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.
They are perhaps the best example of how poor habitat and care shortens the lifespan of aquarium fish. The majority of Goldfish are not properly cared for, and as a result live only a few years. Other fish that live longer include loaches, such as the Clown Loach and Weather Loach, which often life 10 to 15 years.ettas on average live little more than two years, while Goldfish live for decades. Short Lifespans. Killifish are among the aquarium fish with the shortest lifespan. They generally only live a year or two.