Life-History Aspects of the Yellow Irish Lord (Hemilepidotus jordani) in the Eastern Bering Sea and Aleutian Islands

Abstract

Growth, reproduction, and diet of the Yellow Irish Lord (Hemilepidotus jordani) were examined and compared between 2 adjacent geographical regions of Alaska, the eastern Bering Sea and Aleutian Islands, where its biology is not well understood. The Yellow Irish Lord is the most common member of the genus Hemilepidotus encountered during Alaska Fisheries Science Center bottom-trawl surveys of these regions. Based on our data, there was no significant difference in sizes of Yellow Irish Lords caught between regions. The von Bertalanffy growth models fitted to length-at-age data, however, indicate that male and female Yellow Irish Lords in the Aleutian Islands grew more slowly than those in the eastern Bering Sea. Histological assessment of ovary condition indicated that Yellow Irish Lords from both regions appear to spawn once annually during the summer. Relationships between size (length and weight) and fecundity between the 2 regions were significantly different, with Yellow Irish Lords from the Aleutian Islands being more fecund. Diet analysis showed that the Yellow Irish Lord is a benthic predator and their summer diets in both regions consist of a wide variety of prey, but appear to favor benthic crustaceans, particularly abundant crab species. However, the largest individuals appear to have more opportunities for piscivory in the Aleutian Islands. It appears that at least some variation in the life-history aspects of this species exists between these regions. This information may provide a scientific basis for developing management strategies of the Yellow Irish Lord in Alaskan waters.