UN HARVARD UNIVERSITY Library of the Museum of Comparative Zoology (7a// 8(7,3 MUS. COMP. ZOOL LIBRARY OCCASIONAL PAPERS MAr 2 2 1982 of the MARVARO MUSEUM OF NATURAL HISToS?a,TY The University of Kansas Lawrence, Kansas NUMBER 98, PAGES 1-15 MARCH 5, 1982 LIFE HISTORY OF THE FRECKLED MADTOM, NOTURUS NOCTURNUS, IN MILL CREEK, ILLINOIS (PISCES: ICTALURIDAE) By Brooks M. Burr1 and Richard L. Mayden2 The freckled madtom, Noturus nocturnus, is widely distributed in the lower and central Mississippi River basin and other Gulf of Mexico tributaries in Alabama, Mississippi, Louisiana and Texas (Taylor 1969; Map 4). The species is seldom found in large numbers and in spite of its wide range almost nothing is known con- cerning its life history. Taylor (1969), in his systematic revision of Noturus, described the external morphology, habitat occurrence and associated madtom species of N. nocturnus. Pflieger (1975) collected female N. nocturnus with fully developed eggs from southeastern Missouri in late May, and Cross and Collins (1975) stated that the species eats insects and small crustaceans in Kansas. Larimore (1981) recently emphasized the need to accumulate information on all life-history aspects of warmwater fishes and the importance of even fragmentary observations. During a life history study of the brindled madtom, Noturus miurus (Burr and Mayden 1982), we collected some life history information on the syntopic N. nocturnus. Our purpose is to describe growth, reproduction, de- velopment, diet and demography of N. nocturnus in Mill Creek, Pulaski County, Illinois. STUDY AREA The study site, Mill Creek, a small tributaiy of the Cache River system (Ohio Drainage), 2.4 km NW of Ullin, Pulaski County, 1 Department of Zoology, Southern Illinois University at Carbondale, Car- bondale, Illinois 62901. 2 Museum of Natural History, University of Kansas, Lawrence, Kansas 66045. 2 OCCASIONAL PAPERS MUSEUM OF NATURAL HISTORY Illinois, was described by Burr and May den (1982). The study area is surrounded by cultivated fields and is a common dumping ground for trash by local residents; the large accumulations of cans, bottles and other debris probably contribute to suitability for reclusive madtoms. Mill Creek has a few rocky or brushy riffles, pools with mixed mud, silt and rock bottoms, and in the study area has a width vary- ing from 2 to 4 m and a depth varying from 0.5 to 1.5 m. Stream banks are steep and brushy and were tree-lined until recent chan- nelization. Water temperatures varied from 1° C in January to 30° C in July. Twenty-three species of fishes occur at this site. The most com- mon madtom at Mill Creek is N. miurus; N. nocturnus is less abun- dant but regularly present, and the tadpole madtom, N. gyrinus, is rarely captured. Other species of fishes collected with the madtoms include Campostoma anomalum, Notropis lutrensis, Pimephales notatus, Semotilus atromaculatus, Erimyzon oblongus, Mimjtrema metonops, Moxostoma erythrurum, Ictalurus natalis, Fundulus olivaceus, Gam- busia affinis, Aphredoderus sayanus, Lepomis cyanellus, L. rnega- lotis, Pomoxis annularis, Etheostoma chlorosomum, E. gracile, E. proeliare, E. squamiceps, Percina caprodes and P. maculata. On one occasion a single specimen of a mudpuppy, Necturus maculosus, was collected with N. nocturnus. METHODS Methods of study followed Mayden and Burr ( 1981 ) except as noted. Observations and minnow seine collections were made at approximately one-month intervals from 27 August 1978 to 29 February 1980. During the breeding season observations were made more frequently. Additional observations and collections of breeding individuals were made in June 1981. In all, 145 speci- mens were preserved and examined. Most collections were made at