New epibiotic association in the deep-sea: The amphipod Caprella ungulina and the Patagonian lobsterette Thymops birsteini in the South-western Atlantic

Abstract

The present study reports for the first time the association between the decapod Thymops birsteini (Nephropidae) and the amphipod Caprella ungulina (Caprellidae). A benthic biodiversity survey was carried out to explore the Mar del Plata Submarine Canyon, off the Argentine coast, in the South-western Atlantic Ocean. A total of 205 caprellids (181 juveniles, 4 males and 20 not-classified individuals) were found attached to 7 specimens of T. birsteini caught between 1087-2212 m depth. The epibiotic parameters showed that the prevalence of C. ungulina on T. birsteini was 50%; the mean abundance was 14.64 and the intensity value was 29.29. In addition, specimens of C. ungulina were recorded mainly on mouthparts of T. birsteini (31.22%), followed by chelipeds (18.05%), cephalothorax (4.88%) and pereiopods (0.98%). Our finding of C. ungulina provides the deepest record until now; additionally, this epibiont is reported in a new host belonging to an infraorder and a family of crustacean that had not previously been found as basibionts. The potential mechanisms implied in the wide distribution of C. ungulina are discussed.