If you’ve ever eaten a fish fillet, you’ve probably had the ‘pleasure’ of picking out fish bones from your meal. While most fish are, indeed, bony (superclass: Osteichthyes), certain lineages of fish have cartilaginous skeletons, meaning that their skeletal structure is composed of cartilage, like a human ear or nose, rather than bone. Elasmobranchs (sharks, skates, … [Read more…]
Ampullae of Lorenzini are a network of electroreceptors, sensory organs that detect electric fields in water, found in chondrichthyes (sharks, rays, and chimaeras). The ampullae are a series of symmetrical pores, concentrated around the snout and nose, connected by gel-filled canals. They can conduct electrical impulses so small, that chondrichthyes are likely to be more sensitive … [Read more…]
Elasmobranchs, including sharks, rays, and sawfishes, belong to the taxonomic subclass of cartilaginous fish Elasmobranchii. Like most chondrichthyes, they have exposed gills, no swim bladder, internal fertilization, and placoid denticles. They differ from the other subclass, chimaera (subclass: Holocephali), in that they have rigid dorsal fins, placoid denticles cover most of their bodies, and they … [Read more…]
Chondrichthyes are a taxonomic class of cartilaginous fishes that encompass sharks and rays (elasmobranchs) and chimaera. Though there are exceptions, in general, Chondrichthyes have exposed gills, no swim bladder, internal fertilization, and placoid denticles. These characteristics differentiate them from the more evolutionarily derived branch of fishes, bony fish (Osteichthyes).