Variations in caudal pigmentation in late-stage pre-extrusion larvae from marinus- and mentella-type female redfish from the Newfoundland area

Abstract

Late stage pre-extrusion larvae have been examined from 37 marinus-type and 44 mentella-type redfish, obtained from three localities in the Newfoundland area. Examination of 120 larvae from each fish has revealed that a difference exists between the two types, in the relative presence or absence of caudal melanophores in their larvae. The caudal melanophores, when present, are situated near the base of the caudal fin and ventral to the vertebral column. Caudal melanophores were absent in only 2.3% of the larvae from mentella-type parents in contrast to the absence of caudal melanophores in 76.1% of the larvae from marinus-type parents. When only those larvae having caudal melanophores are considered, larvae from marinus-type, parents usually have but a single melanophore whereas those from mentella-type parents usually have two caudal melanophores.This difference between larval samples provides evidence of the existence of a real genetic difference between mentella and marinus types of redfish in the Northwest Atlantic.