The ecological role of brachiopods in the Namuncurá MPA/Burdwood Bank, off southern South America

DE ARANZAMENDI, MARÍA CARLA; BAYER, MARÍA SOL; MORÁN, GISELA A.; GORDILLO, SANDRA; TAVERNA, ANABELA

Marine Biodiversity

Springer Berlin Heidelberg

Año: 2019 p. 1 - 15

1867-1616

Extant brachiopods have been very little studied, despite being abundant along the Argentine marine platform and southern areasof the Subantarctic region. In this survey, we examined brachiopod assemblages from the Namuncurá MPA/Burdwood Bankarea, off southern South America. The material (n = 1203) was recovered from 43 stations ranging in depth from 50 to 785 mduring two oceanographic expeditions. Two species (Liothyrella uva and Terebratella dorsata) together represent 95% of thetotal abundance, with no significant decrease in body size over depths of 800 and 400mrespectively. A third species (Magellaniavenosa) was found in very small quantities shallower than 200 m, and with a large variation in size. There is a greater proportion(63.37%) of brachiopods with epibionts/encrusters, mainly bryozoans and tubiferous polychaetes, which are more common onthe ventral valves of larger specimens, and mainly at depths shallower than 400 m. It was also observed that empty shells serve asa microhabitat for micromolluscs, mainly bivalves. The brachiopods showed signs of drilling predation (8.74%), but they werealso prey for other unidentified predators. These predators left a different kind of damage concentrated around the shell margins(19.20%), which should be the subject of further investigation. Based on these results, it is interpreted that brachiopods from theNamuncurá MPA/Burdwood Bank appear to play an important role in the biotic and trophic interactions of benthic Subantarcticmarine fauna, whether acting as substrates, refuges, or food.