RNA CONTENT O F THE ANTARCTIC KRILL (EUPHAUSIA SUPERBA DANA), A N ESTIMATOR O F NATURAL GROWTH RATE

• Main Author: Tsutomu Ikeda
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Antarctic; The Antarctic; Wilkes Land; Antarc*; Antarctic Krill; Euphausia superba
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.501.7522; http://polaris.nipr.ac.jp/~penguin/polarbiosci/issues/pdf/1989-Ikeda.pdf

Abstract: The ribonucleic acid (RNA) content of the krill was measured on specimens collected during the KAIYO-MARU cruise to the Wilkes Land, Antactica, January 1980. Of 41 specimens analysed, the RNA content varied from 2.5 to 8.2 % of body protein (mean: 5.1%). A higher RNA content was seen in smaller specimens, and the relationship was log Y =-0.34 log X + 1.27, where Y is the RNA content as percent of protein, and X is the body size as mg protein. Combining this equation with the RNA-growth rate equation of B~MSTEDT and SKJOLDAL (Limnol. Oceanogr., 25, 304,1980), the growth rate of the krill was estimated to be 0.17-0.19mm day-I for specimens greater than 30mm body length. Assuming a favorable feeding period of 6 months in a year for this animal, post-larvae could grow to the final size adults in 201 days. Validity of these results depends on the RNA-growth rate equation. In the light of possible species-specific variation in the RNA-growth rate relationship, this relationship needs to be established for the Antarctic krill in future laboratory experiments. 1.