Prey Capture, Preference and Consumption Bylinatella Caudata (Gastropoda: Tonnoidea: Ranellidae) in Hong Kong

On sheltered rocky beaches in Hong Kong, Linatella caudata preys upon the lower-littoral and sub-littoral fringe fauna. Ascidian tests are cut with the radula, while the proboscis is inserted between the parted shell valves of bivalves. The salivary glands secrete sulphuric acid that is not used in prey penetration, as in the Cassidae, but is more likely used in digestion or defence. In preference experiments, prey were chosen in the sequence: Barbatia virescens (Bivalvia: Arcidae) > Styela plicata (Ascidiacea)/Saccostrea cucullata (Bivalvia: Ostreidae) > Lunella coronata (Gastropoda: Turbinidae) > Balanus amphitrite (Crustacea: Cirripedia). 52% of all attacks were upon Barbatia Lunella and Balanus were attacked rarely. Prey preferences by individual gastropods were also demonstrated. Calibration plots of total weight against wet and dry tissue weight of prey (Barbatia virescens) and, finally, the predator were obtained and used in estimations of consumption. On average, an adult Linatella caudata (10-15g) consumed three B. virescens. week−1 The mean weight of B. virescens flesh consumed. week−1 ranged between 0. 208−0.412g dry weight prey.g dry weight predator−1, i.e., a mean of 28.2% of the predator' body weight.week−1 or 4%.day−1. Such a figure accords well with estimates of consumption obtained for other adult predatory gastropods from Hong Kong.