Raymondcia rigida ( Lorenz, 1886 ) Grischenko & Dick & Mawatari, 2007

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 : 1108-1110

Raymondcia rigida ( Lorenz, 1886) , new combination

( Figure 24 )

Smittina rigida Lorenz 1886, p 91 (9), t 7, Figures 8, 8a .

Smittina rigida: Androsova 1958, p 152 , Figure 80; Kluge 1961, p 137; 1962, p 429, Figure 280; 1975, p 520, Figure 280; Gontar 1980, p 9; Mawatari and Mawatari 1981b, p 53.

? Lepralia bella Busk 1860, p 144 .

? Smittina bella: Powell 1968, p 2304 ; Mawatari and Mawatari 1981b, p 54; Grischenko 1997, p 181.

Not Smittina bella: Osburn 1952, p 403 , Plate 47, Figures 4 , 5 ; Mawatari 1956, p 130, Figures 12a–e , 13 ; Dick and Ross 1988, p 59, Plate 11B.

Material examined

ANC, colony on rock (NHM 2006.2.27.12), colony on rock (NHM 2006.2.27.68), colony on rock (NHM 2006.2.27.69), ancestrular colony on rock (NHM 2006.2.27.70); ACW, colony on rock (NHM 2006.2.27.67); NB, five young colonies on bivalve shell (NHM 2006.2.27.71). Additional material: 124 specimens.

Description

Colony encrusting, unilaminar, coherent, forming circular patches up to 3 cm across, reddish to orange when alive. Zooids ( Figure 24A, B ) hexagonal, oval, or irregularly rectangular, mostly with indistinct meandering boundaries, 0.43–0.78 mm long (0.59¡ 0.07 mm), 0.33–0.45 mm wide (0.38¡ 0.03 mm), separated by shallow undulating groove with suture line at bottom. Frontal wall slightly to moderately convex, finely granulated, covered with numerous large pores; with age, pores became infundibular. Frontal wall rises into a small or prominent conical median umbo ( Figure 24B, D ) in suboral or central region. Primary orifice ( Figure 24C ) round or slightly longer than broad, with wide, variably tall median lyrula; small, sharp lateral condyles evident in some marginal zooids, but usually appear to be lacking ( Figure 24A, C ). Oral spines lacking outside zone of astogenetic change. Secondary orifice irregularly circular, oval, or pyriform in outline, longer than wide, often constricted proximally; surrounded by thin, smooth, angled rim, 0.14–0.19 mm long (0.16¡ 0.01 mm), 0.13–0.18 mm wide (0.15¡ 0.01 mm); cormidial ( Figure 24D ), formed distally by proximal margin of succeeding zooid and laterally by extensions of secondary calcification from adjacent zooid on each side. Median suboral avicularium ( Figure 24D, E ) oval or pyriform in outline, with short-spatulate mandible and complete cross-bar; rising above proximal orificial denticle and lying mostly within peristome, tilted proximally from perpendicular. Avicularian chamber small, semicircular, completely immersed in suboral umbo, often flanked laterally by a minute pore on each side. Ovicell ( Figure 24C–E ) hyperstomial, spherical, imperforate, broader than long, 0.14–0.20 mm long (0.17¡ 0.01 mm), 0.18–0.23 mm wide (0.20¡ 0.01 mm), rapidly immersed, the top flush with colony surface, finely granulated; outer layer cormidial like secondary orifice, with calcification from the succeeding and lateral zooids, the contributions delineated by sutures on surface. Lateral wall of zooids with two distal and six lateral basal pore chambers. Ancestrula ( Figure 24F ) modified tatiform, about 0.42 mm long by 0.33 mm wide; rapidly obscured by periancestrular zooids; opesia a little less than half the length of ancestrula, with an undetermined number of opesial spines. Ancestrula buds a small zooid distally and a pair distolaterally; from the latter arise two proximal periancestral zooids. Zooids in zone of astogenetic change with two to four ephemeral oral spines.

Remarks

Soule et al. (1995) established the genus Raymondcia for species resembling Smittina , but with the secondary orifice and ovicell cormidial, composed of distal and two lateral segments, characters present in our material. Accordingly, we use the new combination R. rigida ( Lorenz, 1886) herein. Raymondcia rigida is similar to R. macginitiei Soule et al., 1995 in having a pyriform secondary orifice and the avicularium orientated nearly vertically within the peristiome; however, in the latter species, the orificial denticle is wider than the width of the suboral avicularium, whereas in R. rigida it is narrow, about the same width as the avicularium. Although the frontal wall is inflated in R. macginitiei , it is distinctly umbonate in R. rigida , which also has considerably larger frontal pores. Finally, the most deeply immersed ovicells of R. rigida are still a little convex and recognizable, whereas those of R. macginitiei became totally immersed.

Distribution

This has been considered a circumpolar Arctic-Boreal species; Kluge (1962, 1975) and Gontar and Denisenko (1989) provided many distributional records. Most of these records need to be re-examined (see Dick and Ross 1988), due to possible confusion with R. bella ( Busk, 1860) , originally described from Shetland, Britain ( Hayward and Ryland 1999). On the Asiatic side, the nominal species has been recorded from eastern Kamchatka, the Commander Islands, the Shantar Archipelago, the Kuril Islands, southern Sakhalin Island, Primorye, and Peter the Great Gulf ( Androsova 1958; Kluge 1961; Gontar 1980; Grischenko 1997). There is a record of nominal R. rigida from Muroran, Hokkaido, Japan ( Mawatari and Mawatari 1981b).

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 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).

Figure 12. Cauloramphus niger n. sp. (A–E) NHM 2006.2.27.16; (F) NHM 2006.2.27.17. (A) Developing zooids at colony margin, unbleached; (B) general view of group of zooids with immersed vestigial ovicells, unbleached; (C) zooids from colony periphery, showing numerous avicularia, unbleached; (D) close up of zooids with avicularia, unbleached; (E) autozooids with immersed ovicells and bases of spines, bleached; (F) ancestrula and periancestrular zooids, bleached. Scale bars: 0.5 mm.

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 24. Raymondcia rigida (Lorenz, 1886). (A) NHM 2006.2.27.68; (B, D) NHM 2006.2.27.67; (C, E) NHM 2006.2.27.12; (F) NHM 2006.2.27.70. (A) Colony margin with developing zooids; (B) immature zooids; (C) autozooids with developing ovicells; (D) umbonate mature zooids with ovicells covered by merging segments from adjacent zooids; (E) inflated mature zooids; (F) ancestrula with periancestrular zooids. Scale bars: 0.5 mm.