Tuesday, September 25, 2012

Animal Pictures and Description - All about TROUT around the world

Trout is the name for a number of species of freshwater fish belonging to the genera Oncorhynchus, Salmo and Salvelinus, all of the subfamily Salmoninae of the family Salmonidae. The word trout is also used as part of the name of some non-salmonid fish such as Cynoscion nebulosus, the spotted seatrout or speckled trout.

Trout are closely related to salmon and char (or charr): species termed salmon and char occur in the same genera as do trout (Oncorhynchus - Pacific salmon and trout, Salmo - Atlantic salmon and various trout, Salvelinus - char and trout).

Most trout such as Lake trout live in freshwater lakes and/or rivers exclusively, while there are others such as the Rainbow trout which spend two or three years at sea before returning to freshwater to spawn, a habit more typical of salmon.

Trout are an important food source for humans and wildlife including brown bears, birds of prey such as eagles, and other animals. They are classified as an oily fish.






 


Animal Pictures and Description - All about TARSIER around the world

Tarsiers are haplorrhine primates of the family Tarsiidae, which is itself the lone extant family within the infraorder Tarsiiformes. Although the group was once more widespread, all the species living today are found in the islands of Southeast Asia.

The phylogenetic position of extant tarsiers within the order Primates has been debated for much of the past century, and tarsiers have alternately been classified with strepsirrhine primates in the suborder Prosimii, or as the sister group to the simians (=Anthropoidea) in the infraorder Haplorrhini. Analysis of SINE insertions, a type of macromutation to the DNA, is argued to offer very persuasive evidence for the monophyly of Haplorrhini, where other lines of evidence, such as DNA sequence data, remain ambiguous. Thus, some systematists argue the debate is conclusively settled in favor of a monophyletic Haplorrhini. In common with simians, tarsiers have a mutation in the L-gulonolactone oxidase (GULO) gene which confers need for vitamin C in the diet. Since the strepsirrhines do not have this mutation and have retained the ability to make vitamin C, the genetic trait which confers the need for it in the diet would tend to place tarsiers with haplorrhines.

At a lower phylogenetic level, the tarsiers have, until recently, all been placed in the genus Tarsius, while it was debated whether the species should be placed in two (a Sulawesi and a Philippine-western group) or three separate genera (Sulawesi, Philippine and western groups). Species level taxonomy is complex, with morphology often being of limited use compared to vocalizations. Further confusion existed over the validity of certain names. Among others, the widely used T. dianae has been shown to be a junior synonym of T. dentatus, and comparably, T. spectrum is now considered a junior synonym of T. tarsier.