night; observations of nesting were made during the day. Lengths throughout the text refer to standard lengths in millimeters (SL, mm); total length (TL) is used in the description of embryos and larvae. All aquarium-held pairs that spawned were injected with human chorionic gonadotropin (HCG) at 50 IU at a volume of 0.05 ml per injection. HABITAT During fall and winter, young occurred primarily in mixed gravel and sand riffles with accumulations of sticks, leaves, trash and other debris. Individuals were often common in the heads or bases of riffles where the current was strong. These riffles averaged LIFE HISTORY OF THE FRECKLED MADTOM 3 15 cm in depth and about 1.5 m in width. Adults were found pri- marily in riffles throughout most of the year but some were col- lected from mud-bottomed pools with N. miurus. During the breeding season (mid May thru July) adults were most common in shallow pools but often were in shallow riffles when the water velocity was greatly reduced. Throughout its range, JV. nocturnus characteristically is found in moderate to fast current over gravel or debris in medium-size to large streams. The water is frequently turbid but clear water is probably preferred (Taylor 1969). REPRODUCTION Reproductive Cycle of the Male Testes of mature males were opaque white, had numerous finger-like projections of various sizes and were nearly identical in appearance to those illustrated or described for the margined madtom, N. insignis (Clugston and Cooper 1960: fig. 3B), the slender madtom N. exilis, and N. miurus (Burr and Mayden 1982, Mayden and Burr 1981). Gonadosomatic indices (GSI) were recorded for specimens taken from August 1978 to July 1979. From August to May, GSI for males 1+ or greater in age remained about the same (X GSI = 2.6, SD = 1.02, N = ll), but increased dramatically in June and July to a maximum of 9.1 (X = 6.2, SD = 2.17, N = 10). Throughout the year, GSI for males less than 1 year old fluctuated little and averaged 2.2 (SD = 0.41, N = 13). A decrease in GSI for older males occurred after July at the end of the breeding season. 150- 140- 130 120- o "0- o o 100- ! 90 -5 80-1 £ 70- £ 60 Li- 0 5CH 1 40 o £ 30 5 20 icH o 1000T = 22.300- 1.3281 +0.019L1. r =.802 ~l 1 1 1 1 1 1 1 1 1 1 1 1 1- 40 45 50 55 60 65 70 75 80 85 90 95 100 105 STANDARD LENGTH (mm) Fig. 1. — Relationship between weight of testes and standard length in 36 male Noturus nocturnus from Mill Creek. OCCASIONAL PAPERS MUSEUM OF NATURAL HISTORY T y * * A B Fie. 2. — Genital papillae of Noturus nocturnus from Mill Creek. A) Breed- ing male 65.7 mm SL collected 19 June 1979; B) Breeding female 73.0 mm SL collected 22 June 1979. Right is anterior. 25 X- The relationship between weight of testes (T) and standard length (L) of males was curvilinear (Fig. 1), and was best depicted by the equation 1000 T = 22.300 - 1.328 L + 0.019 L2, with r = 0.802. Testis weight was negligible until the male exceeded 60 mm SL or 15 months of age. As in other Noturus, breeding males developed swollen lips, genital papillae ( Fig. 2A ) and epaxial muscles on the head between May and July. Nonbreeding males did not develop these features and were similar in appearance to females. Appearance of the gen- ital papilla was useful in distinguishing the sexes of individuals 1+ or greater in age, especially from May to July. Coloration of males did not change with the breeding season and was as described by Taylor (1969). As judged by primary and secondary sexual characteristics and nesting males captured, sexual maturity of males is probably at- tained in the third summer of life (2 years old). This is similar to what has been reported for other long-lived species of Noturus ( Clugston and Cooper 1960, Burr and Mayden 1982, Mayden et al. 