Styela clava Herdman, 1881

Lambert, Gretchen, 2003, New records of ascidians from the NE Pacific: a new species of Trididemnum, range extension and redescription of Aplidiopsis pannosum (Ritter, 1899) including its larva, and several non-indigenous species, Zoosystema 25 (4), pp. 665-679 : 676

Styela clava Herdman, 1881

Styela clava Herdman, 1881: 70 (type locality: Japan). — Abbott & Johnson 1972: 95-105. — Kott 1985: 115. — Lambert & Lambert 1998: 675-688.

Styela barnharti Ritter & Forsyth, 1917: 452 . — Van Name 1945: 309.

MATERIAL EXAMINED. — Canada. Vancouver I., French Creek Marina, 1993-2002, numerous individuals. — Nanoose Bay, on floating dock, 4.IX.1998, 1 small individual. — Nanaimo, Brechin Pt, boat launch floats, 24.IX.1998, 2 individuals. — Maple Bay, 9.XII.2000, a small population was observed by Bill Austin near Duncan at Birds Eye Cove.

USA. Blaine, WA, Drayton Harbor, floating docks, 3.IX.1998, 11.IX.1998, 7.IX.2001, many.

Olympic Peninsula, WA, Neah Bay, Neah Bay Marina, 18.VIII.2001, many.

DISTRIBUTION. — Described from dredged specimens collected near Kobe, Japan, it now occurs worldwide in temperate waters, including Europe, the UK, Australia, Asia, and the east and west coasts of North America. It is considered to have been introduced to these regions via hull fouling or other anthropogenic transport (see Abbott & Johnson 1972; Lambert & Lambert 1998).

DESCRIPTION

See Van Name (1945, under S. barnharti Ritter & Forsyth, 1917 ) and Abbott & Johnson (1972) for detailed descriptions with photos and illustrations. This large (up to 8-9 cm or more in length) cylindrical stolidobranch has a tough but thin brownish tunic and short broadly tapering posterior stalk. Both siphons are short and close together at the anterior end. The tunic is tubercular anteriorly around the siphon bases, while posteriorly it is fold- ed into longitudinal ridges and grooves. There are two to five slender long gonads on the left and four to nine on the right, with numerous small testes attached along the length of the sinuous ovaries.

Family MOLGULIDAE Lacaze-Duthiers, 1877