WebEgg case of a skate. Embryo active inside egg case. An egg case or egg capsule, often colloquially called a mermaid's purse, is the casing that surrounds the eggs of oviparous sharks, skates and chimaeras. Egg … WebBody covering: Their body is covered with tooth-like scales that have an enamel-like covering. These scales help in protection and streamlining. Some of the species have mucous glands as well, and there is evidence that shows a connection between the teeth and the dermal scales.
Scales Protect Skin — Biological Strategy — AskNature
WebThe dorsal fin and spine are erectile. Like male sharks and rays, male chimaeras have claspers that serve to transfer sperm to the female, but in addition they have an erectile … WebChondrichthyes or cartilaginous fishes are jawed fish with paired fins, paired nostrils, scales, two-chambered hearts, and skeletons made of cartilage rather than bone. They … distance from little rock to tekari bihar
Chordates and Fishes Flashcards Quizlet
Body covering. Chondrichthyans have tooth-like scales called dermal denticles or placoid scales. Denticles usually provide protection, and in most cases, streamlining. Mucous glands exist in some species, as well. See more Chondrichthyes is a class that contains the cartilaginous fishes that have skeletons primarily composed of cartilage. They can be contrasted with the Osteichthyes or bony fishes, which have skeletons primarily composed of See more Fertilization is internal. Development is usually live birth (ovoviviparous species) but can be through eggs (oviparous). Some rare species are viviparous. There is no parental care after birth; however, some chondrichthyans do guard their eggs. See more • Note: Lines show evolutionary relationships. See more • Taxonomy of Chondrichthyes • Images of many sharks, skates and rays on Morphbank See more Skeleton The skeleton is cartilaginous. The notochord is gradually replaced by a vertebral column … See more Cartilaginous fish are considered to have evolved from acanthodians.The discovery of Entelognathus and several examinations of acanthodian characteristics indicate that bony fish evolved directly from placoderm like ancestors, while acanthodians represent a … See more • List of cartilaginous fish • Cartilaginous versus bony fishes • Largest cartilaginous fishes See more WebThe basic body plan of Chondrichthyans includes a skull, jaws, teeth, a backbone, fins, but lack ribs. Chondrichthyans have three types of unpaired fins - dorsal, caudal, and … WebBody covering. Chondrichthyans have tooth-like scales called dermal denticles or placoid scales. Denticles usually provide protection, and in most cases, streamlining. Mucous … cpt code for keratosis pilaris