Cellaria limbata, 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 : 2275-2276

Cellaria limbata sp. nov

( Figure 8 )

Material

Holotype. NMNH 1154031 : Eltanin cruise 22, station 1555, 60 ◦ 0 4’ to 60 ◦ 08’ S, 35 ◦ 59’ to 36 ◦ 04’ W, 1976–2068 m, 15 January 1966; a single, incomplete internode, 10 mm long.

Paratypes. Eltanin cruise 7, station 480, 58 ◦ 06’ to 58 ◦ 10’ S, 44 ◦ 56’ to 44 ◦ 47’ W, 2800 m, 15 February 1963; 10 fragments, including four bases, largest 4.4 mm long.

Description

Internodes cylindrical, gently curved, to 1.1 mm diameter; none branched. Autozooids arranged in alternating triple whorls, the lateral walls of adjacent autozooids in each whorl in contact, frontal surface of each much broader than long; each bounded by clear sutures. Calcification nodular. Opesia in distal third of autozooid, wider than long, equivalent to about one-quarter frontal length of autozooid, the rim finely crenulated, proximal edge curving in the frontal plane, slightly projecting and notched proximo-laterally on each side, to appear as a distinct lip. Cryptocyst ridge developed as a raised longitudinal oval, arched and projecting just distal to opesia, less pronounced but complete proximally, just distal to proximal edge of frontal shield. Brooding zooids broader distally, the ovicell visible as a low swelling, the distal edge of the cryptocyst ridge incomplete, in its place a simple transversely oval aperture; a slit-shaped foramen within the cryptocyst rim, disto-lateral to opesia, on each side. No avicularia observed.

Measurements

For all measurements, n = 10, mean ± SD: autozooid length 0.68 ± 0.04 mm; autozooid width 0.59 ± 0.05 mm; length cryptocystal ridge 0.52 ± 0.04 mm; width cryptocystal ridge 0.37 ± 0.03 mm; opesia length 0.13 ± 0.005 mm; opesia width 0.17 ± 0.02 mm.

Etymology

Latin, limbatus: bordered, with reference to the distinct boundaries of each autozooid.

Remarks

The material is fragmentary and it is possible that the complete morphology of the species is not represented, and that avicularia may occur. The diversity of Cellaria worldwide and sources of descriptions and figures of southern hemisphere species have been noted above. Comparing C. limbata with those species shows the rather large opesia, with its projecting proximal lip, to be quite characteristic of the new species. A complete, oval, cryptocystal ridge is seen in several other species of the genus, but the regular, almost hexagonal packing of the autozooids is unusual, and another characteristic feature of this species. Finally, the inconspicuous ovicell, with small simple aperture, and the longitudinal lateral slits distal to the opesia in brooding zooids, are seen in no other species.

Figures

Figure 8. Cellaria limbata sp. nov., Holotype. (A) Part of an internode, with an ovicelled zooid; (B) detail of an autozooid. Scale bars: 0.1 mm.