Drepanophora irregularis, Winston, Judith E. & Vieira, Leandro M., 2013

Winston, Judith E. & Vieira, Leandro M., 2013, Systematics of interstitial encrusting bryozoans from southeastern Brazil, Zootaxa 3710 (2), pp. 101-146 : 127-129

Drepanophora irregularis sp. nov.

( Fig. 18 ; Table 16 )

Material examined. Holotype: MZUSP 742 ( Fig. 18 ), measured specimen #1, BIOTA Stn 211. Paratype: VMNH 70026, measured specimen #2, BIOTA Stn 211.

Etymology. From the Latin, irregularis , not according to rule, for the off-center sharply projecting point of the peristome.

Diagnosis. Sand-encrusting Drepanophora with an irregularly projecting spike at the edge of the peristome and no peristomial avicularium. The laterally pierced ovicell is smaller in size relative to zooid size than that of the closely related Drepanophora torquata Winston & Håkansson, 1986 of the Floridan sand fauna.

Description. Very small uni- to pluriserial colonies attached to shell-grain substrata. Zooids oval, with a convex, coarsely beaded frontal shield and marginal pores. The distal end is raised in a thickly calcified peristome; in the colonies where it has not been broken off a projection comes to a sharp point on one side of the peristome. The primary orifice is rounded with a thorn-like denticle on one side of its proximal edge. Ooecia are rounded helmets with smooth distal and rugose lateral calcification and two large round lateral pores.

Remarks. The Brazilian species differs from its Florida congener, Drepanophora torquata , primarily in its larger and narrower zooids (mean length 0.389 vs 0.278 mm and mean width 0.222 vs 229 mm) and the proportionately enlarged peristomial projection and smaller orificial denticle. Neither of the interstitial species has the peristomial avicularia found in some zooids of Drepanophora species known from larger substrata.

Distribution. São Paulo state, Brazil.

Figures

FIGURE 18. Drepanophora irregularis sp. nov.: A, colony in shelter of a serpulid tube. B, group of zooids, some with ovicells; folliculinid ciliate tubes protrude from two orifices. C, two zooids, one with an ovicell. D, close-up of primary orifice inside peristome and part of an ovicell; one of the two lateral ovicell pores is visible on its lower side. Scale bars: A, 0.5 mm; B, 0.3 mm; C, 0.2 mm; 0.1 mm.

Tables

TABLE 16. Measurements (in mm) of Drepanophora irregularis sp. nov..

	Lz	Wz	Lo	Wo	Lov	Wov
N	12	12	12	12	8	8
Mean	0.389	0.222	0.101	0.080	0.137	0.189
SD	0.041	0.022	0.014	0.012	0.019	0.019
Min	0.324	0.198	0.072	0.054	0.108	0.162
Max	0.468	0.270	0.126	0.090	0.162	0.216