1980, Mayden and Burr 1981). Reproductive Cycle of the Female As indicated by shape and size of the genital papillae (Fig. 2B), the GSI (Fig. 3) and degree of abdominal distention, females be- gan to prepare for spawning in May and were ripe with mature oocytes through July. Breeding females were similar in color to males, but did not develop swollen head muscles and lips. The genital papillae of females were swollen from May to July, but differed from those of breeding males by being more conical, and partially concealed anteriorly by the swelling of adjacent tissues (Fig. 2B). Relative ovary weights exhibited little variation from August LIFE HISTORY OF THE FRECKLED MADTOM 5 to May, but increased markedly to higher levels in June and July (Fig. 3). In June and July, GSI ratios ranged from 20 to 90 (X = 56.7) in the seven females represented in Table 1. In June, the GSI of 40 was of a spent female and in July, the GSI of 21 and 20 were of partially spent and immature females, respectively. The mean GSI for females in June and July, excluding spent and im- mature individuals, was 79.0. The proportionally largest ovaries (equalling 9.0% of adjusted body weight) occurred in a 1-year-old, 69-mm female collected 30 July 1979. In contrast, ovaries repre- sented 24.8 percent of adjusted body weight in breeding females of N. miurus from Mill Creek (Burr and Mayden 1982). From August to April, oocytes of females were small (averaging 1.0 mm) and whitish in color. During the breeding season, two size classes of oocytes were evident in mature females (N = 10); smaller, white oocytes that averaged 0.8 mm and orange, mature oocytes that averaged 2.0 mm (range = 1.8-2.3 mm). The few 1- and 2-year old females collected from May to July had large, mature oocytes and apparently would have spawned I O 100 50-- I in ^ inn-- >- Q o CO Q iu to —t Q < O O o X CO UJ < > o 10 s • : * • • • : — I — I — I — I — I — I — I — I — I — I — I — h- AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN JUL MONTH Fig. 3. — Monthly variations in ovarian weight relative to adjusted body- weight of 35, 2- to 52-month old female Noturus nochirmis from Mill Creek. The vertical axis is a logarithmic scale. 6 OCCASIONAL PAPERS MUSEUM OF NATURAL HISTORY ( those collected in May spawned in aquaria in mid-June ) . Except for young-of-the-year collected in July, no nonbreeding females were collected from May to July. In five mature females ranging in size from 67 to 75 mm, and collected during June and July, the number of mature oocytes ranged from 85 to 116 (X = 102.2; Table 1). Ripe N. miurus and N. exilis females averaged 66.2 and 83.6 mature oocytes, respectively ( Burr and May den 1982, May den and Burr 1981). Small samples of N. nocturnus prevented meaningful comparisons between number of mature oocytes and age, length and weight of the female. Nesting The first evidence of nesting N. nocturnus in Mill Creek was the discovery of a male in a narrow-mouthed glass bottle on 9 May 1979. On 17 May 1979, a male and female in breeding condition were found in a 355 ml beer can. Neither of these nesting sites contained embryos or larvae, but the pair spawned 102 eggs in an aquarium on 18 June 1979, following several injections with human chorionic gonadotropin. On 22 June 1979, two other aquarium-held pairs, injected with HCG, spawned 35 and 40 eggs, respectively. Several additional visits to Mill Creek during the summer of 1979 resulted in the discovery of N. miurus nests containing embryos or larvae (Burr and Mayden 1982), but only males of N. nocturnus were found in beer cans or bottles. On 25 June 1981, three nests of N. nocturnus were found, all in 355 ml beer cans and each containing a clutch of embryos. The nests were located in a shaded area