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Ne* 'Of. 1.609 USA ♦82 - 0300 ^ P.-.., SUPPLEMKxN'TAKV ()B8EK\AT1UN8 UN THE DEVELOPMENT OF THE CANADIAN OYSTER J. 8TAFF0H1). M.A., Pii.D. NEW YORK 1 » 191L' i, [B*print«d. wiltiout eHknga of paging from tlie AhibicaX N'atukaust, 1912 J ^■\ i^ \ 7^ A ' -X W ^> ^,, _ _i H^'^ t^^s-'- - -4/ ^ M REFFRENCI T&SFr:^,. E'tiSlAMVE I iHHAHv .,( HHIIiSH LOI <,IMBI <\y 3 3298 00085 3813 I Kpphntml fri>in Trk Amkrican Nati'RAI.iht, Vol. Xl.VI . .Ian . Ifll'-'l SUl'l'LKMKXTAUY OUSKHVATK »NS OX THK DKVKI.OPMHNT UK TlIK CANADIAN OYSTKK J. STAKKOKI), M A.. l'ii.l». RinTXMiicM. St\tm)v. Dki-abtirk BA^. H. C. In tlic Amkhk AN Xaiihalist of ■lisiuDuy. IIM)"), Janu- ary, 1!»0!), June, liUO, I liave fjiveii s( iiic account of obser- vations (in 1!)04) on tiie (U'velopnu-iit of tlit' oyster at Malpe(|ne. Hiclmiond Hay, I'rince Ivlward Island, Canada. ()l)l)ortunity to verify, continue, and extend tiiese i-l)- servations was again alYorded in HMI!>, when I studied tiie ovster in tiie most ini|H>rtaiit ceiiteis aloii''U|-c.|. Jl^ Wril ;i~ the Irllirtll "I' tln' |irlliMl iif tlifir I'liT -wiiiiiniiitf lil'f. 'I'lii' liirvM' i>liliii I liv I'.rnok-. 1,'ii'.'. I{\(1.T. Win-low. anil utlicr- w-tc ol.tiiint'd by nil liiif riHin rci-tili/.t il •■i;u>. anil wnr at innvt ^i\ - nM. anil in tlic >nun'4 -fi-ai;:,lit hinv,''- -lairc In Ijirnpi' iar\a- lit' a similar afjfc, >i/.i' ami -tiurtiin' liiul Ih'imi lakfii from tlic intra liraiii'liial cavity of tiic parent i)y>tfr hy Da- \ainf. i.ai-a/r Dutliirr-. ( o-t.', !»«• la IJlan-in'T.'. (i\v>ii .l.'ffrii-. Saumli r-, Saltiisky. MilMiis. Ilnrst anil Iln\lt'y. lint tlic oilier, latei- oi- laryer -ta>,'es were unite unknown. 'I'lii- left room for -nine -pei niatioii a- to tlie exact time, place ami manner in wliidi tlie -ncceeilinir --fai^'es stioiiM lie fnuinl. a- well a- occa-ioiicil the prevalent mi>take tliat the free larva -ettle- ili.wn at tlii> peiiml to iieeome a lisi.il -|ial, r.rook- wrote. ••.Ml m> attempts to i;'et later -taue- than tlie-e faileil . . . ami 1 am therefore unahle to ili-crihe the manner in which the --wimniinu- emhrvo hccome- converted into the adult. Imt 1 hope that tlii- uap will he tilled, eitlier l>y future oIis.m'v atioii- of my own or hv those of some other eiiihrv olouist." In a similar way dack-oii. at a later period, speak- of --a Idaiik in the kilowledl,'e of the developmelit of the oy-te.." 'i'his •■iraii" or ••hiaiik"" i- now coinpletelv filled .M v -tudies jirove that the larva continues to live a> a larva in the -ea water almut oyster-heds for two or three weeks loiiirer. where it swim< nliont. feeds, firows and ehanj^os in structure, and that it tirst -ettles down to hecoiiu' a M'dentary spat, lixed to >liell> or other olijects. at an a.^-e of three to fiuir wi'ek- from fertili/ation the lemrth of time deliendim;' to some extent on temperature, food, individuality or >ncli causes. This information lias been trained through the method of piocurinu' ov>ter larvie from the waters of oyst.'i- areas b\ means of a plankton- uet. and connectinii- tliem in serie- with yicuiirer stau'es obtaincil by fertilization and culture and with older -ta^es obtained bv catchiim- s])at on irlass. shells, etc.. so a- to make out the com])lete life-liisfory. 'i'he di.-eovcrv that the hitherto unknown -taues of the - .,■■ -..T^- -fS.,'1- -' N(. .'.n rill C.WMil I \ DYslIll 31 oyster larva can Im' coiiv fiii nlitaiiicd liy a i>laiikti>ii iH't carries witli it tin- |(n->iliility ..t" a i-raetiral a|>iili<"i tiori "f int'stiinahlf \aliif in tln' cnltiirf n{ ov-tcrs. From t!ic time ill' the caily l{"!i!ai! KiMpii-' it lia^ li,..'ii kiiDwn that nvstcr si)at can sometimes lie ohtaiiicd on ropes, anchors, jiiles of wliarves. stones, shells or other natural or artificial ohjects in the ^ea. and some sort of methoil of cnltMic has lonir hceii in use in many countries. At times men have risen to exaiteracticaltle, safe and sure i-ictliod <»f catchinir. retaininir, and rearing the younp spat. T i|Uott! W'inslow to the