Comparison of Lipid Components between Two Species of Sand Lance, Ammodytes hexapterus and Ammodytes personatus, in Northern Hokkaido.

Sand lances are utilized as feed for cultured fishes in the aquaculture industry and as raw materials for processed foods such as dried or smoked fishes. In the waters of Cape Soya, two species of sand lances, Ammodytes hexap terus and A. personatus, coexist.1,2) These two species can be distinguished by the comparison of electrophoretic vari ants of their lactate dehydrogenase (Ldh).3) But they are treated as one species because of the inability to differenti ate them based on appearance. Recently, it was shown that the reproductive cycles of these two species are different.') In the waters of Cape Soya, the spawning season of A. hex apterus is from late November to December and that of A. personatus is from late March to early May, 2) and the fish ing season of sand lances is from June to September. It is presumed that lipid and water contents of the two species are different according to the difference in gonad matura tion during the fishing season. There have been few reports on studies pertaining to body components and lipids of in dividual species of sand lances;4-8) and none that we could find that compared the body components of these two spe cies. Lipid components of sand lances affect the growth of cultured fish fed with the sand lances, and also processed food products of sand lance. This study compared these two species from the sea of Cape Soya. caught by otter trawl nets in the east of Cape Soya (Fig. 1) in July and September 1989. The two species were differen tiated by their different Ldh-2 locus. Muscle tissue was used for biochemical analysis. Genotypes at the Ldh-2 lo cus were detected on horizontal electrophoresis as de scribed in the previous paper.3) Whole bodies and gonads