  them  only  a  narrow  margin  to  feed  upon. 


Family   Aiiatidse.      DUCKS. 

Querquedula  discors  Linnaeus.     BLUE-WINGED  TEAL. 

One  specimen  of  Blue-winged  Teal,  taken  on  Atitlan  by  Mr. 
Barber  in  February,  was  the  only  duck  encountered  that  could  be 
identified.  A  flock  of  several  hundred  ducks  was  seen  at  Ama- 
titlan, but  they  were  so  wild  that  it  was  impossible  to  approach 
near  enough  to  make  out  what  they  were.  The  same  uncertainly 
prevailed  with  regard  to  a  few  other  ducks  at  Atitlan. 


Family   Ardeidse.     HERONS. 

Butorides  virescens  Linnaeus.     GREEN  HERON. 

Green   Herons  were  found   scatteringly  in  all   parts  of  the 

*For  an  account  of  the  birds  collected  on  this  Expedition,  see  Publica- 
tion 125  Field  Mus.  Nat.  Hist.,  Ornithological  Series,  Vol.  i,  No.  3,  69  to  138, 
1907. 


APRIL,  1908.       LAKES  AMATITLAN  AND  ATITLAN  —  MEEK.  195 

Republic  that  were   visited.     In   the  collection   made  by  Mr. 
Barber  at  Atitlan  is  one  specimen. 


Family    Kallida'.     RAILS;  COOTS. 

Porzana  Carolina  Linnaeus.     CAROLINA  RAIL. 

Carolina  Rails  winter  sparingly  about  the  shores  of  both  these 
lakes,  specimens  being  taken  at  each  of  them.  They  follow  the 
fringe  of  tules  wherein  are  food  and  seclusion. 

(iallinule  galeata  Lichtenstein.     FLORIDA  GALLINULE. 

A  single  Florida  Gallinule,  the  only  one  observed,  was  taken 
at  Amatitlan  in  February.  It  was  living  in  a  patch  of  tules 
adjacent  to  a  hot  spring. 

Fulica  americana  Gmelin.     COOT. 

Coots  winter  abundantly  at  both  lakes.  They  procure  most 
of  their  food  by  diving,  a  short  distance  out  from  shore,  though 
they  feed  more  or  less  in  the  strip  of  tules  that  fringes  the  water's 
edge.  They  dive  without  difficulty,  notwithstanding  the  fact 
that  when  they  come  to  the  surface  to  breathe  and  swallow,  they 
come  up  as  buoyantly  as  pieces  of  cork.  Coots  are  captured  by 
the  native  boatmen  at  Atitlan  in  the  same  manner  as  Grebes  are, 
that  is  to  say, —  by  running  down,  when  a  blow  from  a  paddle 
quickly  ends  the  chase.  This  mode  of  pursuit  was  observed 
frequently  at  Atitlan  by  both  Dr.  Meek  and  Mr.  Barber,  but  at 
Amatitlan  the  gun  was  the  only  weapon  used  against  any  sort  of 
water- fowl. 


Family  Scolopacidxe.     SNIPES. 

Gallinago  delicata  Ord.     WILSON'S  SNIPE. 

Several  Wilson's  Snipe  were  seen  at  Atitlan  in  March  by  Mr. 
Barber. 

Acititis  macularius  Linnaeus.     SPOTTED  SANDPIPERS. 

A  few  Spotted  Sandpipers  winter  in  this  region.     One  was 
seen  at  Amatitlan  and  two  were  secured  at  Atitlan. 


196  FIELD  COLUMBIAN  MUSEUM  —  ZOOLOGY,  VOL.  VII. 

Family  Charadriidse.     PLOVERS. 

Oxyechus  vociferus  Linnaeus.     KILLDEER. 

The  Killdeer  winters  in  some  parts  of  Guatemala  —  notably 
along  the  Motagua  River  —  in  considerable  numbers.  One  was 
observed  at  Atitlan  on  April  gth. 

