Age and growth of juvenile ladyfish (Elops sp) in Tampa Bay, Florida, USA

Abstract

The age and growth of juvenile ladyfish (Elops sp) in Tampa Bay, Florida (USA) was examined using two cost-effective age and growth methods: length-frequency analysis (LFA) and captive rearing. The progression of monthly ladyfish size significantly increased from the beginning (i.e., when many young and small individuals were collected) to the end (i.e., when fewer older and larger individuals were collected) of the recruitment period. In most years, ladyfish growth (i.e., mean length) in Tampa Bay increased consistently from March to July. Juvenile ladyfish growth calculated by the LFA approach ranged from 0.30 to 1.3 mm day-1, whereas captive reared ladyfish grew between 0.60 and 0.70 mm day-1. Captive rearing data, together with length-frequency data, suggests that juvenile ladyfish reach between 212 and 297 mm SL by age-1. Individuals raised in tanks grew faster than those in the natural environment during the first 90 days, but slower after 90 days.