Catenicella glabrosa, Branch & Hayward, 2005

Branch, M. L. & Hayward, P. J., 2005, New species of cheilostomatous Bryozoa from subantarctic Marion and Prince Edward Islands, Journal of Natural History 39 (29), pp. 2671-2704 : 2686-2687

Catenicella glabrosa sp. nov.

( Figure 7 B–E)

Material

Holotype: St. 45 Marion Island (47 ° 00 9 S, 37 ° 55 9 E), 420–540 m, SAM A27556 . Paratype: St. 53 Marion Island (46 ° 55 9 S, 37 ° 33 9 E), 606–775 m, SAM A27087 .

Other material. St. 54 Marion Island (46 ° 55 9 S, 37 ° 35 9 E), 70–135 m, SAM A27061 .

Description

Colony erect, branching, jointed, up to 10 mm or more high. Sterile internodes consist of a single, slender autozooid, 0.85X 0.28 mm; dichotomous branching occurs at bizooidal internodes, the disto-lateral autozooid slightly narrower than the other autozooids; fertile internodes subterminal, bizooidal, the proximal zooid short and broad, the ovicell as long as the zooid, occupying most of the frontal surface of the distal zooid. Frontal shield smoothly calcified, imperforate; each zooid with a pair of narrow and elongate, curving, lateral pore chambers (vittae), extending from just distal to the node, to level with the orifice, each with a single line of pores. Primary orifice D-shaped, as wide as long, 0.12 mm; proximal border formed by an inconspicuous pair of residual costae, with a single minute pore medioproximally; condyles not apparent. Distolateral corners of single autozooids each with a small avicularium, with obtuse-triangular rostrum, 0.03 mm long, distally directed. A small (suprascapular?) chamber apparent distal to the avicularium in single autozooids; presence or absence of a (subscapular) chamber proximal to it not established. Originating autozooids at a dichotomy with a single avicularium; ovicell-bearing zooids with a pair of short, cylindrical disto-lateral processes (damaged in all specimens). Ovicell as long as wide, smoothly calcified, imperforate but with indistinct, longitudinal frontal striations.

Etymology

Latin, glaber, smooth, with reference to the calcification of the zooids.

Remarks

The generic assignment of this species is only provisional. Its slender autozooids, with narrow, elongate vittae and short disto-lateral processes, are similar to those of many species of Catenicella . However, the ovicell of C. glabrosa differs from those of other described species of the genus in its smooth, imperforate ectooecial calcification. The apparent lack of condyles is also unusual for a species of Catenicella . Taliυittaticella Gordon and d’Hondt, 1985 is characterized by a very reduced costate frontal shield, visible as three to five minute costae, closely fused just proximal to the primary orifice, and by subterminal, bizooidal fertile internodes. SEM reveals a single pair of much reduced costae constituting the proximal edge of the primary orifice in C. glabrosa sp. nov., and the bizooidal fertile internodes are also similar to those seen in Taliυittaticella. However, the ovicell of Taliυittaticella, in those species in which it is known, typically has an uncalcified portion of ectooecium frontally, and the vittae are broad and shallow, with very few pores. Unfortunately, much of the material available for study is damaged; details of the morphology of the distolateral chambers and avicularia are unclear, and confident generic assigment must await the collection of better, more extensive material.

Figures

Figure 7. (A) Taliυittaticella frigida, SAM A27058, autozooid, X110. (B–E) Catenicella glabrosa sp. nov., SAM A27556: (B) autozooid and ovicelled autozooid, X80; (C) autozooid, X100; (D) portion of colony showing internodes, X40; (E) detail of avicularium, X300.