effect that "'i'lioiisands of dollais would ]h' annually saveil hy ttie Connecticut oystermcn if tliey could determine, with e\ en appro\imate accuracy, tin' date when the attachment of llie younir ovstei' would occur. Hundreds of thousands would he saved if they Imtl any rdiaide method of detcrminiiii;' the prolmliilities of tlie season." This is now possiide. It is well known that oyster or other shells dried am? whiteneti in tlie sun form the \cry hest oystercoileet(U-s or cultch. To put these hack into the water liapha/ai'd has often resulteil solely in the loss of all the lahor of proj)aration. Iir cncu a few da\s the> ma\ become cov- ei'ed wiflr a slimy coatiiiir which reiluces or' lari^ely destroys their etliciency. The jioirrt is to he ahle to deter mine with accuracy, f(U- each seasoir and for- e\'er-\ local- ity, when o\ ster laiNM' are pieseirt in tlie water full- iji'own and I'eady to settle as spat, so as not to run the risk of losiiii^ ade(|uate value foi' the laboriously ]i|-e- pared cultch. -V man instructed and (|ualilied in tho method of taking plankton and in ideiitifvinu' oyster- larva- can tell almost to a day when is the proper tinu' to put out cultch so as to obtain an abundant and copious sft of si)at. It is not enousjjh to know aiiout the time, or to know tiio time for certain previous years, oi- to know the averaii^c time. Three methods are open to the expert: (1) Examina- tion of tlie ~tfi- lar\a' ari' ]>n-.cnt ,mtau'i'. C!) t'xainiiiatinii ,<( natural <>r iniprovisc .1 (.lijects iii the water til ilixovci' it' y.-mitf >pat ate alreaiiy i'nrincd. 'riie lii>t i> rint iiiim (Ictcrmiiiativc lic.'aii-i' of tlic Ions; p.Tiu.l ill' i|fVflu|iniriit -riiaiatiiii,' Npawnini,' an u-e of tlie e(ilal nuiuhef of larviu lavishly provided hy nature to " up and tuin into the sea would not ma- terially alter the n\mil)er of succes.-ful individuals in the set of spat. r>ut on the other hand a few ciUturists could enoiniou-l> increase the chances for a >uccessful catch hv >preadinii an ahumlance of suitaitl.v prejiared cult<'h at the proper time and place. in the paper of lHHit 1 have descrihed the method of elilainin^- iilankton. the aiMiearauces and measurements of the (ivvter laivM' to lie recduni/.cd, the time of the year to he^'in makiim- olisersatioiis. In the paper on " IJivalve |.ar\a'" 1 distini,'ui>h in sizes, sliapo, colors, tlie com monly occuirinu' a--ociates uf the oyster-larva' winch nii.u'lit he taken for the latter. In the ]iresent jiajier, after Idiii,^ reflection. 1 suuu'ot a practical apiili tin- niilliit:; were rcarrd in luaki r> of -ca water at a temptTiitnif little alinve JO ('. and witl! a -jieiilie u'ravity (saiiiiits I \ aryiii« x.niewliat iindfi- iDJd. I alxi carriiMl ( 'araiiiietle Dvsters f(i Mal|iei|iie and raided up larv:r t'rian ei,'i;> ei(>» fcrtili/ed lietween two -neji i.liv ii.ll-l> dilfelent \arietie-. as tlie small, nairnw. eur\ ed. tliiek, hard and heavy ( 'arn qnette oNstef aiid the line, laiKe. liTiiad, >traiulit. tlie Canadian (iov einmeid Inid .\tluntie ny>tei> tians-liiped tu the I'a.ilir and put out at si'lected plaee-. ill tile latter year some of tlic jtlaees were clio-eii h\ Captain Kemp. I'Spert in oNster culture. iieiiiiT orrnpied Ihi- -uiiiiiier at oiir I'anlic r.iolo^Mcal Station, I have taken advantatre (altlioufili not re(|iu'sted to do so) of my proximity to three of these nlaees to search for tlie transplanted I'liiice ivlward Island oysters, and to examine plankton taken in the vicinity. At tiie lirst place, Hammond itay. heimr a small liay and close to hand, I could easily o\er run all the heach at low water, and soon discovered the dead shells that had heen deposited too far above low- water mark. .\t Nanoose Hay, some tv, e!ve miles away, perha]>s tive miles lout; and a mile and a half wide, with extensive flats at low tides, this was noL so easily done. Having spent three suminers with Captain Kemp, 1 tlioi-ght now to test my judgment of where he wouhl select to dejiosit the oysters. As the tide wis iinfavorahle at my tirst visit 1 used the ilredge, and was afterwards surprised to learn that 1 had actually calculated to within a few rods of the jilace. At the second visit I went to look at other parts of the hay, iait on the thini returned and. with a favorahle tide. coiiUi wade and i>ick up some of the oysters. This was at .