Social tunicate collected from fouling community, floating platform, Boat Channel, Marine Corps Recruit Depot (MCRD), San Diego, California, photographed in unfiltered and filtered bay water with film (ASA 200).

Identified months later (27 Apr 2014) - PROVISIONAL IDENTIFICATION - Request review by tunicate specialists as I am not a tunicate specialist. "Internet picture taxonomy" and known marine ecological studies in San Diego Bay provide the basis of this provisional identification

The following description include my observations following study of photos and knowledge of Internet information.

Individual zooids clumped in a social colony resembling a tight bouquet. Zooids joined at the base by a narrowing stalk and leading to root-like structure - bundled stolons. Zooids opaque, body appears smooth, and mostly free of debris and other marine organisms. Individual zooids ranging from globular (which might the defensive contraction) to vase to club-shaped with short stubby siphons directed away from each other at a short angle from distal. The almost equal-sized oral and atrial siphons, show four dark (almost black) vertical stripes separating four white lobes. The white appears more like the white in pastry glaze - broken and in varied concentrations. The white on each lobe appears T-shaped with the "wings" of the "T" pressing into the adjacent black striping and pinching off the width of the black stripes at each siphon rim's edge. Very difficult to see, two very faint black lines extend proximal in parallel from the rim on the upper part middle of the white "T". Dissecting scope micrographs needed to visualize the detail better. The distribution of exterior white extending from siphon rim seem to stop on the lower portion of the siphon, and meeting the olive coloration of the zooid body extending up the siphon. The extent of black stripe also stops upon meeting the olive extending onto the siphon with some black striping slightly further proximal down the siphon than the white stripes of the siphon. On siphons extended by the living relaxed tunicate, the alternating black and white extend into the rims of the siphons The V-shaped "cleft" between adjoined atrial and oral siphons not deep, both joining to the body with some of the cleft indentation extending further down the body of the zooid like the "cheeks of a human buttocks." On extended siphons, the alternating white and black coloration on each siphon seem to stop before the cleft and zooid body junction. Each extended siphon seen to possess a zone or "neck" of olive before joining to the main zooid body. Siphon openings appears circular to square shaped, between 1 to 2m in diameter. Below the siphons, coloration of the distal half of the zooid outer tunic olive-brown in color gradually changing to yellow-green towards the taping basal stalk

Second and third photo was taken on 2 May 2014 from same location. Unknown annelid worm parchment tube with three attached individual tunicates separated spatially. Photos of individuals on worm tube depict attachment by basal stolons. Globular body shape might result from a freedom to spread laterally when not clustered tightly in a social colony. Two tunicates were removed off the worm tube to show some detail of individual tunicates.

Note: The alternating black and white striping limited to the tips of short, stubby almost equal-sized oral and atrial siphons directed at a short angle away from each other, the olive-green-brown vase like body, the clustering of the zooids in a tight social colony with each individuals free except for the basal attachment of root-like stolons might be distinctive characteristics for tentative field identification.

Introduced species - occurs worldwide, introduction likely by ballast and fouling community on boats, noted from several locations in San Diego Bay and nearby Mission Bay in other studies. Flickr photograph by Jay Vavra of specimen collected at Grape Street Pier San Diego, San Diego Bay. Unusual photograph of colony encased in unknown mucus-like substance or water collected tightly around the specimen when collected tunicate photographed in air. The siphons closed tight and zooid bodies retracted and rounded. Photograph does show alternating black and white on short stubby siphons with siphons located near distal and directed at a short angle away from each other, brown coloration and the basal stolons. Light might be distorted due to exposure in bright sunlight.

http://www.flickr.com/photos/43973579@N08/4943592318

I was initially confused viewing the great variability among posted Internet photos labeled as P. zorritensis. Some posted Internet photographs from around the world appear NOT to match the original description by Willard G. Van Name(1931), ascidian taxonomist with the American Museum of Natural History. Van Name originally described the organism as Stolonica zorritensis in 1931, unfortunately Van Name did not collect the type specimen from the type locality at Zorritos, Peru. Field notes especially of appearance of living specimens and ecology NOT included in Van Name's original description. A pen and ink? black and white drawing (fig 6C) depicted portion of the a colony, stalked zooids with stolons at the base, and short stubby siphons directed distally.Van Name's description of internal anatomy quite detailed. Unfortunately Van Name original description did not described any external color distribution of preserved specimens. Later in 1945 an update entitled "The North and South American Ascidians", Van Name moved genus Stolonica into genus Polyandrocarpa based on internal anatomy of the testes. Still no mention by Van Name of color or ecology in the 1945 update. I understand color in preserved museum specimens may be altered. Yet, field biologist rely on color presents clues to make tentative field identification. Color distribution and ecology must be noted in field notes by people collecting and studying living P. zorritensis specimens. In addition, field and lab photography of living specimens plays a great role. Tunicates must be photographed in water in order to show relaxed siphons and body.

Current Internet-posted photos display varying morphology, and color patterns on photos identified as P. zorritensis. Some photos likely misidentified. Internet research revealed genus Polyandrocarpa contains a number of named species, and the Polyandrocarpa zorritensis complex likely contains population variants. For instance, an Italian photograph of Mediterranean collected Polyandrocarpo zorritensis showed zooids with up to eight black strips, the siphon tips somewhat crenulated and slightly flaired, white on the siphon lobes not as bright, and a red coloration the zooid tests.

http://www.marinealien.sinanet.isprambiente.it/uploads/Polyandrocarpa%20zorritensis.pdf

Another Internet photo of Mediterranean P. zorritensis showing a close-up of zooids bearing numerous orange flecks (photo 2). Orange flecks not seen in observed San Diego specimens.

http://www.naturamediterraneo.com/forum/topic.asp?TOPIC_ID=215441

Clarification of the genus Polyandrocarpa greatly needed. West coast tunicates still poorly known. Introduction of the now commonly found P. zorritensis to the west coast of North America seems to be a relatively recent. Lambert and Lambert (1998) first reported the species from Southern California harbors in the late 1990's. Field guides and taxonomic keys published in the 1990s and earlier do not include the now commonly found P. zorritensis in listings and identification keys. Currently,websites devoted to marine invertebrate introductions show limited reporting for P. zorritensis on the west coast of North America. Marine photographers at the moment passing up photographing the introduced small brown colonial tunicate.

Internet-shared photos along with field notes of living P. zorritensis greatly needed for comparative study, and to clearly photo document varying morphology and the true nature of its recent introduction both on the west coast and around the world. -

Request a photographic comparison via the Internet of living and relaxed, identified Polyandrocarpa zorritensis from all parts of the world. Photograph sites like iNaturalist.org could function as a clearing house for storage and comparison of posted photos.