Celleporella Gray, 1848

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 : 1097-1099

Genus Celleporella Gray, 1848

Celleporella hyalina (L., 1767) species complex

( Figure 19 )

Material examined

ANC, ancestrular colony on rock (NHM 2006.2.27.54); ACT, two intact colonies (NHM 2006.2.27.55); DIN, three intact colonies (NHM 2006.2.27.56); MAC, three colony fragments (NHM 2006.2.27.57); DIW, colony fragment (NHM 2006.2.27.58). Additional material: 847 specimens.

Description

Colony encrusting, coherent, unilaminar when young ( Figure 19A ), multilaminar, often several layers thick, with age; forming irregularly circular patches up to 2.5 cm across, white to tan in colour when alive. Primary layer consists of autozooids only; male polymorphs, ovicellate female zooids, and autozooids budded frontally in secondary layers. Zooids elongate-elliptical, spindle-shaped, widest in middle, rounded distally, tapering proximally, 0.45–0.78 mm long (0.61¡ 0.09 mm), 0.20–0.30 mm wide (0.25¡ 0.03 mm), separated by a deep groove, with slit-like lacunae and incipient zooeciules evident between young, marginal zooids. Autozooids distinct only in primary layer ( Figure 19A ) in marginal budding zone and in young colonies; proximal ends of zooids submerged under distal parts of preceding zooids. Frontal wall hemicylindrical, smooth, translucent, convex, rising distally into lunate suboral umbo. Autozooidal orifice ( Figure 19B, D, E ), including sinus, roughly circular, longer than broad, 0.11–0.15 mm long (0.13¡ 0.01 mm), 0.10–0.13 mm wide (0.11¡ 0.01 mm), with condylar shelves bearing small condyles pointing distally, distomedially, or medially, often with a notch between condyle and orificial rim; between condylar shelves is a deep, broadly U-shaped proximal sinus. Orifice surrounded laterally and distally by a sharp, thin, raised peristomial rim. Orifice of male zooids ( Figure 19C–E ) similar in shape to that of autozooidal orifice, but about one-half to one-third the length and width; proximal sinus sometimes appears proportionately longer and narrower in male zooids. Orifice of female zooids ( Figure 19C, D ) semicircular, broad, with a concave proximal margin. Ovicell ( Figure 19C–E ) hyperstomial, spherical, smooth, variable in shape, size and orientation, 0.17–0.23 mm long (0.20¡ 0.01 mm), 0.18–0.25 mm wide (0.22¡ 0.02 mm), covered with a variable number of pores, some occluded. Spines and avicularia lacking. Six pore chambers along basal side of lateral wall and two to three in distal vertical wall. Ancestrula ( Figure 19F ) similar in form to autozooid, though smaller and shorter. Early astogeny a spiral budding pattern, with first zooid budding distolaterally from ancestrula and each following periancestrular bud arising from angle between ancestrula and preceding zooid.

Remarks

Celleporella hyalina (L., 1767) has been considered a cosmopolitan species ( Osburn 1952; Androsova 1958; Kluge 1962), distributed around the world from the Arctic to tropical latitudes. Recent studies, however, have suggested that nominal C. hyalina likely involves a worldwide complex of similar, perhaps cryptic species (see discussion by Dick et al. 2005, p 3726). Until further data are available from morphological, molecular, and reproductive compatibility studies, we simply refer the material from Akkeshi to the Celleporella hyalina (L., 1767) species complex. Variation among some of our specimens (e.g. compare number and distribution of ovicellar pores between Figure 19D and 19E ) may be indicative of more than one representative of this species complex at Akkeshhi.

Figures

Figure 19. Celleporella hyalina (L., 1767) species complex. (A, C–E) NHM 2006.2.27.57; (B) NHM 2006.2.27.55; (F) NHM 2006.2.27.54. (A) Colony margin with developing zooids; (B) autozooids in primary layer; (C, D) autozooids in primary layer (large orifices), frontally budded male zooids (small orifices), and frontally budded ovicellate zooids; (E) central colony region with predominance of ovicellate zooids; (F) ancestrula and periancestrular zooids with spiral budding pattern. Scale bars: 0.5 mm (A–C, F); 0.4 mm (D, E).