DESCRIPTION OF EGGS, LARVAE, AND EARLY JUVENILES OF 



GULF MENHADEN, BREVOORTIA PATRONUS, AND COMPARISONS 



WITH ATLANTIC MENHADEN, B. TYRANNUS, AND 



YELLOWFIN MENHADEN, B. SMITHI ] 



William F. Hettler 2 



ABSTRACT 



Morphometric, merist ic, and pigmentation descriptions of laboratory-reared gulf menhaden, Brevoortia pa- 

 tronus, and Atlantic menhaden.fi. tyrannus, indicate that larvae of these species can be distinguished from 

 each other by the number of myomeres and vertebrae; that Atlantic menhaden can be distinguished from 

 yellowfin menhaden, B. smithi, by the number of myomeres and vertebrae, by pigmentation, and by 

 morphometries; and that gulf menhaden can be separated from yellowfin menhaden by pigmentation and 

 morphometries. Unlike yellowfin menhaden, gulf and Atlantic menhaden lacked paired melanophores along 

 the dorsal midline forward of the dorsal fin and along the ventral midline between the paired fins. Compared 

 with yellowfin menhaden larvae of equal lengths, gulf menhaden had less body depth, shorter heads and 

 snouts, smaller eyes, and longer prepelvic and predorsal distances. Gulf menhaden eggs averaged 1.29 mm in 

 total diameter, 0.95 mm in yolk diameter, and 0.20 mm in oil droplet diameter. Twelve-hour-old larvae had a 

 snout-notochord tip length of 3.3 mm. Their growth rate averaged 0.30 mm/day through 90 days of rearing at 

 20°C. On specimens 6-17 mm the mean number of myomeres was 44.6; on specimens >15 mm the mean 

 number of vertebrae was 45.3. Postdorsal-preanal myomeres decreased from 5.3 to 1.8 as the dorsal fin grew 

 and the gut shortened during development. Transformation from larva to juvenile in laboratory-reared gulf 

 menhaden was completed at a smaller size than reported for field-caught fish (25 vs. 28 mm SL). 



Eggs and larvae of gulf menhaden, Brevoortia pa- 

 tronus Goode, have not been described, even though 

 this species is the most economically important 

 clupeid in the United States. The gulf menhaden 

 purse seine fishery landed an average of 660,368 t 

 annually from 1977 to 1981, making it the largest 

 fishery in the United States (U.S. National Marine 

 Fisheries Service 1982). Gulf menhaden, one of three 

 species of Brevoortia in the Gulf of Mexico, are found 

 from Florida Bay to the Gulf of Campeche, Mexico. 

 They spawn in the northern gulf at least as far 

 offshore as the 80 m isobath between mid-October 

 and late March, with a peak in December (Christmas 

 and Waller 1975'); juveniles are estuarine depen- 

 dent. Yellowfin menhaden, B. smithi, and finescale 

 menhaden, B. gunteri, co-occur with gulf menhaden, 

 but contribute <1% to the landings. The Atlantic 

 menhaden, B . tyrannus , which supports a large purse 

 seine fishery along the U.S. Atlantic coast, is a large- 



■Contribution No. 83-33B of the Southeast Fisheries Center, 

 Beaufort Laboratory, National Marine Fisheries Service, NOAA. 



-Southeast Fisheries Center Beaufort Laboratory, National 

 Marine Fisheries Service, NOAA, Beaufort, NC 28516-9722. 



'Christmas, J. Y., and R.S. Waller. 1975. Location and time of 

 menhaden spawning in the Gulf of Mexico. Unpubl. manuscr., 20 

 p. Gulf Coast Research Laboratory, Ocean Springs, MS 39564. 



Manuscript accepted July 1983. 



FISHERY BULLETIN: VOL. 82, NO. 1, 1984. 



scaled cognate of the gulf menhaden, but does not 

 occur in the Gulf of Mexico (Hildebrand 1963). 

 Distribution of yellowfin menhaden is contin- 

 uous around Florida to as far north as North Caro- 

 lina. 



Menhaden larvae superfically resemble the larvae 

 of other clupeids with which they co-occur and can be 

 distinguished from them (Houde and Fore 1973; 

 Houde and Swanson 1975), but current descriptions 

 (Suttkus 1956; Houde and Fore 1973; Houde and 

 Swanson 1975; Jones et al. 1978) are not adequate to 

 separate sympatric Brevoortia larvae. Eggs, larvae, 

 and juveniles of yellowfin menhaden have been de- 

 scribed (Houde and Swanson 1975), whereas the 

 early development of finescale menhaden has not. 

 Gulf and yellowfin menhaden hybrids in the eastern 

 Gulf of Mexico (Hettler 1968; Turner 1969; 

 Dahlberg 1970) further complicate separation by 

 species. Although gulf and Atlantic menhaden larvae 

 cannot be confused in ichthyoplankton collections 

 because of their allopatric separation by the Florida 

 Peninsula, Atlantic and yellowfin menhaden larvae 

 may be confused in collections from the east coast of 

 Florida, where both species are known to spawn dur- 

 ing the winter (Dahlberg 1970). 



In this paper, I describe the eggs, larvae, and early 



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