Nucleic acid contents and growth of first‐feeding walleye pollock larvae in response to prey densities typical of sub‐Arctic ecosystems

• Published in: Journal of Fish Biology
• Main Author: Canino, M. F.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1997
• Subjects: Arctic; Theragra chalcogramma
• Online Access: http://dx.doi.org/10.1111/j.1095-8649.1997.tb02512.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1095-8649.1997.tb02512.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1095-8649.1997.tb02512.x

The growth, nucleic acid and protein contents of walleye pollock Theragra chalcogramma larvae reared at prey densities of 10, 30, 50, and 500 prey 1 ‐1 were measured for the first 9 days after the feeding initiation at 6° C. Incremental growth rates of larvae (mm day ‐1 ) were low and variable for the first 7 days after feeding initiation. Growth rates and rates of RNA, DNA, and protein accumulation by larvae reared at 500 prey 1 ‐1 were positive while those of larvae reared at the lower prey levels did not differ significantly from zero. The RNA/DNA ratio was variable and exhibited no significant trend among food treatments. Estimates of instantaneous protein growth rates ranged from ‐ 6·7 to 13·2% day ‐1 at food densities of 10 and 500 prey 1 ‐1 , respectively, and were moderately correlated with larval RNA/DNA ratios ( r = 0·628). The results suggest that in situ protein growth rates of first‐feeding pollock larvae may be influenced by prey fields within the range of ambient food densities reported for sub‐Arctic ecosystems.