Family    Alcedinidse.     KINGFISHERS. 

Ceryle  alcyon  Linnaeus.     BELTED   KINGFISHER. 

Belted  Kingfishers  were  not  uncommon  at  Atitlan,  where 
several  were  seen  and  one  taken.  One  was  seen  at  Amatitlan. 

Ceryle  americana  septentrional  is  Sharpe.     TEXAS  KINGFISHER. 

Texas  Kingfishers  were  found  at  both  lakes,  but  more  com- 
monly at  Atitlan,  where  two  specimens  were  secured. 


THE  ZOOPLANKTON  OF  LAKES  AMATITLAN  AND  ATITLAN. 

The  lowest  forms  of  microscopic  animals  found  in  these  lakes 
are  treated  under  this  head.  They  do  not  occur  in  any  very 
great  abundance  and  the  number  of  species  is  small.  The  follow- 
ing account  of  these  forms  was  kindly  furnished  me  by  Mr.  H. 
Walton  Clark,  Assistant,  U.  S.  Bureau  of  Fisheries,  Washington, 
D.  C. 


Family    Volvocidse. 

Ccelastrum  microporum  Naegeli. 

Not  uncommon.  A  few  specimens  were  found  scattered 
through  samples  No.  19  (Feb.  5th,  Amatitlan,  towing  made  at  noon 
from  bottom  to  top  in  no  feet  water)  and  No.  20  (Jan.  iyth,  Lake 
Amatitlan,  in  front  of  hotel).  None  of  the  specimens  showed 
the  tubercles  on  the  cells  shown  in  many  illustrations,  but  accord- 
ing to  descriptions  and  a  few  figures,  these  may  be  absent.  One 
colony  appeared  to  possess  eye-spots,  one  in  each  cell.  One  colony 
examined  measured  60  //.  diameter,  cells  15  ,«;  full  grown  col- 


APRIL,  1908.       LAKE  AMATITLAN  AND  ATITLAN — MEEK.  197 

onies  are  said  to  attain  a  diameter  of  40-100  /.*.,  and  individual 
cells  as  much  as  25  /*. 

Eudorina  stagnate  Wolle. 

This  is  one  of  the  common  elements  of  the  plankton,  occurring 
in  the  greater  number  of  samples,  never  in  great  abundance,  but 
usually  several,  and  often  numerous  examples  could  be  seen  in  the 
field  at  the  same  time.  It  was  quite  frequently  found  in  stages 
of  active  division. 

I  have  not  had  opportunity  to  compare  carefully  Wolle's 
description  of  Eudorina  stagnate  with  the  description  of  the 
European  form,  elegans  Schmidle.  In  a  recent  article  on  Algae 
from  Brazil,  he  identifies  the  Eudorina  found  there  as  elegans. 


Family   Peridinidse. 

Peridinium  tabulatum  Ehrenberg. 

Common  in  most  of  the  plankton,  abundant  in  a  good  deal  of  it. 
The  form  at  hand  is  that  with  the  cleft  anterior  portion ;  diameter 
of  a  specimen  measured,  65  /*.  Griffith  and  Henfrey  give  the 
length  as  1-480",  which  reduces  to  5  2  /*.  All  our  examples  appear 
to  be  of  nearly  uniform  size.  They  are  exceedingly  abundant 
in  sample  8,  collected  at  the  west  end  of  Lake  Amatitlan,  on  the 
surface.  This  catch  consisted  mostly  of  insect  exuviae,  and  it 
is  remarkable  that  the  greater  number  of  the  Peridiniums  were 
crowded  densely  in  the  cast-off  skins,  as  if  they  had  worked  their 
way  in  for  food  or  shelter. 

Peridinium  hirundinella  O.  F.  Muller. 

Rather  common;  scattered  through  most  of  the  phyto- 
plankton  from  Lake  Amatitlan,  and  also  in  the  Atitlan  material. 
Our  specimens  agree  very  well  with  the  figures  found  in  Kent, 
and  in  the  figures  in  the  Riverside  Natural  History.  All  are 
robust  and  quite  rough. 

