Pycnoclavella stanleyi

Pycnoclavella stanleyi
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Subphylum: Tunicata
Class: Ascidiacea
Order: Aplousobranchia
Family: Clavelinidae
Genus: Pycnoclavella
Species:
P. stanleyi
Binomial name
Pycnoclavella stanleyi
Berrill & Abbott, 1949

Pycnoclavella stanleyi is a species of sea squirt[1] that was initially described from specimens collected in the vicinity of Pacific Grove, California, including at Asilomar State Beach.[2]

Description

Pycnoclavella stanleyi is a colonial ascidian with widely separated individuals sharing a base, a leathery tunic typically covered in sand grains.[2] P. stanleyi can be recognized by its seven rows of gill slits and striking gold or yellow-orange pharynx coloration. This coloration overlaps with the introduced Botrylloides violaceus, but that species is chained without clear outer separation of individuals. Overall, this is a small species with individuals not exceeding 1 cm in height.[3]

Reproduction

Like other ascidians, P. stanleyi can reproduce both sexually and asexually.[2] Asexual reproduction takes place via budding. Sexual reproduction results in the formation of larvae, which resemble tadpoles, with an oval body with a long tail. Within the body, there is a dark spot, which is the ocellus, a type of simple eye.[2] Unlike many other sea squirt larvae, they lack an otolith.[2]

Range

Pycnoclavella stanleyi inhabits the Eastern Pacific shoreline, from British Columbia to Baja California.[4]

Habitat

This tunicate prefers shallow water; it is found encrusting surf-pounded rocks [5] near sandy bottoms from a depth of 0 to 10 m.[4] It often occurs near seaweed holdfasts.[2]

Ecology

Like other sea squirts, P. stanleyi is a sessile filter feeder; it pulls food particles from fast-moving water using its pharynx with gill slits.[5] P. stanleyi is one of the vanadium-sequestering tunicate species, with circulating vanadocytes in the bloodstream.[6]

Etymology

Pycnoclavella stanleyi is named after John Stanley, a colleague of N. J. Berrill, who initially described this species with D. P. Abbott.[2]

References

  1. ^ "Yellow Social Ascidian (Pycnoclavella stanleyi)". iNaturalist. Retrieved 30 January 2026.
  2. ^ a b c d e f g Berrill, N. J.; Abbott, D.P. (1949). "The structure of the ascidian, Pycnoclavella stanleyi n. sp., and the nature of its tadpole larva". Canadian Journal of Research. 27 (2): 43–49.
  3. ^ "Key to Class Ascidiacea (Tunicates, sea squirts)". Retrieved 30 January 2026.
  4. ^ a b "Pycnoclavella stanleyi Berrill & Abbott, 1949 Social tunicate". Seabase. Retrieved 30 January 2026.
  5. ^ a b "Subphylum Urochordata". Seabase. Retrieved 30 January 2026.
  6. ^ Levine, Estees P. (1961). "Occurrence of Titanium, Vanadium, Chromium, and Sulfuric Acid in the Ascidian Eudistoma ritteri". Science. 133 (3461): 1352–1353. doi:10.1126/science.133.3461.1352.