Meristic Differences between Spring- and Autumn-Spawning Atlantic Herring (Clupea harengus harengus) from Southwestern Newfoundland

Abstract

Numbers of vertebrae, gill rakers, and of pectoral, anal, and dorsal fin rays of spring- and autumn-spawning Atlantic herring (Clupea harengus harengus Linnaeus) in 10 samples from the coastal waters of southwestern Newfoundland were compared. There was no significant difference (P > 0.05) between mean vertebral numbers of spring and autumn spawners. Mean numbers of gill rakers and of pectoral, anal, and dorsal fin rays were all higher (P < 0.01) for autumn spawners than for spring spawners with gill-raker and pectoral fin-ray numbers exhibiting the greatest degree of difference. It is suggested that the differences in fin-ray numbers between spring and autumn spawners are related to water temperatures during larval development and to differences in developmental rates of spring- and autumn-hatched larvae.