• P. M., July 17. and 1 took Ki tine living siieciiiieiis of the Malpcque oyster for examination two or three of them with pieces of I'rince Kdward Island red samlstone still 34 Tin: AMEIUC.W XAir'iAT.IST rvoi,. xi.vi attached to tlu'iii. Tlit'>- varitMl from two and three fourtlis to live Indies in lenjjtli, some of tliem sliowinj? ,'onsi(leralile j^rowtli. This ])roves tliat Atlantic oysters can be trans) ihuited to the racitic and remain liealthy and ^row. I'pon I'eachini: home ' proceeded to examine some of the oysters and it turned out that onl> one ha spawned wiiih' tiie otiier litteen were ripe and fjeiierally somewiiat distended with ejjj^s or s])erm. This ))r()ves that tlie trans))laiited oysters can come to maturity and rii)en tlie r i>r()dnctive eh'ments. At 7.10 1*. M. of tlie sanie (Jay I j)ut togetiier cjr^'s and sperm in a tunihier of sea-water and at 7 A. .\r. next mornin<; tiiere was an alamdance (tf se,irmentatii>n stajjes and free-swimminj; hu\a'. Tiii> proNcs tiiat tlie oysters ("in spawn and that the e^'^s can develop into youiifr. 1 make these statements because of a prc\ailinfj; opinion that the transplanted oysters have all died, and the few peojile who think there are still some liviiiii' are do^Miuitic in their assertion that they do not breed. Plankton taken at intervals at Hammond and Nanoose l>ays had not yielde(| any oystei' larva', which became ex- plainable upon liudiiifir the condition of the reproductive organs. A further o))servatiou on this was afforded on the "Jtith of July, when I examined a second lot (obtained at a very low I'de *ho day before) from Nanoose Bay. The forty seventh oyster examineil was the first to yield iiood ripe eiifj;s — all previous ones were s])awned with the exception of four or fivi; which were ri, ' males. The interval between these two visits had been the hottest of file summer and the oysters had nearly all spawned in this i>eri()(l- sliirlitly later than is usual on the Atlantic. * )n the 27tli 1 made a tri)) to Oyster Harbor (Ladysraith), iibout fifteen miles from here, where T had better luck in irettinii ti'ack of tli" few transplanted oysters. Tn a similai' way 1 examined several individuals and took plankton which for the first time contained larvjc of the Atlantic oyster — recoiin'zable by their slia))e and meas- urements but not pi'esentin.ii' such a deeii ))ink or brown I Xo. .')41 1 TUK r.i.v in/.i.v orsirm 36 coloration as in their native lionie. For comparison with my former jiajjers I will jrive the me..surements oi a sinjifle specimen with tlie characteristic ])ostero-dorsal hi;;h nmbos. the larffe convex kft valve, and the smaller and flatter ri^ht valve, velum, foot, pij?ment spot and the rest. ( )cular V, ohjective 4, 42 long by ."57 high (=^.28!) X .-55 mm.). This prov.-s that larva; grow up. There is only one other bit of evidence possible and that is to find spat. This 1 lia\e not done as yet. It is too early for tliis year's spat and I have not seen any un- doubted specimens of a former year's spat. One can judge that the comparatively few descendants of two and a half barrels dejjosited at Hammond Bay. five barrels at Xanoose l^ay. and one barrel at Oyster Harbor, when dis]iersed over the broad areas at their command, would not pi'ove very conspicuous objects, which is again complicated by the presence of millions of British Columbian oysters of varying sizes, shapes, and comjilexions. I regard my findings as conclusive and would urge the transplanting of Atlantic oysters (Osfrra rirqinica Gmel.) to the Pacific in greater quantities. Tlie At- lantic clam (MjKi (ire)iiiriii Fj.) has projiagated enor- mously here notwithstanding the fact that it has more comi)etitors in its jiarticuiar habit than in