The Ascidians of the Japan Sea. I

Abstract

The ascidian fauna in the Japan Sea was studied by examination of new material mainly from littoral areas and the type or other available specimens and by a literature survey of previous records. A total of 163 species, including infraspecific taxa, belonging to 50 genera of 14 families were recorded from this sea. Included are descriptions of five new species, proposal of a new replacement name and many taxonomic amendments. The fauna thus understood has been analyzed zoogeographically mainly in terms of biogeographic elements. Consideration of the results supports in many respects the previous knowledge about the biotic peculiarities of the sea, but also gives some new findings.

Stolidobranch ascidians from the tropical western Indian Ocean

“…Another species, S. reptans (Oka, 1927b), has a testis with two simple lobes. Nishikawa (1991) redescribed this species after examining numerous specimens. This species seems highly variable in the number of stigmata rows (8-11) and stomach folds (9-13).…”

Aplidium sagresensisn. sp. (Ascidiacea, Polyclinidae) from the Atlantic coast of the Iberian Peninsula

“…Finally, A. pliciferum Redikorzev, 1927(Kott 1963, Nishikawa 1990) possesses 8-15 stigmatal rows, 18-32 stomach plications and a trifid atriallanguet. However, Downloaded by [University of California, San Diego] at 12:47 29 June 2016 it, too, differs from A. sagresensis in that its larvae have anterior unpaired ampullae.…”

“…This region includes in Europe a Portuguese zone (Peres 1964, Saldanha 1974, Monteiro & Andrade 1981)and a Spanish zone (Peres 1959, Ramos 1988, and, on the African coast, Morocco (Sluiter 1927, 1928, Millar 1967, Monniot & Bitar 1983, Bitar 1984 and the Canary Islands (Lozano 1972, Rios & Brito 1984, Rios 1985. Our knowledge of both the littoral and bathyal ascidian fauna ofthe Straits sector has increased recently with the accounts by Monniot & Monniot (1988, 1990, Turon (1988) and Ramos et al (1992, in press). …”

Description of Sidneioides peregrinus sp. nov. (Tunicata: Ascidiacea: Polyclinidae): a possible exotic species in the Atlantic Ocean

“…The fact that the atrial languet was absent in those specimens argues against their placement in Sidneioides, given that it is present in all other species in the genus. Sidneioides tamaramae was registered on the west coast of Australia (KOTT 1992), S. japonense occurs in Japan coast and the Banda Sea (Indonesia) and S. snamoti is also in Japan (NISHIKAWA 1990, TOKIOKA 1953, MILLAR 1975. This distribution pattern, and the fact that all five other genera in Polyclinidae have Atlantic representatives (although fewer in number than in the Pacific) suggests that Sidneioides is native to the western Pacific and the absence of any sister group of S. peregrinus in the Atlantic is additional evidence that its presence in Paranaguá Bay is not the result of natural biogeographic processes.…”

“…Both S. peregrinus sp. nov. and S. tamaramae differ from S. japonense and S. snamoti in that the latter two species have flatter colonies, longer zooids, larger number of rows of stigmata, and thoracic musculature not restricted to the thorax, converging into two muscle bands that extend along the left side of the abdomen (TOKIOKA 1953, MILLAR 1975, NISHIKAWA 1990. Despite the similarity between S. tamaramae and S. peregrinus sp.…”