PEREZ-REYES, O.*; HERNANDEZ-GARCIA, P.; ROSA-MOLINAR, E.; Univ. of Puerto Rico-Rio Piedras; Univ. of Puerto Rico-Rio Piedras; Univ. of Puerto Rico-Rio Piedras: The motor neurons innervating the pereiopods of “Atya lanipes”” and “A. scabra“

Members of the genus, “Atya” (family Atyidae) have a passive filtration system that involves complex adaptations (anatomical and ecological specializations) in their chelae. Retrograde axonal transport and fluorescent retrograde labeling was used to identify motor neurons controlling the chelae. Filter paper saturated with the fluorescent tracer lysine-fixable 3000 MW Texas Red”^“�” (TDA) was inserted into a muscle controlling the terminal tufts of setae on the first and second pereiopods of “Atya lanipes”” and “A. scabra“. After 6 hours survival time, TDA was found to have labeled motor neurons in the subesophageal ganglion. This result indicates that after uptake by the axon terminals, TDA was retrogradely transported through axons of motor neurons, thus identifying the parent cell bodies controlling specialized chelae used primarily for filtering the water column and transferring the entrapped food to the oral machinery. Supported in part by NSF-0091120 (to ER-M).