Corella eumyota Traustedt, 1882

Monniot, Françoise, 2013, The genus Corella (Ascidiacea, Phlebobranchia, Corellidae) in the Southern Hemisphere with description of a new species, Zootaxa 3702 (2), pp. 135-149: 138-140

publication ID

http://dx.doi.org/10.11646/zootaxa.3702.2.3

publication LSID

lsid:zoobank.org:pub:E972F88B-7981-4F38-803D-8F4F92FE6A37

persistent identifier

http://treatment.plazi.org/id/D258A424-513A-FFAA-FF31-287A2E9BB2C2

treatment provided by

Plazi

scientific name

Corella eumyota Traustedt, 1882
status

n.sp.

Corella eumyota Traustedt, 1882  from Chile

Figs 3View FIGURE 3, 4AView FIGURE 4. A.

Material examined

- 42 ° 27 ’ S – 73 ° 45 ’ W, 24 /08/ 1972, coll. Coloma.

- Chili without precision, 26 /03/ 1970, coll. Gallardo. - Guaitecas Islands, 44 ° S –073° W, 24 m, SMNH 126199, Arnback-Christie-Linde coll.

The type of Corella eumyota  from Chile (Valparaiso) could not be found among the Traustedt material (pers. com. Zoologisk Museum Copenhagen).

We have examined Corella  samples present in the MNHN collections collected close to the type station and they correpond well to the Traustedt description. Ärnback-Christie-Linde (1929) described from Chili (Guaitecas Islands) small specimens with the same musculature and gonads as in C. eumyota  but the gonoducts are not mentioned. We examined her specimens and they probably belong to the same species as the ones described by Traustedt. They are from a near by area. In her discussion she already doubted of the identity with true Antarctic specimens. The anatomical characters correspond to the Traustedt description.

Some of the specimens mentioned above are aggregated; the largest is 4.5 cm long. The tunic is translucent when fixed. It has a rather smooth surface but wears some thin papillae and a few epibionts. Its consistency is cartilaginous. The oral siphon has 6 low lobes and is terminal and protruding with ocellli. The atrial siphon forms a short tube at 1 / 3 of the body length; its rim has also 6 lobes and ocelli. The animals were fixed by the right side. The tentacles are numerous in 3 orders of size. Their number varies according to the size and the stations. The dorsal tubercle is U-shaped and anteriorly open. The pre-pharyngeal band dorsally curves to become a groove anterior to the dorsal languets. The musculature on the siphons is strong. The longitudinal fibres coming from the oral siphon extend along 1 / 5 to 1 / 4 of the body length on both sides. On the left side transverse muscular bundles start from the ventral line and divide to make a dense network with the transverse ribbons issued from the dorsal side ( Fig. 3View FIGURE 3 A). The body wall around the gut has no muscles ( Fig. 3View FIGURE 3 A).

The branchial sac is flat, and thin ( Fig. 3View FIGURE 3 B). The dorsal lamina is attached to the body wall and to the intestine ending at the level of the oesophagus entrance. The dorsal languets are equal in length less numerous than the transverse vessels, and inserted on a flat imperforated lamina strongly linked to the rectum. There is an average of 35 longitudinal sinuses on each side, thin and rarely interrupted. The stigmata are not regularly lined. The spirals ( Fig. 3View FIGURE 3 B) are irregular in 2-3 interrupted turns and often subdivided, the number of turns is lower in the part of the branchial sac located over the gut.

The digestive tract is large and occupies a large part of the right body side ( Fig. 3View FIGURE 3 A). The oesophagus entrance has a thick lip. The olive-shaped stomach has longitudinal folds hidden internally by the gonads. On the external side of the cardia, the typhlosolis can be more easily seen. The intestine draws a vertical closed loop and curves below the oesophagus to join the dorsal line to which it is attached along its whole length. The anus has a circular outline with small round lobes ( Fig. 3View FIGURE 3 D). The testis vesicles are irregularly but mostly grouped on the external side of the intestinal loop and included among pyloric vesicles. The male ducts sink inside the gut and are hardly visible, opening on the internal side of the gonad by a simple fringed hole ( Fig. 3View FIGURE 3 C arrow). The oviduct opens close to the male aperture in a wide hole with small round papillae on its rim ( Fig. 3View FIGURE 3 C arrow).

Eggs were present into the atrial cavity, but no tadpoles have been found.

Kingdom

Animalia

Phylum

Chordata

Class

Ascidiacea

Order

Enterogona

Family

Corellidae

Genus

Corella