Lumbriculus variegatus : A Biology Profile. The freshwater oligochaete, Lumbriculus variegatus is not widely known to biologists but may be used to vividly illustrate a wide variety of biological phenomena such as: patterned regeneration of lost body parts, blood vessel pulsations, swimming reflex, peristaltic crawling behavior, giant nerve fiber action potentials, and sublethal sensitivity to pharmacological agents or environmental toxicants. This brief document provides general background information about Lumbriculus biology that is not generally available in biology or invertebrate zoology texts. Classification and Evolution Although superficially resembling tubifex worms, Lumbriculus is placed in the Order Lumbriculida, a group that is separate from both tubifex worms and earthworms, which are in the orders Tubificida and Haplotaxida, respectively Jamieson, :. Evolutionary relationships between this group and other annelids are not well understood or agreed upon.
Marine Biology. Gonadal indices revealed an annual reproductive cycle. Spawning occurred in the late winter and early spring between August and November. Pyloric caecal indices did not show a clear annual cycle or a reciprocal relationship with gonadal indices. The population appears to be sustained only by fission, as only males were found.
Although small, earthworms provide big benefits to soil by aerating it as they burrow and enriching it as they eat and excrete organic material. One myth of earthworm reproduction is that if you cut them in half, the two halves will regenerate into two new worms. Although worms can regenerate small portions of their bodies, they do not reproduce this way.