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Elasmobranchii is one of the two subclasses of cartilaginous fish in the class Chondrichthyes, the other being Holocephali . Members of the elasmobranchii subclass have no swim bladders, five to seven pairs of gill clefts opening individually to the exterior, rigid dorsal fins, and small placoid scales. The teeth are in several series; the ...
Elasmobranchii is a subclass that includes the sharks and the rays and skates. Members of the elasmobranchii have no swim bladders, five to seven pairs of gill clefts opening individually to the exterior, rigid dorsal fins, and small placoid scales. The teeth are in several series; the upper jaw is not fused to the cranium, and the lower jaw is ...
Many had hypocercal tails in order to generate lift to increase ease of movement through the water for their armoured bodies, which were covered in dermal bone. They also had sucking mouth parts and some species may have lived in fresh water. The taxon contains the subgroups Heterostraci, Astraspida, Arandaspida. † Thelodonti (extinct)
They and their close relatives, the sharks, compose the subclass Elasmobranchii. Rays are the largest group of cartilaginous fishes, with well over 600 species in 26 families. Rays are distinguished by their flattened bodies, enlarged pectoral fins that are fused to the head, and gill slits that are placed on their ventral surfaces.
Pages in category "Elasmobranchii" The following 15 pages are in this category, out of 15 total. This list may not reflect recent changes. ...
Reproduction in this species is aplacental viviparous, with the unborn young sustained by yolk. There is only one known record of a pregnant female, which was gestating 114 embryos; this ranks among the largest known litters from any shark. The young are probably under 40 cm (16 in) long at birth. [7]
Guitarfish have a body form intermediate between those of sharks and rays. The tail has a typical shark-like form, but in many species, the head has a triangular, or guitar-like shape, rather than the disc-shape formed by fusion with the pectoral fins found in other rays.
Reproduction is oviviviparous. A clutch of three to seven young develop inside the mother, receiving nourishment at first from their egg yolks, but later from fluids secreted by their mother into her uterus. [3] The gestation period is 6–8 months long, after which the female gives birth to between three and seven live pups.