Abstract

The tripletail, Lobotes surinamensis, is a migratory, pelagic species that occurs throughout the tropical and subtropical seas of the world. In the western Atlantic Ocean tripletail occur from Massachusetts to Argentina, including Bermuda, and throughout the Gulf of Mexico and the Caribbean Sea. The tripletail suppons a recreational fishery in the Gulf of Mexico, however, life history data required for stock assessment of Gulf tripletail are lacking. In a preliminary investigation of age and growth of tripletail from the northern Gulf of Mexico, 10 hardparts (dorsal fin spines #1 - 5, anal fin spines #1 - 3, the left pelvic fin spine and the first anal fin ray) from each of 10 specimens caught in the northern Gulf recreational fishery during 1996 - 1997 were examined for legibility of growth patterns on transverse thin-sections and usefulness in age estimation. Transverse sections of dorsal spines #2 5, anal spines #2 and #3, the left pelvic spine, and the first anal ray generally revealed only ambiguous markings and large eroded areas which essentially rendered them ineffective as ageing structures. Sections from 50% of the first anal spines were marginally acceptable. Most (90%) of the first dorsal spine sections revealed a succession of distinct, alternating opaque and translucent bands. Though not validated as annuli, translucent bands (typically comprised of multiple small rings) on first dorsal spine sections were considered probable indicators of age and were counted For a sample of 53 specimens. Interpretation of the early growth of a few large specimens was complicated by minimal vascular erosion of the first dorsal spine’s central core region, however, readers were able to count with some degree of certainty the bands which were affected. Mean length-at-estimated age data based on translucent band counts were derived for the small sample.

PDF Preview