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.
Most published information about the life span of saltwater fish are from public aquariums where the fish are kept in the best possible conditions. Many saltwater fish succumb to illness early in life due to poor husbandry. Some saltwater species only live an average of 2 to 4 years.
Goldfish Size and Life Expectancy. If kept in a suitable environment, single tail goldfish normally grow to 10 inches (25cm) and can sometimes reach 12 inches (30cm). Fancy goldfish normally grow to 8 inches (20cm). The normal life expectancy of a single tail goldfish is about 20 years.f kept in a suitable environment, single tail goldfish normally grow to 10 inches (25cm) and can sometimes reach 12 inches (30cm). Fancy goldfish normally grow to 8 inches (20cm). The normal life expectancy of a single tail goldfish is about 20 years.