Abstract

Studies on microevolutionary processes in deep-sea environments, allow testing the contrasting hypotheses about the environmental stability. Some of these consider those environments as stable or suffering periodical disturbances. In those cases the species will answer according to its genetic potential and phylogenetic constrains. In this context. the genetic variability in the rat tail fish Caelorinchus fasciatus was studied. Using starch electrophoresis the enzymatic products of 28 presumptive loci were screened; only three of them were polymorphic PGI-1, PGI-2 and PGM-1. 1. The low genetic variability found (H=0,026) is seen as typical of habitat generalist species. Compared with Macrourus holotrachys, the single Chilean species that has genetic records. 12 loci show, similar electrophoretic expression in both species, including 5 loci of total proteins. The Genetic Identity between both species was I=0.409 and the Genetic Distance was D=0,894. Moreover, our results support the Gauldie's hypothesis that it is possible to find low variability in the enzymatic systems PGI and PGM. or in one of them but never high variability in both of them simultaneously.