of the creek with some current, about 0.5 m wide and about 10-15 cm deep, where the water tem- perature was 25° C. Four other solitary males in breeding condi- Table 1. Relationship between size, age and ovary weight of Noturus nocturnus females and the number of mature oocytes. Number Adjusted Weight of of mature SL, body weight" Month of Age in ovaries (orange) mm (g) collection Months (g) oocytes GSIh 62 3.45 June 12 0.18 94 52 63 4.17 June 12 0.37 115 89 65 4.15 June 12 0.17 16 40 75 5.90 June 24 0.50 116 85 68 5.64 July 13 0.12 85 21 69 5.58 July 13 0.50 101 90 69 5.36 July 13 0.12 — 20 " Adjusted body weight is the specimen's weight after removal of the ovaries, stomach, intestine and liver. b Equals ( weight of ovaries X 1000) /adjusted body weight. LIFE HISTORY OF THE FRECKLED MADTOM 7 Hon were found in 355 ml beer cans, evidently in preparation for spawning. Numerous pairs of N. miurus were found in beer cans but only one nest contained a single male with embryos. Nest cans of N. nocturnus usually contained some tightly packed mud or silt against the bottom. Similar to N. miurus, N. nocturnus prob- ably nests under rocks but, due to the turbidity of Mill Creek, we were unable to search these areas. As in other species of Noturus we have studied (albater, elegans, exilis, flavater, flavus, miurus), embryos adhered to each other in a roundish mass but not to other surfaces. Embryos were spherical and lemon-yellow. All males found in beer cans were 2 or 3 years old and like nesting males of other species of Noturus had empty stomachs. Nesting males were 73.0, 75.3 and 75.4 mm SL, and had 154, 139, and 47 eggs in their nests, respectively. The clutch of 47 embryos may have only b?en partially complete, since females of some species of Noturus probably lay at least two clutches of eggs per year (Mayden and Burr 1981). Unlike other madtoms, breeding male and female N. nocturnus developed numerous abrasive, tiny, white structures over their heads and bodies. Histological preparations of skin of both breeding and nonbreeding males revealed that these structures were taste buds. The roughness of the taste buds during the nesting season and the close contact maintained in the nesting situation between males and females suggests that these structures might be analogous to breeding tubercles and serve as a stimulus to courtship or spawning. As stated earlier, the heads of adult males become swollen dur- ing the breeding season and increased in both width and depth. Head width in 10 breeding males ranged from 18.5-26.5 mm (X = 21.7) and head depth ranged from 11.1-15.9 mm (X = 13.3). 'Pop-top' beer and soda can openings ranged from 18.5-28.0 mm in length (X = 23.7) and 13.0-20.0 mm in width (X = 16.2). Thus, there was little room to spare at the opening of a can once a male was inside and in his characteristic position. As judged from aquarium-held individuals, breeding males typically faced the open- ing of the can, blocking entry of virtually all potential predators. Pflieger (1975) reported female N. nocturnus with fully de- veloped eggs from the last week of May in Missouri and suggested that the species spawns in spring or early summer. At the latitude of southern Missouri and southern Illinois we have found eight species of madtoms nesting only in late June and July. It is unlikely that any madtom spawns in the spring in this region. The spawning and nesting season for N. miurus and N. nocturnus overlaps considerably from mid-June to late July in Mill Creek. Because most breeding pairs or individuals of both species that 8 OCCASIONAL PAPERS MUSEUM OF NATURAL HISTORY we observed use cans or bottles for nests, there may be some competition for nest sites between the two species. DEVELOPMENT On 18 