Search results
Results from the WOW.Com Content Network
Fishes are a paraphyletic group and for this reason, the class Pisces seen in older reference works is no longer used in formal taxonomy.Traditional classification divides fish into three extant classes (Agnatha, Chondrichthyes, and Osteichthyes), and with extinct forms sometimes classified within those groups, sometimes as their own classes: [1]
Clupeiformes / ˈ k l uː p iː ɪ f ɔːr m iː z / is the order of ray-finned fish that includes the herring family, Clupeidae, and the anchovy family, Engraulidae. The group includes many of the most important forage and food fish. Clupeiformes are physostomes, which means that their gas bladder has a pneumatic duct connecting it to the gut.
Class Cephalaspidomorphi - lampreys; Superclass Gnathostomata Vertebrates with jaws Class Chondrichthyes (cartilagineous fish - sharks and rays) Class Osteichthyes (bony fish), which has two subclasses: Actinopterygii (ray-finned fish) Sarcopterygii (lobe-finned fish) Full details of higher order fish taxonomy can be found in the Chordata article.
Bony fish include the lobe-finned fish and the ray finned fish. The lobe-finned fish is the class of fleshy finned fishes, consisting of lungfish and coelacanths . They are bony fish with fleshy, lobed paired fins, which are joined to the body by a single bone. [ 12 ]
Siphonophorae (from Greek siphōn 'tube' + pherein 'to bear' [2]) is an order within Hydrozoa, which is a class of marine organisms within the phylum Cnidaria.According to the World Register of Marine Species, the order contains 175 species described thus far.
The principal ranks in modern use are domain, kingdom, phylum (division is sometimes used in botany in place of phylum), class, order, family, genus, and species. The Swedish botanist Carl Linnaeus is regarded as the founder of the current system of taxonomy, as he developed a ranked system known as Linnaean taxonomy for categorizing organisms ...
In practice, fish anatomy and fish physiology complement each other, the former dealing with the structure of a fish, its organs or component parts and how they are put together, such as might be observed on the dissecting table or under the microscope, and the latter dealing with how those components function together in living fish. The ...
Like other fish, sharks extract oxygen from seawater as it passes over their gills. Unlike other fish, shark gill slits are not covered, but lie in a row behind the head. A modified slit called a spiracle lies just behind the eye, which assists the shark with taking in water during respiration and plays a major role in bottom–dwelling sharks.