its original home. Ostrni liiriila Carp. — Even before making any head- way in the foi-egoing researches, I had begun to gather information on the occurrence, size, shape, color, struc- ture, breeding, etc.. of the British Columbia oyster. This s])ecies is not common in Dejiarture Bay, or in Hannnond Bay, but a few sjiocimens may be found under stones exposed at about one hour from low water in front of the C. P. R. caitle house in the former, and just inside the far point of the latter, and are usually so broadly and solidly attached (with the left valve against the under side of the stone and hence uppermost) that it is scarcely possible to separate them without destroying :i6 I in: AMHiiK w xMrnAi.i>r Vol.. M.VI .--£. ■ . _sr . -S the attaclied siirt'iicc. Hut on tlic extensive Hats at the upper ends of Xanoose I'.ay and of Oyster llarlior tliey occur free on tlie surface hy thousands and more or leas covered with harnacU's. (lood si)eciniens reacli two inciies in leiifftli t)y an inch and a lialf in hreadth. witli a straiirlit dorsal niarf,'in and a semicircular ventral curvature. The right, upper or smaller valve is nearly Hat or hut little convex and (its into the margins of the larger, convex, lower or left valve, the greater part of tlie lower and posterior margin being scalloped, while the left valve has corresponding ridges and points. The color is usually dark (those under stones lighter) with the older parts weathered grayish and the umhoiuil region of the left valve is often attached to a small stone or another oyster or hears a scar. In- ternally the shell is extensively iiigmented, dark, with smaller hands or hlotches of lighter ])earl. while the muscle scar is lather lighte" and handed. The mantle is broadly margined with dark, whicli nuiv also creep up on to the abdomen. The most interesting feature in connection with the Pacific oyster of Canada is its divergence in some re- spects from the mode of breeding of our Atlantic species. In the British Columbia form there is no jirimary sepa- ration of individiuds into males and females — the sexes are united in eacli individual. In other w<»rds each in- c. \', oli.j. 7 72. Aiiotlicr iii inch - fully twice the diameter (if the efifj of the Atlantic oyster, and perhaps identical in size with the elip. The nucleus is between one half and two thirds the diameter of the cfiir. Upon turning particularl> to spermatozoa I found them in every individual — even between tlie eggs of those containing eggs in tlie gonad. The younger indivi the sjierm of the Rritish Columbia oyster is smaller than that of the Prince Edward Isbvnd oyster, which may have some relation to the particular mode of fertilization, such as being introduced by the respiratory current. Tn some ]>arts of the gonad ova may be plenti- ful. whil(> at other parts there are only sperm-balls. k 5^ 38 I in: .\Mh:ni(\\ .v.i/r/,M/./>/ 1 Vol.. xi-vi Later, in tlu- waniicr wcatlicr, tlic siicriu may be pretty well iiiii off and tlic n'i)r(>(liictivc orj^Mii coiitaiii mostly t'f^irs. In tliis way tlic yonnf^iT oysters, and tlu' older oysters at tlie l)e<,'iuninfr «>f the season, may lu- physio- lojii.ally males, wliile ol(ler oysters at tlie !iei-!it of tl\e breeding season may be pliysioloj^ically females. Oysters from liaimnond l?ay siiowed the ^ame plie iiomeiia. rpoii tinditiir an aiumdanee of hujjer oysters on ttie surface at Nanoose Hay, I brought horn- a iKiil-full of picked si.eciiiiens to serve as a convenient stock for ob- servation and experiment. On .Inly Hi T fo'ind a sj) -ci men with periiaps half a teasi)oonfnl of e.i!;,i,'s in various sta,i,'es of sejrmentation, lyinj? free in the lower valve— a mass of white granules. The v\]M' ejrffs ooze into the infra brancliial cavity and lie on and l)etween the sills, (. (.. between tiie two folds of the mantle, where they are retaiiKMl apparently without any retaininir, sticky matrix. 