Pterygascidia kanakae, Monniot, 2021

Monniot, Francoise, 2021, New records of deep-sea ascidians (Tunicata, Ascidiacea) from the New Caledonia region, Zootaxa 4996 (3), pp. 443-468 : 450-452

publication ID

https://doi.org/ 10.11646/zootaxa.4996.3.2

publication LSID

lsid:zoobank.org:pub:A1982CE0-AD2F-496B-80AB-FB3C4FA69F7A

DOI

https://doi.org/10.5281/zenodo.5074695

persistent identifier

https://treatment.plazi.org/id/03A6FD6C-FF9D-E832-55E3-310FFDBCFA92

treatment provided by

Plazi

scientific name

Pterygascidia kanakae
status

sp. nov.

Pterygascidia kanakae sp. nov.

Figures 8 View FIGURE 8 , 9 View FIGURE 9

Station: Kanadeep 12-742-03. One specimen (Holotype MNHN P1 About MNHN .PTE 3 – slide A1. 1903) .

Very soft and transparent 23.5 cm long ( Fig. 8A View FIGURE 8 ) the body has the general shape of the genus with the thorax and abdomen included in a single segment followed without a neat constriction by a wide and long peduncle.The anterior part of the body was a little damaged when collected, but most of the internal organs are preserved. The oral aperture opens at the base of the siphon developed into a hood which contains muscular fibres ( Fig. 8B View FIGURE 8 , 9A View FIGURE 9 ). The atrial aperture has eight round lobes above a few circular muscle fibres. No wing-shaped extensions of the tunic were seen associated with the atrial siphon, but the tunic is partly torn at this level.An average of 60 oral tentacles is distributed in two orders of size. The musculature is restricted to the thorax. The muscles are in transverse spaced fibres running from the endostyle to the middle of each body side and shorter transverse fibres are along the dorsal side. The dorsal tubercle opens in a slit. The dorsal lamina comprises pointed languets. The thin branchial tissue ( Fig. 8C View FIGURE 8 ) extends to the posterior end of the body; about 50 longitudinal vessels were counted on the right side with a single stigma per mesh ( Fig. 8C View FIGURE 8 ). The digestive loop is long and straight; it begins with a short oesophagus in continuity with an olive-shaped horizontal stomach sided by two round glandular masses ( Fig. 9C View FIGURE 9 ). The state of the stomach wall does not allow seeing if it has ridges. The intestine ends in a smooth-edged anus ( Fig. 9B View FIGURE 9 ) The gonad is totally different from those described for P. longa ( Van Name, 1918) . In the present specimen the gonad is hermaphrodite in a single organ, parallel to the intestine but not adherent to it ( Fig. 9C View FIGURE 9 ). It begins in the bottom of the gut loop and extends parallel to the intestine up to the base of the atrial siphon. Several groups of testis vesicles( Fig. 9D View FIGURE 9 ) are applied along the axis of the long tubular ovary. The sperm duct issuing from each group of testis lobes connects to a common sperm duct running along the length of the ovary ending in four genital papillae. In Pterygascidia kanakae sp.nov. male and female elements are associated in a single gland and represent a different organisation from the status described by several authors for Pterygascidia longa ( Van name 1918; Millar 1963; Tokioka 1971a, 1971b; Monniot & Monniot 2003 Figs 3A View FIGURE 3 , 4B View FIGURE ; Kott 2008). In P. longa the testis vesicles are spread along a large part of the intestine wall, the common sperm duct emerges in the bottom of the gut loop to join the base of the tubular ovary and remains applied to the ovary passing the female papilla and ending in a single male papilla.

Kott (2008) established the synonymy of the genera Pterygascidia Sluiter, 1904 and Ciallusia Van Name, 1918 , a status generally accepted. Concerning the species, a doubt about the synonymy of P. mirabilis Sluiter, 1904 and P. longa remains, especially that of Tokioka (1971b) who re-examined Sluiter’s material, the descriptions of the tunic extensions are slightly different.

MNHN

Museum National d'Histoire Naturelle

Kingdom

Animalia

Phylum

Chordata

Class

Ascidiacea

Order

Enterogona

Family

Agneziidae

Genus

Pterygascidia

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