Males and females have delicate, interlocking copulatory organs. Genital morphological features have been described in detail, but mating has never been observed. The copulatory apparatus of the male is partly calcified and is thought to be derived from the first anal ray. The penis rests on a pedestal surrounded by muscular pseudoclaspers and covered by a fleshy urogenital hood. The urogenital pore of the female is similarly protected. Most bythitids have the capability of sperm storage in the oviduct or ovary. Fertilization is internal, and embryos grow rapidly. Late embryos are well developed, with pigmented eyes and fully developed and functional digestive system, musculature, gills, and caudal fin. Newborn young are about 0.5 in (12 mm) in length, and brood size is about 14 individuals.
Was this article helpful?