Young King Mackerel, Scomberomorus Cavalla, in the Gulf of Mexico, a Summary of the Distribution and Occurrence of Larvae and Juveniles, and Spawning Dates for Mexican Juveniles

To further our understanding of recruitment, spawning areas and times and stock structure we summarized all available published and unpublished information on early life stages of king mackerel. New data, 248 larvae and small juveniles (≤50 mm SL) from 676 neuston samples (1 x 2 m 0.947 mm and 0.760 mm mesh net) collected between 1983 and 1986 from west Florida (83°W long.) and the U.S. Mexican border (26°N lat.), are included. Previously unreported data (mostly large juveniles >50 mm SL) were collected during over 105,000 h of trawling between 1952 and 1985, and from an almadraba (pound net) and shrimp trawls in Mexico in 1985, 1986 and 1987. Sampling effort appropriate for collecting early life stages of king mackerel has been extensive (>7,200 collections), but heavily concentrated in U.S. waters during warm months (April to October). Larvae (≤10 mm SL) and small juveniles (11–50 mm SL) have been collected throughout the Gulf of Mexico (N = 1384), but mostly off Texas and between east Louisiana and northwest Florida. Most larger juveniles (>50 mm SL) have been collected off the Louisiana–Mississippi coast and southern Mexico. Seasonal occurrences of young stages clearly delineate the spawning season in U.S. waters as May to October, with a peak in September. Spawning dates backcalculated using daily ages determined from saggital otolith microstructure suggest that juveniles collected off Mexico were spawned January to September.