Polyandrocarpa Griffithsi

''Polyandrocarpa'' is a genus of ascidian tunicates within the family Styelidae.

Taxonomy

Tunicates are a subphylum of the Chordata and occupy a diverse range of marine habitats such as shallow water, near shore, open ocean, and the deep sea. Tunicates are invertebrates, and their bodies are surrounded by a tunic resembling cartilage, composed of proteins, carbohydrates, and tunicin, with thickness ranging from thin and delicate to transparent and gelatinous. The three classes of tunicates are Ascidiacea, Thaliacea, and Appendicularia.

The Ascidiacea class, also known as the sea squirts, are primarily sessile species that filter-feed and reproduce by budding. This class contains three orders: Aplousobranchia, Phlebobranchia, and Stolidobranchia.

The order Stolidobranchia are distinguished from other tunicates due to the presence of folded pharyngeal baskets. The order Stolidobranchia contains three families: Molgulidae, Pyuridae, and Styelidae.

Styelidae contain both colonial and solitary species, and a number of these species have intermediate morphologies. For example, certain social species within the Styelidae family reproduce clonally, and others grow in large clusters that resemble social colonies; some species brood larvae, and others are solitary, free-spawning species; and some species within Styelidae exhibit direct development.

''Polyandrocarpa'' are a genus within the family Styelidae. Characteristics of ''Polyandrocarpa'' species include bilateral symmetry, colonial organization, a soft-bodied skeletal structure, i.e., invertebrates, and may possibly include an ocelli visual system. Species are filter feeders in marine benthic and shallow environments.

Species

Species within the genus ''Polyandrocarpa'' include:

* ''Polyandrocarpa abjornseni'' Michaelsen, 1927
** ''Polyandrocarpa abjornseni'' have two, long-oval gonads on each side of the body, each with six pairs of male follicles, differing from most known species of ''Polyandrocarpa'' that have short, numerous polycarp-type gonads.
* ''Polyandrocarpa anguinea'' Sluiter, 1898
** ''Polyandrocarpa anguinea'' has a known distribution of the Southeastern United States (Florida), Panama, Martinica, Southeastern Brazil, Sierra Leone, South Africa, Mauricius Island, Indonesia, Philippines, Australia, and New Caledonia.
* ''Polyandrocarpa arianae'' Monniot F., 2016
** ''Polyandrocarpa arianae'' has a polycarpid gonad.
* ''Polyandrocarpa aurorae'' Monniot F., 2018
* ''Polyandrocarpa australiensis'' Kott, 1952
* ''Polyandrocarpa chendurensis'' Renganathan & Krishnaswamy, 1985
* ''Polyandrocarpa colemani'' Kott, 1992
** ''Polyandrocarpa colemani'' have a large colony of zooids and a thick layer of muscles within the body wall.
* ''Polyandrocarpa colligata'' Sluiter, 1913
* ''Polyandrocarpa durbanensis'' Millar, 1955
* ''Polyandrocarpa glandulosa'' Monniot C., 1987
* ''Polyandrocarpa gravei'' Van Name, 1931
* ''Polyandrocarpa griffithsi'' Monniot C., Monniot F., Griffiths & Schleyer, 2001
* ''Polyandrocarpa lapidosa'' Herdman, 1891
* ''Polyandrocarpa misakiensis'' Watanabe & Tokioka, 1972
* ''Polyandrocarpa oligocarpa'' Millar, 1970
* ''Polyandrocarpa ordinata'' Monniot C., 1983
* ''Polyandrocarpa pilella'' Herdman, 1881
* ''Polyandrocarpa placenta'' Herdman, 1886
* ''Polyandrocarpa polypora'' Monniot F. & Monniot C., 2001
* ''Polyandrocarpa robusta'' Sluiter, 1919
* ''Polyandrocarpa rollandi'' Tokioka, 1961
* ''Polyandrocarpa shimodensis'' Brunetti, 2007
* ''Polyandrocarpa simulans'' Kott, 1972
* ''Polyandrocarpa sparsa'' Kott, 1985
* ''Polyandrocarpa triggiensis'' Kott, 1952
* ''Polyandrocarpa watsonia'' Kott, 1985
* ''Polyandrocarpa zorritensis'' Van Name, 1931
** ''Polyandrocarpa zorritensis'' has a known distribution of Japan, Guam, and Hawaii, with a probable geographical origin of the Western Pacific region. It is a colonial species with an asexual life cycle.

Habitat and distribution

''Polyandrocarpa'' have been found in marine environments globally. Species can range from shallow environments to benthic environments. For example, ''Polyandrocarpa zorritensis'' is a shallow species, whereas ''Polyandrocarpa arianae'' have been found deeper than 90 meters in the Mediterranean Sea.

''Polyandrocarpa'' have been reported in various regions, including the coasts of North America, South America, Europe, Africa, Asia, Australia, and in the Atlantic, Pacific, and Indian Oceans.

Some species of ''Polyandrocarpa'' are invasive in certain regions. For example, ''Polyandrocarpa zorritensis'' is native to the Atlantic Ocean but is considered a threat to certain marine species in the Mediterranean Sea.

Habitats of ''Polyandrocarpa'' species include coral reefs, estuaries, rocky or other hard surfaces, and marine benthic environments. Species attach to surfaces using an adhesive secretion.

Species of ''Polyandrocarpa'' play an important role in marine ecosystems as filter feeders, helping to remove small particles and pollutants from the water.

Diet

''Polyandrocarpa'' feed on small particles and plankton.

Life history

''Polyandrocarpa'' are characterized by their small size and simple body structure. They typically form small, spherical colonies that consist of multiple individuals, or zooids, connected together.

''Polyandrocarpa'' form colonies composed of multiple individuals.

''Polyandrocarpa'' can have colonies with embedded zooids or separate zooids joined by basal stolons, though the majority of species within this genus do not have completely embedded zooids. Each zooid has a sac-like body with two siphons: an inhalant siphon that draws in water and food particles, and an exhalant siphon that expels waste and water back into the surrounding environment. An exception to this is ''Polyandrocarpa colligata''. ''P. colligata'' has completely embedded zooids and an encrusting colony.

Tunicates can reproduce both sexually and asexually. ''Polyandrocarpa zorritensis'' have the ability to reproduce via non-embryonic development (NED), i.e., asexual budding. ''Polyandrocarpa'' are capable of regenerating body parts.

Some ''Polyandrocarpa'' species have adapted to high-flow environments and are tolerant to temperature and salinity changes.

Uses by humans

Some species of Polyandrocarpa are also used in biomedical research due to their ability to regenerate body parts, which may have implications for human tissue engineering and organ transplantations in the future.

References

{{Taxonbar, from=Q4909458

Styelidae
Tunicate genera