Fishery Bulletin 90(1). 1992 



Gulf of Mexico (Ortner et al. 1989). Acartia, for exam- 

 ple, occurs in greater abundance inshore, in less saline 

 waters, whereas Oncaea and Corycaeus are more abun- 

 dant in water of traditional salinities offshore (Ortner 

 et al. 1989). Prior experience and learning can influence 

 the capture efficiency, food selection, and ingestion 

 rates of larval fishes (see review in Stoecker and Govoni 

 1984); and because larval round herring occupy more 

 offshore waters, they may be conditioned to feed pref- 

 erentially on the cyclopoids Oncaea and Corycaeus. 



The difference in larval growth between these two 

 species may reflect differences in the physical environ- 

 ment where these larvae grow. Offshore water in the 

 northern Gulf of Mexico is typically warmer than in- 

 shore water during the winter. Inshore-offshore gra- 

 dients in average water column temperature among the 

 three stations along the three transects were 19.2 to 

 20.7 to 22.1°C for the Cape San Bias transect in 

 December 1980; 16.1 to 15.0 to 18.1, 16.9 to 19.5 to 

 19.8, and 12.9 to 18.5 to 19.0°C for the Mississippi 

 Delta, Cape San Bias, and Galveston Bay transects in 

 February 1981. Temperature differences of this mag- 

 nitude can account for intraspecific differences in 

 growth rates among larval fish (Jones 1986, Warlen 

 1988) as seen here in the slower growth of round her- 

 ring larvae in the cooler water of February 1981. The 

 faster, early growth of round herring larvae, overall, 

 probably results from the warmer waters of its offshore 

 occurrence. 



Acknowledgments 



The collection of specimens examined in this paper was 

 supported by a contract to the Beaufort Laboratory 

 of the Southeast Fisheries Science Center, National 

 Marine Fisheries Service, NOAA, from the Ocean 

 Assessment Division, National Ocean Services, NOAA. 

 This paper was developed while the senior author was 

 a visiting scientist at the National Marine Fisheries 

 Service, NOAA, Beaufort Laboratory. 



Citations 



Campana, S.E., and J.D. Neilson 



1985 Microstructure of fish otoliths. Can. J. Fish. Aquat. Sci. 

 42:1014-1032. 

 Christinas, J.Y., and R.S. Waller 



1975 Location and time of menhaden spawning in the Gulf of 

 Mexico. Gulf Coast Res. Lab., Ocean Springs, MS, 20 p. 

 Fahay, M.P. 



1983 Guide to the eariy stages of marine fishes occurring in 

 the western North Atlantic Ocean, Cape Hatteras to the 

 southern Scotian Shelf. J. Northwest Atl. Fish. Sci. 4:1-423. 



Fore, P.L. 



1971 The distribution of eggs and larvae of the round herring, 



Etrumeus teres, in the northern Gulf of Mexico. Am. Soc. Biol. 



Bull. 18, 34 p. 

 Govoni, J.J., D.E. Hoss, and A.J. Chester 



1983 Comparative feeding of three species of larval fishes in 

 the northern Gulf of Mexico: Brevoortia patronus, Lewstomus 

 xanthwrus, and Micropogonias undulatus. Mar. Ecol. Prog. 

 Ser. 13:189-199. 



Govoni, J.J., P.B. Ortner, F. AI-Yamani, and L.C. Hill 



1986 Selective feeding of spot, Leiostomus xanthurus, and 

 Atlantic croaker, Micropogomas undulatus, larvae in the north- 

 ern Gulf of Mexico. Mar. Ecol. Prog. Ser. 28:175-183. 



Govoni, J.J., D.E. Hoss, and D.R. Colby 



1989 The spatial distribution of larval fishes about the Missis- 

 sippi River plume. Limnol. Oceanogr. 34:178-187. 

 Hales, L.S. 



1987 Distribution, abundance, reproduction, food habits, age, 

 and growth of round scad, Decapterus punctatus, in the South 

 Atlantic Bight. Fish. Bull, U.S. 85:251-268. 



Hettler, W.F. 



1984 Description of eggs, larvae, and early juveniles of gulf 

 menhaden, Brevoortia patronus, and comparisons with Atlantic 

 menhaden, B. tyrannus, and yellowfin menhaden, B. smithi. 

 Fish. Bull., U.S. 82:85-95. 



Houde, E.D. 



1977 Abundance and potential yield of the round herring, 

 Etrumeus teres, and aspects of its early history in the eastern 

 Gulf of Mexico. Fish. Bull., U.S. 75:61-89. 



Houde, E.D., and P.L. Fore 



1973 Guide to identity of eggs and larvae of some Gulf of Mex- 

 ico clupeid fishes. Fia. Dep. Nat. Resour., Mar. Res. Lab., 

 Leafl. ser. IV, pt. 1, no. 23, 14 p. 



Jones, C. 



1986 Determining age of larval fish with the otolith increment 

 technique. Fish. Bull., U.S. 84:91-103. 

 Kappenman, R.F. 



1981 A method for growth curve comparisons. Fish. Bull, 

 U.S. 79:95-101. 

 Miller, J.M., W. Watson, and J.M. Leis 



1979 An atlas of common nearshore marine fish larvae of the 

 Hawaiian Islands. Misc. Rep. PO-02, Univ. Hawaii Sea Grant 

 Prog., Honolulu, 179 p. 



Ortner, P.B., L.C. Hill, and S.R. Cummings 



1989 Zooplankton community structure and copepod species 

 composition in the northern Gulf of Mexico. Continental Shelf 

 Res. 9:387-402. 



O'Toole, M.J., and D.P.F. King 



1974 Early development of the round herring, Etumeus teres 

 (De Kay) from the south-east Atlantic. Vie Milieu 24:443-452. 



Reintjes, J.W. 



1980 Marine herring and sardine resources of the northern Gulf 

 of Mexico. In Flandorfer, M., and L. Skuplen (eds.), Workshop 

 for potential fishery resources of the northern Gulf of Mex- 

 ico, New Orleans, 1980. Publ. MASGP-80-012, Miss.-Alabama 

 Sea Grant Consort., 14 p. 



Roel, B.A., and Y.C. Melo 



1990 Reproductive biology of the round herring, Etrumeus 

 whitekeadi. S. Air. J. Mar. Sci. 9:177-187. 



Schoener, T.W. 



1970 Nonsynchronous spatial overlap of lizards in patchy 

 habitats. Ecology 51:408-418. 



