Comparative study on Antarctic krill (Euphausia superba) in gravid stage in the northern Antarctic Peninsula

Abstract:

Based on the data collected from the northern Antarctic Peninsula from January 23 to February 13,2010. with supporting by Antarctic Marine Living Resource Survey Programme, the present study compared the biology of Antarctic Krill (Euphausia superba) in the gravid stage (KRI-G). The results showed that: (1) SL range and average SL of KRIG in AR 3 is greater than that of AR 1 and AR 2. Significant difference can be found for standard length (L_S) and carapace length (L_C) distribution of KRI-G among 3 study subareas. The CL range and average CL are similar for the KRI-G between AR 1 and AR 2, but the values in AR 3 are greater than that of AR 1 and AR 2. (2) The L_CL_S relationship is not different significantly between AR 1 and AR 2, however, remarkable difference can be found between AR 3 and AR 1 or AR 2. (3) The average WW of KRI-G in AR 1 is greater than AR 2 and AR 3 and the value in AR 2 is at lowest level. Different range can be found for the wet weight of KRI-G among study subareas and significant difference can be found on WW distribution and the L_SWW relationship. (4) The feeding intensity is similar between AR 1 and AR 2, i.e., the proportion of stage Ⅰ is highest and decreasing trend can be found from stage Ⅱ to stage Ⅳ. Although the proportion of stage Ⅰ is highest in AR 3, the similar proportion can be found for stage Ⅱ and stage Ⅳ, and the value is lower for stage Ⅲ. Remarkable difference can be found for the feeding intensity of KRI-G among 3 study subareas. The present study can provide basic data for exploiting Antarctic krill resources and a reference for recruitment status of Antarctic krill.