Essential for the organization of sarcomeric thin filaments in skeletal muscle. expressed in muscle (at protein level). Morpholino knockdown of the protein causes short bodies, bent tails, and reduced tail birefringence, consistent with abnormal skeletal muscle organization, in fish larvae, 3 days after fertilization. Larvae exhibit reduced trunk size, that generate less force than that of wild-type counterparts, and aberrant accumulation of alpha-actinin. Mutant embryos show abnormal motor function, with reduced spontaneous coiling and diminished touch-evoked escape responses. Belongs to the tropomodulin family.