1. Pertaining to or resembling a cartilage; gristly; consisting of cartilage.

2. In ichthyology, cartilaginous fishes are those whose muscles are supported by cartilages instead of bones, or whose skeleton is cartilaginous. Many of these are viviparous, as the ray and shark, whose young are excluded from an egg hatched within them. Others are oviparous, as the sturgeon. Some of them have no gill-covers, but breathe through apertures, on the sides of the neck or top of the head; others have gill-covers, but destitute of bony rays.