Bathypera splendens Michaelsen, 1904

Monniot, Françoise, Dettai, Agnès, Eleaume, Marc, Cruaud, Corinne & Ameziane, Nadia, 2011, Antarctic Ascidians (Tunicata) of the French-Australian survey CEAMARC in Terre Adélie, Zootaxa 2817, pp. 1-54 : 34-42

Bathypera splendens Michaelsen, 1904

( Figures 22 AC, 23A, 24AC)

Michaelsen, 1904: 192. Vinogradova 1962: 205. Kott 1969: 140 figs 192-193 and synonymy; 1971: 64; Monniot & Monniot 1983: 85. Primo & Vazquez 2006: 125.

Stations (events when several trawling operations per station): 2-3-5-6(103)-8-11(424)-21-27(45)-30(66)-34- 36(68)-42-62-65(322)-79.

All specimens have the same spherical shape with a rough surface without wrinkles. The siphon apertures are in a slit and distant from each other ( Fig. 22 C). The surface of fixation is narrow. The tunic is thin entirely covered with dense external calcareous spicules. They are stub-like implanted by a round base; their upper side is divided in spines of equal size ( Fig. 22A ).They are 300 µm in length and 200 µm in diameter on the body, smaller at the siphons. The body wall does not adhere to the tunic. The muscular fibres are regularly criss-crossed, dense on the dorsal body side only ( Fig. 24A , C); the transverse fibres become thinner and shorter toward the ventral side, a part of them does not reach the ventral line ( Fig.24A ) The oral tentacles are long with 3 orders of ramifications. The dorsal tubercle opens anteriorly in a C. The branchial sac is voluminous with 6 high folds on each side. The dorsal lamina is double at the beginning and further it is made of long languets. Between the folds the spiral stigmata are irregular, some under the longitudinal vessels and other between them ( Fig. 23 A). On the sides of the folds the stigmata are straight but spirals can be seen at the top of the folds. The gut occupies the ventral part of the left side ( Fig. 24 C).The oesophagus is narrow, the plicated stomach well delimited. The intestine in a simple loop ends in a rolled up anus with an undulated rim. There is no hepatic gland. One long gonad lies on each side ( Fig. 24 C), the left one inside the gut loop. The male and female ducts open together near the oesophagus. The endocarps, variable in number, are only present in the ventral half of the body, on each side of the right side gonad, on each side of the gut loop and inside the loop ( Fig. 24 C).A ring of round papillae circles the base of the atrial siphon.

All characters of this species are constant and correspond to previous descriptions. They are also the same as those of B. hastaefera except the spicules and a stronger musculature in the later.

One sequence for specimen S2 BAT.B 31 (BOLD: ASCAN031-10). No close hit in BOLD (best: 72.59%).

B. splendens is eurybathic and distributed in the whole Antarctic area.

Culeolus antarcticus Vinogradova, 1962 ( Figure 25 )

Vinogradova, 1962: 207. Monniot & Monniot 1982: 117 and synonymy; Sannamyan & Sanamyan 2002: 342 fig. 24.

Stations: 1 – 32A – 66A.

The largest specimen 9 x 4.5 cm has a peduncle 23 cm long. The tunic is covered with ampullae containing a clear granule. The postero-ventral crest is made of a row of papillae with the same ampullae. The musculature consists in siphonal sphincters and wide spaced ribbons on the whole body ( Fig. 25 B, C). The oral tentacles are large and stout in 3 orders of size. The dorsal tubercle opens in a C to the left. The branchial sac has 6 folds on each side, the formula on the right side of a 4cm specimen is:

E – 2 - 6 – 3 – 8 – 4 – 12 – 4 – 14 – 4 – 6 – 3 – 11 – DL.

The dorsal languets are long. The gut ( Fig. 25 A) forms a double loop: the primary loop is wide and contains the left gonad. The secondary loop at right angle is short. The anus has 2 multilobate lobes ( Fig. 25 A). The hepatic gland covers the stomach. There is one gonad on each side made of successive lobes, 3 or 4 in the left gonad and 5 in the right one ( Fig. 25 A). The genital papillae are short and joined. Spicules are present in all organs but not abundant and thin.

