Role of particle wettability in capture by a suspension - feeding crab ( Emerita talpoida )

Role of particle wettability in capture by a suspension-feeding crab (Emerita talpoida) Abstract Suspension feeders sometimes depend on adhesion between particle and collector to capture food. If food particles have di€erent adhesive properties than other particles, food could be passively selected by adhesive mechanisms. In this regard, the e€ect of particle wettability on adhesion to arti®cial and natural collectors was studied. First, the adhesion of glass particles to arti®cial collectors, both varying in wettability, was assessed to determine if wettability in¯uenced adhesion in seawater. The adhesive force between glass particles and arti®cial collectors was measured by increasing the force pulling particles away from the collector until 50% of the particles fell o€ the collector. Adhesion increased as particle wettability decreased. Next, glass particles were used to determine if the antennal collector of the suspension feeding mole crab Emerita talpoida captured particles based on particle wettability. 0.5 to 10 and 15 to 25 lm particles were suspended in a recirculating ¯ow tank ®lled with seawater, and ablated antennae were exposed to this ¯ow, after which the captured particles were counted. Results for the 0.5 to 10 lm particles con®rmed predictions based on results from arti®cial collectors; particle capture increased as particle wett-ability decreased. The 15 to 25 lm particles may have been captured by sieving, and consequently did not follow predictions based on adhesion. Passive selection of particles based upon wettability di€erences can occur.