Pycnoclavella stanleyi Berrill & Abbott, 1949

Lambert, Gretchen, 2019, The Ascidiacea collected during the 2017 British Columbia Hakai MarineGEO BioBlitz, Zootaxa 4657 (3), pp. 401-436 : 416

Pycnoclavella stanleyi Berrill & Abbott, 1949

Figure 9 B–D

IHAK 15 BHAK 1008 Calvert Island, headland between Sixth and Seventh Beach. A dominant member of a low intertidal tide pool.

RHAK 6 BHAK 0634 UF 2485. Seventh Beach, north wall, low intertidal tide pool. May be the same tidepool as IHAK 15 but sampled on a different day. One colony with completely encrusted and embedded grey sand in many small narrow heads; clumps with Eudistoma ritteri , Aplidium kottae and A. californicum .

ZHAK 35 BHAK 3252 UF 2570. Sasquatch Commode tidepool, with Eudistoma ritteri and Metandrocarpa taylori Huntsman, 1912 .

Bright yellow or orange tiny thoraxes emerge independently from a base in which the elongate abdomens are embedded in a matrix encrusted and impregnated with sand, with a maximum zooid length of less than 2 cm. The zooids, though tightly packed together, are actually independently covered by their own tunic and only share a common tunic at the base, as figured by Trason (1963). Each thorax has seven rows of stigmata, easily visible in the enlargement of part of a colony in Fig. 9B , photographed underwater in situ by G. Paulay. There may be some yellow or orange pigment on the abdomens ( Trason 1963), or pigment may be occasionally lacking and the zooids including thoraxes are colorless and transparent, as pictured in Lamb & Hanby (2005). A complete description is given by Berrill & Abbott (1949) and Trason (1963). Distribution: British Columbia to northern Mexico ( Lamb & Hanby 2005).

Figures

FIGURE 9. Aplousobranchia. A–D: Clavelinidae. A: Clavelina huntsmani. B–D: Pycnoclavella stanleyi. B: expanded orange thoraxes extended beyond sandy tubes. C: thoraxes partially contracted. Photo includes four zooids of orange Metandrocarpa taylori. D: zooids fully contracted; only a bit of orange is visible. E, F: Euherdmaniidae, Euherdmania claviformis. E: zooids fully retracted into long sand-encrusted tubes. F: In this colony the anterior portions of the tubes not sand-encrusted, though the colorless zooid thoraxes are partially contracted. Scale bars: A, 7 mm; B, 2 mm; C, 4 mm; D, 1 cm; E, 1.2 cm; F, 1 cm. A, B, D, F photos by G. Paulay.