REPRODUCTIVE-BIOLOGY OF THE DWARF HERRING (JENKINSIA-LAMPROTAENIA) INTHE VIRGIN-ISLANDS

The temporal pattern of inshore aggregation, gonadal condition, and pr esumed spawning activity of a population of the tropical clupeiform, J enkinsia lamprotaenia, were examined along the south shore of St. John , U.S. Virgin Islands, Gonad condition varied through the lunar month (P < 0.0001); ripe individuals occurred close to the full moon and nea rly all individuals examined were spent after lunar day 21 (new moon = lunar day 1). Gonadosomatic index differed among lunar days (P < 0.00 01), peaking just prior to the full moon each month, followed by a rou ghly constant rate of decline. Jenkinsia aggregations invariably moved offshore at dusk, therefore the results supported the hypothesis that inshore aggregations of Jenkinsia are comprised of prespawning indivi duals taking refuge during daylight.