Gregarinidra serrata ( MacGillivray, 1869 )

Chae, Hyun Sook, Kil, Hyun Jong & Seo, Ji Eun, 2016, Taxonomic study on bryozoans - new additions to the Korean fauna and new species of Petraliella from Seogwipo waters of Jeju Island, Journal of Species Research 5 (3), pp. 551-565 : 554

** 10. Gregarinidra serrata ( MacGillivray, 1869) ḃŋŘŦŋÑnjḇNj (신ḡ) ( Fig. 3 )

Membranipora serrata MacGillivray, 1869: 131 .

Spiralaia spinuligera : Okada and Mawatari, 1936: 53.

Spiralaia serrata : Silén, 1941: 57; Mawatari, 1952: 272; 1965: 599.

Hippoflustra serrata : Mawatari and Mawatari, 1979: 35.

Gregarinidra serrata : Gordon, 1984: 25; 1986: 28.

Material examined. NIBRIV0000325943, Geomeunyeo (underwater cave), 7 Jan. 2011 (B.S. Min; H.J. Yang) by SCUBA diving .

Substratum. Gastropod shells, rocks and sponges.

Description. Colony encrusting. Zooids ( Fig. 3A ) arranged very vertically, no cryptocyst and gymnocyst, bordered by 8­10 pairs of spines along thin mural rims. Marginal spines variable in shape. First distal pair short, erect, and usually bifurcate. Second distal pair larger, ending into 2-3 flame forks, curved towards distal side, overlap or contact at middle line of frontal area ( Fig. 3C ). The rest 6­8 pairs of spines similar to second ones in shape, but slightly rise with small 2­3 spikes and each spines overlapping at middle line of frontal surface. Avicularium ( Fig. 3B ) interzooidal, placed at bifurcation of zooidal row, elongate triangular, directs obliquely and extending between distal zooids. Mandible with hooked end, rostral end serrated, crossbar incomplete. Ovicell internal, occurring beneath proximal end of distal zooid or immersed in avicularium. Communication pores in lateral wall ( Fig. 3D ).

Remarks. The genus Gregarinidra was recorded in the Korean fauna for the first time by Seo(1996). Gregarinidra serrata is easily distinguished from G. corbula by having 10­15 pairs of triangular spines.

Distribution. Korea, Japan, Hauraki Gulf, Auckland Harbours, Foveaux Strait.

Figures

Fig. 3. Gregarinidra serrata (MacGillivray, 1869). A. zooids. B. avicularium. C. shape of spines. D. lateral wall. Scale bars: 100 μm (A­D).