Incidence of Subcaudal Melanaphores in Pre-extrusion Larvae of Redfish Species in the Newfoundland-Labrador Area

Wilfred Templeman

J. L. Paton Chair of Marine Biology and Fisheries
Memorial University of Newfoundland
St. John's, Newfoundland, Canada

Source - Journal of Northwest Atlantic Fishery Science, Volume 1: 7-19
ISSN-0250-7408

 

Templeman, W. 1980. Incidence of Subcaudal Melanaphores in Pre-extrusion Larvae of Redfish Species in the Newfoundland-Labrador Area. J. Northw. Atl. Fish. Sci. 1: 7-19. https://doi.org/10.2960/J.v1.a1

 

Abstract

Pre-extrusion larvae of female redfish from the Newfoundland-Labrador area in 1958-66 were examined for the presence or absence of subcaudal melanophores. The larval samples from the sharp-beaked mentella-type redfish were readily separated into two groups. one with all or nearly all of the larvae possessing subcaudal melanophores and recognized as Sebastes tescietus, and the other tending to have a small fraction or none of the larvae with these melanophores and recognized as Sebastes mentella. Moreover, the larvae of S. fasciatus had on the average a greater number of subcaudal melanophores which were also usually larger than those of S. mentella. However. the presence of these melanophores in many of the North American S. mentella contrasts with the reported absence of subcaudal melanophores in larvae of Icelandic and Northeast Atlantic and of the North Atlantic oceanic populations of S. mentella. The female parents of larvae assigned to S. fasciatus had significantly lower vertebral. anal fin-ray and dorsal fin-ray numbers than those of larvae assigned to S. mentella.

The occurrence of subcaudal melanophores in Sebastes marinus larvae generally resembled that in the North American S. mentella (as distinct from S. fasciatus) except that the former tended to have more larvae with melanophores than the latter. The meristic characteristics of the S. marinus parents more closely resembled those of S. mentella than those of S. tescietus. but the fin-ray numbers in S. marinus tended to be lower than in S. mentella.

In the Northwest Atlantic area from Flemish Cap to southern Labrador, the spawning females of S. mentell a appear to live deeper and extrude larvae earlier in the year than those of S. fasciatus and S. marinus. These differences in distribution and biology and the occurrence of large immature S. mentella in the northern part of Newfoundland-Labrador area have management implications which are discussed.

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Language - English
Publisher - Northwest Atlantic Fisheries Organization (NAFO), Dartmouth, N.S., Canada
Publication Date - December 1980
Publication Type - Journal Article
Descriptors - Atlantic redfish, larvae, Newfoundland area  

Citation: Templeman, W. 1980. Incidence of Subcaudal Melanaphores in Pre-extrusion Larvae of Redfish Species in the Newfoundland-Labrador Area. J. Northw. Atl. Fish. Sci. 1: 7-19. https://doi.org/10.2960/J.v1.a1