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Trididemnum alexi

Trididemnum alexi

Lambert, 2003

GBIF:159167980

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ABOUT

Descriptions(1)

Figure 4 D – F IHAK 52 BHAK 2870 UF 2557. Mouth of Kwakshua, Scuba, 5 – 22 m. On branching bryozoan. IHAK 55 BHAK 1732, 1733 UF 2543, 2544. Kwakshua Petroglyph Cliff, Scuba, 17 – 20 m, high current, vertical rock wall. Five colonies. IHAK 60 BHAK 3241 UF 2560. Rattenbury Pinnacle, Scuba, 17 – 20 m. On living unidentified scallop; with many small amphipods Polycheria osborni Calman, 1898 in burrows on tunic surface. The colonies are thick, encrusting and may attain a large size of 10 cm or more across and up to 2 cm in thickness. They are usually a dark purple or purplish brown in color, due to numerous pigment granules in the tunic and zooids. Small stellate tunic spicules are sparse. Colonies of what are probably this species were collected by dredging by Huntsman (1912 a) near Nanaimo, British Columbia but identified only as dark colonies of Trididemnum sp. with sparse spicules. For complete description see Lambert (2003). Distribution: British Columbia to Washington (Lambert 2003; Lamb & Hanby 2005).
Lambert, Gretchen (2019): The Ascidiacea collected during the 2017 British Columbia Hakai MarineGEO BioBlitz. Zootaxa 4657 (3): 401-436, DOI: 10.11646/zootaxa.4657.3.1

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CLASSIFICATION

Taxonomic Classification Tree

AnimaliaChordataAscidiaceaEnterogonaDidemnidaeTrididemnumTrididemnum alexi

MULTIMEDIA

Media Files(1)

FIGURE 4. Aplousobranchia, Didemnidae. A–C: Diplosoma listerianum. A: colony on Scyra acutifrons; B, C: close-ups of zooids from two different color morphs. D–F: Trididemnum alexi. D: colony on living scallop; E: same colony closeup with amphipod Polycheria osborni burrowed into tunic surface; F: tunic spicules. Scale bars:A, 1 cm; B, 1.5 mm; C, 1.3 mm; D, 1.6 cm; E, 3.2 mm; F, 35 µm. Photos B and D by G. Paulay.

Imageimage/png© Lambert, GretchenLambert, Gretchen

IMAGES

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Source Information

The Ascidiacea collected during the 2017 British Columbia Hakai MarineGEO BioBlitz

checklist

This dataset contains the digitized treatments in Plazi based on the original journal article Lambert, Gretchen (2019): The Ascidiacea collected during the 2017 British Columbia Hakai MarineGEO BioBlitz. Zootaxa 4657 (3): 401-436, DOI: 10.11646/zootaxa.4657.3.1

Abstract

A three-week intensive marine biodiversity survey was carried out at a small remote region of the central British Columbia coast at and near the Calvert Island Marine Station (Hakai Institute) July 21–August 11, 2017. The survey included daily sampling by the staff and a number of visiting taxonomists with specialties covering all the major groups of invertebrates. Many marine habitats were sampled: rocky and sand/gravel intertidal and tidepools, eelgrass meadows, shallow and deeper subtidal by snorkel and Scuba, plus artificial surfaces including the sides and bottom of the large floating dock at the Institute and settlement plates set out up to a year previously at various subtidal sites. Many new species were recorded by all the taxonomists. In this very biodiverse remote area 36 ascidian species were identified: 18 Aplousobranchia, 7 Phlebobranchia, and 11 Stolidobranchia, comprising a total of 15 solitary and 21 colonial species including two undescribed colonial species. This represents almost one third of all the known North American species from Alaska to southern California in this limited very remote area. Remarkably, only two are possible non-natives. Diplosoma listerianum (Milne-Edwards, 1841), was collected mostly on natural substrates including deeper areas sampled by Scuba, and one colony occurred on a settlement plate. A few Ciona savignyi Herdman, 1882 were collected, two from natural substrates and four from artificial surfaces. There were no botryllids, Styela clava Herdman, 1881, Didemnum vexillum Kott, 2002, or Molgula manhattensis (De Kay, 1843), though these are all common and sometimes very abundant non-natives in other parts of BC and along much of the U.S. west coast. Most of the species encountered are known in northern California, Washington, and southern BC, but only a small number are represented among the few known Alaska species.

Lambert G, plazi (2019). The Ascidiacea collected during the 2017 British Columbia Hakai MarineGEO BioBlitz. Plazi.org taxonomic treatments database. Checklist dataset https://doi.org/10.11646/zootaxa.4657.3.1 accessed via GBIF.org on 2026-06-15.

CC0Published 8/20/2019View dataset
GBIF Usage Key
159167980
Dataset Key
3414318d-7570-49ac-9013-be4e1f1e6347
Origin
source
Backbone Key
4356435
Taxon ID
6A2E3761A938FFCF1390FF6ADE73FD47.taxon
Last Crawled
6/10/2026
Last Interpreted
6/10/2026
View on GBIFSource Reference