Didemnum, Savigny, 1816

Lambert, Gretchen, 2019, The Ascidiacea collected during the 2017 British Columbia Hakai MarineGEO BioBlitz, Zootaxa 4657 (3), pp. 401-436 : 409

Didemnum sp. 2

Figure 5F, G

IHAK 31 BHAK 1692. Triquet Island Macro site, Scuba, 8 m. On boulder .

IHAK 42 BHAK 1709. Starfish Rocky Reef Site, Scuba, 18 m, rock outcrop.

Very dense superficial spicule layer, none in middle region of tunic and at most a thin spicule layer in basal region. Spicules small, stellate with short but sharply pointed rays. Zooids bright yellow-orange. Six very sharply pointed lobes on oral siphon, long muscular process extending into tunic from base of thorax. Single testis, about seven turns of the sperm duct but it was not possible to count accurately. No larvae were observed. This species may be D. carnulentum Ritter & Forsyth, 1917 , but additional work is required to determine whether this is an already named or new species.

Figures

FIGURE 5. Didemnidae. A–E: Didemnum sp. 1, undescribed species. A: whole colony on kelp holdfast. B: detail of tunic surface showing one cloacal opening. C: bifurcated testis from a zooid showing numerous coils of the sperm duct; D: tunic spicules. E: two cryptically colored lamellarid nudibranchs above a colony piece from which they were collected. F, G: Didemnum sp. 2. F: numerous small colonies or pieces of same colony; G: two cross sections of a different colony showing distribution of spicules. Scale bars: A, 1 cm; B, 1.5 mm; C, 0.1 mm; D, 20 µm; E, 1 cm.; F, 9 mm; G, 4 mm.