CALLOPORIDAE Norman, 1903

Grischenko, Andrei V., Dick, Matthew H. & Mawatari, Shunsuke F., 2007, Diversity and taxonomy of intertidal Bryozoa (Cheilostomata) at Akkeshi Bay, Hokkaido, Japan, Journal of Natural History 41 (17 - 20), pp. 1047-1161 : 1070-1072

Family CALLOPORIDAE Norman, 1903

Genus Callopora Gray, 1848

Callopora craticula ( Alder, 1856)

( Figure 7 ) Membranipora craticula Alder 1856, p 144 , Plate 8, Figure 3 . Callopora craticula: Osburn 1950, p 67 , Plate 6, Figure 7 ; Androsova 1958, p 96, Figure 7 ;

Kluge 1962, p 288, Figure 171; 1975, p 344, Figure 171; Gontar 1979, p 235; 1980, p 5;

Mawatari and Mawatari 1980, p 40, Figure 8 ; 1981b, p 45; Dick and Ross 1988, p 33,

Plate 1C; Kubanin 1997, p 121; Grischenko 1997, p 160; 2002, p 113; Hayward and

Ryland 1998, p 164, Figure 42, C; Dick et al. 2005, p 3696, Figure 2A–D .

Material examined

ANC, colony encrusting erect bryozoan Phidolopora elongata (NHM 2006.2.27.29); ACT, colony encrusting erect bryozoan Phidolopora elongata (NHM 2006.2.27.30). Additional material: one specimen.

Description

Colony encrusting, unilaminar, multiserial, more or less circular, small, less than 1 cm across, whitish to yellowish in colour when alive. Zooids ( Figure 7A–D ) elongate-oval, broadest in middle, narrowing proximally, 0.30–0.45 mm long (0.35¡ 0.04 mm), 0.15–0.25 mm wide (0.20¡ 0.02 mm), separated by deep grooves. Mural rim raised, sharp. Cryptocyst a narrow, smooth, sloping shelf inside marginal rim. Opesia oval, often widest proximally, 0.16– 0.21 mm long (0.18¡ 0.02 mm), 0.09–0.14 mm wide (0.11¡ 0.01 mm), 60–70% of zooidal length. Gymnocyst smooth, laterally narrow and sloping, proximally smooth, extensive, tapering, occupying up to 30–40% of zooid length. Spines 12–16 around mural rim; distal three pairs hollow, longer, and vertical; proximal 6–10 spines thinner, acuminate, arched over opesia, converging at or near midline, becoming progressively shorter toward proximal end of zooid. Frontal avicularia with raised chamber on proximal gymnocyst, close to opesial margin, often abutting ovicell of preceding zooid; avicularian chamber with nearly vertical sides, crossbar complete, mandible long-triangular, usually pointing distally or distolaterally if preceded by ovicell, laterally or proximally if not. Vicarious avicularia ( Figure 7D ) occur sporadically; almost as large as autozooids, with raised, acute, long-triangular mandible pointing distally. Ovicells ( Figure 7A, C ) hyperstomial, prominent, globular, imperforate, 0.09–0.14 mm long (0.11¡ 0.02 mm), 0.12–0.16 mm wide (0.14¡ 0.01 mm), with a decurved transverse ridge across top marking proximal extent of ectooecium, separated from proximal ooecial margin by a lunate or quadrate area. Four pore chambers in each lateral wall and three or four single pores in distal wall. Ancestrula not observed.

Distribution

This is a circumpolar, Arctic-Boreal species. Gontar and Denisenko (1989) summarized numerous previous records from the Arctic. In the eastern Atlantic, C. craticula extends southward to Scotland and northern England in Britain ( Hayward and Ryland 1998), but its occurrence in the western Atlantic is uncertain ( Winston et al. 2000). In the eastern Pacific it extends as far south as Ketchikan ( Dick et al. 2005). In the western Pacific, it has been recorded from Saint Lawrence Island, Avacha Inlet ( Kluge 1961), Commander Islands ( Grischenko 1997, 2004), Sea of Okhotsk, Kuril Islands ( Gontar 1980), northern Sea of Japan along Primorye and western Sakhalin Islands ( Androsova 1958), and from Kushiro, Akkeshi, and Hakodate on Hokkaido, northern Japan ( Mawatari and Mawatari 1980, 1981b).

Figures

Figure 2. Dendrogram (below) showing similarity of sampling localities based on species presence/absence, and a map (above) showing the geographical distribution of three groups of sampling localities (circled) that are less than 70% similar in species composition between groups.

Figure 3. Electra korobokkura Nikulina, 2006. (A–C) NHM 2006.2.27.1; (D) NHM 2006.2.27.2. (A) Colony fragment with uniserial branches; (B) colony fragment with anastomosing, multiserial branches; (C) zooids without spinous processes; (D) zooids with spinous processes. All unbleached. Scale bars: 2 mm (A, B); 1 mm (C); 0.5 mm (D).

Figure 7. Callopora craticula (Alder, 1856). NHM 2006.2.27.29. (A) General view of colony fragment, unbleached; (B) immature zooids near colony margin, unbleached; (C) mature zooids showing ovicells and associated avicularia, unbleached; (D) group of immature zooids and vicarious avicularium on right, unbleached. Scale bars: 0.5 mm (A); 0.2 mm (B–D).

Figure 8. Callopora sarae n. sp. (A, E) NHM 2006.2.27.5; (B) NHM 2006.2.27.3; (C, D, F) NHM 2006.2.27.4. (A) Zooids at colony edge, unbleached; (B) immature zooids with spines, lateral and proximal avicularia, unbleached; (C) immature zooids, showing bases of spines and lateral avicularia, bleached; (D) two immature zooids showing bases of additional spines on outer distolateral gymnocyst, bleached; (E) mature zooids with ovicells and associated avicularia, unbleached; (F) mature zooids with heavily calcified ovicells, bleached. Scale bars: 0.5 mm (A–C, E, F); 0.4 mm (D).