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Craniata also includes all lampreys and armoured jawless fishes, armoured jawed fish, sharks, skates, and rays, and teleostomians: spiny sharks, bony fish, lissamphibians, temnospondyls and protoreptiles, sauropsids and mammals. The craniate head consists of a three-part brain, neural crest which gives rise to many cell lineages, and a cranium ...
Chimaeras also have some characteristics of bony fishes. A renewed effort to explore deep water and to undertake taxonomic analysis of specimens in museum collections led to a boom during the first decade of the 21st century in the number of new species identified. [2] A preliminary study found 8% of species to be threatened. [14]
A bathtub faucet with built-up calcification from hard water in Southern Arizona. Hard water is water that has a high mineral content (in contrast with "soft water"). Hard water is formed when water percolates through deposits of limestone, chalk or gypsum, [1] which are largely made up of calcium and magnesium carbonates, bicarbonates and sulfates.
The anatomy of fish is often shaped by the physical characteristics of water, the medium in which fish live. Water is much denser than fish, holds a relatively small amount of dissolved oxygen, and absorbs more light than air does. The body of a fish is divided into a head, trunk and tail, although the divisions between the three are not always ...
A) Overall view of common mudpuppy mouth. B) Ventral view of vomerine and premaxillary teeth, located on the upper part of the mudpuppy mouth. C) Lower jaw, or dentary from a common mudpuppy showing the homodont dentary teeth. Specimen from the Pacific Lutheran University Natural History collection. Mudpuppies use rows of teeth to eat their ...
Both species have small, square-shaped teeth on the lower jaw, but M. birostris also has enlarged teeth on the upper jaw. Unlike M. alfredi, M. birostris has a caudal spine near its dorsal fin. [10] Mantas move through the water by the wing-like movements of their pectoral fins. [11] Their large mouths are rectangular, and face forward.
The teeth are in several series; the upper jaw is not fused to the cranium, and the lower jaw is articulated with the upper. The eyes have a tapetum lucidum. The inner margin of each pelvic fin in the male fish is grooved to constitute a clasper for the transmission of sperm. These fish are widely distributed in tropical and temperate waters. [15]
Many Teleosts, for example the Atlantic wolffish, exhibit durophagous behaviour and crush hard prey with their appropriately adapted jaws and teeth. Other fish use of their pharyngeal teeth, with the aid of their protrusible mouth for enabling the grabbing of prey to draw it into their mouth. The pharyngeal jaws found in more derived teleosts ...