The role of neuromasts in non-visual feeding of larval striped bass (Morone saxatilis)

Abstract

Striped bass larvae, native to the Shubenacadie River, catch invertebrates in darkness using mechanoreception via lateral line neuromasts. The neuromast total increased from 17 at first feeding (5 to 7 dph) to 135 by the juvenile stage (27 dph). A 5 mM neomycin dose ablated neuromasts, confirmed by fluorescent and confocal microscopy. In feeding trials, larvae with and without functional neuromasts were offered Artemia salina in darkness or light. To identify ontogenetic changes in feeding, experiments were repeated at 10, 13, 17, and 20 dph. In darkness, neomycin treated larvae caught fewer prey (~5 Artemia h-1 at all ages, p<0.05) than larvae with intact neuromasts (10 dph, 16 Artemia h-1; 20 dph, 72 Artemia h-1). In light, neomycin did not affect feeding, indicating no deleterious side-effects. Neomycin did not damage olfactory or taste cells judged by FM1-43FX and calretinin staining. The results support the contribution of mechanoreception to non-visual feeding.