Gender Differences in Foraging Behavior of the Euphausiid Euphausia pacifica in the East Sea (Japan Sea) in Spring

• Published in: Ocean science journal Vol. 54; no. 2; pp. 287 - 295
• Main Authors: Im, Dong-Hoon, Kim, Seung-Kyu, Suh, Hae-Lip
• Format: Journal Article
• Language: English
• Published: Seoul Korea Institute of Ocean Science & Technology and The Korean Society of Oceanography 01.06.2019; Springer Nature B.V; 한국해양과학기술원
• Subjects: Aquatic Pollution; Blooms; Depth; Earth and Environmental Science; Earth Sciences; Epipelagic zone; Euphausia pacifica; Females; Foraging; Foraging behavior; Gender; Gender differences; Males; Marine & Freshwater Sciences; Oceanography; Particulate flux; Primary production; Spring; Stable isotopes; Surface layers; Waste Water Technology; Water Management; Water Pollution Control; 해양학; Japan; stable isotope analysis; East (Japan) Sea; feeding ecology; gender differences
• ISSN: 1738-5261; 2005-7172
• DOI: 10.1007/s12601-019-0006-x

Although it is known that there are gender differences in the energetic requirements for the reproductive strategies of euphausiids, sufficient information about differences in the feeding ecology is still lacking. In this study, we investigated the resource utilization of Euphausia pacifica within the epipelagic zone (0–200 m depth) in the East Sea (Japan Sea) during spring bloom, using stable isotope analysis. The δ 13 C and δ 15 N values of pico- to micro-particulate organic matters (POMs) from the surface to 200-m depth layers were significantly different. The δ 13 C and δ 15 N values of E. pacifica adults showed significant differences between sexes. Stable isotope analysis showed that E. pacifica females fed mainly on the surface layer POM, whereas the males fed primarily in the deeper layers, since the contributions of POMs in the 100-m and 200-m depth layers to their diets were relatively high. We suggest that high primary productivity in the surface layer in spring and the sinking particles derived from it may provide sufficient energy for the reproduction of E. pacifica females and male development, respectively.