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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]
Many species of salmon are anadromous and can migrate long distances up rivers to spawn Allowing fish and other migratory animals to travel the rivers can help maintain healthy fish populations. Fish migration is mass relocation by fish from one area or body of water to another. Many types of fish migrate on a regular basis, on time scales ...
Highly migratory species – a term which has its origins in the United Nations Convention on the Law of the Sea. It refers to fish species which undertake ocean migrations and also have wide geographic distributions. It usually denotes tuna and tuna-like species, shark, marlins and swordfish. See also transboundary stocks and straddling stocks.
Catalog of Fishes is a comprehensive on-line database and reference work on the scientific names of fish species and genera. It is global in its scope and is hosted by the California Academy of Sciences. It has been compiled and is continuously updated by the curator emeritus of the CAS fish collection, William N. Eschmeyer.
Now in its fifth edition (2016), the work is a comprehensive overview of the diversity and classification of the 30,000-plus fish species known to science. The book begins with a general overview of ichthyology, although it is not self-contained.
The sauger (Sander canadensis) is a freshwater perciform fish of the family Percidae that resembles its close relative, the walleye. The species is a member of the largest vertebrate order, the Perciformes. [3] It is the most migratory percid species in North America. [4]
Most oceanic species (78 per cent, or 44 per cent of all fish species), live near the shoreline. These coastal fish live on or above the relatively shallow continental shelf. Only 13 per cent of all fish species live in the open ocean, off the shelf. Of these, 1 per cent are epipelagic, 5 per cent are pelagic, and 7 per cent are deep water. [16]
The classification of the Indo-Pacific blue marlin (M. mazara) and the Atlantic blue marlin (M. nigricans) as separate species is under debate. [1] Genetic data suggest, although the two groups are isolated from each other, that they are both the same species, with the only genetic exchange occurring when Indo-Pacific blue marlin migrate to and ...