posterior root the posterior, or sensory, division of each spinal nerve, attached centrally to the spinal cord and joining peripherally with the anterior root to form the nerve before it emerges from the intervertebral foramen; each posterior root bears a spinal ganglion that conveys sensory fibers to the spinal cord.he sensory division of each spinal nerve, attached centrally to the spinal cord and joining peripherally with the ventral root to form the nerve before it emerges from the intervertebral foramen.
Freshwater. Many freshwater fish average about 1 to 3 years of life. Some of the more popular species with this short life span include fantail guppies, swordtail platy, mollies, rainbow fish, hatchet fish, corydoras catfish, some cichlids, rasboras and tiger barbs. There are also several fish that live around 3 to 5 years, with proper care and feeding.
Little is known about how the fish lives, what it eats, how it reproduces, or how many of them are left. The new discovery was based on dissections (pictured) and scans of infant and adult coelacanth samples, as well as 3D reconstructions.he structure is of no use to the living species, which, like all other fish, breathes using gills. Coelacanth fossils have been dated to around 400 million years ago and the species was thought to have died out towards the end of the Mesozoic era, which stretched from 250 to 66 million years ago.