Metandrocarpa taylori Huntsman, 1912

Common name(s):  Taylor's social tunicate, Taylor's colonial tunicate, Orange social ascidians, Orange social sea squirt, Red sea buttons

Synonyms: Metandrocarpa taylori
Phylum Chordata
Subphylum Urochordata
Order Stolidobranchia
Family Styelidae
Metandrocarpa taylori near Skyline Marine, 19 m depth.
(Photo by:  Kirt Onthank, July 2007)
Description:   These small tunicates are social (in close association, even touching and connected by tissue) but not colonial (so closely in contact with one another that the colony is a single mass embedded in a common tunic).  The individuals are about as tall as wide, an opaque orange, orange-red, red, brick red, or yellowish or rarely greenish and have a wide attachment to the substrate.  The siphons are usually fairly close together and more darkly or strongly colored than the rest of the individual.  Individuals are joined at least temporarily to one another by small stolons or thin extensions of the tunic; the connections may not be obvious without close observation.  Individuals are often nearly hemispherical or slightly oblong.  Diameter to nearly 7 mm.  Colonies can reach up to 20 cm or so in diameter.

How to Distinguish from Similar Species: Metandrocarpa dura has much more obvious connections between individuals and generally live in more massive aggregations.  They usually live on kelp but may also be found on rocks. Cnemidocarpa finmarkiensis is solitary and has a smooth, shiny tunic. Distaplia occidentalis is a true colonial form with many individuals within the same tunic.

Geographical Range:  Southeast Alaska to San Diego, CA

Depth Range:  Intertidal or subtidal to about 20 m

Habitat:  Sides and undersurfaces of rocks in areas of strong current..  They may be especially common on granite substrates.

Biology/Natural History:  This species routinely reproduces asexually.  Runners extend from the base of adults, then grow up into a new individual.  Young colonies have widely spaced individuals but in older colonies the individuals are often more tightly packed together.  During budding of new individuals, the entire individual is formed from ectodermal tissue instead of from endoderm, mesoderm, and ectoderm as occurs in the larva.  Many of these connections later break.  In Washington both asexual and sexual reproduction occur year-round but probably most commonly in the spring and summer.  The tadpole larvae are brooded in the atrial cavity, then released in the morning.  They settle and metamorphose into adults after swimming for 2-48 hours, and are ready to feed within about 11 days.



Dichotomous Keys:
  Kozloff 1987, 1996
  Smith and Carlton, 1975

General References:
  Gotshall, 1994
  Harbo, 1999
  Kozloff, 1993
  Morris et al., 1980
  O'Clair and O'Clair, 1998
  Ricketts et al., 1985

Scientific Articles:

       Abbott, D.P., 1953.  Asexual reproduction in the colonial ascidian Metandrocarpa taylori Huntsman.  Univ. Calif. Publ. Zool. 61: 1-78

Haven, N.D., 1971.  Temporal patterns of sexual and asexual reproduction in the colonial ascidian Metandrocarpa taylori Huntsman.  Biological Bulletin 140: 400-415

Watanabe, H. and C.C. Lambert, 1973.  Larva release in response to light by the compound ascidians Distaplia occidentalis and Metandrocarpa taylori.  Biological Bulletin 144: 556-566

Watanabe, H. and A.T. Newbarry, 1976.  Budding by oozooids in the polystyelid ascidian Metandrocarpa taylori.  Ann. Soc. Roy. Zool. Belg., Sci. (2)16: 1-59 

Zeng, Liyun, Molly W. Jacobs, and Bill J. Swalla, 2006.  Coloniality has evolved once on Stolidobranch ascidians.  Integrative and Comparative Biology 46:3 pp 255-268

Web sites:

General Notes and Observations:  Locations, abundances, unusual behaviors:


A closeup view of another colony.  Photo by Kirt Onthank, July 2007

Authors and Editors of Page:
Dave Cowles (2007):  Created original page
CSS coding for page developed by Jonathan Cowles (2007)