This  species  is  almost  cosmopolitan,  having  been  reported 
from  England,  India  (Kent),  the  Great  Lakes  (Riverside  Nat. 
Hist.),  and  from  lakes  in  Iceland  (Ostenfold).  (I  have  so  far 
found  none  in  Lake  McDonald,  Alaska,  though  there  are  several 
other  species  represented.)  Apstein  (1,  c.)  notes  slender  3 -horned 
specimens  as  occurring  in  the  Dorbesdorfer  Sea.  All  the  exam- 


igS          FIELD  COLUMBIAN  MUSEUM  —  ZOOLOGY,  VOL.  VII. 

pies  seen  from  Lake  Atitlan  were  4-horned,  but  many,  perhaps 
the  majority,  from  Lake  Amatitlan,  were  3 -horned.  They  did  not 
appear  to  be  more  slender  than  the  others,  however.  Kent  gives 
the  size  as  "Length  1-120"  to  i-9o"-2o8  ,«  to  277  /->.."  The 
examples  at  hand  measured  220  /*  long,  and  70  ,«  wide  at  the 
broadest  portion  of  the  body. 


SPONGE  IN  LAKE  AMATITLAN. 


Family   Spoiigilidfle.     FRESH-WATER  SPONGES. 

Spongilla  fragilis  Leidy.     FRESH-WATER  SPONGE. 

So  far  as  I  was  able  to  discover,  there  is  but  one  species  of 
Fresh-water  Sponge  in  Lake  Amatitlan  (none  was  observed  in 
Lake  Atitlan) .  This  sponge  is  not  very  abundant,  and  is  usually 
found  growing  on  rocks  or  pieces  of  wood  in  the  water.  It  appears 
on  these  objects  usually  as  light  brown  patches,  although  its  color 
may  vary  from  nearly  white  to  a  bright  green.  The  shade  of 
color  depends  much  on  the  amount  of  light.  The  lighter  shades 
are  found  in  the  darkest  places,  and  the  green  color  in  bright  sun- 
light. 

In  general,  this  sponge  bears  some  resemblance  to  our  com- 
mercial sponges  which  grow  in  the  sea.  The  important  differ- 
ence between  those  in  salt-water  and  fresh-water  is  in  the  com- 
position of  the  spicules —  the  harder  skeleton  mass.  The  spicules 
of  the  salt-water  forms  are  made  up  of  a  horny  elastic  fibre,  while 
those  of  fresh  water  are  composed  of  silica. 

The  patches  of  sponges  found  on  rocks  along  the  shore  of  Lake 
Amatitlan  are  subcircular,  being  thin  at  the  edges  and  thicker  in 
the  middle. 

This  sponge  is  not  abundant  and  is  of  no  commercial  value. 
It  is  apparently  of  no  economic  importance,  so  far  as  the  fish 
supply  of  the  lake  is  concerned. 

This  species  is  very  widely  distributed  over  North  America, 
but  is  not  known  from  bodies  of  water  farther  south  than  Lake 
Amatitlan.  For  the  identification  of  this  species,  I  am  indebted 
to  Dr.  Edward  Potts,  of  Philadelphia. 


APRIL,  1908.       LAKES  AMATITLAN  AND  ATITLAN  —  MEEK.  199 

THE  LEECHES  OF  LAKE  AMATITLAN. 
By  J.  PERCY  MOORE.* 

Family   (wlossiphoniidee.     SNAIL  LEECHES. 

Glossophonia  lineata  (Verrill). 

This  little  leech  was  originally  described  from  Nebraska  and 
Florida.  It  is  now  known  to  range  very  extensively  over  the 
Pacific  side  of  South  America,  through  Central  America,  Mexico, 
the  entire  United  States,  and  into  the  southern  half  of  Canada, 
and  is  carried  from  place  to  place  attached  to  the  feet  of  migrating 
water  birds.  Several  specimens  were  taken,  in  association 
with  E.  triannularis,  under  stones  in  Lake  Amatitlan. 

