Additional records of bathyal ascidians (Tunicata) from the New Caledonia region
Author
Exbodi, Françoise Monniot
text
Zootaxa
2022
2022-10-12
5195
3
201
223
journal article
163383
10.11646/zootaxa.5195.3.1
64857dc9-9d69-49d4-be4b-f87c810e6018
1175-5326
7187776
44C449B1-1536-40BE-AB30-4D728A90EC30
Oligotrema psammites
Bourne, 1903
Figure 19
Station:
SPANBIOS: DW 5257,
2 specimens
.
The body is oval covered with thin tunic filaments and coated with sediment. The oral aperture is lined by six pinnate equal lobes (
Fig. 19A
). The atrial siphon protrudes slightly at the opposite end of the body (
Fig. 19A
). Extracted from the tunic the body wall appears translucent. The oral musculature has a strong sphincter and short longitudinal fibres. Six short strong longitudinal muscles run on the ventral side of the body “neck”. Transverse muscular fibres are regularly spaced around the whole body (
Fig. 19 B,C
). The anal siphon has no sphincter. The oral aperture has a ring of flat tentacles. The neural ganglion is anteriorly prolonged by six stout nerves (
Fig. 19E
) and posteriorly extends along the whole dorsal line. The neural gland is situated at the right side of the neural ganglion. The anterior part of the pharynx is enlarged in a funnel with multiple perforations on each side (
Fig. 19D,E
). Posteriorly the oesophagus is long and enters into a large stomach pouch. The intestine forms a loop applied to the left side of the stomach. A network of pyloric tubules encloses the intestine. A large kidney containing a concretion occupies the right side of the atrial cavity (
Fig. 19C
). A thin-walled endocarp can be seen ventrally on each body side. There is one gonad on each side (
Fig. 19B,C
). The testis consists of a group of ramified lobes applied to the left and right sides of the stomach and has a short sperm duct. The ovaries are long curved tubes ending near the atrial aperture (
Fig. 19B,C
).
Remarks.
Kott (1989)
synonymised
Sorbera unigonas
Monniot & Monniot, 1984
,
Oligotrema psammites
Bourne, 1903
and
Oligotrema psammathodes
(
Sluiter, 1905
)
considering that no major differences occur in samples collected in wide geographical areas. The genus
Oligotrema
having priority the name
Oligotrema psammites
was employed by
Monniot & Monniot (2003)
for specimens from
New Caledonia
,
Philippines
and
Solomon Islands
and is used here for the Spanbios samples. Detailed descriptions of this species under the name
Sorbera unigonas
can be found in
Monniot & Monniot (1984
and
1990
).