June 1979, a freshly-laid clutch of N. nocturnus eggs was removed from a nesting pair that had spawned in a 355 ml beer can in an aquarium. Egg diameters ranged from 3.6 to 4.5 mm (X = 3.9, N = 5); yolk diameters ranged from 3.1 to 4.0 mm (X = 3.3, N = 6). Of the clutch of 102 eggs, 60 were incubated in a culture dish and the remaining were returned to the parent nest where they were later consumed by the parents. At 25° C, eggs hatched in 139-161 hr (5.8-6.7 days), a shorter developmental time than N. cxilis and N. miurus. At 25° C, N. exilis hatched in 187-210 hr; N. miurus hatched in 189-215 hr ( Mayden and Burr 1981, Burr and Mayden 1982). Based on the 60 eggs, hatching success was 100 percent. Hatchlings (Fig. 4A) ranged from 7.5 to 8.0 mm TL (X = 7.7, N = 3 ) , had a few scattered melanophores on top of the head and heavily pigmented eyes. All fins were formed but only the caudal fin showed any differentiation of rays. Three pairs of rudimentary barbels were present. N. nocturnus hatchlings were virtually identical in appearance to those of N. exilis ( Mayden and Burr 1981: fig. 17C and D) and N. miurus (Burr and Mayden 1982: fig. 4A). One-day-old larvae ranged from 9.7 to 10.8 mm (X = 10.1, N = 4 ) , had more melanophores concentrated on the top of the head and had rays differentiated in all fins. Four pairs of barbels were present. Four-day-old larvae ranged from 10.7 to 11.5 mm TL (X = 11.1, N = 2) and were beginning to appear adult-like in their phys- iognomy. The body shape at this age and size is stockier than N. exilis and N. miurus of about the same size and age (Mayden and Burr 1981: fig. 18C and D, Burr and Mayden 1982: fig. 4B). Melanophores were sparse but evenly distributed over the head and body, and an early, open cephalic lateral-line canal was present. Spines were partially developed in the pectoral and dorsal fins. Over one-half the yolk sac was absorbed ( Fig. 4B ) . At eight days, larvae ranged from 11.7 to 12.9 (X = 12.3, N = 5) and had large melanophores concentrated over the head and body. The yolk sac was over three-fourths absorbed and the cephalic lateral-line system was partially closed (Fig. 4C). At 15 days, larvae ranged from 14.8 to 15.5 (X=15.0, N = 3) and had melanophores distributed over the head, body and fins in a pattern like that of an adult. The yolk sac was completely absorbed and the overall morphology was adult-like (Fig. 4D). LIFE HISTORY OF THE FRECKLED MADTOM 9 The smallest specimen collected by seine from Mill Creek was an 11.8 mm SL individual taken in July. This individual had the yolk sac absorbed but was not as darkly pigmented as some 15- day-old laboratory-reared individuals. Fig. 4. — Representative stages of development in Noturus nocturnus from Mill Creek. A) Hatchling, 7.9 mm TL; R) 4-day-old larva, 11.5 mm TL; C) 8-day-old larva, 12.4 mm TL; D) 15-day-old larva, 14.1 mm TL. 25x. 10 OCCASIONAL PAPERS MUSEUM OF NATURAL HISTORY GROWTH Rate of increase in length declined with age; half of the first year's growth was attained in about eight weeks (Fig. 5). The relationship between standard length (Y) and age in months (X) for males was Y == 18.776 + 43.434 Log X, with r = 0.923, and for females was Y = 16.830 + 43.409 Log X, with r = 0.894. Males and females grew at nearly the same rate in length, but males lived slightly longer (54 versus 52 months). From 13 to 18 months males (N = 6) averaged 40.7 mm and females (N = 5) averaged 38.5 mm. From 19 to 24 months males (N = 6) averaged 55.6 mm and females (N = 5) averaged 50.5 mm. At 25 to 30 months males (N = 4) averaged 64.7 mm and females (N = 4) averaged 66.1 mm. Reyond these ages, sample sizes were too small to be meaningful. The largest specimen collected from Mill Creek was a 101.5 mm female