Although  presenting  many  varieties,  a  general  characteristic 
of  the  species  is  the  double  line  of  small  conical  papilla  along  the 
middle  of  the  back.  The  striking  color  pattern  of  brown  and 
white  in  vivid  contrast  is  also  limited  to  this  and  one  other  species 
of  the  genus. 

Besides  seeking  concealment  beneath  stones  and  leaves  in  the 
water,  it  attaches  itself  to  the  bodies  of  snails,  frogs  and  larger 
leeches,  upon  the  first  of  which,  as  well  as  upon  small  worms  and 
insects,  it  subsists.  In  common  with  other  members  of  the 
genus  it  bears  its  eggs  and  young  on  the  ventral  surface,  pro- 
tected by  the  inrolled  margins,  and  supplied  with  currents  of  fresh 
water  by  the  rythmic  undulations  of  the  body.  When  disturbed, 
it  rolls  into  a  ball  and  remains  for  a  time  quiescent. 


Family  Erpobdellidje.     WORM  LEECHES. 

Erpobdella  triannulata    SP.  NOV. 

Form  moderately  slender,  width  greatest  at  caudal  end  of 
clitelhim,  thence  nearly  uniform,  but  tapering  gently  to  caudal 
end;  subterete  in  pre-clitellar  region,  moderately  depressed,  and 

*Two  species  of  Leeches  were  found  in  Lake  Amatitlan,  but  none  was 
was  taken  in  Lake  Atitlan,  as  no  special  search  was  made  for  them  there. 
These  leeches  are  small,  and  one,  or  both,  species  is  quite  abundant  under 
stones.  The  small  size  of  these  animals,  and  the  fact  that  they  are  hidden, 
render  them  of  little  if  any  economic  importance.  The  account  here  given 
of  these  leeches  was  prepared  for  this  paper  by  Dr.  J.  Percy  Moore,  of  the 
University  of  Pennsylvania. —  [S.  E.  M.] 


200          FIELD  COLUMBIAN  MUSEUM  —  ZOOLOGY,  VOL.  VII. 

in  cross-section  elliptical  in  post-clitellar  part;  lateral  margins 
rounded  except  near  the  caudal  sucker,  where  thin  lateral  wings 
extend  for  a  short  distance. 

Mouth  moderate,  the  upper  lip  rather  short  and  broad  and 
moderately  furrowed.  Eyes  3  pairs,  the  first  much  the  largest 
and  most  conspicuous,  situated  in  the  dorsum  of  somite  II,  the 
other  two  pairs  equal  and  situated  one  above  the  other  at  the  sides 
of  the  mouth  on  somite  IV.  Clitellum  thick,  completely  zonular, 
extending  over  15  annuli  (X  b 5  to  XIII  b 4  inclusive),  well  defined 
and  broader  than  contiguous  segments.  Genital  orifices  separated 
by  three  full  annuli,  the  male  being  situated  between  the  second  and 
third  rings  of  somite  XI I  (XII  b2/a2),  the  female  at  XII/XIII.  On 
mature  worms  the  male  orifice  is  prominent,  with  rugose  margins 
and  elevated  on  a  broad  conical  papilla.  When  the  atrial  chamber 
is  everted  this  region  appears  as  a  slightly  elliptical  disk  with  the 
longer  diameter  transverse,  with  a  slightly  raised  marginal  rim, 
and  near  the  center  two  small  openings  of  the  prostate  horns. 
Completely  quinque-annulate  somites  have  all  annuli  of  equal 
length,  and  not  further  subdivided  except  on  much  contracted 
specimens,  which  have  all  rings  equally  subdivided  by  transverse 
furrows  across  the  middle.  Anus  large,  with  radical  furrows  sur- 
rounding it,  situated  3  annuli  in  front  of  the  anus.  Posterior  suck- 
er thin,  flat,  its  diameter  about  two-thirds  the  greatest  width 
of  the  body,  marked  on  each  side  by  several  raised  radiating 
lines. 

