Saevitella jejuensis, Yang & Seo & Gordon, 2018

Yang, Ho Jin, Seo, Ji Eun & Gordon, Dennis P., 2018, Sixteen new generic records of Korean Bryozoa from southern coastal waters and Jeju Island, East China Sea: evidence of tropical affinities, Zootaxa 4422 (4), pp. 493-518 : 503

Saevitella jejuensis n. sp.

( Fig. 18 )

Etymology. Alluding to the provenance of the species on the south coast of Jeju Island.

Material examined. Holotype: NIBRIV0000805887, unique colony found at Munseom Island, Seogwipo , Jeju Island, 24 December 2016, 20 m, on oyster shell, collected by Ho Jin Yang.

Description. Colony encrusting, multiserial, unilaminar, up to 23 mm across. Autozooids subhexagonal to subrectangular, longer than wide, margins indicated by thin but distinct suture lines. Lepralioid frontal shield densely and evenly pseudoporous, no granules or tubercles. Orifice subcircular to roundly subquadrate, as wide as long, with no condyles and no distinction between anter and poster, entirely surrounded by smooth, raised peristomial rim. No oral spines. No avicularia.

Ooecium of modest size, somewhat recumbent on distal zooid, as wide as long or a little wider, distally rounded the sides parallel or subparallel, pseudoporous like the frontal shield; proximal margin as smooth and thick as orificial peristome but separated from it at proximolateral corners by thin suture lines. Opening not closed by zooidal operculum.

Ancestrula not seen.

Measurements. ZL 514–717 (645) µm; ZW 246–476 (364) µm; OrL 122–146 (137) µm; OrW 130–165 (149) µm; OoL 169–224 (192) µm; OoW 234–272 (257) µm.

Remarks. Saevitella is a relatively little-known genus, first recognized in the Miocene of Austria ( Bobies 1956), and subsequently in the Miocene of Algeria ( Moissette 1988) and of Borneo ( Di Martino & Taylor 2015). Berning (2012) pointed out that some little-known Italian Pliocene species should also be included in the genus and determined that Recent Lepralia peristomata Waters, 1899 from Madeira belongs to Saevitella, hence the genus ranges to the present day. Saevitella jejuensis n. sp. constitutes the second living species, extending the geographic range of the genus considerably into the northwest Pacific.

Saevitella jejuensis n. sp. closely resembles the type species, Saevitella inermis Bobies, 1956 , in all major characters, i.e. shape of orifice, raised peristome, modest size of ooecium, and absence of spines and avicularia, differing from it in the smaller size and greater density of pseudopores; S. inermis also has a tiny pair of orificial condyles. It differs from S. peristomata in having a thicker, less sinuate peristome.

Distribution. Korea: Seogwipo, Jeju Island, 20 m depth.

Figures

FIGURE 18. Saevitella jejuensis n. sp., holotype, Munseom Island, showing an autozooid and ovicellate orifices. FIGURES 19–21. Bryopesanser ascendosolaris Tilbrook, 2006, Munseom Island. 19, ovicellate zooid; 20, autozooid and two ovicellate orifices; 21, articular ridges and orificial sinus. FIGURE 22. Jodoella koreensis n. gen. et sp., holotype, Jodo Island, showing autozooids. Scale bars: 18–20, 300 µm; 21, 20 µm; 22, 200 µm.