Chaperiopsis auriculata, Hayward & Winston, 2011

Hayward, Peter J. & Winston, Judith E., 2011, Bryozoa collected by the United States Antarctic Research Program: new taxa and new records, Journal of Natural History 45 (37 - 38), pp. 2259-2338 : 2261-2262

Superfamily CALLOPOROIDEA Norman, 1903

Family CHAPERIIDAE Jullien, 1888 Chaperiopsis auriculata sp. nov.

( Figure 1 )

Chaperiopsis patulosa: Hayward and Thorpe, 1988a: 60 , figs 4D,F

not Chaperia patulosa Waters, 1904: 33 , pl. 2, fig. 5

Material

Holotype. Eltanin cruise 9, station 740, 56 ◦ 06’ to 56 ◦ 07’ S, 66 ◦ 19’ to 66 ◦ 30’ W, 494– 384 m, 18 September 1963, a small colony.

Description

Colony unilaminar, encrusting. Autozooids oval, closely juxtaposed, separated by distinct grooves. Opesia oval, wider than long, equivalent to half total autozooid length; bordered by a distinct rim of granular cryptocyst, narrowed adjacent to the proximal spine pair, but as broad distally as proximally; mural rim clearly developed. Occlusor laminae conspicuous, extending on each side for almost whole length of opesia, intersecting distal rim of opesia separately and linked there by a thickened transverse strut. Two pairs of disto-lateral spines, the proximal pair stouter than the distal pair. Smooth gymnocystal calcification visible lateral to opesia; proximal gymnocyst usually obscured by a large, broad-based avicularian cystid, or by ovicell of the preceding autozooid; avicularian rostrum acute to frontal plane, directed laterally or proximolaterally, scaphoid, with the rounded tip upcurved, no crossbar or palate. Ovicell prominent, domed, recumbent on distally succeeding autozooid; ectooecium smooth, with large, triangular frontal foramen, its rim raised and medially peaked, exposing granular entooecium. Most ovicells surmounted by two avicularia, with columnar cystids, which appear to originate by frontal budding from adjacent autozooids; rostrum short, triangular, directed disto-laterally, oblique to frontal plane, reminiscent of a pair of ears.

Measurements

Opesia length (n = 20) 0.23 ± 0.01 mm (mean ± SD); opesia width (n = 20) 0.30 ± 0.01 mm.

Etymology

Latin, auricula: little ears, with reference to the small avicularia surmounting the ovicell.

Remarks

Hayward and Thorpe (1988a) wrongly attributed material from three Discovery stations on the southern Patagonian Shelf to the Antarctic Chaperiopsis patulosa (Waters) . Closer examination of the idiosyncratic drawing of Waters (1904) shows autozooids with four or five slender spines, the proximal pair being distinctly forked, and a short, broad ovicell with a small, transversely oval frontal foramen. Kluge (1914) described, but did not figure, Waters’s species from Wilhelm II Land, while d’Hondt and Redier (1977) listed it from Kerguelen but neither described nor figured it. The specimens described and figured by Hayward (1995) were from the same Patagonian Shelf samples reported by Hayward and Thorpe (1988a), and the Antarctic C. patulosa has not been illustrated since its original description.

Figures

Figure 1. Chaperiopsis auriculata sp. nov., Holotype. (A) Single autozooid; (B) group of ovicelled zooids. Scale bars: 0.1 mm.