Klugerella olasoi, Garciâa Goâmez, 2000

Garciâa Goâmez, C. M. Loâpez De La Cuadra J. C., 2000, The Cheilostomate Bryozoa (Bryozoa: Cheilostomatida) collected by the Spanish`AntaÂrtida 8611 ’ Expedition to the Scotia Arc and South Shetland Islands, Journal of Natural History 34, pp. 755-772 : 763-765

Klugerella olasoi n. sp.

(®gures 9±11)

Material

HOLOTYPE:` AntaÂrtida 8611’ st. 167 ( South Georgia). One colony, fragmented, 5 mm diameter. MNCN 25.03 /1902.

Material of other species examined for comparison

Klugerella aragoi (Audouin) n. comb.: BMNH 1965.8.6.2. Florida. Material examined and ®gured by Cook (1967).

Klugerella magni ®ca (Thornely): holotype, BMNH 1936.12 .30.171. Cargados (Indian Ocean) .

Klugerella marcusi (Cook) n. comb.: Tarifa ( Spain), Straits of Gibraltar. Collection of the authors.

Membraniporella nitida (Johnston) : Tarifa ( Spain), Straits of Gibraltar. Collection of the authors.

Description

Colony encrusting unilaminar. Autozooids oval in shape. Zooidal dimensions are given in table 3. Narrow gymnocyst. Frontal shield of 9±11 costae, branching once or twice, conūent and crossing medially. The distalmost pair is wider than the remaining costae, a feature which is more pronounced at the base of the costae. Ori®ce D-shaped, with chitinized operculum. Two oral spines, long (approximately the length of a zooid) and laterally ¯attened, not branching, with chitinous bases. Interzooidal communication through uniporous mural septula. Ovicell and avicularia not found.

Discussion

The genus Klugerella Moyano was proposed for several species formerly included in Membraniporella Hincks ( Moyano, 1991) . These species have costae generally branching, uniporous mural pore chambers and ovicells with a triangular or crescentic frontal area of uncalci®ed ectooecium. Klugerella olasoi n. sp. shows the two former features (®gures 9±11), but the ovicell has not been found. The presence of two oral spines as long as the zooid (®gure 10) distinguishes K. olasoi from all other species included in the genus, and particularly from its geographical neighbour K. antarctica (Kluge) , type species of Klugerella , which has two or four short oral spines often branching. The frontal shield is also diOEerent in both species: K. olasoi has 9±11 costae crossing but not fusing in the median line (®gures 9, 10), of which the distal pair is wider at the base than the remaining costae; K. antarctica has more costae [13±21 after Moyano (1991), 16±20 after Hayward (1995)], fusing at the median line and all of them equivalent in width.

Moyano (1991) included in Klugerella , together with K. antarctica , three species previously attributed to Membraniporella : M. magni ®ca Thornely (®gure 12), from the Indian Ocean, only known by the type material and not previously ®gured by SEM; M. bifurca Powell and M. gordoni Moyano , from the Paci®c Ocean. There are two Atlantic species currently included in Membraniporella that are better placed in Klugerella : Flustra aragoi Audouin (®gure 13) and Membraniporella marcusi Cook (®gure 14). Both Klugerella aragoi n. comb. and Klugerella marcusi n. comb. show the diagnostic characters of Klugerella , described above, thus being very diOEerent from Membraniporella nitida (Johnston) (®gure 15), type species of Membraniporella Hincks , in which costae do not branch, and which has basal multiporous chambers, ovicells with membranous ectooecium, except for a calci®ed basal rim, and small adventitious avicularia, all of these features lacking in any species of Klugerella . The presence of avicularia is variable in Klugerella , but when present (they are known in K. antarctica , K. bifurca and K. gordoni ) they are vicarious, similar to an autozooid but with enlarged operculum, and never small, adventitious like those of Membraniporella nitida . Although the diOEerences between Klugerella and Membraniporella have been previously established ( Moyano, 1991; Hayward, 1995), SEM micrographs of M. nitida together with some species of Klugerella are included for a better comparison. The attribution of Klugerella aragoi and Klugerella marcusi to this genus extends considerably its known distribution ( Moyano, 1996), to the northern hemisphere and even to European coasts, where K. marcusi has been found (LoÂpez de la Cuadra and GarcõÂa GoÂmez, 1993). A revision of other supposed species of Membraniporella is necessary, such as those described by Osburn (1950), M. crassicosta , M. aragoi var. paci ®ca (probably not conspeci®c with Klugerella aragoi ) and M. pulchra . Although specimens have not been examined during this study, the very detailed ®gures of Osburn (1950) show features which indicate that these species are probably not congeneric with M. nitida , but similar to Klugerella .

Etymology: olasoi refers to Ignacio Olaso, member of the`AntaÂrtida 8611’ and BENTART 95 Expeditions and Chief of the BENTART 94 Expedition, in recognition of his contribution to Spanish research in Antarctica.