Styela montereyensis, also called the stalked tunicate, Monterey stalked tunicate, and the long-stalked sea squirt is a solitary

ascidian Ascidiacea, commonly known as the ascidians or sea squirts, is a paraphyletic class in the subphylum Tunicata of sac-like marine invertebrate filter feeders. Ascidians are characterized by a tough outer test or "tunic" made of the polysaccharid ...

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 ...

. It has a cylindrical, yellow to dark reddish-brown body and a thin trunk that anchors it to rocks. It is found in

subtidal The neritic zone (or sublittoral zone) is the relatively shallow part of the ocean above the drop-off of the continental shelf, approximately in depth. From the point of view of marine biology it forms a relatively stable and well-illuminate ...

areas of the western coast of North America from

Vancouver Island Vancouver Island is an island in the northeastern Pacific Ocean and part of the Canadian province of British Columbia. The island is in length, in width at its widest point, and in total area, while are of land. The island is the largest ...

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 ...

Taxonomy

The species was first described by American malacologist

William Healey Dall William Healey Dall (August 21, 1845 – March 27, 1927) was an American natural history, naturalist, a prominent Malacology, malacologist, and one of the earliest scientific explorers of interior Alaska. He described many mollusks of the Pacifi ...

in 1871 as ''Cynthia montereyensis'', and later (1889) by

Jesse Walter Fewkes Jesse Walter Fewkes (November 14, 1850 – May 31, 1930) was an American anthropologist, archaeologist, writer, and naturalist. Early life and education Fewkes was born in Newton, Massachusetts on November 14, 1850, and initially trained as a ...

as ''Clavelinopsis rubra''. William E. Ritter placed it in ''Styela'' in 1893.

Description

''Styela montereyensis'' is yellow to dark red brown in colour. It is a solitary species, growing, often in loose groups. It normally grows to about in exposed sites. However, in the more rare, calm habitats, it can grow up to about . The body of ''Styela montereyensis'' is elongate and cylindrical, and is attached to a thinner stalk approximately the same length as the body. Its siphons are close together at the distal end, with its oral siphon pointing to the side or downward. The atrial siphon points straight upward. It has a leathery tunic displaying noticeable longitudinal grooves and ridges that extend down the entire length of the body. This species is commonly fouled with foreign matter and small organisms such as

alga Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular microalgae, suc ...

e and

hydroids Hydroids are a life stage for most animals of the class Hydrozoa, small predators related to jellyfish. Some hydroids such as the freshwater '' Hydra'' are solitary, with the polyp attached directly to the substrate. When these produce buds, ...

when occurring in harbors, but remains clean in wave-swept habitats. The feeding mechanism of ''S. montereyensis'' uses the force generated from underwater current to push water through a feeding apparatus. The flexible stem allows the organism to have its position adjusted passively and the orientation of the siphons optimized by the current, and so foraging is a relatively low-energy activity. Styela montereyensis typically conforms osmotically to their environment due to its limited hyperosmotic capacity, which allows it to adapt to varying salinities in their environment.Sims, L. (1984). Osmoregulatory capabilities of three macrosympatric stolidobranch ascidians, Styela clava Herdman, S. plicata (Lesueur), and S. montereyensis (Dall). 82(2-3), 117–129. https://doi.org/10.1016/0022-0981(84)90098-4 ‌ Their maximum lifespan is not known with certainty, but one individual was known to have lived for three years and attained a length of .

Distribution

This species occurs from

and

Hope Island Hope Island may refer to: Places Antarctica * Hope Island (Graham Land), an island on d'Urville Island * Nadezhdy Island (Hope Island) Australia * Hope Island, Queensland, a suburb of Gold Coast City * Hope Island (Tasmania) * Hope Islands (Queen ...

south to

Habitat

''Styela montereyensis'' lives in the low intertidal zone up to approximately in depth. It is a fairly common species within its range, and can be found firmly attached to substrata, pilings, jetties, and on subtidal reefs in waters ranging from calm to extremely rough. Specimens in the

Pacific Northwest The Pacific Northwest (PNW; ) is a geographic region in Western North America bounded by its coastal waters of the Pacific Ocean to the west and, loosely, by the Rocky Mountains to the east. Though no official boundary exists, the most common ...

rarely occur in inland waters, but are normally found in the outer straits and open coast. Populations on the west coasts of Vancouver Island and Washington harbour the crustacean

copepod Copepods (; meaning 'oar-feet') are a group of small crustaceans found in nearly every freshwater and saltwater habitat (ecology), habitat. Some species are planktonic (living in the water column), some are benthos, benthic (living on the sedimen ...

species '' Pygodelphys aquilonaris'' in their branchial sacs.

References

External links

Images
{{Taxonbar, from=Q4912659 Styelidae Animals described in 1872 Western North American coastal fauna