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.
For Hammerhead sharks, their life expectancy ranges from 20 to 30 years. Brown sharks and sandbar sharks are thought to live between 25 to 30 years. A research conducted in 2004 by joung identified that the lifespan of brown sharks is about 25 years while sandbar sharks can live up to 30 years.heir lifespan vary by kind. Even though most of them live about 20 to 30 years in the wild, there are some types that live longer than others. For instance, the dogfish has one of the longest lifespan of more than 100 years while blue shark has an average lifespan of about 15-16 years in the wild.