collected 27 October 1979 that weighed 19.6 g. The largest male, collected 28 December 1979, was 99.2 mm and weighed 17.5 g. The largest specimen Taylor (1969) examined was 121.5 mm SL from Missouri. We found a 122.6 mm SL individual from Nolin Reservoir, Kentucky ( specimen at University of Louisville ) . Taylor ( 1969 ) stated that most specimens of N. nocturnus were under 100 mm SL and that the Missouri specimen was an exceptionally large one. Adjusted body weight increased at a constant rate for both sexes; one half of the first year's mean body weight was reached in about three months for both sexes (Fig. 6). The relationship be- no-- • • Y = 18.776 + 43 434 LOG X, MALE, r = .923 100-(- c Y = 16 830+ 43.409 LOG X, FEMALE, r = . 894 90 ' ' ' M I I I I I I I I | | | | | | | | | | | | | [ | | | | | | | | | | | | | [ [ | | | | | | [ | | [ | | | 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 AGE IN MONTHS Fig. 5. — Growth in standard length of 145 Noturus nocturnus collected from Mill Creek. Dots represent means for males; circles represent means for females. LIFE HISTORY OF THE FRECKLED MADTOM 11 20- 19-- 18-. 17.. I O >- Q O m • — • W =0.487+ 0.31 7A, MALE, r= . 945 o o W = -0.366 + 0.349A. FEMALE, r = .927 H 1 1 1 1 h H 1 1 1 1 1 1 1 1 h H 1 h H h 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 SO 52 54 AGE IN MONTHS Fig. 6. — Growth in adjusted body weight of 71 Noturus nocturnus from Mill Creek. Dots represent means for males; circles represent means for females. tween adjusted body weight (W) and age in months (A) for males was W = 0.487 + 0.317 A, with r = 0.945, and for females was W = - 0.366 + 0.349 A, with r = 0.927. Linear growth equations for body weight did not differ significantly between the sexes. DEMOGRAPHY Composition Of the 145 N. nocturnus collected in Mill Creek between 27 August 1978 and 25 June 1981, 61.4 percent were up to 1 year old, 22.8 percent were between 1 and 2 years old, 10.3 percent were be- tween 2 and 3 years old and 5.5 percent were 3 years or older (Table 2). Table 2. Distribution of sexes and year classes in samples of Noturus nocturnus from Mill Creek. Number by Year Class Sex 0 1+ 2+ 3+ 4+ Total Males Females Total 43 46 89 19 14 33 10 5 15 5 0 5 2 1 3 79 66 145 12 OCCASIONAL PAPERS MUSEUM OF NATURAL HISTORY There was no significant (a = 0.05) deviation from a 1:1 sex ratio in the first (0) or second (1+) year class. Sampling was biased toward males in older age classes, particularly during the nesting season, thus a meaningful comparison of the sex ratio of older age classes was not possible. Survival Of the 79 males collected 54.4 percent were up to 1 year old, 24.1 percent were between 1 and 2 years old, 12.7 percent were between 2 and 3 years old and 8.9 percent were 3 years or older. Of the 66 females collected 69.7 percent were up to 1 year old, 21.2 percent were between 1 and 2 years old, 7.6 percent were between 2 and 3 years old and 1.5 percent were 3 years or older (Table 3). Males lived slightly longer than females in Mill Creek. The oldest male was 54 months collected in December, the oldest female was 52 months collected in October. Males and females of N. miurus lived as long as 36 and 25 months, respectively, in Mill Creek (Burr and Mayden 1982). Notimis exilis, N. flavus, N. gyrinus and N. insignis all live at least 4 years ( Mayden and Burr 1981, Scott and Crossman 1973, Mahon 1977, Clugston and Cooper 1960). DIET An examination of 41 stomachs of N. noctumus from all seasons of the year (Table 4) revealed that aquatic insect larvae were the Table 3. Relative survival of year classes of Noturus noctumus in Mill Creek expressed as proportions of the 0 year class (IX1), the 1+ year class (lx2), the 2+ year class ( lx3) and the 3+ year