Citizendia

Elephant fish
Blunt-jawed elephantnose (Gnathonemus tamandua)
Blunt-jawed elephantnose (Gnathonemus tamandua)
Scientific classification
Kingdom:Animalia
Phylum:Chordata
Class:Actinopterygii
Order:Osteoglossiformes
Family:Mormyridae
Subfamilies

Mormyrinae
Petrocephalinae

The family Mormyridae, sometimes called elephantfish, are freshwater fishes native to Africa in the order Osteoglossiformes. Chordates ( Phylum Chordata) are a group of Animals that includes the Vertebrates together with several closely related Invertebrates The Actinopterygii (the plural form of Actinopterygius) comprise the class of the ray-finned fishes. Osteoglossiformes (Gk "bony tongues" is a relatively primitive order of Ray-finned fish that contains two sub-orders the Osteoglossoidei Osteoglossiformes (Gk "bony tongues" is a relatively primitive order of Ray-finned fish that contains two sub-orders the Osteoglossoidei It is by far the largest family in the order with around 200 species.

They are not to be confused with the Australian ghost shark which are called elephant fishes as well but they are better known as the elephant shark (Callorhinchus milii) in the scientific community. The Elephant Shark ( Callorhinchus milii) is a cartilaginous fish ( Chondrichthyes) belonging to the subclass Holocephali ( Chimaera)

Members of the family are popular, if challenging, aquarium species, notable for their ability to generate weak electric fields that allow the fishes to sense their environment in turbid waters where vision is impaired by suspended matter. An aquarium (plural aquariums or aquaria) is a Vivarium consisting of at least one transparent side in which Water -dwelling Plants In Physics, the space surrounding an Electric charge or in the presence of a time-varying Magnetic field has a property called an electric field (that can The generation of these electric fields and their use in providing the fishes with additional sensory input from the environment is the subject of considerable scientific research, as is research into communication between and within species.

Electric discharges are most often pulsitile discharges, with Gymnarchus niloticus being an exception to this rule, discharging its electric organ near approximately 500 Hz, giving it a near-sinusoidal like discharge. Gymnarchus niloticus, other names in English including aba, aba aba, frankfish, and African knifefish, is the only species in The electric organ is a muscular organ common to all Electric fish used for the purposes of creating an Electric field; a behavior used for navigation The electric organ is a structure that is well established in the scientific literature to be developmentally related to muscle, as in Gymnotiform electric fish, as well as in electric rays and skates. Muscle (from Latin musculus, diminutive of mus "mouse" is contractile tissue of the body and is derived from the The Gymnotiformes is a lineage of Ostariophysan Teleost Electric fishes Common names found in the literature include the Neotropical electric There is a surprising degree of convergent evolution between the South American Gymnotiforms and the African Mormyridae, particularly in the sensory apparatus for detecting and processing electrical signals involved in electrolocation and electrocommunication. Convergent evolution describes the acquisition of the same biological trait in unrelated lineages Electroreception, sometimes written as electroception, is the biological ability to perceive Electrical impulses It is particularly common among aquatic creatures

Some species possess modifications of the mouthparts to facilitate feeding upon small invertebrates buried in muddy substrates, the shape and structure of these leading to the popular name of "elephant nosed fish" for those species with particularly prominent mouth extensions. An invertebrate is an Animal lacking a Vertebral column. The group includes 98% of all animal Species — all animals except those in the Chordate The extensions to the mouthparts (usually consisting of a fleshy elongation attached to the lower jaw) are flexible, and equipped with touch (and possibly taste) sensors.

Among those members of the family lacking extended mouthparts, the body shape and general morphology of the fishes has led to some being known among aquarists by the name of "baby whale", despite the fact that true whales are mammals. Whales are marine mammals which are neither Dolphins (ie members of the families Delphinidae or Platanistoidae) nor Porpoises Orcas Mammals ( class Mammalia) are a class of Vertebrate Animals characterized by the presence of Sweat glands, including sweat glands Other "mormyrid mammalian misnomers" include the term "dolphin fishes", in reference to certain members of the Genus Mormyrops.

Classification

Genera and Species

The family Mormyridae contains the following Genera:

Among the species that belong to this family are:

  • Gnathonemus petersi, Peters' elephantnose fish;
  • Gnathonemus tamandua, the Blunt-jawed elephantnose;
  • Gnathonemus elephas;
  • Marcunesias macrolepidotus;
  • Marcunesias senegalensis;
  • Pollimyrus castelnaui, known among aquarists as the "baby whale"', along with other relatives in the genus Pollimyrus;
  • Pollimyrus isidori;
  • Brienomyrus niger, the "black baby whale";
  • Campylomormyrus rhynchophorus;
  • Hippopotamyrus discorhynchus;
  • Mormyrops deliciosus, a large member of the family utilised as a food fish by humans;
  • Petrocephalus catostomus, the smallest member of the family (7 cm SL);
  • Mormyrus lapinus, sometimes called the "dolphin fish" or "freshwater dolphin" by aquarists;
  • Brienomyrus brachyistius, the "brown baby whale"

Sources

© 2009 citizendia.org; parts available under the terms of GNU Free Documentation License, from http://en.wikipedia.org
 Dapyx Software network: MP3 Explorer | Ebook Manager | Zenithic