Drepanophora gutta Tilbrook, Hayward & Gordon, 2001

Dick, Matthew H., Ngai, Nguyen Danh & Doan, Hung Dinh, 2020, Taxonomy and diversity of coelobite bryozoans from drift coral cobbles on Co To Island, northern Vietnam, Zootaxa 4747 (2), pp. 201-252 : 217

Drepanophora gutta Tilbrook, Hayward & Gordon, 2001

( Fig. 7E, F )

Drepanophora gutta Tilbrook, Hayward & Gordon, 2001, p. 74 , fig. 10E, F.

Drepanophora gutta: Gluhak, Lewis & Popijac 2007, p. 414 , fig. 20A–C.

Drepanophora cf. gutta: McCuller & Carlton 2018, p. 153 , suppl. fig. S18C, D

Material examined. One colony detected, VNMN-0227 (CT-33), on SEM stub with Celleporaria triangula .

Measurements. AzL, 0.31–0.43 (0.370 ± 0.045); AzW, 0.20–0.32 (0.253 ± 0.035) (n = 13, 1). OrL, 0.085 – 0.087 (0.086 ± 0.001); OrW, 0.125 –0.128 (0.127 ± 0.002) (n = 2, 1). OvL, 0.11–0.17 (0.137 ± 0.018); OvW, 0.16–0.20 (0.183 ± 0.014) (n = 9, 1).

Description. Colony encrusting, unilaminar, sheet-like.

Zooids small, variable in shape, distinct, delineated by shallow groove and 4–7 small, irregular marginal pores along each lateral margin. Frontal wall convex, imperforate, coarsely pustulose. Primary orifice broader than long but clearly visible only in marginal zooids; with conspicuous, broad, alate or truncate lyrula in midline. Mature zooids with primary orifice obscured by raised peristome having pustulose sculpturing like rest of frontal wall. Several oral spine bases observed, off-center, indicative of at least two oral spines.

Most zooids with small avicularium in midline on proximal side of peristome, just below peristomial opening, mandible short-triangular, directed laterally to one side or other. Secondary orifice quadrate or irregular, sometimes with asymmetrical sinus between avicularian rostrum and small opposing peristomial projection.

Ooecium hyperstomial, lying on frontal wall of next-distal zooid, surface smooth; ooecium bearing pair of peripheral foramina, one distolaterally on each side; imperforate centrally; peristome continues as collar around proximal edge of ooecium.

Distribution. This species was originally described from a single colony found among coral debris at Port Vila Harbor, Efate, Vanuatu ( Tilbrook et al. 2001). Gluhak et al. (2007) found it at Taiwan, and McCuller & Carlton (2018) reported it from Crook Point, Oregon, USA, on drift plastic presumably originating from Japan as the result of the 2011 tsunami.

Figures

FIGURE 7. A–D. Celleporaria triangula Seo, 1994, VNMN-0227. A. Colony, overgrowing small colony of Drepanophora gutta at lower left. B. Autozooids at colony margin. C. Enlargement showing orifice and suboral avicularium. D. Ooecium (arrow) and vicarious avicularium (arrowhead). E, F. Drepanophora gutta Tilbrook, Hayward & Gordon, 2001, VNMN-0227. E. Autozooids with and without ooecia; arrowheads indicate suboral avicularia, scarcely visible in frontal view. F. Frontodistal view showing shapes of primary and secondary orifices. Scale bars: A, 2.0 mm; B, D, E, 250 µm; C, 100 µm; F, 150 µm.