Best Mp3 Player: December 2012

Saturday, 29 December 2012

Butterflyfish

The butterflyfish are a group of conspicuous tropical marine fish of the family Chaetodontidae; the bannerfish and coralfish are also included in this group. Found mostly on the reefs of the Atlantic, Indian and Pacific Oceans, there are approximately 120 species in 10genera. A number of species pairs occur in the Indian and Pacific oceans, members of the huge genus Chaetodon. Butterflyfish look like smaller versions of angelfish (Pomacanthidae) but unlike these lack preopercle spines at the gill covers. Some members of the genus Heniochus resemble the Moorish Idol (Zanclus cornutus) of the monotypic Zanclidae. Among the paraphyletic"Perciformes", the former are probably not too distantly related to butterflyfish, whereas the Zanclidae seem far less close. Butterflyfish mostly range from 12 to 22 centimetres (4.7 to 8.7 in) in length. The largest species, the lined butterflyfish and the saddle butterflyfish, C. ephippium, grow to 30 centimetres (12 in). The common name references the brightly coloured and strikingly patterned bodies of many species, bearing shades of black, white, blue, red, orange and yellow. Other species are dull in colour. Many have eyespots on their flanks and dark bands across their eyes, not unlike the patterns seen on butterfly wings. Their deep, laterallynarrow bodies are easily noticed through the profusion of reef life. The conspicuous coloration of butterflyfish may be intended for interspecies communication. Butterflyfish have uninterrupted dorsal fins with tail fins that may be rounded or truncated, but are never forked. Generally diurnal and frequenting waters of less than 18 metres (59 ft) (though some species descend to 180 metres (590 ft)), butterflyfish stick to particular home ranges. The corallivoresare especially territorial, forming mated pairs and staking claim to a specific coral head. Contrastingly, the zooplankton feeders form large conspecific groups. By night butterflyfish hide in reef crevices exhibit markedly different coloration. Their coloration also makes butterflyfish popular aquarium fish. However, most species feed oncoral polyps and sea anemones. Balancing the relative populations of prey and predator is complex, leading Hobby aquarists to focus on the few generalists and specialist zooplankton feeders. Butterflyfish are pelagic spawners; that is, they release many buoyant eggs into the water, which become part of the plankton, floating with the currents until hatching. The fry go through what is known as a tholichthys stage, wherein the body of the post-larval fish is covered in large bony plates extending from the head. They lose their bony plates as they mature. Only one other family of fish, the scats (Scatophagidae) express such an armored stage

Butterflyfish

Bull shark

The bull shark, Carcharhinus leucas, also known as the Zambezi shark (UK: Zambesi shark) or unofficially Zambi in Africa andNicaragua shark in Nicaragua, is a shark commonly found worldwide in warm, shallow waters along coasts and in rivers. The bull shark is known for its aggressive nature, predilection for warm shallow water, and presence in brackish and freshwater systems including estuaries and rivers. The bull shark can thrive in both saltwater and freshwater and can travel far up rivers. They have even been known to travel as far up asKentucky in the Ohio River, although there have been few recorded attacks. They are probably responsible for the majority of near-shore shark attacks, including many attacks attributed to other species.[2] Bull sharks are not actually true freshwater sharks, despite their ability to survive in freshwater habitats (unlike the river sharks of the genus Glyphis).

Bull shark

Monday, 24 December 2012

Brown Trout

The brown trout (Salmo trutta) is an originally European species of salmonid fish. It includes both purely freshwater populations, referred to Salmo trutta morpha fario and S. trutta morpha lacustris, and anadromous forms known as the sea trout, S. trutta morpha trutta. The latter migrates to the oceans for much of its life and returns to freshwater only to spawn. Sea trout in the UK and Ireland have many regional names, including sewin (Wales), finnock (Scotland), peal (West Country), mort (North West England) and white trout (Ireland). The specific epithet trutta derives from the Latin trutta, meaning, literally, "trout". The lacustrine morph of brown trout is most usually potamodromous, migrating from lakes into rivers or streams to spawn, although evidence indicates stocks spawn on wind-swept shorelines of lakes. S. trutta morpha fario forms stream-resident populations, typically in alpine streams, but sometimes in larger rivers. Anadromous and nonanadromous morphs coexisting in the same river appear not to be genetically distinct. What determines whether or not they migrate remains unknown. The brown trout is normally considered to be native to Europe and Asia, but the natural distribution of the migratory forms may be, in fact, circumpolar.[citation needed] Landlocked populations also occur far from the oceans, for example in Greece and Estonia.

Brown Trout

Brotula

Brotulas are a family, Bythitidae, of ophidiiform fishes, also known as viviparous brotulas as they bear live young. They are found in tropical and subtropical waters throughout the world. They are small fishes, around 5 centimetres (2.0 in) to 10 centimetres (3.9 in) in length, and live in surface waters or around reefs. A few species are freshwater: for example, the Mexican blind brotula, Ogilbia pearsei, is found in caves and sinkholes in the Yucatán Peninsula, Mexico. Since 2002, more than 110 new species have been added to this family. In 2005, 26 new species were described in a single paper by Danish and German scientists and in 2007, an additional 8 new genera with 20 new species were described in another paper by the same scientists.

Brotula