1 sniipose that it is here they tirst meet with riix' si^erms from other individuals, for T do not believe tiiat at this time the sjierms of tiie same individual are physio- loirically capable. The whole oy>ter a]ipears exhausted, the wills rent, the tlesh collai>sed, soft and jiarts of it almost rotten. On .Inly 24 I ojiened one hundred of the stock siijiply and found six with ejrss, embryos or conchiferous younir, in the infra-branchial cavity. .\11 the other- were in ])rocess of sy),.rnioiienesis and oofjenesis. An experiment that has often seemed ]iossible to me is to do the same with the Euroi»ean oyster, by way of artificial fertilization, as T.rooks did with the American oyster. Now that T hatl an oyster essentially the same as tiie European T tried it, and ^\ith seeming success, but of course it is difficult to be sure that sperm from another liad not already hail access to the esgs. Unripe eugs are no good; eggs already freed from the gonad may have come in contact -with sperm. This restricts one to finding a specimen .just before but ,iust im the point of -^l i -^'^ - vr- I -.^v ■^. '^'J^-:^^ No..>»l| Tin-: (\i\'AI)I.\.\ OYSIKH 39 cxtnidiiif? its Cliffs. I jilso tried Atlantif oyster eijffs with Piicilic ()\-ter >|ienris. as well as Atlantic oyster >pei'iiis witli Pacific u\ stei' effffs, hilt witiuiut success, as .irie laifflit siippose. I put effff>. eiiiiiryos and larva- of hoth s](ecies tciffet her under the same coverslip for coiu- parisoii -those of tlie snuill I'.ritisli Coluinhia oyster Inokinff like yiants heside tliose of tlie larffe Prince Kd ward Island oy>ter. Tliis is a curious pheiiomenoii which I ha\c several times oliserxcd on other s])ecies. I. (I., the ver> laiffe effffs of Astarte comi)ared with tiie small eirffs of iariic species liko Mactra. I'or the >tlld\ o|' >ci;inentatioll. etc., the Athmtic species i~ of .I'K antaffe on account of smaller si/.e and ffrt'atcr ( ran-paieiicy. The order of sejiiiieiitation ajipcars to he tlie same in hoth both ^iiliject to xariatioiis such that it would re(|nire a i;reat iiuiiiiier of paiustakiiii;- ohsei'va lions to decide exactl> wliat is tlie normal mode in ffood heaitiiv euus. I havf. on hoth sides of this continent, ^ji.'nt coiisideialile time in tiyinu' to determine the order ot' sei;nielitation. the cell-lineaye, the planes of cleasaye. the sncressidii (if nuclei, tile et"i'e<'t of Ufa vitat ioll. the constant and continuous orientation of successive stages, the origin of the sliell-ffland and tiie niede of formation of the shell, etc., hut can not discuss such suh.jects here. I ma\ hrietix state, however, that 1 lielie\e Hrooks failed to observe the shell ffland, in his orii^iiial work, and at one ]iaiticiilar staiic mistook the relation of the sliell- \al\cs to the blastopore which made it necessary to re- verse his orientation of the embryo- -luauo bis use of the terms dorsal and ventral are niisleadins;. The polar bodies are dorsal at first later, if tlie> ]iersist. they ma\ become displaced anteriorlv . 'I'he blasto])ore is xcntral. the velum anterior, the sliell-,s;land dorsal, the mouth ventral, 'i'lnu'e is no foot. iKU' rudiment of it in jire- conchiferons stages. I have found conchiferous youiiir of the P.ritish Colum- bia oyster retained within the parent's slieil until their own minute shells wore .loS mm. in length. I belicM- 40 I HE .\MFliir.\X XATlltMlsT | Vol.. XLVI •->.■-! gV:^ m they remain longer, for, acconlinjr to Mobins the younp of tlu' KuroiM-an oyster leaves tlie parent at a size of .I'l to 18 mm. (Horst ^ves .!(! mm.; ITnxley '1,v. inch). I have taken larva> of (). lundn in i-huikton (identified by comimrison with those from a parent, and also by the strneture. shape and size) of a len.utl, of .ICf) mm. as well as different hir-er sizes. Tliey still had a straisl't-hmRe line of half tlie len-th of tlie sliell - unlike the 0. nnn»'r,i whieh at this size is already passing into the un.bo-stas;." and with a nuieh sla.rter hintre line. The larva> of O. hiiuhi are not pink or brown but have tive or six dark blotches in tlie re^'ion of tlie liver and in the velum, m eontrast to the -eiieral liirht shade of tlie rest of the animal. i am