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]
There are seven main taxonomic ranks: kingdom, phylum or division, class, order, family, genus, and species. In addition, domain (proposed by Carl Woese ) is now widely used as a fundamental rank, although it is not mentioned in any of the nomenclature codes, and is a synonym for dominion ( Latin : dominium ), introduced by Moore in 1974.
In biology, a phylum (/ ˈ f aɪ l əm /; pl.: phyla) is a level of classification or taxonomic rank below kingdom and above class. Traditionally, in botany the term division has been used instead of phylum, although the International Code of Nomenclature for algae, fungi, and plants accepts the terms as equivalent.
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 ...
Shark finning yields are estimated at 1.44 million metric tons (1.59 million short tons) for 2000, and 1.41 million metric tons (1.55 million short tons) for 2010. Based on an analysis of average shark weights, this translates into a total annual mortality estimate of about 100 million sharks in 2000, and about 97 million sharks in 2010, with a ...
The phylum is typically divided into 7 or 8 taxonomic classes, [8] of which two are entirely extinct. Cephalopod molluscs, such as squid , cuttlefish , and octopuses , are among the most neurologically advanced of all invertebrates —and either the giant squid or the colossal squid is the largest known extant invertebrate species.
2.1 Class Ascidiacea: ... 3.2.1 Class Placodermi: Armoured fish ... This article contains a list of all of the classes and orders that are located in the Phylum Chordata.
A fish (pl.: fish or fishes) is an aquatic, anamniotic, gill-bearing vertebrate animal with swimming fins and a hard skull, but lacking limbs with digits.Fish can be grouped into the more basal jawless fish and the more common jawed fish, the latter including all living cartilaginous and bony fish, as well as the extinct placoderms and acanthodians.