Cryptosula zavjalovensis Kubanin, 1976

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 : 1127-1129

Cryptosula zavjalovensis Kubanin, 1976

( Figure 32 )

Cryptosula zavjalovensis Kubanin 1976, p 33 , Figure G, H.

Cryptosula zavjalovensis: Kubanin and Tarasova 1985, p 109 ; Kubanin 1997, p 125; Grischenko 2004, p 40; Dick et al. 2005, p 3749, Figure 18A, B .

Lepralia reticulata Okada 1929, p 24 , Plate 5, Figures 4 , 5 ; not Leprlia reticulata J. MacGillivray, 1842 .

Lepralia reticulata: Okada 1933, p 215 ; Androsova 1958, p 129, Figure 46; Kluge 1961, p 131; Gontar 1978a, p 61; 1978b, p 13; Mawatari and Mawatari 1981b, p 52.

Lepralia pallasiana: O’Donoghue 1925, p 19 , Plate 2, Figure 6 ; not Eschara pallasiana Moll, 1803 .

Eurystomella reticulata: Gontar 1980, p 9 ; 1981, p 102.

Eurystomella zavjalovensis: Gontar 1992, p 131 .

Cryptosula okadai Dick and Ross 1988, p 53 , Plate 5F; Grischenko 1997, p 176. Cryptosula pallasiana: Dick and Ross 1986, p 89 .

Material examined

KAI, ancestrular colony on rock (NHM 2006.2.27.60); MBS, five colony fragments (NHM 2006.2.27.61). Additional material: 240 specimens.

Description

Colony encrusting, unilaminar, coherent, irregularly circular, up to 4 cm across. Living colonies bright yellow, tan, or brownish in colour and exude a foul, pungent odour. Zooids ( Figure 32A–C ) subrectangular to roughly hexagonal, rounded distally, 0.67– 0.95 mm long (0.80¡ 0.08 mm), 0.28–0.45 mm wide (0.37¡ 0.05 mm), delineated by a fine suture formed by raised adjacent vertical walls. Frontal wall cryptocystidean, convex, perforated with large, uniform pores covering entire surface; with age pores become infundibular and the frontal wall reticulate, with rounded ridges between pores; frontal wall rises to suboral umbo ( Figure 32B, C ) varying from low, conical bulge to tall, costate process. Orifice ( Figure 32C ) hat-shaped in outline, 0.16–0.21 mm long (0.19¡ 0.01 mm), 0.17–0.26 mm wide (0.22¡ 0.02 mm); large, semicircular anter delineated from short, broad poster by long, low, wedge-shaped condyles. Peristome lacking. Area of smooth frontal wall lacking pores borders orifice proximally and laterally. Spines, avicularia, and ovicells lacking. Zooidal communication via multiporous septula. Occasionally scattered kenozooids present, similar to autozooids but lacking orifice. Ancestrula ( Figure 32D ) tatiform, oval, 0.53 mm long by 0.44 mm wide, with large opesia occupying almost entire frontal surface, 0.49 mm long by 0.38 mm wide, without spines; basal wall contains uncalcified window. Ancestrula buds triplet of smaller zooids distally; surrounded by eight zooids.

Remarks

This species and its convoluted synonymy were discussed by Dick and Ross (1988) and Dick et al. (2005). Cryptosula zavjalovensis is patchily abundant in Akkeshi Bay. It is one of the main components of the fouling community on the vertical cement surfaces of the pier of the Akkeshi MBS, where layers of zooids form a thick crust, with free spaces or slits between layers. These spaces provide a habitat for other benthic invertebrates, mainly spirorbid worms, but also small isopod and amphipod crustaceans and errant polychaetes. The external surface of living colonies of C. zavjalovensis remains largely free from encrusting epizoonts, perhaps due to allelopathic activity of the substance responsible for the unpleasant, pungent odour.

Distribution

A Boreal Pacific species, this is one of the most common and widespread bryozoans found intertidally around the north Pacific Rim, extending from the mid-intertidal zone to a depth about 40 m ( Androsova 1958). On the North American side it has been reported from the eastern Aleutian Islands, Bering Sea, northern Gulf of Alaska, Kodiak Island, and Ketchikan, Alaska ( O’Donoghue 1925; Dick and Ross 1988; Dick et al. 2005). On the Asian side there are records from numerous localities, including the Gulf of Anadyr, Kamchatka, Commander Islands, Sea of Okhotsk, Kuril Islands, Sakhalin Island, Primorye, and northern sector of the Sea of Japan ( Androsova 1958; Kluge 1961; Gontar 1980; Kubanin 1997; Grischenko 1997, 2004). In Japan, C. zavjalovensis has been previously reported from Shirikishinai, southern Hokkaido ( Mawatari and Mawatari 1981b), and Mutsu Bay, northern Honshu ( Okada 1929).

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 18. Integripelta novella Gordon, Mawatari, and Kajihara, 2002. NHM 2006.2.27.53. (A) General view of colony fragment; (B) immature zooids; (C) maternal zooids showing distal kenozooidal chambers possessing triangular, oval, and crescentic foramens; (D) close up of maternal zooids with foramen varying in size and form. Scale bars: 0.5 mm.

Figure 32. Cryptosula zavjalovensis Kubanin, 1976. (A–C) NHM 2006.2.27.61; (D) NHM 2006.2.27.60. (A) Colony margin with developing zooids; (B) group of zooids, showing small and large orifices; (C) heavily calcified autozooids; (D) ancestrula and radially arranged periancestrular zooids. Scale bars: 0.5 mm (A–C); 1 mm (D).