Because organisms living in Florida's fully-flooded caves depend upon allochthonous input for food, abundances of cave fauna may be related to distance from cave openings. Distributions of cave crayfish and catfish were investigated within 16 fully-flooded cave systems. In each cave, a transect was established beginning at the edge of the aphotic zone and continuing into the cave for 244 m. Transects were divided at their mid-points, and abundances from the outer half-transects were compared to abundances from the inner half-transects. Crayfish abundances were not significantly different between half-transect pairs, but catfish abundances were significantly greater along outer half-transects (p<0.05, Wilcoxon matched-pairs signed ranks test). During this investigation, three species of catfish were observed along transects—the yellow bullhead,Ameiurus natalis, the brown bullhead,Ameiurus nebulosus, and the channel catfish,Ictalurus punctatus.