Gulf killifish, continued 



Juvenile Size Range : In a captive rearing study, fish 4 

 to 6 weeks old had grown to an average weight of 0.1 

 g in a temperature range of 1 2.5 to 33°C and salinities 

 of 5 to 10%o (Tatum et al. 1978). After 52 days, these 

 fish had reached a mean weight and total length of 2.0 

 g (range: 0.8-7.2 g) and 56 mm (range: 40-84 mm). 

 Temperatures during this period ranged from 22° to 

 35.5°C, and salinity varied from 1 1 to 16%o. 



Age and Size of Adults : Field studies of gulf killifish 

 show age class I fish range from 1 8 to 30 mm standard 

 length (SL). Fish in class II average 68 mm SL and 

 attain reproductive maturity during this time when they 

 reach 40 to 50 mm total length (TL). Adults range in 

 size from 40 to 141 mm TL and weigh up to 45.0 g. 

 These fish survive into class III size, but rarely into 

 class IV (Gunter 1945, Gunter 1950, Reid 1955, 

 Simpson and Gunter 1 956, Renf ro 1 960, Springer and 

 Woodburn 1960, Franks 1970, Swingle 1971, Christ- 

 mas and Waller 1 973, Waas 1 982, Waas et al. 1 983). 

 The gulf killifish is one of the largest species of Fundu- 

 lus occurring in southern Florida coastal marshes 

 (Loftus and Kushlan 1987). 



Food and Feeding 



Trophic Mode : Gulf killifish are opportunistic predators, 

 but they can also feed omnivorously. Feeding is 

 throughout the water column during daylight hours 

 (Ruebsamen 1972, Tatum et al. 1982, Relyea 1983, 

 Rozas and LaSalle 1 990). Young fish are detritivores, 

 but become more carnivorous with increased age and 

 size. 



Food Items : The diet of the gulf killifish varies with the 

 habitat in which it is feeding (Rozas and LaSalle 1 990). 

 Crustaceans and insects form a large portion of this 

 fish's diet. Food items include: mosquitoes, isopods, 

 amphipods, tanadaceans, pelecypods, gastropods, 

 annelids, polychaetes, insects, fishes, crabs, larval 

 grass shrimp, fiddler crabs, hermit crabs, detritus, 

 substrate, vascular plant tissue, and some algae prob- 

 ably as a consequence of amphipod grazing (Simpson 

 and Gunter 1956, Springer and Woodburn 1960, 

 Harrington and Harrington 1961, Odum 1971, 

 Ruebsamen 1972, Subrahmanyam and Drake 1975, 

 May 1977, Levine 1980, Relyea 1983, Perschbacher 

 and Strawn 1986, Rozas and LaSalle 1990). 



Biological Interactions 



Predation : Predators include wading birds and larger 

 piscivorous fishes (Jenni 1969, Perschbacher and 

 Strawn 1986). 



Factors Influencing Populations : The incidence of para- 

 sitism by Eimeria funduli (Protozoa: Eimeriidae) has 

 been reported over a broad area of the range of the gulf 

 killifish (Solangi and Ogle 1981). Although heavily 



infected fish can have 80 to 85% of both liver and 

 pancreatic tissues replaced by E. funduli oocytes, the 

 disease does not appear to cause mortality in infected 

 fish maintained in the laboratory. Growth rate, how- 

 ever, is considerably reduced, which could adversely 

 affect the reproductive potential of local populations, 

 and commercial production of this species for bait 

 (Solangi and Ogle 1981). 



Personal communications 



Peterson, Mark S. Gulf Coast Research Lab., Ocean 

 Springs, MS. 



Van Hoose, Mark S. Alabama Division of Marine 

 Resources, Dauphin Island, AL. 



References 



Able, K.W., and D. Hata. 1 984. Reproductive behavior 

 in the Fundulus heteroclitus-F. grandiscomp\ex. Copeia 

 1984:820-825. 



Bernardi, G., and D. A. Powers. 1995. Phylogenetic 

 relationships among nine species from the genus 

 Fundulus (Cyprinodontiformes, Fundulidae) inferred 

 from sequences of the Cytochrome B gene. Copeia 

 1995(2):469-473. 



Blair, W.F., A.P. Blair, P. Brodkorb, F.R. Cagle, and 

 G.A.Moore. 1968. Vertebrates of the United States, 

 2nd ed. McGraw-Hill, Inc., New York, NY, 616 p. 



Christmas, J.Y., and R.S. Waller. 1973. Estuarine 

 vertebrates, Mississippi. /nCooperative Gulf of Mexico 

 Estuarine Inventory and Study, Mississippi, p. 320- 

 434. Gulf Coast Res. Lab., Ocean Springs, MS. 



Comp, G.S. 1985. A survey of the distribution and 

 migration of fishes in Tampa Bay. In Proc. Tampa Bay 

 Area Sci. Info. Symp., p. 393-425. 



Courtney, L.A., and J.A. Couch. 1984. Usefulness of 

 Cyprinodon variegatus and Fundulus grandis in carci- 

 nogenicity testing: advantages and special problems. 

 Natl. Cancer Inst. Monogr. 65:83-96 



De Vlaming, V.L., A. Kuris, and F.R. Parker, Jr. 1978. 

 Seasonal variation of reproduction and lipid reserves in 

 some subtropical Cyprinodontids. Trans. Am. Fish. 

 Soc. 107(3):464-472. 



Duggins, C.F., Jr., K.G. Relyea, and A.A. Karlin. 1 989. 

 Biochemical systematics in southeastern populations 

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