class ( lX4). Year Class Number of Specimens Survival Sample IX1 IX2 IX3 IX4 Males 0 43 1.000 1 + 19 .442 1.000 — — 2 + 10 .233 .526 1.000 — 3 + 5 .116 .263 .500 1.000 4 + 2 .047 .105 .200 .400 Females 0 46 1.000 — — — 1 + 14 .304 1.000 — — 2 + 5 .109 .357 1.000 — 3 + 0 .000 .000 .000 1.000 4 + 1 .022 .071 .200 .000 Total Sample 0 89 1.000 — — — 1 + 33 .371 1.000 — — 2 + 15 .112 .455 1.000 — 3 + 5 .056 .152 .333 1.000 4 + 3 .034 .091 .200 .600 LIFE HISTORY OF THE FRECKLED MADTOM 13 -O o E C 00 u <—< -v -i o c« •fcJ cS C T3 £ so -g< E 2 < < cs <- ^3 -~ s a *• cS E C — I o d 1 i-H d drtd o CM o o o c^ in o 02 d CO -i 1 00 co 1— 1 1 oo in 1 00 n-J in o o o CO l d in 1 d d in in o o CO -t in o mcdo d d i 1 i> 1 d l in d oo co d CM CO "* ■— I CO O I co 1> cS 5J a CS 3 "° a ropte era ra dae cs S • 3 o c s 5 S sraf2 cS 3 2'-o g .3 o £*JH j 5 o i< w on U D CO -C 0 a oho s 14 OCCASIONAL PAPERS MUSEUM OF NATURAL HISTORY predominant food items. Ephemeropterans, trichopterans, and chironomid larvae made up the bulk of the diet and were consumed during all seasons of the year; simuliids were eaten during the fall, winter and spring. Crustaceans, nematodes, oligochaetes, and arachnids made up only small portions of the diet (Table 4). In Kansas, N. nocturnus from the Arkansas River system is re- ported to eat insects, insect larvae and small crustaceans (Cross and Collins 1975). Clark (1978) in her unpublished Masters thesis reported that the stomachs of three N. nocturnus captured in April, 1977, from Black Creek, Mississippi, contained the remains of three speckled madtoms, Noturus leptacanthus. PARASITISM Hoffman (1967) did not list any parasites of N. nocturnus. The only endoparasite found during examination of stomach contents was the fluke Crepidostomum (in four specimens). The ectopara- sitic copepod Lernaea was found on two specimens, one from June and one from July. ACKNOWLEDGMENTS We are indebted to P. A. Burr, K. S. Cumin ings, S. L. Dewey, W. W. Dimmick, K. C. Fitzpatrick, J. M. Grady, P. W. Mayden, M. A. Morris, A. Rauch, T. E. Shepard, and M. E. Retzer for aid in collecting specimens; to Karen Schmitt, Scientific Photography and Illustration Facility of the Southern Illinois University at Car- bondale Graduate School for assistance in preparation of the illus- trations; to Sharon L. Dewey for the original drawings of larval stages and genital papillae; to George Bicego for assistance with histological preparations, and to Robert L. Price for the identifica- tion of parasites. Kevin C. Fitzpatrick shared his reproductive data from aquaria-held specimens of N. nocturnus. Dr. Lawrence M. Page, Illinois Natural History Survey and Stephen J. Walsh, South- ern Illinois University at Carbondale, offered helpful comments on the manuscript. This research was supported, in part, by grants to B. M. Burr from the Southern Illinois University at Carbondale Office of Re- search Development and Administration and the U.S.D.A. Forest Service. SUMMARY The life history of Noturus nocturnus was studied at Mill Creek, Pulaski County, Illinois, between 27 August 1978 and 25 June 1981. A total of 145 specimens from 1 to 54 months in age was collected. Males were sexually mature at 2 years; those found in nests ranged LIFE HISTORY OF THE FRECKLED MADTOM 15 in size from 67.0 to 75.4 mm SL. Females had mature oocytes from late May through July; some females reached sexual maturity by 1 year of age. The number of mature oocytes produced by a female ranged from 85 to 116 (X = 102.2). Three nests, each containing a single clutch of eggs and guarded by a single male, were found in 355 ml beer cans in shaded, narrow riffles with reduced flow on 25 June 1981, at a water temperature of 25 C. Clutch sizes were 47, 139 and 154; eggs