Yellowfin menhaden, continued 



in less than 24 hours above 22°C (Houde and Swanson 

 1975), 34 hours at 21 °C, 26 hours at 26°C, and within 

 46 hours at 19°C (Reintjes 1962, Hettler 1968). 



Age and Size of Larvae : The standard length (SL) of 

 larvae at hatching is about 3.0 mm (Houde and Swanson 

 1975). Larvae begin transforming at about 14.0 mm, 

 with transformation being complete between 20 and 23 

 mm (Houde and Swanson 1975). Larval growth is 

 rapid, and is probably dependent on temperature and 

 food availability (Reintjes 1 969, Ahrenholz 1 991 ). Larval 

 growth at 20°C averaged 0.36 mm/day over a 32 day 

 period, and 0.45 mm/day at over 20 days at 26°C 

 (Hettler 1984). 



Juvenile Size Range : Juveniles reach a fork length 

 (FL) of 160 mm by the end of their first summer and 

 approximately 220 mm by the end of their second 

 summer. Sexual maturity is attained during the second 

 winter for most individuals (Reintjes 1969). In one 

 study, the smallest ripe adults reported were a 1 86 mm 

 FL female and a 215 mm FL male (Hettler 1968). 



Age and Size of Adults : Adults differ from juveniles and 

 young adults in that their scales are more strongly 

 serrated and their bodies are not as deep. The largest 

 recorded total length (TL) for a specimen is 330 mm 

 (Hildebrand 1963), and the maximum life span is 

 thought to be somewhere between 5 and 12 years 

 (Ahrenholz 1991). 



Food and Feeding 



Trophic Mode : Menhaden selectively sight-feed on 

 individual planktonic organisms from the larval stage 

 into the prejuvenile stage. After metamorphosis, juve- 

 nile yellowfin menhaden become filter-feeding plankti- 

 vores (Ahrenholz 1991). 



Food Items : The diet of this species consists of phy- 

 toplankton, small zooplankton, and detritus strained 

 from the water column (Ahrenholz 1 991 , Hettler pers. 

 comm.). 



Biological Interactions 



Predation : Menhaden are potential prey throughout 

 their life cycle (Ahrenholz 1991). Larval and juvenile 

 piscivorous fish and some invertebrates (e.g., cha- 

 etognaths) can prey on menhaden larvae. Other 

 potential invertebrate predators may include squids, 

 ctenophores, and jellyfish. Many piscivorous fishes 

 (sciaenids, bluefish, bonito, etc.) prey opportunistically 

 on juvenile and adult menhaden. Menhaden are also 

 an important forage item for piscivorous birds such as 

 the brown pelican and the common loon. Marine 

 mammals are also reported to prey on menhaden. A 

 potential also exists for menhaden to feed on their own 

 eggs. 



Factors Influencing Populations : There is little pub- 

 lished information on yellowfin menhaden due to its low 

 abundance and lack of commercial importance 

 (Ahrenholz 1991). This species is known to hybridize 

 with Atlantic menhaden (B. tyrannus) and gulf menha- 

 den (B. patronus) (Dahlberg 1970, Ahrenholz 1991). 

 Parasitic copepods have been found on yellowfin men- 

 haden, and parasitic isopods have been found on 

 yellowfin x gulf menhaden hybrids (Ahrenholz 1991). 



Personal communications 



Hettler, William F., Jr. NOAA National Marine Fisher- 

 ies Service, Beaufort, NC. 



Smith, Joseph W. NOAA National Marine Fisheries 

 Service, Beaufort, NC. 



References 



Ahrenholz, D.W. 1991. Population biology and life 

 history of the North American menhadens, Brevoortia 

 spp. Mar. Fish. Rev. 53(4): 3-19. 



Christmas, J.Y., D.J. Etzold, and L.B. Swanson. 1 983. 

 The menhaden fishery of the Gulf of Mexico United 

 States: A regional management plan. Gulf States Mar. 

 Fish. Comm. Pub. No. 8, Gulf States Marine Fisheries 

 Commission, Ocean Springs, MS. 



Christmas, J.Y., D.J. Etzold, L.B. Simpson, and S. 

 Meyers. 1988. The menhaden fishery of the Gulf of 

 Mexico United States: a regional management plan, 

 1 988 revision. Gulf States Mar. Fish. Comm. Pub. No. 

 18, Gulf States Marine Fisheries Commission, Ocean 

 Springs, MS, 77 p. 



Dahlberg, M.D. 1970. Atlantic and Gulf of Mexico 

 menhaden genus Brevoortia (Pisces: Clupeidae). Bull. 

 Fla. St. Mus. 15(3):91-162. 



Deegan, L.A. 1985. The population ecology and 

 nutrient transport of gulf menhaden in Fourleague Bay, 

 Louisiana. Ph.D. dissertation., Louisiana St. Univ., 

 Baton Rouge, LA, 136 p. 



Ditty, J.G..E.D. Houde, and R.F.Shaw. 1994. Egg and 

 larval development of Spanish sardine, Sardinella aurita 

 (Family Clupeidae), with a synopsis of characters to 

 identify clupeid larvae from the northern Gulf of Mexico. 

 Bull. Mar. Sci. 54(2):367-380. 



Ditty, J. G., G.G. Zieske, and R.F. Shaw. 1988. Sea- 

 sonality and depth distribution of larval fishes in the 

 northern Gulf of Mexico above latitude 26°00'N. Fish. 

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