Reproductive biology of wahoo, Acanthocybium solandri, from the Atlantic coast of Florida and the Bahamas

Abstract

Despite its economic importance to many coastal nations, assessments of wahoo, Acanthocybium solandri, are hampered by a lack of basic life history information. In this study, wahoo were collected from Florida’s Atlantic coast and the northern Bahamas during 1997–2006 to examine reproductive seasonality, maturation, spawning frequency and fecundity. These samples demonstrated only a single, summer-spawning season, which did not support earlier postulations of spring spawning by wahoo near the Bahamas. The size and age at 50% female maturity were 925 mm fork length and 0.64 years, respectively. Spawning frequency was, on average, every 5 days during June–August, but 13% of mature females were inactive during this period. Batch fecundity was positively correlated with fish size, and varied between 0.44 and 1.67 million eggs. Parasites, previously unreported to occur in wahoo gonads and identified only as philometrid nematodes, were evident in 11% of these females. Most parasitised fish had vitellogenic oocytes, several even with oocytes with migrating nuclei or post-ovulatory follicles, so these parasitised fish were capable of spawning. Although wahoo have been noted to have relatively small gonads, and parasites are often found in female gonads, annual fecundity estimates are of the order of 10–100 million eggs. The significant contribution of older, larger females to egg production should be considered in managing this fishery.