Evolutionary relationships of the Tehuelche scallop Aequipecten tehuelchus (Bivalvia: Pectinidae) from the south-western Atlantic Ocean

TROVANT, BERENICE; REAL, LUCIANO E.; PARMA, ANA M.; ORENSANZ, J.M.; BASSO, NÉSTOR G.

JOURNAL OF THE MARINE BIOLOGICAL ASSOCIATION OF THE UNITED KINGDOM

CAMBRIDGE UNIV PRESS

Lugar: Cambridge; Año: 2018 p. 1 - 9

0025-3154

This study addresses aspects of the phylogeneticrelationships of the commercial Tehuelche scallop, Aequipecten tehuelchus s.l. (Bivalvia: Pectinidae), from southernSouth America using molecular techniques. The Tehuelche scallop presents twodifferent putative subspecies, A. t.tehuelchus and A. t. madrynensis,and a potentially related sympatric species, Flexopecten felipponei. The Tehuelche scallop is a very importantcomponent of ecosystems and is the target of artisanal fisheries in thenorthern Patagonian gulfs of Argentina. Despite its importance, the systematicrelationships of these taxa have not been fully addressed. The main goal ofthis study is to place the Tehuelche scallop within a partial phylogeneticframework of the family Pectinidae. Scallops were sampled at 10 localitiesdistributed along the south-western Atlantic Ocean. Phylogeneticreconstructions were carried out from two mitochondrial (12S rRNA and 16S rRNA)and two nuclear markers (28S rRNA and H3) using Bayesian, maximum likelihoodand maximum parsimony analyses. Our phylogenetic analysis indicates that thetwo putative subspecies of the Tehuelche scallop together with F. felipponei form a monophyletic clade,without differentiating at the specific level. Observed differences would bethe result of phenotypic plasticity, probably caused by environmental factors.However, further analysis using genes with faster evolution rate are needed tocorroborate it. Our phylogenetic analysis resolved to Aequipecten aspolyphyletic. The Tehuelche scallop has a basal position within the Argopecten groupand we recommend that it should be transferred to this genus. The relationshipbetween the hypotheses about the origin of the Tehuelche scallop implicit inthe literature and our results are discussed.