were spherical and lemon-yellow in color and ranged in diameter from 3.6 to 4.5 mm. Eggs incubated in the laboratory at 25° C hatched in 139-161 hr with a hatching success of 100 percent. Individual freckled madtoms grew in length at a decreasing rate and in body weight at a constant rate for at least 4 years. One-half of the first year's mean growth in length was reached in about 8 weeks; about 12 weeks was required to attain one-half of the first year's mean body weight. Ephemeropteran, trichopteran and chironomid larvae were consumed during all sea- sons of the year and made up the bulk of the diet in 41 stomachs examined. LITERATURE CITED Burr, B. M., and R. L. Mayden. 1982. Life history of the brindled madtom, Noturus miurus, in Mill Creek, Illinois (Pisces: Ictaluridae ) . Am. Midi. Nat. 107:25-41. Clark, K. E. 1978. Ecology and life history of the speckled madtom Noturus leptacanthus (Ictaluridae). Unpubl. M.S. Thesis, Univ. of Southern Mississippi, Hattiesburg. 134 p. Clugston, J. P., and E. L. Cooper. 1960. Growth of the common eastern madtom, Noturus insignis in central Pennsylvania. Copeia 1960:9-16. Cross, F. B., and J. T. Collins. 1975. Fishes in Kansas. Univ. Kans. Mus. Nat. Hist. Public Educ. Ser. 3. 189 p. Hoffman, G. L. 1967. Parasites of North American freshwater fishes. Univ. of Calif. Press, Berkeley. 486 p. Larimore, R. W. 1981. Progress and challenges of the fishery biologist in warmwater stream investigations. Pages 120-126 in L. A. Krumholz, editor. The warmwater streams symposium. Proc. Symp. Univ. of Tennessee, Knoxville, South. Div. Am. Fish. Soc. Mahon, R. 1977. Age and fecundity of the tadpole madtom, Noturus gyrinus, on Long Point, Lake Erie. Can. Field-Nat. 91:292-294. Mayden, R. L., and B. M. Burr. 1981. Life history of the slender madtom, Noturus exilis, in southern Illinois (Pisces: Ictaluridae). Occ. Pap. Mus. Nat. Hist. Univ. Kan. 93:1-64. , B. M. Burr, and S. L. Dewey. 1980. Aspects of the life history of the Ozark madtom, Noturus albater, in southeastern Missouri (Pisces: Ictaluridae). Am. Midi. Nat. 104:335-340. Pflieger, W. L. 1975. The fishes of Missouri. Mo. Dept. Cons. Jefferson City. 343 p. Scott, W. B., and E. J. Crossman. 1973. Freshwater fishes of Canada. Bull. Fish. Res. Board Canada 184. 966 p. Taylor, W. R. 1969. A revision of the catfish genus Noturus Rafinesque, with an analysis of higher groups in the Ictaluridae. Bull. U.S. Nad. Mus. 282. 315 p. University of Kansas Publications MUSEUM OF NATURAL HISTORY The University of Kansas Publications, Museum of Natural History, beginning with volume 1 in 1946, was discontinued with volume 20 in 1971. Shorter research papers formerly published in the above series are now published as Occasional Papers, Museum of Natural History. The Miscellaneous Publications, Museum of Natural History, began with number 1 in 1946. Longer research papers are published in that series. Monographs of the Museum of Natural History were initiated in 1970. All manuscripts are subject to critical review by intra- and extramural specialists; final acceptance is at the discretion of the publications committee. Institutional libraries interested in exchanging publications may obtain the Occasional Papers and Miscellaneous Publications by addressing the Exchange Librarian, The University of Kansas Li- brary, Lawrence, Kansas 66045. Individuals may purchase separate numbers of all series. Prices may be obtained upon request addressed to Publications Secretary, Museum of Natural History, The Univer- sity of Kansas, Lawrence, Kansas 66045. Editor: E. O. Wiley Managing Editor: Joseph T. Collins PRINTED BY UNIVERSITY OF KANSAS PRINTING SERVICE LAWRENCE, KANSAS j 7 0 I 14 3 2044 093 361 699 DATE DUE APD 1 *} onfM HWUrJ ZuU4 DEMCO, INC. 38-2931