Ascidia scaevola ( Sluiter, 1904 )

Kott, Patricia, 2006, Observations on non-didemnid ascidians from Australian waters (1), Journal of Natural History 40 (3 - 4), pp. 169-234 : 210-211

publication ID

https://doi.org/ 10.1080/00222930600621601

DOI

https://doi.org/10.5281/zenodo.7223030

persistent identifier

https://treatment.plazi.org/id/011D87C1-FFD9-CD69-1FBF-FC9BE3FBFCFF

treatment provided by

Felipe

scientific name

Ascidia scaevola ( Sluiter, 1904 )
status

 

Ascidia scaevola ( Sluiter, 1904) View in CoL

( Figure 10G View Figure 10 )

Styelopsis scaevola Sluiter 1904, p 89 .

Ascidia scaevola: Kott 1985, p 53 View in CoL and synonymy.

Distribution

Previously recorded (see Kott 1985): South Australia   GoogleMaps (Great Australian Bight, St Vincent Gulf); Victoria (Lakes Entrance, Sale, Port Phillip Bay   GoogleMaps ); Queensland (Moreton Bay, Gladstone, Bowen Townsville, Nymph I.); Indonesia. New records: South Australia (Edithburgh, 3–4 m, SAM E2871 View Materials ); Tasmanian Canyons (40.79269 ° S, 144.21916 ° E, 94 m) .

Description

The specimens are up to 14 cm long. As usual, they are dorso-ventrally flattened with the body wall closely adherent to the stiff, brittle, thin, sandy test. The sessile branchial and atrial openings, respectively, are at the base of the incurrent and excurrent pseudosiphons, which rise vertically from the upper surface. In the largest specimen the outer half of each tube is bent in the same direction. Internally the thin body wall, branchial wall, short transverse muscle bands, large branchial fold and flat, double gut loop are as previously described ( Kott 1985).

Remarks

The collector has noted that the Edithburgh specimens are buried in sand, only the pseudosiphons projecting above the sea floor. The pseudosiphons of the present species are distinctive, as are the short muscle bands. But in some respects the species resembles Phallusia polytrema ( Herdman, 1906) and Microgastra granosa (see below) and they all appear to occupy sea-floor habitats where they are buried in sand. They all have thin, brittle sand-filled test, a thin body wall adhering closely to the test and delicate branchial sacs. However, in the former species, the descending limb of the gut loop accumulates sand and the gut forms a simple J-shaped loop; while in the latter species (which has a dorsal branchial fold like A. scaevola ), the small gut loop is evaginated from the body wall and the distinctive gonads and neural organs with their associated part of the body wall, are embedded in the test.

SAM

South African Museum

Kingdom

Animalia

Phylum

Chordata

Class

Ascidiacea

Order

Phlebobranchia

Family

Ascidiidae

Genus

Ascidia

Loc

Ascidia scaevola ( Sluiter, 1904 )

Kott, Patricia 2006
2006
Loc

Ascidia scaevola: Kott 1985 , p 53

Kott P 1985: 53
1985
Loc

Styelopsis scaevola

Sluiter CP 1904: 89
1904
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