Cribellopora connata ( Ortmann, 1890 )

Arakawa, Shinji, 2024, Descriptions of Three Cheilostomatid Bryozoan Species from the Continental Shelf off Boso Peninsula, Japan, Species Diversity 29 (1), pp. 99-110 : 102

Cribellopora connata ( Ortmann, 1890)

( Figs 3B–F , 4A, B )

Hippothoa connata Ortmann, 1890: 52 , pl. 4, fig. 7.

Cribellopora connata : Arakawa 1999: 78, pl. 9, fig. F; Arakawa 2020b: 55.

Rogicka connata : Hirose 2010: 113, pl. 193, figs A–F.

Material examined. NMNS PA 20501 (uncoated colony on molluscan shell), 20502 [colony on molluscan shell, with Micropora plana Arakawa, 2016 ( NMNS PA 16836) and Monoporella projecta Arakawa, 2020 ( NMNS PA 18452)], 20503 (single zooids A–C), Station 1734, R / V Hakurei-Maru cruise GH-80-2. NMNS PA 20504 (a single ovicellate zooid), 20505 (single zooids A, B), Station 1746, R / V Hakurei-Maru cruise GH-80-2.

Measurements (in mm). NMNS PA 20501, 20503– 20505. Autozooids (12, 7): ZL, 1.03–1.18 (1.096 ±0.051); ZW, 0.71–0.84 (0.791 ± 0.047); OrL, 0.13–0.18 (0.153 ± 0.016); OrW, 0.17–0.21 (0.182 ± 0.015).

Description. Colony encrusting, uniserial ( Fig. 3B, C ). Zooids oval, with communication pores at proximal and distal ends, and two or three on each side ( Fig. 4B ). Frontal shield much inflated, uniformly covered with small cribellate pseudopores; median imperforate area lacking. Orifice raised somewhat above frontal shield, semicircular, with rounded-v-shaped sinus and thick, grooved condyles ( Fig. 3E, F ); larger in ovicellate than non-ovicellate autozooids ( Fig. 4A ). Four stout oral spines present. Avicularia lacking. Ovicell globular, wider than long (0.403 mm long, 0.497 mm wide); ooecium completely covered with cribellate pseudopores ( Fig. 4A ). Ancestrula occluded with kenozooidal calcification (regenerated); a pair of daughter zooids budded ( Fig. 3D ).

Distribution. Sagami Bay, depth 370 m ( Ortmann 1890); Fukuura, western Sagami Bay, depth 150 m ( Hirose 2010); east of Boso Peninsula, depths 154 and 155 m (this study).

Remarks. The specimens from Sagami Bay ( Ortmann 1890; Hirose 2010) have three oral spines, but this may represent intraspecific variation, because all other characters are as in my material. Although Hirose (2010) placed this species in Rogicka Uttley and Bullivant, 1972 , based on the cribellate pseudopores and the presence of oral spines, these characters are also observed in Cribellopora . Rogicka differs from Cribellopora in having numerous close-set spines ( Gordon 1984).

Among Recent species of Cribellopora , C. siri Gordon, 1989 from New Zealand and C. constellata Winston, 2005 from Florida resemble C. connata in the small frontal pseudopores. However, the former has an imperforate ovicell with small marginal pores, and the latter has stellate (not cribellate) pseudopores and an imperforate ovicell ( Table 1). Ovicells evenly perforated by pseudopores as in C. connata have been illustrated for C. trichotoma by Cook (1985), “ Schizoporella trichotoma ” by Osburn (1952), and Schizoporella pulchra Neviani, 1895 (see Cook 1968).

Hirose (2010) reported another Cribellopora from Sagami Bay as C. trichotoma , based on the description of that species from New Zealand by Gordon (1984). Hirose’s comparison is correct, but Gordon (1989) revised that species to C. divisopora ( Waters, 1887) , thus extending the known distribution of C. divisopora to Japan.

Figures

Fig. 3. Tessaradoma japonicum sp. nov. (A) and Cribellopora connata (Ortmann, 1890) (B–F). A, Inner surface of frontal wall, paratype, NMNS PA 20500; B, colony on molluscan shell, uncoated specimen, NMNS PA 20501; C, colony with ancestrula, NMNS PA 20502 (arrow, zooid enlarged in E); D, ancestrula in C; E, zooid indicated by arrow in C; F, orifice, NMNS PA 20503B. Scale bars: A, E, 200µm; B, 1mm; C, 500µm; D, 100µm; F, 50µm.

Fig. 4. Cribellopora connata (Ortmann, 1890) (A, B) and Hippomenella (?) coronula (Ortmann, 1890) (C–E). A, Ovicell and orifice, NMNS PA 20504; B, oblique view of zooid; arrows, three lateral communication pores, NMNS PA 20503B; C, single zooid with large avicularium, NMNS PA 20506B; D, single zooid, with relatively broad median imperforate area, NMNS PA 20506C; E, largest specimen, NMNS PA 20506A.Scale bars: A, B, 100µm; C–E, 200µm.