Puellina harmeri ( Ristedt, 1985 )

Yang, Ho Jin, Seo, Ji Eun, Min, Bum Sik, Grischenko, Andrei V. & Gordon, Dennis P., 2018, Cribrilinidae (Bryozoa: Cheilostomata) of Korea, Zootaxa 4377 (2), pp. 216-234 : 229-231

Puellina harmeri ( Ristedt, 1985)

(Figs 36–38)

Cribrilaria harmeri Ristedt, 1985: 26 , figs 1, 6–9; Hayward 1988: 290, pl. 3c; Scholz 1991: 287, pl. 6, figs 1, 3–4. Puellina harmeri: Dick et al. 2006: 2213 , fig. 6A, C, E, G; Dick & Grischenko 2017: 170, fig. 9.

Material examined. Jeju Island: Seogwipo (13 colonies).

Description. Colony encrusting, unilaminar, multiserial, up to 13.2 mm across, transparent. Autozooids roundly subhexagonal to suboval. Frontal shield (Figs 36–37) comprising 12–21 pinnate costae including suboral pair (mean 17), each tapering to midline, opposing tips meeting or alternating; 3–5 (mostly four) lacunae between adjacent costae; costal midline smooth, not ridged or peaked. Lateral gymnocyst narrow, slightly more developed proximally or proximolaterally. Orifices dimorphic. Autozooidal orifice transversely D-shaped, highly arched, bordered by 7 articulated oral spines. First pair of costae (orificial bar) with small elevated crest where they meet, with tiny suture or small foramen. Interzooidal avicularia produced from pore-chambers (Fig. 38); rostrum narrowly elongate, its rim smooth or with fine denticulation; small mandibular pivots present, no crossbar. Maternal zooids with subquadrate primary orifice visible at colony margin, longer than wide, at lower level than ooecial orifice; distal rim straight with rounded distolateral corners. Ooecium prominent, smooth-surfaced, with faint creases meeting at peak; ooecial orifice resembling that of ordinary autozooids; 4 oral spines present. Laterooral avicularia of ovicellate zooids entirely adventitious, small-based, not resting on substratum (Fig. 37). Up to four basal pore chambers on each distolateral side of zooids at colony margin, plus distal pore-chambers. Ancestrula not seen.

Measurements. ZL, 277–369 (324) µm; ZW, 190–256 (226) µm; OrL, 40–53 (45) µm; OrW, 53–59 (56) µm; AvL 119–158 (139) µm; AvW 25–34 (30) µm; OoL 85–108 (96) µm; OoW 100–119 (110) µm.

Remarks. The present material accords well with that described by Ristedt (1985) and Dick et al. (2006), one of the distinctive features of the species being the two types of avicularia: interzooidal and budded from autozooids, and adventitious on ovicellate zooids. Another similar seven-spined species discussed by the latter authors is Puellina vulgaris Ryland & Hayward, 1992 —as they pointed out, it is not entirely clear what separates the two species, other, perhaps, than the number of spines on the tatiform ancestrula. Ryland & Hayward (1992) surprisingly did not mention Ristedt’s species so it is possible they overlooked it. Both are accorded a tropical distribution, with P. harmeri from the Philippines, Red Sea and Seychelles ( Ristedt 1985), Mauritius ( Hayward 1988) and Hawaii ( Dick et al. 2006), and P. vulgaris from the Great Barrier Reef ( Ryland & Hayward 1992), Vanuatu ( Tilbrook et al. 2001) and the Solomon Islands ( Tilbrook 2006). For the latter species, the published illustrations and descriptions do not provide enough information to determine if both types of avicularia occur in P. vulgaris , so the question remains open. One other seven-spined species in the tropical western Pacific is Puellina septemspinosa d’Hondt, 1986 from New Caledonia. It has consistently paired adventitious avicularia and fewer frontal-shield costae (10–12) than in P. harmeri .

Distribution. Red Sea, Seychelles, Mauritius, Philippines, Hawaii, South China Sea (Paracel and Spratly Islands), Okinawa, Korea, 0–60 m depth.