Yellowfin menhaden, continued 



Table 5.18. Relative abundance of yellowfin 



menhaden in 31 Gulf of Mexico estuaries (from 



Volume I). ... 



Life stage 



Relative abundance: 



# Highly abundant 



® Abundant 



O Common 



V Rare 



blank Not present 



Life stage: 



A - Adults 

 S - Spawning 

 J - Juveniles 

 L - Larvae 

 E - Eggs 



Habitat 



Type : The yellowfin menhaden is a neritic species 

 (Dahlberg 1970, Hettler pers. comm.). Larvae and 

 juveniles probably occur in all tidal waters of the 

 spawning area (Gunterand Hall 1963, Reintjes 1969, 

 Ahrenholz 1991). Adults frequent estuaries and tidal 

 embayments during a portion of the year, and are 

 typically found in depths less than 1 8 m (Reintjes 1 960, 

 Turner 1969, Dahlberg 1970). 



Substrate : This species inhabits the water column, and 

 no substrate preference is apparent. 



Physical/Chemical Characteristics : Eggs have been 

 collected in waters with surface temperatures ranging 

 from as low as 1 6.4° (Reintjes 1 962) to 25.4°C (Houde 

 and Swanson 1975) and salinities as low as 20.1%o 

 (Reintjes 1962) to 33%o (Houde and Swanson 1975). 

 Juveniles have been reported from a temperature 

 range of 17.0° to 26.1 °C and in salinities of 0.19 to 

 27.2% (Gunterand Hall 1 963, Wang and Raney 1 971 ). 



Migrations and Movements : This species has no ap- 

 parent systematic, annual migratory behavior. There 

 is some evidence, however, for an increased north- 

 ward distribution in late summer, and a southward 

 movement of the species during the spawning season 

 (Reintjes 1 969, Turner 1 969, Dahlberg 1 970, Ahrenholz 

 1991). 



Reproduction 



Mode : Reproduction is sexual, with separate male and 

 female sexes (gonochoristic). Milt and roe are broad- 

 cast, and fertilization is external. 



Spawning : The yellowfin menhaden is a winter spawner. 

 The spawning season appears to be relatively short, 

 and occurs nearshore, apparently in tidal waters 

 (Reintjes 1960, Dahlberg 1970, Ahrenholz 1991). 

 Spawning may occur as early as November, but is 

 probably most common from February to March 

 (Ahrenholz 1991). Yellowfin menhaden reportedly 

 spawn laterthan gulf menhaden (Hettler 1 968, Reintjes 

 1969). Larvae are known to occur in Gulf of Mexico 

 waters from December through March (Ditty et al. 

 1988). 



Fecundity : Determinate fecundity is likely for menha- 

 den, but this condition has not been demonstrated, nor 

 has batch fecundity been estimated for any menhaden 

 species (Ahrenholz 1991). 



Growth and Development 



Embryonic Development Embryos develop ovipa- 

 rously. Egg diameters range from 1.21 to 1.48 mm 

 (Houde and Swanson 1 975, Ditty et al. 1 994). The time 

 of hatching varies with temperature. Hatching occurs 



145 



