CHORDATA:

THE TUNICATA (= UROCHORDATA) AND THE

CEPHALOCHORDATA

P.A. Gainey

The Chordata are animals possessing a single, hollow dorsal nerve chord. Gainey, in Spalding, A., (Ed) 1997, has previously reviewed the status of the tunicates and cephalochordates around the Cornish coastline and the Isles of Scilly. This section deals with the subphyla the Tunicata (= Urochordata) and the Cephalochordata. The Tunicata are a marine group of which there are 60 British species; of these, approximately 50 have been recorded around Cornwall and the Isles of Scilly. Five sources were used when preparing this account (Marine Biological Association, 1957; Millar, 1970; Hayward & Ryland, 1990; Sanderson, 1996a; Sanderson, 1996b). There is no Red Data Book which includes these species. From these sources and the author’s experience, 11 species of chordates in the region have been classified as pNS or Locally Scarce.

1. Cephalochordata

Branchiostoma lanceolatum Lancelet

2. Tunicata (= Urochordata)

Aplidium glabrum

Archidistoma aggregatum

Diazona violacea

Didemnum lahillei

Leptoclinides faeroense

Molgula oculata

Phallusia mammillata

Pycnoclavella aurilucens Orange Lights Sea-squirt

Sidnyum elegans

Synoicum pulmonaria Tennis Ball Ascidian