Bellulopora Lagaaij, 1963

Judith L Winston, 2016, Bryozoa of Floridan Oculina reefs, Zootaxa 4071 (1), pp. 1-81 : 11

Genus Bellulopora Lagaaij, 1963

Bellulopora bellula (Osburn, 1950) ( Fig. 3 ; Table 2 )

Colletosia bellula Osburn, 1950: 188 , pl. 29, fig. 1.

Bellulopora bellula: Lagaaij 1963a: 183 , pl. 4, fig. 2; Winston 1982: 134; Winston & Håkansson 1986: 20, figs 46, 47.

Material examined. VMNH no. 70600; USNM 1283228.

Description. Colonies small, unilamellar, encrusting calcareous substrata ( Fig. 3 A). Zooids oval, about 0.5 mm long, with very narrow gymnocyst surrounding frontal surface of 5–7 pairs of radiating kenozooidal costae with rows of slit-like lacunae between fusions. Orifice broadly cleithridiate ( Fig. 3 B, D), with small raised heterozooid on either side. Two oral spines. Ooecium hemispherical, closed by zooidal orifice, constructed of fused costae pertaining to distal kenozooid, with membranous frontal wall beneath, serving as ooecium floor. Ancestrula tatiform.

Remarks. Osburn (1950) described this species based on material from the Gulf of California and Galapagos with 2–4 oral spines and avicularia. Floridan Oculina specimens have no mandibles on the avicularium-like heterozooids ( Fig. 3 B–D), their tips being membranous. However, zooid size and overall morphology are similar to west coast and Gulf of Mexico specimens, so the significance of other differences in heterozooid morphology is still unknown.

In another rearrangement of cheilostome phylogeny Ostrovsky (2013) has argued that Bellulopora should be recognized as representative of a suborder independent of Flustrina, its unique kenozooidal brood chambers having originated independently from a malacostegan-grade ancestor with many kenozooidal mural spines. His classification is followed here.

Distribution. Western Atlantic: Cape Hatteras to Florida and Gulf of Mexico. Also recorded from the Pacific coast.

Figures

FIGURE 3. Bellulopora bellula (Osburn, 1950): A, growing edge of colony; B, C, orifice, showing spines and heterozooids; C, ovicelled zooid; D, autozooid at growing edge of colony. Scale bars: A, 0.4 mm; B, C, 0.1 mm; D, 0.04 mm.

Tables

TABLE 2. Measurements (in mm) of Bellulopora bellula (Osburn, 1950).

	Lz	Wz	Lo	Wo	Lov	Wov
N Mean	18 0.487	18 0.309	18 0.093	18 0.068	16 0.234	16 0.235
SD	0.046	0.022	0.012	0.006	0.029	0.014
Min	0.414	0.270	0.072	0.054	0.198	0.216
Max	0.576	0.360	0.108	0.072	0.288	0.252