Color,  yellowish  olive  or  dull  green,  marked  for  the  entire 
length  with  four  longitudinal  stripes  composed  of  numerous  small 
black  spots  with  pale  centers  in  which  sensory  papillae  are  situ- 
ated. The  middle  (paramedian)  pair  is  usually  the  darker,  and 
the  supra-marginal  duller  and  more  diffuse,  while  the  median 
light  area  is  paler  than  those  between  the  two  pairs  of  dark  stripes. 
Ventral  surface  and  lateral  margins  plain  gray  or  ashy  and  quite 
unpigmented.  Other  specimens  have  the  dorsal  pigmentation 
diffuse,  giving  an  effect  of  dull  brown  or  brownish  black,  the 
paramedian  region  being  always  deepest.  In  such  specimens, 
the  furrows  are  always  pale,  and  the  rings  speckled  with  small 
white  spots  indicating  the  position  of  the  sense  organs. 

Atrium  with  median  chamber  relatively  spacious,  much  as  in 
Dina  microstoma,  not  deeply  bilobed  nor  much  incised  by  the 
nerve  cord ;  prostate  cornua  small,  curved  laterally  and  downward 
to  meet  the  vasa  deferentia,  which  pass  forward  as  long  loops  as 
far  as  ganglion  XI. 


APRIL,  1908.       LAKES  AMATITLAN  AND  ATITLAN  —  MEEK.  201 

Length  in  moderately  extended  resting  condition  25-30  mm., 
maximum  width  at  posterior  end  of  clitellum  3  mm.,  greatest 
depth  nearly  2  mm. 

Egg-cases  very  flat,  thin,  yellowish,  chitinoid  capsules,  ellip- 
tical, not  produced  at  the  ends,  and  with  slightly  developed  thin 
margins;  3-4 . 5  mm.  long  and  2-3  mm.  wide.  They  are  attached 
by  one  face  to  the  under-side  of  stones,  sticks,  etc.,  and  each  con- 
tains several  eggs  or  young  immersed  in  albumen. 

In  the  digestive  tracts  were  found  the  remains  of  small  insect 
larvae,  oligochaete  annelids,  and  other  leeches,  including  their 
own  species. 

Very  abundant  under  rocks  about  the  shores  of  Lake  Amatit- 
lan,  Guatemala,  associated  with  Glossiphonia  lineata  (Verrill) 
Moore.  I  have  also  received  specimens  from  other  parts  of  Cen- 
tral America,  Mexico,  and  the  mountains  of  southern  California. 

A  small,  slender  leech,  seldom  exceeding  30  mm.  in  length, 
pale  ashy  below  and  of  a  yellowish  olive  or  dull  green  color  above, 
marked  by  two  or  four  dusky  longitudinal  stripes,  which  may  be 
diffuse  and  coalesced.  On  the  head  are  three  pairs  of  eyes,  the  first 
and  largest  on  the  upper  lip,  the  other  close  together  at  the  sides  of 
the  mouth.  In  addition  to  some  features  of  the  internal  structure, 
this  species  is  distinguished  from  related  leeches  by  having  all  of 
the  rings  of  the  middle  of  the  body  of  equal  length  and  similar 
structure,  and  three  complete  rings  intervening  between  the  male 
and  female  external  genital  pores. 

It  abounds  about  the  shores  of  Lake  Amatitlan,  seeking  con- 
cealment by  day  beneath  stones  and  similar  objects  in  the  shallow 
waters,  and  at  night  becoming  active  in  the  pursuit  of  small 
worms,  insect  larvae,  and  even  the  smaller  members  of  its  own 
species,  which  constitute  its  chief  food.  Having  no  toothed  jaws, 
it  is  not  an  habitual  blood-sucker,  though  it  doubtless,  like  related 
species,  attacks  abraded  surfaces  of  higher  animals  when  oppor- 
tunity offers. 

