Hippaliosina setiformis Tilbrook, 2006

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 : 507-509

Hippaliosina setiformis Tilbrook, 2006

( Fig. 28 )

Hippaliosina setiformis Tilbrook, 2006: 271 , pl. 60C–F.

Material examined. Seven colonies (NIBRIV0000805891, MBRBKW17–22), Munseom Island , Jeju, 20 m, collected by Ho Jin Yang.

Description. Colony encrusting, multiserial, unilaminar, pale creamy-orange, up to 16 mm across. Autozooids more or less elongate-rectangular, often narrower proximally. Frontal shield non-pseudoporous with up to 26 areolar-septular pores around zooidal margin; 6–13 on each lateral margin, 5–8 distally or not apparent at all. Shield surface evenly coarsely granular. Orifice semi-cleithridiate, with high-arched anter separated from poster by stout, angular condyles; poster a broad rounded-V shape, shaped like round cleaver or more angular, sometimes wider than anter. Usually small narrow area of frontal wall distal to orifice. No oral spines.

Avicularia lateral to anter, always paired, inclined obliquely toward distal arch of anter; sides of rostrum raised, elongate-triangular, tip rounded, no crossbar, just angular pivots, with smooth, descending opesial cryptocyst. Occasionally an avicularium replaced by much larger, more-elongate avicularium with expanded cystid that is angled, rarely slightly curving, past orifice; zooids bearing enlarged avicularia wider than normal. Gymnocystal margins of avicularia continuous with smooth peristomial rim.

Female zooids dimorphic, with much broader, angular poster; ovicell concealed, but frontal area above ovicell larger than in ordinary autozooids

Ancestrula not seen.

Measurements. ZL 303–479 (400) µm; ZW 179–296 (261) µm; OrL 80–108 (94) µm; OrW 49–70 (62) µm; ♀ OrL 87–108 (98) µm; ♀ OrW 58–76 (68) µm; AvL 85–270 (135) µm; AvW 33–81 (50) µm.

Remarks. Our material accords in all respects with the unique characteristics described by Tilbrook (2006) in material from western New Guinea and the islands of Flores and Halmahera. It also had dimorphic orifices and two sizes of avicularia on autozooids.

Distribution. Indonesia: Lesser Sunda Islands, Maluku (Molucca) Islands West Papua. Korea: Jeju Island.

Depth range 0–45 m.

Figures

FIGURE 28. Hippaliosina setiformis Tilbrook, 2006, Munseom Island, showing, at centre, a female zooid (♀) with enlarged orifice and ooecium, surrounded by autozooids with two types of avicularia. FIGURES 29–31. Torquatella imperforata n. sp., holotype, Munseom Island. 29, ovicellate and non-ovicellate zooids from colony margin to colony center; 30, autozooid at colony margin and ooecium of proximal zooid; 31, two orifices, each with an intraperistomial avicularium. FIGURE 32. Stephanollona boreopacifica n. sp., holotype, Munseom Island, showing a six-spined autozooidal orifice (right), ovicellate orifices and two types of adventitious avicularia. Scale bars: 28, 500 µm; 29, 400 µm; 30, 31, 100 µm; 32, 300 µm.