Pseudobiceros hancockanus
Encyclopedia
Pseudobiceros hancockanus is a species
of hermaphroditic flatworm
in the family Pseudocerotidae.
P. hancockanus is very similar in appearance to P. uniarborensis, although the margin of P. uniarborensis is translucent gray with a white line only on the outside, while the margin of P. hancockanus is pure bright white.
reefs, other times among coral fragments or stones. It has been observed near such places as Indonesia
, Fiji
, and Kenya
.
genus , P. hancockanus is hermaphroditic with each individual able to function as either a male or female. Mating between two such worms involves penis fencing
, as each worm tries to inject sperm into the other with one of its two stubby penises, while trying to avoid being inseminated itself. One explanation advanced for this behavior is that the female role entails more investment in the resulting fertilized eggs. Another possible explanation is that the duel awards mating advantage to the better of two dueling partners--so that penis duel's loser, becoming the "female," is compensated by creating offspring with genes even better than hers.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of hermaphroditic flatworm
Flatworm
The flatworms, known in scientific literature as Platyhelminthes or Plathelminthes are a phylum of relatively simple bilaterian, unsegmented, soft-bodied invertebrate animals...
in the family Pseudocerotidae.
Description
According to the Baensch Marine Atlas, "P. hancockanus is intense blue to black with white and orange peripheral bands and a purple fringe. The two short cephalic antennaie are easily overlooked because they are the same color as the body. Inferiorly, this species is purple with a medial line."P. hancockanus is very similar in appearance to P. uniarborensis, although the margin of P. uniarborensis is translucent gray with a white line only on the outside, while the margin of P. hancockanus is pure bright white.
Habitat and distribution
Pseudobiceros hancockanus lives in warm seas, sometimes on coralCoral
Corals are marine animals in class Anthozoa of phylum Cnidaria typically living in compact colonies of many identical individual "polyps". The group includes the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton.A coral "head" is a colony of...
reefs, other times among coral fragments or stones. It has been observed near such places as Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
, Fiji
Fiji
Fiji , officially the Republic of Fiji , is an island nation in Melanesia in the South Pacific Ocean about northeast of New Zealand's North Island...
, and Kenya
Kenya
Kenya , officially known as the Republic of Kenya, is a country in East Africa that lies on the equator, with the Indian Ocean to its south-east...
.
Behavior
Pseudobiceros hancockanus can travel long distances, swimming by undulating the edges of its body.Reproduction
Like other members of the PseudobicerosPseudobiceros
Pseudobiceros is a genus of flatworms. Like all flatworms, Pseudobiceros are hermaphrodites. This particular genus engages in penis fencing...
genus , P. hancockanus is hermaphroditic with each individual able to function as either a male or female. Mating between two such worms involves penis fencing
Penis fencing
Penis fencing is a mating behavior engaged in by certain species of flatworm, such as Pseudobiceros hancockanus. Species which engage in the practice are hermaphroditic; each individual has both egg-producing ovaries and sperm-producing testes....
, as each worm tries to inject sperm into the other with one of its two stubby penises, while trying to avoid being inseminated itself. One explanation advanced for this behavior is that the female role entails more investment in the resulting fertilized eggs. Another possible explanation is that the duel awards mating advantage to the better of two dueling partners--so that penis duel's loser, becoming the "female," is compensated by creating offspring with genes even better than hers.