Euherdmania claviformis ( Ritter, 1903 )

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

Euherdmania claviformis ( Ritter, 1903)

Figure 9 E–F

IHAK 60 BHAK 3243, 1738 UF 2549. Rattenbury Pinnacle, Scuba, 17–20 m.

RHAK 6 BHAK 0995. Low rocky intertidal. Tubes 6 cm long.

Clumps of long thin colorless zooids usually almost completely encrusted and embedded with grey sand, each zooid separate except at the common base formed from tightly interwoven branching basal stolons. Sometimes the anterior individual tubes are clear of sand ( Fig. 9F ). The thorax is comprised of 12 rows of very short stigmata. The esophageal region is very extended, with the ridged stomach (about six or seven plications) near the posterior end, followed by the testes and the heart. Ritter (1903) described this species in great detail, so impressed by its difference from all other known colonial ascidians that he established a new family and genus for it. While Ritter himself had to change the family and genus names due to their being preoccupied ( Ritter 1904), this single genus family is still recognized as unusual, and contains only a few species. A detailed morphological description is also given by Van Name (1945); Trason (1957) described the larva and early post–settlement development. The present study extends the distribution from California ( Abbott & Newberry 1980; Abbott et al. 2007) northward to Washington (unpublished observations) and British Columbia (present study).

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.