Micropora acuminata Winston, 2005

Judith L Winston, 2016, Bryozoa of Floridan Oculina reefs, Zootaxa 4071 (1), pp. 1-81 : 24

Micropora acuminata Winston, 2005

( Fig. 12 ; Table 11 )

Micropora coriacea: Smitt 1873: 13 , pl. 3, fig. 74; Canu & Bassler 1928a: 62, text-fig. 8e; Osburn 1940: 373; 1947: 17; Marcus 1949: 16, fig. 19; 1955: 285; Winston 1982: 125, fig. 39.

Micropora acuminata Winston, 2005: 25 , figs 69–72.

Material examined. VMNH no. 70613, 70614; USNM no. 1283237.

Description. Colony ( Fig. 12 A) encrusting dead shell, coral rubble, etc. Zooids oval distally, angular proximally, variable in size, a distinct shallow groove marking adjoining lateral walls ( Fig. 12 B, C). Frontal membrane underlain by cryptocyst with about 26–36 small pores and a granular surface texture. Orifice small, transversely narrowly D-shaped, with smooth calcification around entire rim, although on its proximal edge the adjoining cryptocystal granularities may confer a minutely serrated appearance from certain angles. Raised smooth tubercles of calcification curve around each side of the orifice, with a slit-like opesiule on each side of the frontal surface just below it. Helmet shaped ooecium, small relative to zooid size, closed by zooidal operculum, with granular, imperforate outer covering and a smooth, triangular, proximofrontal surface with a rounded apex ( Fig. 12 E, F). Small spatulate avicularia with a raised hooded rostrum may occur distally to the zooids ( Fig. 12 D).

Remarks. Prior to the availability of scanning electron microscopy, Micropora species were usually lumped together as Micropora coriacea Johnston, 1847 . Winston (2005) distinguished the Western Atlantic species, first noted by Smitt (1873), from M. coriacea on the basis of its narrow sloping distal tubercles and small ovicells with elevated ectooecial crests.

Distribution. Cape Hatteras to Brazil, Gulf of Mexico, Caribbean.

Figures

FIGURE 12. Micropora acuminata Winston, 2005: A, colony encrusting Oculina branch; B, group of zooids and avicularia; C, close up of zooids; D, close up of avicularium; E, zooid with ooecium; F, ooecium and orifice of fertile zooid. Scale bars: A, 1 mm; B, C, D, F, 0.1 mm; E, 0.3 mm.

Tables

TABLE 11. Measurements in mm of Micropora acuminata Winston, 2005.

	Lz	Wz	Lo	Wo	Lov	Wov	Lav	Wav
N	18	18	18	18	12	12	14	14
Mean	0.497	0.376	0.057	0.127	0.127	0.231	0.101	0.120
SD	0.067	0.050	0.007	0.012	0.012	0.013	0.014	0.025
Min	0.396	0.306	0.045	0.108	0.108	0.216	0.081	0.072
Max	0.684	0.450	0.072	0.144	0.144	0.252	0.126	0.144