IS MORPHOLOGY ENOUGH TO DEFINE A BIOLOGICAL SPECIES? Munida gregaria (Anomura: Galatheidae) AS A CASE-STUDY.

PÉREZ-BARROS, PATRICIA; AVALOS, CECILIA; LOVRICH, GUSTAVO A.

Congreso; 7th International Crustacean Congress; 2010

In South America, there has been a large controversy about the existence of two different species: Munida gregaria and M. subrugosa. In the Beagle Channel both are easily distinguished, inhabit the same places, and breed at the same time of the year. We tested their taxonomic status under the hypothesis of the existence of two biological species, and found: (i) no reciprocal monophyly for 4 genes (16S, COI, ND1, ITS1). (ii) The absence of prezygotic behavioural isolation , since morphs  showed no mating preference  during experimental mating trials. (iii) No “hybrid” intrinsic inviability, since the number and survival of the hatched larvae were similar for homo and heterotypic mating couples. (iv) No postzygotic trophic based ecological isolation, since both morphs share the same trophic niche. Hence, we confirm the existence of two morphs in M. gregaria. So far the only difference we found between both morphotypes is that adult benthic animals of the pelagic gregaria have higher potential capacity of aerobic metabolism and activity compared to the benthic subrugosa. Gregaria showed shorter SDA, and higher activities of citrate-synthase and piruvate-kinase than subrugosa.