Filtration and respiration of the deep living bivalve Acesta excavata (J.C. Fabricius, 1779) (Bivalvia; Limidae)

Here we report the first study of clearance rate and respiration rate of a deep living bivalve, Acesta excavata (J.C. Fabricius, 1779) (Mollusca: Limidae). We found that A. excavata had extreme values both for clearance and respiration rates compared to other bivalves. It has the second largest clearance rate ever reported, 13.36 l h− 1 g− 1, and the second lowest value of respiration rate, 0.12 ml O2 h− 1 g− 1. The gill area of 7063 mm2 g− 1 is one of the largest found in bivalves so far. We suggest that these values indicate a physiological adaptation to the low and irregular food supply in the deep sea rather that a specific adaptation to depth.