Not  confined  to  Lake  Amatitlan.  It  has  been  found  through 
Central  America,  Mexico,  and  in  the  mountains  of  southern  Cali- 
fornia, inhabiting  streams  as  well  as  lakes  and  ponds.  The  eggs 
are  deposited,  several  together,  in  a  quantity  of  albuminous  jelly, 
in  small,  very  flat,  elliptical,  somewhat  horny  capsules,  provided 
with  a  thin,  often  frilled  border,  and  attached  firmly  to  the  under 
side  of  stones. 

Type  No.  2389  Collection  Academy  of  Natural  Sciences  of 
Philadelphia. 


202          FIELD  COLUMBIAN  MUSEUM  —  ZOOLOGY,  VOL.  VII. 
i 

CRUSTACEA  OF  LAKES  AMATITLAN  AND  ATITLAN. 

Two  species  of  larger  Crustacea  occur  in  Lake  Amatitlan,  but 
one  of  these,  the  Freshwater  Crab,  occurs  in  both  lakes.  During 
the  breeding  time  for  these  species,  they  form  a  considerable 
amount  of  the  food  supply  taken  from  Lake  Amatitlan. 

For  notes  and  the  identification  of  these  species  I  am  indebted 
to  Miss  Mary  J.  Rathbun,  of  the  Smithsonian  Institution,  Washing- 
ton, D.  C. 

Family   Palremoiiiila*.     SHRIMPS:  CAMARONS. 

Bithynis  jamaicensis  Herbst.     CAMARON. 

The  Camaron  is  a  large  shrimp  which  is  quite  abundant  in  the 
Pacific  Coast  streams  of  Middle  America.  It  is  now  quite  abun- 
dant in  Lake  Amatitlan,  but  is  difficult  to  capture,  except  in  April, 
May,  and  June  during  its  breeding  season.  This  species  inhabits 
fresh  waters  from  Lower  California  and  Texas  to  Ecuador  and 
Rio  de  Janeiro.  It  is  also  abundant  in  the  West  Indies,  and 
wherever  found  it  is  much  prized  as  an  article  of  food.  This  large 
Shrimp  or  Camaron  does  not  inhabit  Lake  Atitlan.  The  fact 
that  it  is  abundant  in  the  Pacific  coast  streams  indicates  that  it 
is  possibly  native  to  Lake  Amatitlan,  although  it  is  reported  to 
have  been  introduced  there.  Lake  Atitlan  has  no  outlet,  and  it 
also  has  a  very  limited  fish  fauna,  and  so  the  absence  of  this 
crustacean  might  be  expected.  This  Camaron  is  reported  as 
abundant  in  the  west  coast  rivers  of  Nicaragua,  but  is  said  not  to 
occur  in  Lakes  Managua  and  Nicaragua;  but  neither  of  these 
lakes  communicates  with  the  west  coast  streams.  Except 
during  the  spring  months,  this  species  is  said  to  go  to  deep  water. 
At  any  rate  they  are  seldom  seen,  or  seldom  captured,  except 
during  the  breeding  season.  As  an  article  of  food,  this  Shrimp 
is  very  highly  prized.  Lake  Amatitlan,  abundant  in  breeding 
season. 

Family  Potamonidse.      CRABS;    CANGREJOS. 

Potamocarcinus  guatemalensis  Rathbun.     CAXGREJO. 

This  crab  is  quite  abundant  in  Lake  Amatitlan,  but  like  the 
Camaron  is  more  easily  captured  during  the  breeding  time,  which 


APRIL,  1908.       LAKES  AMATITLAN  AND  ATITLAN  —  MEEK.  203 

is  in  February,  March,  and  April.  The  eggs  of  this  species  are 
laid  and  then  attached  to  the  legs  and  caudal  appendages,  and 
are  thus  carried  until  the  young  are  of  sufficient  size  to  care  for 
themselves.  The  eggs  and  young  of  the  Camaron  are  carried  in 
the  same  way.  To  capture  these  animals  when  thus  loaded  with 
eggs  or  the  young  means  much  destruction  to  the  species.  The 
Cangrejo  is  much  prized  for  food.  Individuals  when  taken 
loaded  with  young  should  at  once  be  returned  to  the  water.  If 
water  animals  are  to  become  abundant  and  useful,  the  wholesale 
destruction  of  the  young  should  be  avoided. 

