111.4 Tuesday, Jan. 7 08:45 Nematode worms infect, but do not manipulate, sand crabs (Lepidopa benedicti) JOSEPH, M*; FAULKES, Z; The University of Texas-Pan American; The University of Texas-Pan American email@example.com
Sand crabs (Albuneidae) are a cosmopolitan group of crustaceans, but because they spend most of their time submerged in sand, their ecology is little known. Parasites often shape the ecology of a species, so we investigated what parasites infected sand crabs (Lepidopa benedicti), and whether these parasites manipulate their hosts. Most (87%) L. benedicti were infected with nematodes (mean = 25.8, SD = 23.9). The number of nematodes was significantly correlated with host size (r = 0.58, p < 0.0001, n = 46). We predicted that if these nematodes were manipulating sand crabs that the number of nematodes would correlate to how long sand crabs would stay above the surface of the sand, because being visible above sand should increase the chances of being eaten by a predator. We measured how long it took sand crabs dropped into water at the top of a tank to submerge into sand, then determined the number of nematodes in each. The number of nematodes did not correlate with time above sand (r = -0.18, p = 0.29, n = 37), so nematodes do not appear to manipulate L. benedicti. This suggests these parasites have a simple life cycle that does not require transmission to another host, or that sand crab infections are “accidental” and the preferred host is some other species, such as mole crabs (Emerita benedicti), which are often found in the same locations as L. benedicti.