Genetic differentiation between morphotypes in the Antarctic limpet Nacella concinna as revealed by Inter-Simple Sequence Repeat (ISSR) markers

DE ARANZAMENDI, CARLA; SAHADE, R; TATIÁN M; CHIAPPERO, M

MARINE BIOLOGY

Springer

Año: 2008 vol. 154 p. 875 - 885

0025-3162

The limpet Nacella concinna (Strebel 1908) was the focus of numerous studies dealing with Antarctic benthos. One of the main characteristics of the species is the presence of two distinguishable morphotypes that inhabits one in the intertidal (during summer) and the other in the subtidal. For a long time these forms were considered as an expression of phenotypic plasticity since previous studies did not find genetic differences between them. In the present work, ISSRs-PCR markers were used to asses the genetic differentiation and genetic diversity of these two forms in three stations sampled at Potter Cove, South Shetland Islands. The results confirmed the morphological differences reported in other Antarctic localities but contrary to previous studies, the two forms can be considered as genetically different populations. Depending on the heritability of the migration character, which separate both populations in summer time when reproduction takes place, the difference can be increased into an speciation process if the heritability is high. The genetic cohesion of the species would be maintained if the heritability is low. The genetic differentiation can be reflected in the morphology, in behavioral aspects and probably in physiological traits, which points out the importance of assessing future studies in this species taking into account the potential differences in the response of both populations to different conditions.