Gastrotricha
Common Name: Gastrotricha
Scientific Name: Gastrotricha
Phylum: Gastrotricha
Class: Platyzoa
Specimen #:54
Circumstance: Observed online
Specimen Condition: Specimen presumed dead
Location: Unknown (online)
Typical Habitat: abundant in fresh water and marine environments.
Invasive? Not an invasive species
Natural area of growth: abundant in fresh water and marine environments.
Relationship with humans: No known relationship with humans
Evolutionary Significance: Gastrotrichs are simultaneous hermaphrodites, possessing both male and female sex organs. There is generally a single pair of gonads, including sperm-producing cells anteriorly, and producing ova from the posterior part. Sperm are released through ducts that open on the underside of the animal roughly two-thirds of the way along the body. Once the sperm are produced, they are picked up by an organ on the tail that functions as a penis to transfer the sperm to the partner. Fertilisation is internal, and the eggs are released by rupture of the body wall. Many species of chaetotonid gastrotrichs reproduce entirely by parthenogenesis. In these species the male portions of the reproductive system are degenerate and non-functional, or, in many cases, entirely absent. Some species are capable of laying eggs that can remain dormant during times of desiccation or cold temperatures; these species, however, also produce regular eggs during good environmental conditions, which hatch in one to four days.
The eggs hatch into miniature versions of the adult. The young typically reach sexual maturity in about three days, and gastrotrichs can live up to ten days under laboratory conditions.
Sources: http://en.wikipedia.org/wiki/Gastrotrich
Barnes, Robert D. (1982). Invertebrate Zoology. Philadelphia, PA: Holt-Saunders International. pp. 263–272. ISBN 0-03-056747-5.
Scientific Name: Gastrotricha
Phylum: Gastrotricha
Class: Platyzoa
Specimen #:54
Circumstance: Observed online
Specimen Condition: Specimen presumed dead
Location: Unknown (online)
Typical Habitat: abundant in fresh water and marine environments.
Invasive? Not an invasive species
Natural area of growth: abundant in fresh water and marine environments.
Relationship with humans: No known relationship with humans
Evolutionary Significance: Gastrotrichs are simultaneous hermaphrodites, possessing both male and female sex organs. There is generally a single pair of gonads, including sperm-producing cells anteriorly, and producing ova from the posterior part. Sperm are released through ducts that open on the underside of the animal roughly two-thirds of the way along the body. Once the sperm are produced, they are picked up by an organ on the tail that functions as a penis to transfer the sperm to the partner. Fertilisation is internal, and the eggs are released by rupture of the body wall. Many species of chaetotonid gastrotrichs reproduce entirely by parthenogenesis. In these species the male portions of the reproductive system are degenerate and non-functional, or, in many cases, entirely absent. Some species are capable of laying eggs that can remain dormant during times of desiccation or cold temperatures; these species, however, also produce regular eggs during good environmental conditions, which hatch in one to four days.
The eggs hatch into miniature versions of the adult. The young typically reach sexual maturity in about three days, and gastrotrichs can live up to ten days under laboratory conditions.
Sources: http://en.wikipedia.org/wiki/Gastrotrich
Barnes, Robert D. (1982). Invertebrate Zoology. Philadelphia, PA: Holt-Saunders International. pp. 263–272. ISBN 0-03-056747-5.