Bony Tongues and Relatives: Osteoglossiformes

Some bony tongues and their relatives are nocturnal (nahk-TER-nuhl), often hiding during the day in dense plant cover or under other kinds of cover and coming out to hunt in the evening. Others are active during the day, spending most of their time patrolling very close to the surface. During the summer, when the water surface becomes very hot, the fishes stay in deeper, cooler areas.

Most bony tongues and their relatives breed during the rainy season, usually the spring. The size of the eggs, or female reproductive cells, ranges from 0.07 inches (1.8 millimeters) to 0.6 inches (16 millimeters). Eggs number between a few hundred and more than one thousand, depending on the species, or type of fish. Some bony tongues spawn, or produce and release eggs, every few days, and others spawn once every several weeks. Some bony tongues are mouth brooders: the female or the male, depending on the species, takes the fertilized (FUR-teh-lyzed) eggs, the ones that have joined with sperm, or male reproductive cells, and have begun development, into its mouth and keeps them there until they hatch. In some species the males and, in others, the females guard and fan the nest, that is, use their fins to move water over the eggs to keep them clean and give them oxygen.