Fenestrulina orientalis Liu, Liu, and Sun, 2003

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 : 1129-1131

Fenestrulina orientalis Liu, Liu, and Sun, 2003

( Figure 33 )

Fenestrulina orientalis Liu, Liu, and Sun 2003, p 209 , 221, Plate 4, Figures 3–5 .

Fenestrulina orientalis: Liu et al. 2001, p 671 , 815, Plate 70, Figures 4–6 .

? Microporella malusii: Okada 1929, p 27 , Text figure 12; Androsova 1959, p 50, 65, Plate 2, Figure 13 ; not Cellepora malusii Audouin, 1826 .

? Fenestrulina malusii: Mawatari and Mawatari 1981b, p 53 ; Huang et al. 1990, p 748. Not Cellepora malusii Audouin, 1826 .

Material examined

ANC, young colony on rock (NHM 2006.2.27.11), colony on rock (NHM 2006.2.27.12). Additional material: 181 specimens.

Description

Colony encrusting, unilaminar, coherent, more or less circular, up to 2 cm in diameter, pale yellow to whitish when alive. Zooids ( Figure 33A, B ) rounded-hexagonal to oval, 0.50– 0.73 mm long (0.58¡ 0.06 mm), 0.35–0.53 mm wide (0.40¡ 0.04 mm), separated by a deep groove between smooth, inward-sloping, lateral walls. Frontal wall moderately convex, thin, translucent, smooth and imperforate in central area proximal to ascopore; stellate pores in a single marginal row in proximal half of zooid, two or three marginal rows in distal half, and two rows between ascopore and orifice. Orifice ( Figure 33C ) semicircular, curving slightly inward at proximolateral corners; broader than long, 0.10– 0.12 mm long (0.11¡ 0.01 mm), 0.12–0.16 mm wide (0.14¡ 0.01 mm), with straight proximal margin. Non-ovicellate marginal zooids have three short, hollow spines ( Figure 33A–C ) closely set around distal curvature of orifice; ovicellate zooids also have three spines, the lateral two are more widely separated than in zooids that will not produce an ovicell and remain close to proximal corners of ovicell. Ascopore separated from proximal border of orifice by a distance about equivalent to length of zooidal orifice; crescentic, with a denticulate edge, located on a small, oval, elevated prominence which sometimes coincides with highest point of frontal wall, but more often lies on its distal slope. Ovicell ( Figure 33D ) hemispherical, prominent, conspicuous, 0.22–0.28 mm long (0.25¡ 0.01 mm), 0.24–0.30 mm wide (0.27¡ 0.02 mm), smooth, without ribs, imperforate except for large marginal pores inside raised border. No avicularia. Zooids communicate via two distal and two distolateral basal pore chambers. Ancestrula ( Figure 33E ) tatiform, oval, 0.33 mm long, 0.25 mm wide, with smooth, narrow gymnocyst and large, oval opesia, 0.22 mm long, 0.16 mm wide, surrounded by 10 short, jointed hollow spines. The ancestrula becomes modified ( Figure 33F ) by formation of a frontal shield and loss of spines proximal to level of orifice, thereby coming to resemble periancestrular zooids. Ancestrular orifice irregularly oval, 0.09 mm long, 0.11 mm wide, with slightly concave proximal margin. Frontal wall convex, smooth, with only one row of stellate pores along periphery; slit-like ascopore on small oval prominence at highest point of frontal wall. Ancestrula buds triplet of zooids distally, eventually surrounded by six zooids; periancestrular zooids with three to five oral spines.

Remarks

Specimens from Akkeshi Bay agree well with the original description and illustrations of F. orientalis ( Liu et al. 2003) . Many previous records of Fenestrulina from the northwestern Pacific (e.g. Androsova 1959; Kluge 1961; Gontar 1980; Mawatari and Mawatari 1981b; Kubanin 1997; Grischenko 1997) were nominal F. malusii ( Audouin, 1826) , which has been long considered a widely distributed, cosmopolitan species. However, Soule et al. (1995) determined that F. malusii does not occur in the eastern Pacific, at least, and that previous records of that species there actually comprised a complex of two genera and several species. According to Hayward and McKinney (2002), F. malusii occurs throughout the Mediterranean and northwards to the British Isles and western Norway.

The date of original description of this species is ambiguous, and we were not able to resolve this ambiguity. In their monograph, Liu et al. (2001) included ‘‘ Fenestrulina orientalis Liu et Liu, 2001 ’’ and listed ‘‘ Liu & Liu, 2001: 13, pl. 5, figs. 3–5’’ as the citation in the synonymy. However, Liu et al. (2001) did not list Liu and Liu (2001) among the monograph’s references. Furthermore, in a separate paper whose title indicated ‘‘seven new species’’ of microporellids, Liu et al. (2003) reported ‘‘ Fenestrulina orientalis Liu sp. nov. ’’ in the portion of the paper written in Chinese, and ‘‘ Fenestrulina orientalis sp. nov. ’’ in the portion of the paper containing an English translation; this paper contained no reference to Liu and Liu (2001), which indeed we have not been able to locate. We thus consider the authorship and date of Fenestrulina orientalis to be Liu, Liu, and Sun, 2003.

Distribution

Liu et al. (2003) originally described Fenestrulina orientalis from China, but other authors had previously reported it from the Yellow Sea (as Microporella malusii or Fenestrulina malusii ) ( Androsova 1959). Some records of F. malusii from Japan, e.g. from Akkeshi, Muroran, Shirikishinai, northern to middle Honshu ( Mawatari and Mawatari 1981b) and Mutsu Bay ( Okada 1929), may represent F. orientalis .

Figures

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 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 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 33. Fenestrulina orientalis Liu, Liu, and Sun, 2003. (A–D, F) NHM 2006.2.27.12; (E) NHM 2006.2.27.11. (A) Colony margin with differentiating zooids; (B) immature zooids; (C) distal half of immature zooid, showing orifice with oral spines and ascopore; (D) mature zooids with completed hemispherical ovicells; (E) tatiform ancestrula and periancestrular zooids; (F) modified ancestrula with acquired frontal shield, surrounded by periancestrular zooids. Scale bars: 0.5 mm (A, B, D–F); 0.2 mm (C).