There  are  many  species  of  fresh  water  crabs  found  in  tropical 
waters,  inhabiting  streams,  lakes,  ditches  and  damp  woods. 
Their  food,  like  that  of  the  Camaron,  consists  of  insects  and  other 
small  animals,  and  of  water  plants.  Their  abundance  in  Lake 
Amatitlan  will  depend  largely  upon  the  protection  given  them 
during  the  time  they  are  taking  care  of  their  young.  Lakes 
Amatitlan  and  Atitlan,  common. 

The  smaller  Crustacea  were  comparatively  more  abundant 
in  Lake  Atitlan  than  in  Lake  Amatitlan.  Many  hauls  were  made 
with  the  tow  net  at  or  near  the  surface  at  nearly  all  hours  of  the 
day,  and  never,  except  once,  were  these  forms  taken  in  any  con- 
siderable quantity.  On  February  lyth,  at  about  4:30  P.M.,  I  made 
a  surface  towing  in  Lake  Atitlan,  near  San  Lucas,  with  only 
average  results.  A  second  short  haul,  made  about  three-quarters  of 
an  hour  later  resulted  in  securing  about  a  pint  of  these  small  forms. 
This  haul  was  made  just  as  it  began  to  rain.  It  was  evident  to  the 
naked  eye  that  the  surface  of  the  water  was  alive  with  these 
small  Crustacea.  These  forms  were  not  observed  to  be  at  the 
surface  in  such  numbers  on  several  other  evenings,  about  this 
same  time,  when  examinations  were  made. 

The  collections  made  at  both  Lakes  Amatitlan  and  Atitlan 
were  studied  by  Dr.  E.  A.  Birge,  Professor  of  Zoology  of  the 
University  of  Wisconsin,  and  by  his  assistant,  Professor  C.  Juday. 
The  following  account  of  the  Phyllopoda  was  prepared  by  Dr.  E.  A. 
Birge. 


Family    Sididee. 

Diaphanosoma  brachyurum  (Lieven)  G.  O.  Sars. 

A  considerable  number  of  females,  not  distinguishable  from 
the  North  American  representatives  of    this    species,    as   found 


204  FIELD  COLUMBIAN  MUSEUM  —  ZOOLOGY,  VOL.  VII. 

in  the  collections  from  Lakes  Atitlan  and  Amatitlan.     Length 
i.o  mm.;    height  to  0.45  mm. 


Family     Daplinithr. 

Daphnia  pulex  De  Geer. 

By  far  the  most  abundant  member  of  the  Cladocera  in  the 
collection  is  a  stout,  semi-transparent  representative  of  this 
species.  The  antennae  are  not  very  strong,  and  only  slightly 
ciliated.  The  first  and  second  abdominal  processes  are  united 
at  the  base.  There  are  17-18  abdominal  teeth.  The  distal 
pecten  bears  6-8  teeth,  of  which  the  proximal  is  smaller  than  the 
others.  The  proximal  pecten  has  about  10  small  teeth.  Length 
to  2  . 5  mm. ;  height  to  i .  6  mm.  Lakes  Atitlan  and  Amatitlan. 

Oaphnia  longispina  O.  F.  Muller. 

A  single  specimen  of  this  species  was  found  in  the  collections 
from  Lake  Amatitlan.  It  is  of  the  variety  galeata  Sars,  and  is 
not  far  from  the  form  figured  in  Lilljeborg's  Cladocera  Sued®, 
PI.  XVII,  fig.  9.  Length  1.56  mm.,  including  spine  0.4  mm. 
long;  height  0.53  mm. 

