Species associations and environmental factors influence activity of borers on Ostrea puelchana in northern Patagonia

Abstract

Seven borer species were identified affecting Ostrea puelchana in the southwestern Atlantic Ocean, including the sponges Clionaopsis platei, Pione angelae and Cliona celata (Clionaidae), the borer bivalve Lithophaga patagonica (Mytilidae) and the polychaetes Polydora rickettsi (Spionidae), Dodecaceria cf. choromyticola and Caulleriella cf. bremecae (Cirratulidae). Higher prevalences of borer sponges (55%) occurred in oysters from Puerto Lobos, Golfo San Matías (42°00′S, 65°3′W), while higher values of L. patagonica (80%) and borer polychaetes (93%) were recorded in oysters from Fracasso Beach, Golfo San José (42°25′S, 64°07′W). Lithophaga patagonica was the most harmful borer organism, lowering the condition index of the oyster. There was a positive association between the presence of L. patagonica and borer polychaetes, suggesting that the borer activity of L. patagonica favored the settlement of polychaetes.