New records of deep-sea ascidians (Tunicata, Ascidiacea) from the New Caledonia region
Author
Monniot, Francoise
text
Zootaxa
2021
2021-07-06
4996
3
443
468
journal article
10.11646/zootaxa.4996.3.2
1175-5326
5074595
A1982CE0-AD2F-496B-80AB-FB3C4FA69F7A
Clavelina
sp.
Figure 7
Station: Kanadeep CP 5102. Both solitary specimens have the same shape with a long body anchored to the substrate by a tuft of hair-like filaments agglomerating sand (
Fig. 7
). The body lengths are
5.5 cm
and
4.6 cm
, and the anterior width
7 mm
. The tunic is thin soft and transparent on the body but becomes somewhat harder at the base. The anterior part is a little enlarged and represents the thorax, but all tissues have disappeared inside it. When stained a layer of non-organised tissue appears but with no trace of muscles or branchial sac. Nevertheless the siphonal apertures can be seen on the tunic, the oral one apical with a smooth margin and the atrial siphon at a short distance dorsally with six petal-like lobes. The abdomen is deeply retracted in the posterior part of the body and contains a long gut loop with an enlargement inside the basal part of the body covered with rhizoids. The detailed structure of the gut cannot be seen but inside of the gut loop there are some testis vesicles and the ovary placed more anteriorly.
FIGURE 7.
Clavelina
sp.
two specimens, scale bar = 1cm.
In the absence of thoracic organs and branchial tissue these New Caledonian specimens can only be assigned to belong to the
Clavelina
genus. This hypothesis is due to the similarity in shape and deep habitat with
Clavelina michaelseni
Millar, 1982
from
New Zealand
at
640 m
depth.