Cauloramphus spinifer ( Johnston, 1832 )

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 : 1083-1085

Cauloramphus spinifer ( Johnston, 1832)

( Figure 13 ) Flustra spinifera Johnston 1832, p 266 , Plate 9, Figure 6 . Cauloramphus spinifer: Osburn 1950, p 55 , Plate 5, Figure 9 ; Mawatari 1956, p 118,

Figure 4a ; Androsova 1958, p 106, Figure 15 ; Kluge 1962, p 295, Figure 179; 1975, p 353, Figure 179; Gontar 1980, p 6; Mawatari and Mawatari 1981a, p 43, Figure 10 ; 1981b, p 44; Dick and Ross 1986, p 89; Grischenko 1997, p 162; 2004, p 40; Hayward and Ryland 1998, p 172, Figure 48.

Cauloramphus spinifera: Kubanin 1997, p 121 .

Cauloramphus spinifer: Dick and Ross 1988, p 39 , Plates 2D, E, 13D.

Not Cauloramphus spinifer: Kubota and Mawatari 1985a, p 80 , Figure 5 .

Material examined

ANC, colony on rock (NHM 2006.2.27.13); KAI, ancestrular colony on rock (NHM 2006.2.27.17), colony on rock (NHM 2006.2.27.38), colony on rock (NHM 2006.2.27.41); BAC, two colony fragments (NHM 2006.2.27.18). Additional material: 855 specimens .

Description

Colony unilaminar, encrusting, coherent, more or less circular, up to 2.5 cm across, light tan in colour when alive. Zooids ( Figure 13A–D ) elongate-oval to irregularly hexagonal, 0.47–0.68 mm long (0.56¡ 0.05 mm), 0.30–0.40 mm wide (0.33¡ 0.03 mm), closely set, separated by a fine groove. Mural rim ( Figure 13C ) slightly raised; cryptocyst relatively narrow, sloping, granulated; distal and lateral gymnocyst reduced or lacking; proximal gymnocyst narrow or tapering back between adjacent zooids, smooth, distinct from granulated mural rim. Opesia ( Figure 13C ) oval, commonly widest in middle, sometimes proximally, 0.35–0.43 mm long (0.40¡ 0.03 mm), 0.18–0.25 mm wide (0.22¡ 0.02 mm), with crenulate outline, occupying 80–90% of zooidal length. Around mural rim, 8–13 spines; three (rarely two or four) orificial spines orientated vertically, one in midline and one to each side of orifice, slightly blunter, thicker but not longer than opesial spines; 5–10 opesial spines slightly thinner, more acuminate, angling over opesia; sometimes most proximal spine vertically orientated, thicker, longer, blunter even than distal spines. Avicularia ( Figure 13A, B ) usually paired, sometimes single or lacking on a zooid, arising from distolateral gymnocyst between orificial and opesial spines, in line with proximal edge of orifice; peduncle short, with expanded portion comprising most of the avicularium; about as long as proximal spines, typically turned inward and angled over opesia, with rostral plane facing proximomedially; mandible elongate-triangular, with hooked tip. Embryos brooded endozooidally; fertile zooids have a smooth, moderately well-developed kenozooidal ooecium ( Figure 13C ) comprising the sharp mural rim distal to the orifice. Six pore chambers in each lateral wall and two in distal wall. Ancestrula ( Figure 13D ) tatiform, oval, with fully calcified basal wall, 0.34 mm long by 0.26 mm wide; oval opesia 0.25 mm long by 0.18 mm wide; 12 spines around opesial margin, three distal pairs straight and vertical, six proximal spines thin, curved over opesia; ancestrula buds triplet of small zooids distally and distolaterally, each with 10 or 11 spines.

Remarks

Dick and Ross (1988) discussed diagnostic characters and geographic variation in spine number for C. spinifer .

Distribution

This is a circumboreal species extending into the Arctic. In the eastern Atlantic, it is widely distributed in cool-temperate waters, from the White Sea ( Gostilovskaya 1978) and Barents Sea ( Kluge 1962) southward to the Shetland Isles and northern coast of France. In the eastern Pacific, C. spinifer is known from Kodiak Island, Gulf of Alaska; previous records from farther south need to be re-examined ( Dick and Ross 1988). In the western Pacific it has been reported from the Gulf of Anadyr and the vicinity of St Lawrence Island in the Bering Sea; Commander Islands; Sea of Okhotsk; Kuril Islands; Sakhalin Island; and Primorye and Gulf of Peter the Great in the northern Sea of Japan ( Gontar 1980; Kubanin 1997; Grischenko 1997, 2004). From Japan, C. spinifer is known from the Pacific coast of Hokkaido, including Akkeshi, Kushiro, Mori, Muroran, and Shirikishinai, southward to middle Honshu ( Mawatari and Mawatari 1981a, 1981b). We have determined material from Oshoro Bay, western coast of Hokkaido, Sea of Japan, identified by Kubota and Mawatari (1985a) as C. spinifer , actually to be C. magnus .

