Bay anchovy, continued 



(Reid 1955, Bechtel and Copeland 1970, Daly 1970). Personal communications 



Food Items : Young anchovies are plankton strainers. 

 They consume zooplankton such as copepod nauplii 

 and rotifers until a body length of approximately 7 mm 

 is reached, at which time they switch to copepodites 

 and copepods (Darnell 1958, Detwyler and Houde 

 1970). Some detritus is also consumed, but phy- 

 toplankton generally is not, which suggests that food 

 straining occurs near the bottom (Darnell 1958). As 

 anchovies grow in size their diet becomes increasingly 

 selective, shifting from copepods to small shrimp, 

 larval and juvenile fish, mysids, insect larvae, crab 

 zoeae, clam larvae, cladocerans, schizopods, gastro- 

 pods, copepods, isopods, malacostracans, oligocha- 

 etes, polychaetes, and supplemented by detritus from 

 occasional bottom feeding (Hildebrand 1943, Reid 

 1954, Reid 1955, Darnell 1958, Arnold et al. 1960, 

 Darnell 1961, Bechtel and Copeland 1970, Detwyler 

 and Houde 1 970, Carr and Adams 1 973, Weaver and 

 Halloway 1974, Sheridan 1978, Levine 1980). Gut 

 analysis of anchovies 30 to 49 mm long showed the 

 following diet proportions: 9% microinvertebrat.es; 58% 

 zooplankton, and 33% organic detritus (Darnell 1 961 ). 

 Benthic animals and sand are most frequently encoun- 

 tered during the winter, suggesting more intensive 

 benthic feeding at this time (Darnell 1958). 



Biological Interactions 



Predation : The small size and high abundance of this 

 species makes it one of the most important forage 

 species in the Gulf of Mexico (Robinette 1983). Many 

 species are known to consume bay anchovies, includ- 

 ing snook, gar (Lepisosteus species), red drum, sand 

 seatrout, spotted seatrout, silverperch, Atlantic needle- 

 fish (Strongylura marina), inshore lizardfish (Synodus 

 foetens), ladyfish (Elopssaurus), blue catfish (Ictalurus 

 furcatus), Atlantic croaker, southern flounder, crevalle 

 jack, and cobia (Rachycentroncanadum) (Gunter 1 945, 

 Reid 1955, Darnell 1958, Darnell 1961, Carr and 

 Adams 1973, Sheridan 1978, Rozas and Hackney 

 1 984, Killam et al. 1 992, Franks et al. 1 996). 



Factors Influencing Populations : Population density 

 appears to be primarily influenced by food supply (i.e., 

 zooplankton) present in the water column (Reid 1 955). 

 This probably accounts for their preference for bay 

 habitats and, when found in the Gulf, bay water masses 

 (Hoese1965). 



Ditty, J.G. Louisiana State University, Coastal Fisher- 

 ies Institute, Baton Rouge, LA. 



Houde, Edward D. University of Maryland, Chesa- 

 peake Biological Laboratory, Solomons, MD. 



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

 Springs, MS. 



References 



Allshouse, W.C. 1983. The distribution of immigrating 

 larval and postlarval fishes into the Aransas-Corpus 

 Christi Bay complex. M.S. thesis, Corpus Christi St. 

 Univ., Corpus Christi, TX, 118 p. 



Arnold, E.L., R.S. Wheeler, and K.N. Baxter. 1960. 

 Observations on fishes and other biota of East Lagoon, 

 Galveston Island. U.S. Fish Wildl. Serv., Spec. Sci. 

 Rep. No. 344, 30 p. 



Barrett, B.B., J.L. Merrell.T.P. Morrison, M.C. Gillespie, 

 E.J. Ralph, and J.F. Burdon. 1978. A study of 

 Louisiana's major estuaries and adjacent offshore 

 waters. Louis. Wildl. Fish. Comm. Tech. Bull. No. 27, 

 197 p. 



Bechtel, T.J., and B.J. Copeland. 1970. Fish species 

 diversity indices as indication of pollution in Galveston 

 Bay, Texas. Contrib. Mar. Sci. 15:103-132. 



Carr, W.E.S., and C.A.Adams. 1973. Food habits of 

 juvenile marine fishes occupying seagrass beds in the 

 estuarine zone near Crystal River, Florida. Trans. Am. 

 Fish. Soc. 102(3):51 1-540. 



Christmas, J.Y., G. Gunter, and E.C. Whatley. 1960. 

 Fishes taken in the menhaden fishery of Alabama, 

 Mississippi, and eastern Louisiana. U.S. Fish Wildl. 

 Serv., Spec. Sci. Rep. Fisheries No. 339, 10 p. 



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

 vertebrates, Mississippi. In: Christmas, J.Y. (ed.), Co- 

 operative Gulf of Mexico Estuarine Inventory and Study, 

 Mississippi. Gulf Coast Research Lab., Ocean Springs, 

 MS, p. 320-406. 



Chung, K., and K.Strawn. 1982. Predicted survival of 

 the bay anchovy(Ancrtoa mitchilli) in the heated efflu- 

 ent of a power plant on Galveston Bay, Texas. Environ. 

 Biol. Fishes 7(1 ):57-62. 



157 



