Reproduction of asteroids from Balsfjorden, Northern Norway: Analyses of lipids in the gonads of Ctenodiscus crispatus, Asterias lincki and Pteraster militaris

1432-1793

Springer Online Journal Archives 1860-2000

Biology

Abstract Seasonal lipid analyses were performed on the gonads and residual bodies of Ctenodiscus crispatus (Retzius) and Asterias lincki (Müller & Troschel), collected from Balsfjorden, northern Norway during March 1978–February 1980. The ovaries of both species had high percentages of total lipid (in the region of 60% of the dry weight) that were relatively constant throughout the season. Testes from both species had in the region of 20% of their dry weight as lipid, again with little seasonal variation. The majority of the total lipid in the ovaries of C. crispatus was accounted for by alkyldiacylglycerols and there was little seasonal variation in lipid class composition. Phospholipid accounted for the bulk of the lipid in the testes of C. crispatus, where alkyldiacylglycerols were present but in minor amounts. A slight degree of seasonal variation occurred in the composition of testis lipid in that maximal percentages of triacylglycerols and alkyldiacylglycerols occurred in January–April. The ovaries of A. lincki contained both triacylglycerols and alkyldiacylglycerols as major neutral lipids. Significant seasonal variation occurred in lipid class composition in the ovaries in that neutral lipids showed transient minima in February–April. The testes of A. lincki had substantial amounts of both triacylglycerols and alkyldiacylglycerols: maximal percentages of these lipids occurred in January–March. Analyses of gonads of near-mature Pteraster militaris (O. F. Müller) revealed that the ovaries were rich in lipid that was predominantly alkyldiacylglycerols, whereas the testes had much lower levels of lipid accounted for mainly by phospholipids. The residual bodies of all three asteroids had significant but small amounts of alkyldiacylglycerols in their lipids. A. lincki had triacylglycerols as a major lipid class in its body lipids, whereas in C. crispatus the major body lipid was phospholipid. Little seasonal variation was seen in the composition of the residual body lipid of either C. crispatus or A. lincki. The results are consistent with an aseasonal reproductive pattern in C. crispatus, although a main breeding activity occurred in mid-winter. A. lincki is a more seasonal breeder, but also had maximal activity in winter. Irrespective of their breeding habits, all three asteroids produced eggs rich in alkyldiacylglycerols. A major role for this lipid in the development of the large lecithotrophic eggs of asteroids is indicated.

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