Eusynstyela hartmeyeri, MICHAELSEN, 1904

Monniot, Claude, 2002, Stolidobranch ascidians from the tropical western Indian Ocean, Zoological Journal of the Linnean Society 135 (1), pp. 65-120 : 74-75

publication ID	https://doi.org/ 10.1046/j.1096-3642.2002.00017.x
DOI	https://doi.org/10.5281/zenodo.5490260
persistent identifier	https://treatment.plazi.org/id/436F3F3C-FFD9-FFA4-FCBE-F9D1FD611C82
treatment provided by	Carolina
scientific name	Eusynstyela hartmeyeri
status

Treatment

EUSYNSTYELA HARTMEYERI MICHAELSEN, 1904 View in CoL

Eusynstyela hartmeyeri Michaelsen, 1904: 38 View in CoL , 114, pl. 1, fig. 1 – Mozambique 1918: 38 – Red Sea and Mozambique.

Polyandrocarpa violacea Sluiter, 1905: 10 View in CoL , pl. 1 fig. 3 – Djibouti.

Eusynstyela hartmeyeri: Monniot C. & Monniot F., 1997: 1639 View in CoL , fig. 8 – Bahrain.

Eusynstyela aliena Monniot C., 1991: 18 View in CoL , fig. 6 – New Caledonia, Nouméa harbour.

Eusynstyela hartmeyeri: Monniot F. & Monniot C., 2001: 314 View in CoL – Hong-Kong.

Material

Mozambique: Ibo Island, 20 m, coll. C. Monniot, 1995. Djibouti, 3–6 m, coll. C. Monniot, 1996.

Description

The zooids are joined by fusion of their tunic along the sides. The top side may be more or less protruding, depending on the substrates where the colony is attached. The deep red tunic is very resistant.

The internal anatomy is as described by Monniot (1991). The body wall is pigmented and muscular with big sphincters around the siphons. There are four oral tentacles that are clearly longer than the others. The branchial tissue is thin, linked to the body wall by long thin strips. The endostyle is not attached to the body wall. The gut forms a closed, elongated loop with the anus near the oesophagus entrance. The gastric caecum is finger-like. The gonads lie along a line on each side, parallel to the endostyle. The polycarps are oval or round, longer when the ovary is well developed and the two testis lobes regressed. The endocarps are scattered over the body wall. There is a ring of thin tentacles around the base of the cloacal siphon.

Remarks

Our collections from Djibouti and Mozambique persuade us now to place the species Eusynstyela aliena Monniot C., 1991 , from Nouméa Harbour, New Caledonia, in E. hartmeyeri .

We have examined the type specimen of Polyandrocarpa violacea Sluiter, 1905 from Djibouti, MNHN S1 POL.A 4, and we found that species, too, is a synonym of Eusynstyela hartmeyeri . The colour, the body size, the shape of the zooids and the features of the stomach are the same.

Distribution

The natural geographical distribution of H. hartmeyeri seems to be restricted to the Indian ocean; the specimens collected in New Caledonia and Hong Kong harbours were probably imported on ship hulls.