Crepidacantha setigera (Smitt, 1873)

Judith L Winston, 2016, Bryozoa of Floridan Oculina reefs, Zootaxa 4071 (1), pp. 1-81 : 61-63

Crepidacantha setigera (Smitt, 1873)

( Fig. 34 ; Table 33 )

Escharella setigera Smitt, 1873: 58 , fig. 206.

Crepidacantha setigera: Canu & Bassler 1928a: 135 , pl. 21, fig. 10; Cook 1968: 186; Winston, 1982: 140, fig. 68.

Material examined. VMNH no. 70650, 70651; USNM no. 1283258.

Description. Colonies ( Fig. 34 A) encrusting calcareous substrata such as shell fragments and dead Oculina branches. Zooids more or less oval, distinguished by delicate radiating spines, not erect but extending along substratum from distal ends of zooids ( Fig. 34 B–D; in skeletal colonies only remaining evenly spaced marginal pores may show their position. Zooid frontal shield slightly convex, flatter proximally, gradually raised into a low peristome around cleithridiate orifice. Adventitious avicularia paired, one either side of orificial sinus, with small cystid, slightly raised; avicularian lumen somewhat cleithridiate, with extremely long thin mandibles whose tips may reach beyond proximal edge of zooid bearing them ( Fig. 34 D). Ooecia develop as small imperforate hoods ( Fig. 34 E, F), helmet-shaped when completely developed, with imperforate peripheral ectooecium and relatively large central area of exposed entooecium with scattered small pores.

Remarks. The species is difficult to prepare for SEM without colonies separating along zooid margins into single zooids. For that reason, and to show the delicate spines and the long avicularium mandibles, colonies are illustrated without cleaning or bleaching.

Distribution. Florida, Caribbean, tropical East Pacific, West Africa.

Figures

FIGURE 34. Crepidacantha setigera (Smitt, 1873): A, colony encrusting Oculina branch; B, zooids at growing edge, showing outer spines and setose avicularian mandibles; C, two zooids, showing spines; D, group of zooids showing marginal spines and avicularia; E, group of zooids, two with ooecia; F, close up of oecium and orifice. Scale bars: A, 1 mm; B, 0.1 mm; C, D, 0.4 mm; E, 0.5 mm; F, 0.3 mm.

Tables

TABLE 33. Measurements in mm of Crepidacantha setigera (Smitt, 1873).

	Lz	Wz	Lo	Wo	Lov	Wov	Lavm	Wavm
N	18	18	18	18	8	8	12	1
Mean	0.561	0.466	0.130	0.084	0.230	0.266	0.371	0.036
SD	0.072	0.062	0.015	0.012	0.025	0.016	0.048	-------
Min	0.450	0.360	0.108	0.072	0.198	0.234	0.306	0.036
Max	0.702	0.594	0.162	0.108	0.270	0.288	0.450	0.036