Ceriodaphnia  rigaudi  Richard. 

Four  immature  specimens  of  this  species  were  found  in  the 
collection  from  Lake  Amatitlan.  They  included  both  varieties, 
three  having  one  horn,  and  one  specimen  having  two  horns  on  the 
head.  Length  0.4  mm. 


Family   Itosini imhr. 

Bosmina  obtusirostris  G.  O.  Sars. 

A   few   specimens   indistinguishable   from   this   species   were 
found  in  both  lakes.     Length  0.42  mm. 


Family  Lynceidse. 

Alona,  sp. 

Two  immature  specimens  of  a  species  of  this  genus  were 
found  in  the  collection  from  Lake  Atitlan.     Length  o .  3  mm. 


APRIL,  1908.      LAKES  AMATITLAN  AND  ATITLAN  —  MEEK.  205 

The  following  account  of  the  Copepoda  was  prepared  by 
Professor  Chauncy  Juday,  of  the  University  of  Wisconsin. 

In  the  Plankton  collection,  from  Lakes  Atitlan  and  Amatitlan, 
the  Copepoda  are  represented  by  only  two  forms. 


Family  Centropagidae. 

Diaptomus  albuquerquensis  Herrick. 

Four  specimens  of  this  species  were  found  in  the  material 
from  Lake  Atitlan,  and  four  in  that  from  Lake  Amatitlan.  Length 
1.4  to  1.7  mm.  This  form  has  been  reported  from  Colorado, 
New  Mexico,  and  the  City  of  Mexico. 


Family  Cyclopidre. 

Cyclops  oithnoides  Sars. 

A  few  adults  were  found  in  the  collection  from  Lake  Atitlan. 
Length  o .  5  mm.  A  considerable  number  of  immature  specimens, 
which  probably  belong  to  this  species,  was  found  in  the  collec- 
tions from  both  lakes. 


SHELLS  OF  LAKE  AMATITLAN. 

With  the  exception  of  one  species,  Sph&romelania  largillierti, 
shells  are  not  abundant  about  the  shores  of  the  lake.  No  bivalves 
were  taken,  and  probably  none  exists  there.  My  stay  at  Lake 
Atitlan  was  short,  and  no  shells  were  collected  there.  The  few 
unsuccessful  searches  made  for  these  indicate  that  shells  are  not 
abundant  on  the  shores  of  this  lake. 

For  the  identification  of  these  shells  I  am  indebted  to  Dr. 
Ball  and  to  Dr.  Bartsch,  of  the  Smithsonian  Institution. 


Family  llelanideB. 

Sphieromelania  largillierti  Phil. 

This  is  the  largest  and  by  far  the  most  abundant  species  of 
shell  found  in  the  lake.      It  is  found  everywhere  along  the  shore 


206  FIELD  COLUMBIAN  MUSEUM  —  ZOOLOGY,  VOL.  VII. 

on  plants  and  rocks.  This  species  deposits  its  eggs  in  January 
and  February.  The  eggs  are  very  large  and  are  usually  attached 
to  the  under  side  of  rocks.  This  species  is  so  abundant  that  its 
large  gelatin-like  eggs  would  furnish  a  considerable  amount  of 
food  for  small  fishes.  It  is  a  very  abundant  species  in  Guatemala 
and  San  Salvador  to  Central  Nicaragua. 


Family  Amnicolidse. 

Amnicola  guatemalensis  Fisch  &  Crosse. 

A  very  small  species  and  very  scarce.     Of  no  economic  import- 
ance. 

Amnicola  petensis  Morelet. 

Very  small  and  very  scarce.     Of  no  value. 


Family  Limmeida*. 

Ancylus  excentricus  Morelet. 

Very  small  and  very  scarce.     It  is  found  attached  to  rocks. 

Planorbis  subpronus  Von  Martens. 

Very  small,  rather  common.     Of  no  economic  importance. 


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