Figures

Figure 4. Electra arctica Borg, 1931. ZIRAS 36/50535. Colony on rock collected by A. V. Grischenko, 12 September 1992, Sea of Okhotsk, western Kamchatka shelf (57°36.039N, 156°9.009E), depth 78–81 m. (A) Portion of colony showing anastomosing, narrowly multiserial branches; (B) autozooids and kenozooids; (C) enlargement of autozooids and kenozooids; (D) autozooids with operculum in place and kenozooids with nearly completely closed aperture. Specimen lightly bleached. Scale bars: 2 mm (A); 1 mm (B); 0.5 mm (C, D).

Figure 5. Electra asiatica n. sp. (A, G) NHM 2006.2.27.19; (B) NHM 2006.2.27.20; (C, D) NHM 2006.2.27.21; (E, F) NHM 2006.2.27.24. Colony from Ptichiy Island, Sea of Okhotsk (H). (A, B) Colonies radiating in coherent, fan-shaped lobes from the point of origin, unbleached; (C) colony margin with developing zooids, unbleached; (D) astogenetically mature zooids, unbleached; (E) astogenetically mature zooids, bleached; (F) astogenetically mature zooids with a small interzooidal kenozooid (lower right quadrant), bleached; (G) ancestrula and periancestrular zooids; enlargement of ancestrular area seen in panel (A), unbleached; (H) astogenetically mature zooids, bleached. Scale bars: 2 mm (A, B); 0.5 mm (C–H).

Figure 6. Conopeum nakanosum n. sp. (A, F) NHM 2006.2.27.26; (B, D) NHM 2006.2.27.27; (C, E) NHM 2006.2.27.25; (G, H) NHM 2006.2.27.28. (A) Colony margin with differentiating zooids, bleached; (B) zooids with developing angular cone-shaped kenozooids, bleached; (C) mature zooids with erect and curved spines, unbleached; (D) group of mature zooids with granulated cryptocyst, bleached; (E) distally facing triangular avicularia replacing kenozooids, unbleached; (F) distal view of kenozooids, bleached; (G) lateral view of zooids showing multiporous septula, bleached; (H) interior of distal zooidal wall showing developing angular kenozooids and also multiporous septula, bleached. Scale bars: 0.5 mm (A, G); 1 mm (B–D); 0.2 mm (E, F, H).

Figure 9. Cauloramphus cryptoarmatus n. sp. (A, C, E) NHM 2006.2.27.14; (B, F) NHM 2006.2.27.31; (D) NHM 2006.2.27.13. (A) Colony margin with developing zooids, unbleached; (B) zooids at colony margin in interaction with Cribrilina annulata, showing numerous additional avicularia developing along vertical walls from pore chambers, bleached; (C) autozooids, unbleached; (D) autozooids, showing strongly developed granulated cryptocyst, bleached; (E) two zooids showing details of avicularia and spines, unbleached; (F) ancestrula surrounded by periancestrular zooids, bleached. Scale bars: 0.5 mm (A–D, F); 0.4 mm (E).

Figure 10. Cauloramphus magnus Dick and Ross, 1988. (A, C, D) NHM 2006.2.27.33–34; (B) NHM 2006.2.27.54; (E) NHM 2006.2.27.35; (F) NHM 2006.2.27.32. (A) Colony margin with developing zooids, unbleached; (B) same, bleached; (C) autozooids, unbleached; (D) close up of autozooids showing details of avicularia and spines, unbleached; (E) autozooids, bleached; (F) ancestrula and periancestrular zooids, bleached. Scale bars: 0.5 mm (A–C, E, F); 0.4 mm (D).

Figure 13. Cauloramphus spinifer (Johnston, 1832). (A) NHM 2006.2.27.38; (B) NHM 2006.2.27.41; (C) NHM 2006.2.27.18; (D) NHM 2006.2.27.17. (A) Group of autozooids, unbleached; (B) distal half of zooid, showing avicularia, unbleached; (C) autozooids, bleached; (D) ancestrula and periancestrular zooids, bleached. Scale bars: 0.5 mm (A, C, D); 0.1 mm (B).

Figure 15. Tegella arctica (d’Orbigny, 1851). (A, C) NHM 2006.2.27.44; (B) NHM 2006.2.27.46; (D) NHM 2006.2.27.43. (A) General view of group of autozooids, unbleached; (B) zooids from region near colony margin, bleached; (C) immature zooids with small paired angular and large frontal avicularia, unbleached; (D) mature zooids with ovicells and associated frontal avicularia, unbleached. Scale bars: 1 mm (A); 0.5 mm (B, C); 0.4 mm (D).