Sequences for specimen S1 CUL 57a (BOLD: ASCAN041-10) and specimen S1 CUL 56a (BOLD: ASCAN040-10) are identical. No close hit in BOLD (best: 80.04%).

This peri Antarctic species has not been often collected. Its habitat is recorded as abyssal, however the CEAMARC specimens are the less deep collected yet with one at 233 m only.

Pyura bouvetensis Michaelsen, 1904 ( Figures 26 , 27 , 28 )

Michaelsen, 1904: 216. Monniot & Monniot 1983: 88 Fig. 18 D, Pl. 6EF and synonymy. Tatian et al 1998: 150. Sanamyan & Sanamyan 2002: 342 Fig. 23 and synonymy.

Station (events when several trawling operations per station): 6(99)-6(103)-10-13A-28-31-32A-33A-34-35- 37(146)-37(147)-50A-51-54A-57-59-60-62-80.

The spherical body is erect above a long stiff peduncle. On the body the tunic is bristling with spines anchored on a bulbous base ( Fig. 26 , 27 A). Much smaller spiny hairs are crowded between the large spines. The tunic on the peduncle shows the same spines but shorter an even reduced to the basal wart. The triangular spinules of the siphon lining ( Fig. 27 B) are different from those of the tunic surface. In Terre Adélie the bodies are 1.5 to 4.2 cm in diameter, the peduncles are often broken, the largest found is 30cm in length. The internal anatomy is very constant. The body wall penetrates into the peduncle along its whole length. There is an oral and a cloacal velum. There are 12 long oral tentacles and 3 orders of smaller ones. The dorsal tubercle opens in a U with horns internally rolled. The edge of the dorsal lamina is dented. The branchial sac ( Fig. 28 B) has 7 high folds on each side, and generally 2 to 3 longitudinal vessels between the folds joining them posteriorly. The parastigmatic vessels are numerous. The digestive loop occupies a large part of the left body side and contains the left gonad ( Fig. 28 A). The anus has a rolled rim and is attached to the oesophagus. The right gonad is long with 5 lobes ( Fig. 28 A). Male and female papillae are close together. Gut and gonads entirely adhere to the body wall. A voluminous round parietal organ lies in the middle of the body on each side ( Fig. 28 A).

Sequences from specimen S2 PYU 457a (370- 365 m depth, BOLD: ASCAN043-10) and specimen S2 PYU 453a (472-483 m depth, BOLD: ASCAN042-10) display 11.79% divergence. Additional specimens and markers are needed to investigate whether this represents an intra- or inter-specific divergence. No close hit in BOLD (best: 88.02% with Pyura georgiana ).

Pyura bouvetensis is eurybathic and circum Antarctic. Very common in Terre Adélie, it is recorded from 200 to 1100 m depth.

Figures

FIGURE 18. Cnemidocarpa acanthifera n. sp. A, C, body ventrally opened, scale bar A = 5 mm; B, neural area.

FIGURE 23. Branchial tissues: A, Bathypera splendens. B, Bathypera hastaefera.

FIGURE 25. Culeolus antarcticus A, body ventrally opened; B, C, musculature on both sides, tunic removed, scale bar = 2 cm.

FIGURE 26. Pyura bouvetensis with broken peduncle, scale bar = 1 cm.

FIGURE 27. Pyura bouvetensis: A, body spinules on the tunic; B, spinules of the internal siphon lining. Scale bars A, B = 100 µm.

FIGURE 28. Pyura bouvetensis: A, body ventrally opened, scale bar = 1 cm; B, branchial sac.

FIGURE 22. A, B, spicules: A, Bathypera splendens; B, Bathypera hastaefera. C, Bathypera splendens; D, Bathypera hastaefera. Scale bars: A, B = 100 µm; C, D = 3 cm.

FIGURE 24. A, B, musculature of the left body side: A, Bathypera splendens; B, Bathypera hastaefera. C, Bathypera splendens, specimen ventrally opened, scale bar C = 1 cm.