''Aplidium californicum'' is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of colonial sea squirt, a

tunicate Tunicates are marine invertebrates belonging to the subphylum Tunicata ( ). This grouping is part of the Chordata, a phylum which includes all animals with dorsal nerve cords and notochords (including vertebrates). The subphylum was at one time ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Polyclinidae Polyclinidae is a family of tunicates in the order Aplousobranchia. Genera The World Register of Marine Species The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive cata ...

. It is commonly known as sea pork.

Description

''Aplidium californicum'' is a compound tunicate forming sheets, mounds or slabs on rocks and other hard substrates. The tunic is jelly-like in consistency, 1 to 3 cm thick and a shiny yellow, orange, reddish-brown or a translucent white colour. The individual

zooid A zooid or zoöid is an animal that is part of a colonial animal. This lifestyle has been adopted by animals from separate unrelated taxa. Zooids are multicellular; their structure is similar to that of other solitary animals. The zooids can ...

s are brown or buff, 6 mm long and arranged in oval or elongate systems. Each one is subdivided into a thorax, an abdomen and a postabdomen. There are usually 10 to 12 rows of perforations.''Aplidium californicum''
Ascidians. Retrieved 2011-11-21.''Aplidium californicum'' (Ritter & Forsyth 1917)
Marine Biodiversity of British Columbia. Retrieved 2011-11-21.

Distribution

''Aplidium californicum'' is common on the west coast of North America from

British Columbia British Columbia is the westernmost Provinces and territories of Canada, province of Canada. Situated in the Pacific Northwest between the Pacific Ocean and the Rocky Mountains, the province has a diverse geography, with rugged landscapes that ...

south to

Baja California Baja California, officially the Free and Sovereign State of Baja California, is a state in Mexico. It is the northwesternmost of the 32 federal entities of Mexico. Before becoming a state in 1952, the area was known as the North Territory of B ...

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

and the Galapagos Islands. It is found in the intertidal zone and at depths down to 85 metres.

Biology

''Aplidium californicum'' is a

filter feeder Filter feeders are aquatic animals that acquire nutrients by feeding on organic matters, food particles or smaller organisms (bacteria, microalgae and zooplanktons) suspended in water, typically by having the water pass over or through a s ...

. Water is sucked into the interior of the organism through a siphon and then expelled through another one.

Phytoplankton Phytoplankton () are the autotrophic (self-feeding) components of the plankton community and a key part of ocean and freshwater Aquatic ecosystem, ecosystems. The name comes from the Greek language, Greek words (), meaning 'plant', and (), mea ...

and other small organisms get trapped in

mucus Mucus (, ) is a slippery aqueous secretion produced by, and covering, mucous membranes. It is typically produced from cells found in mucous glands, although it may also originate from mixed glands, which contain both Serous fluid, serous and muc ...

threads secreted by the

endostyle The endostyle is an organ found in invertebrate chordate species of tunicates, lancelets, and in the larval stage of vertebrate lampreys. It assists in filter-feeding. It has evolved into the thyroid in vertebrate chordates. Since the endo ...

. The tunicate seems to form a

symbiotic Symbiosis (Ancient Greek : living with, companionship < : together; and ''bíōsis'': living) is any type of a close and long-term biolo ...

relationship with the

bryozoa Bryozoa (also known as the Polyzoa, Ectoprocta or commonly as moss animals) are a phylum of simple, aquatic animal, aquatic invertebrate animals, nearly all living in sedentary Colony (biology), colonies. Typically about long, they have a spe ...

n ''

Bugula neritina ''Bugula neritina'' ( commonly known as brown bryozoan or common bugula) is a cryptic species complex of sessile marine animal in the genus '' Bugula''.Gordon, D. (2015). Bugula neritina (Linnaeus, 1758). In: Bock, P.; Gordon, D. (2015) World Lis ...

''. Certain antineoplastic agents,

bryostatin Bryostatins are a group of macrolide lactones from (bacterial symbionts of) the marine organism ''Bugula neritina'' that were first collected and provided to JL Hartwell’s anticancer drug discovery group at the National Cancer Institute (NCI) by ...

s 4 and 5, have been extracted from ''Aplidium californicum'' and are being evaluated.

References

{{Taxonbar, from=Q4779978 Polyclinidae Animals described in 1917