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 ...
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.
Win a tournament to collect the Quiz Winner userbox! Welcome to the Fish Quiz! This is a friendly quiz competition designed to test your general knowledge of fish. Any registered Wikipedians may answer this quiz's questions, but, only if you get them right may you post another one. Think of this quiz as a fun, interactive version of "Did you ...
3.2.4.2 Class Sarcopterygii: Lobe-finned fish. 3.2.5 Superclass ... This article contains a list of all of the classes and orders that are located in the Phylum Chordata.
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.