Ascidian fauna (Tunicata, Ascidiacea) of subantarctic and temperate regions of Chile
Author
Turon, Xavier
Author
Cañete, Juan I.
Author
Sellanes, Javier
Author
Rocha, Rosana M.
Author
López-Legentil, Susanna
text
Zootaxa
2016
4093
2
151
180
journal article
10.11646/zootaxa.4093.2.1
93e50923-ac4f-4bc5-93cc-4b1e825a8c1d
1175-5326
267667
ECC66298-6885-47B3-B797-8D30AA05927F
Corella eumyota
Traustedt, 1882
Fig. 7
B–D
References and synonymy:
Corella eumyota
Traustedt (1882)
p. 273; Monniot (2013) p. 138.
Localities: 2N, 3N, 6N,
8N.
The specimens measure up to
3 cm
in total length and are fixed ventrally or slightly tilted over the right side. The tunic is translucent and the mantle can be from whitish to orange. There are 7–8 red pigmented spots in the oral siphon and
4–6 in
the atrial siphon.
The musculature of the mantle is well developed on the right hand side, where the fibres form a crisscrossed network dorsally and have a more transverse orientation ventrally. There are many simple tentacles (up to 100 of different sizes). The neural gland has a “U” shaped aperture. The branchial sac is typical, with over 30 longitudinally arranged vessels and coiled stigmata below them. Slender dorsal languets mark the dorsal midline of the branchial sac.
The digestive, as is characteristic of this genus, lies on the right hand side. The stomach is folded (folds are better seen from the external side), and the intestine forms a wide loop occupying up to 3/4 of the right side of the mantle. The final part of the intestine runs adjacent to the dorsal languets and ends in an anus with minute lobes. The interior part of the digestive loop is occupied by the gonads, forming a compact mass of tissue. The genital apertures are inconspicuous (usually staining is required to observe them), on the inner side of the gonad mass, and consist of a narrow slit for the male papilla, and a wider aperture for the female gonad.
Remarks.
Lambert (2004) was the first to note the particular shape and position of the genital ducts in
Corella eumyota
, and this character clearly separates this species from other congeners (Alurralde
et al.
2013).
C. eumyota
was considered until recently the only species of the genus in the southern hemisphere, but Alurralde
et al.
(2013) and Monniot (2013) showed that there are at least three species. Previous reports of
C. eumyota
should therefore be taken with caution. The Chilean populations should retain the original name of
C. eumyota
, described from
Chile
(Valparaiso), and recently introduced into the northern hemisphere (Lambert 2004).