FISHERY BULLETIN: VOL. 82, NO. 1 



reared gulf menhaden or wild specimens of gulf 

 menhaden collected from four locations along the 

 northern Gulf of Mexico had ventral midline pig- 

 ment. Gulf menhaden had more dorsal fin rays, but 

 both species had an equal number of anal rays. Fer- 

 tilized eggs of the two species had the same diameter, 

 but gulf menhaden had a larger oil droplet (0.20 vs. 

 0.15 mm) than yellowfin menhaden. No description 

 of finescale menhaden larvae exists, but presumably 

 they have 42-43 myomeres, based on the number of 

 vertebrae reported for this species (Dahlberg 1970). 

 Although gulf menhaden larvae are geographically 

 separated from Atlantic menhaden larvae, they can 

 be separated by counting myomeres or vertabrae; 

 gulf menhaden, 44-46; and Atlantic menhaden, 47- 

 48. Atlantic menhaden and yellowfin menhaden had 

 nearly equal dorsal and anal fin ray numbers, but 

 Atlantic menhaden had one to four more myomeres 

 and lacked dorsal and ventral midline paired 

 melanophores anterior to the dorsal and pelvic fins. 

 Mophometric differences between Atlantic men- 

 haden and yellowfin menhaden are similar to dif- 

 ferences between gulf menhaden and yellowfin 

 menhaden. 



There are some differences in egg and larval meris- 

 tics and morphology data between my study and the 

 literature, which may be due to differences between 

 laboratory-reared and wild specimens. Houde and 

 Fore (1973) reported that gulf menhaden had 45-48 

 myomeres (vs. 44-46 that I found for gulf menhaden), 

 20-23 anal rays (vs. 19-21), 17-21 dorsal rays (vs. 20- 

 22), and reported that pelvic fins in northern gulf 

 specimens were not developed until 20 mm (vs. 18 

 mm). They also reported that gulf menhaden eggs 

 had a diameter of 1.04-1.30 mm (vs. 1.18-1.34 mm), 

 an oil droplet of 0.08-0.20 mm (vs. 0.16-0.22 mm), 

 and a wide perivitelline space of about 33% (vs. 24- 

 28';). Jones et al (1978) reported that Atlantic 

 menhaden egg diameter was 1.30-1.95 mm (vs. 1.54- 

 1.64 mm that I found for Atlantic menhaden), that 

 yolk diameter was 0.90-1.20 (vs. 0.82-.095 mm), and 

 that the oil droplet diameter was 0.11-0.17 (vs. 

 0.20-0.23). For Atlantic menhaden larvae of 

 unspecified lengths they reported 16-18 dorsal rays 

 (vs. 20-22), 18-20 anal rays (vs. 19-21), and a body 

 depth:standard length ratio of about 0.05 at 23 mm 

 total length (vs. about 0.20 I found at the same 

 length); however, the body depth ratio is undoubt- 

 edly a typographical error. 



Laboratory-reared gulf menhaden and Atlantic 

 menhaden both appeared to transform into juveniles 

 at a smaller size than wild fish. Morphometric data 

 and photographs of specimens of gulf menhaden 

 from Louisiana indicated that the juvenile form was 



not reached until about 30 mm SL (Suttkus 1956). 

 Lewis et al. (1972) indicated that Atlantic menhaden 

 from North Carolina did not complete "prejuvenile" 

 growth until about 33 mm SL. Houde and Swanson 

 (1975) suggested that tank-reared yellowfin men- 

 haden transformed at smaller sizes than did wild fish, 

 and I concur. 



Characters useful for separating eggs and larvae of 

 Brevoortia from other clupeids have been identified 

 (Houde and Fore 1973; Richards et al. 1974; Houde 

 and Swanson 1975; Powles 1977). Sardinella and 

 Opisthonema have about the same total myomere 

 counts as Brevoortia, but usually have 6-9 post- 

 dorsal-preanal myomeres. Ktrumcus has the same or 

 more total myomeres than Brevoortia, but about 10 

 fewer anal rays. The smaller larvae of Sardinella, 

 Opisthonema, and Etrumeus have no pigment on the 

 dorsal side of the notochord tip, whereas Brevoortia, 

 Harengula, and Jenkinsia have this pigment. 

 However, Jenkinsia and Harengula have 42 or fewer 

 myomeres. The spawning seasons of all these genera 

 overlap with the spawning season of Brevoortia 

 species (Houde and Fore 1973; Powles 1977; Jones 

 et al. 1978). Larvae of Dorosoma and Alosa are not 

 normally found in marine waters with Brevoortia. 



ACKNOWLEDGMENTS 



I thank John J. Govoni, William R. Nichols, and 

 Allyn and B. Powell of the Beaufort Laboratory for 

 reviewing the early drafts of the manuscript; Ed 

 Houde of the University of Maryland for his review of 

 a later draft; and Thomas Potthoff of the Southeast 

 Fisheries Center, NMFS, and G. David Johnson of 

 the South Carolina Wildlife and Marine Resources 

 Department for their comments on terminology. This 

 research was supported by a contract from the Ocean 

 Assessments Division, National Ocean Services, 

 NOAA. 



LITERATURE CITED 



Dahlberg, M. D. 



1970. Atlantic and Gulf of Mexico menhadens, Genus 



Brevoortia (Pisces: Clupidae). Bull. Fla. State Mus., Biol. 



Sci. 15:91-162. 

 Hettler, W. F., Jr. 



1968. Artificial fertilization among yellowfin and Gulf 



menhaden [Brevoortia) and their hybrid. Trans. Am. 



Fish. Soc. 97:119-123. 

 1970. Rearing larvae of yellowfin menhaden, Brevoortia 



smithi. Copeia 1 970:775-776. 

 1981. Spawning and rearing Atlantic menhaden. Prog. Fish- 

 Cult. 43:80-84. 

 1983. Transporting adult and larval gulf menhaden and 



techniques for spawning in the laboratory. Prog. Fish- 



94 



