Reproductive Biology of Cero, Scomberomorus regalis, from the Coastal Waters of South Florida

Cero, Scomberomorus regalis, were collected off south Florida during 1980-81 to determine their reproductive biology. Spawning of cero occurs in coastal waters throughout most of the year with a peak in May. Males attain maturity at about 350 mm FL and females at about 380 mm FL. Fecundity estimates from 20 late maturing or ripe females ranged from 161,000 ova for a 380 mm fish weighing 558 g to 2,234,000 ova for a 800 mm fish weighing 4,944 g. Total weight better indicated fecundity than did fork length. The relationship between fecundity and total weight was expressed by the least square equation F = -1.079 x 10-1 + (4.342 x 10-4) TW. The mean number of ova per gram of fish weight was 362

Reproduction of Spanish Mackerel, Scomberomorus maculatus, from the Southeastern United States

Spanish mackerel, Scomberomorus maculatus, were collected during 1977-80 in the Gulf of Mexico and from North Carolina to south Florida during 1980-81 to describe their reproductive biology. The major spawning period extended from May to September in all areas and peaked during the spring and early summer. Most fish were mature at about 350 mm FL, but size at maturity varied between sexes and sampling areas. Males matured at a smaller size than females. Fecundity was estimated from 52 fish from all areas and ranged from about 100,000 eggs for a 328 mm (295 g) fish to 2,113,000 eggs for a 626 mm (2,415 g) fish. Fork length and total weight were equally good predictors of fecundity

Reproductive Biology of Blue Runner (Caranx crysos) from the Eastern Gulf of Mexico

Blue runner were obtained from commercial fisheries in south Florida, northwest Florida, and the Mississippi Delta. Monthly mean gonadosomatic indices indicated that peak spawning occurred in June, July, and August for all areas with a secondary peak in October for northwest Florida. The spawning season was confirmed for the south Florida collection by histological examination of gonads. Probit analysis of 185 northwest Florida blue runner captured during peak spawning months indicated a length-at-maturity of 267 mm. Fecundity varied from 41,000 ova in a 243·mm·FL, 288-gram fish to 1,546,000 ova in a 385·mm·FL, 1,076-gram fish. Sex ratios were 1.15F:1M for Mississippi Delta, 1.66F:1M for northwest Florida and 1.91F:1M for south Florida

Distribution, Seasonality and Abundance of King and Spanish Mackerel Larve in the Northwestern Gulf of Mexico (Pisces: Scombridae)

Larvae of king mackerel, Scomberomorus cavalla, and Spanish mackerel, S. maculatus were collected from 1975 through 1977 off the Texas coast. Both species were captured from May through October. S. cavalla was relatively more abundant of the two species and occurred most abundantly over the middle and outer continental shelf (35-183 m). At least 35% of the larvae were captured in September of each year. S. maculatus larvae occurred most abundantly over the inner continental shelf (12 to 50 m). S. cavalla spawned from May through September to early October, with the greatest spawning intensity occurring over the middle and outer continental shelf during September. S. maculatus spawned from May through September to early October over the inner continental shelf, but spawning was less intensive and more irregular than for S. cavalla. Comparisons with other larval studies of S. cavalla and S. maculatus suggest that the northwestern and northeastern Gulf of Mexico and the coast off the southeastern United Stales are important spawning areas for S. cavalla and that the eastern and northeastern Gulf of Mexico are important spawning areas for S. maculatus

Diets of Young King and Spanish Mackerel Off the Southeast United States

The diet of larval and post-larval (n = 95 and 307), and juvenile (n = 489 and 508) king (Scomberomorus cavalia) and Spanish mackerel (S. maculatus) from the Gulf of Mexico and southeastern Atlantic coastal waters of the U.S. consisted principally of fishes. Carangids, clupeids, and engraulids occurred in 23, 7 and 9% of larval and post-larval king mackerel stomachs and in 20, 40 and 7% of larval and post-larval Spanish mackerel stomachs, respectively. Sciaenids were also common in king mackerel, occurring in 21% of the stomachs. Prey fishes included the genera Cynoscion, Caranx, and Anchoa, and the species Opisthonema oglinum. Invertebrates, principally small crustaceans and nudibranch larvae, occurred infrequently in the diets of both species, but more so in Spanish mackerel than king mackerel. The dominant prey items for juvenile mackerels from the Atlantic were engraulids, clupeids, balistids, and squids, collectively accounting for 73.3% by volume of the diet of king mackerel and 88.8% of Spanish mackerel. More invertebrates occurred in the diet of juvenile Spanish mackerel than king mackerel, but they accounted for a smaller volume, i.e., 2.1% as compared to 5.4% for the Atlantic fish. Chi-square tests indicated significant differences between the diets of juvenile mackerel from the Gulf of Mexico and the Atlantic coast