Aplidium fuegiense (Cunningham, 1871), Cunningham, 1871

Turon, Xavier, Cañete, Juan I., Sellanes, Javier, Rocha, Rosana M. & López-Legentil, Susanna, 2016, Ascidian fauna (Tunicata, Ascidiacea) of subantarctic and temperate regions of Chile, Zootaxa 4093 (2), pp. 151-180: 158-160

publication ID

http://doi.org/10.11646/zootaxa.4093.2.1

publication LSID

lsid:zoobank.org:pub:ECC66298-6885-47B3-B797-8D30AA05927F

persistent identifier

http://treatment.plazi.org/id/03C88E54-FF9E-FFBA-FF77-B08AFEE93363

treatment provided by

Plazi

scientific name

Aplidium fuegiense (Cunningham, 1871)
status

 

Aplidium fuegiense (Cunningham, 1871)  

Fig. 4 View FIGURE 4 A –C

References and synonymy: Amaroucium fuegiense Van Name (1945)   p. 43; Aplidium fuegiense Monniot (1970)   p. 325; Monniot & Monniot (1983) p. 16.

Localities: 2 S, 7 S, 8 S.

Colonies of this species are cushion-like, measuring up to 10 cm in diameter and 4 cm in height. The colour in our specimens is brownish. The zooids form wide, meandering fields separated by narrow tunic stretches without zooids. The tunic is soft but consistent, particularly the outermost layer. The relaxed zooids measure over 20 mm in length (the thorax reaches ca. 5 mm, and the abdomen ca. 4 mm).

The oral siphon is six-lobed, and the atrial aperture is relatively wide, reaching from the second to the fifth row of stigmata. It is surmounted by a short languet that can be simple or, more often, have two, three, or more points. There are between 12 and 15 rows of stigmata (mostly 13–14), with over 20 stigmata per half-row, and 15–16 fine longitudinal muscles run longitudinally through each side of the thorax. The abdomen presents a folded stomach, usually with five folds plus the typhlosole. There is a posterior stomach and an elongated mid-intestine in vertical position in well relaxed zooids. The posterior intestine ends in a bi-lobed anus just at the posterior rim of the atrial aperture. Most zooids have well-developed gonads consisting of several reddish oocytes and white male testes occupying most of the post-abdomen. The space between the posterior intestinal loop and the ovary is filled by a folded and twisted spermduct. In a few zooids, undifferentiated embryos (up to four), of reddish colour, were seen in the posterior part of the peribranchial cavity.

Remarks. this species is widely distributed in Antarctic and subantarctic waters. Most descriptions of the species report wide morphological variation, perhaps encompassing a group of ill-defined species. We did not observe the small orange-reddish bodies in the surface layer of test reported in other descriptions (Millar 1960, 1970, Sanamyan & Schories 2003), which may be regressing bodies. The convoluted spermduct between the ovary and the digestive system (Millar 1960, Monniot 1970, Monniot & Monniot 1983) may be a good diagnostic character.

Kingdom

Animalia

Phylum

Chordata

Class

Ascidiacea

Order

Enterogona

Family

Polyclinidae

Genus

Aplidium

Loc

Aplidium fuegiense (Cunningham, 1871)

Turon, Xavier, Cañete, Juan I., Sellanes, Javier, Rocha, Rosana M. & López-Legentil, Susanna 2016
2016
Loc

Aplidium fuegiense

Monniot 1970
1970
Loc

Amaroucium fuegiense

Van Name 1945
1945