Celleporina abstrusa, 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 : 134-136

Celleporina abstrusa sp. nov.

( Fig. 22 ; Table 20 )

Material examined. Holotype: MZUSP 679, specimen #9, near BIOTA Stn 205, 15 m. Paratypes: MZUSP 680, #10 [7 colonies], near BIOTA Stn 205, 15 m; MZUSP 750, BIOTA Stn 205; MZUSP 751, measured specimen #1, BIOTA Stn 211; MZUSP 752, measured specimen #3, BIOTA Stn 211; MZUSP 753, BIOTA Stn 211; VMNH 70031, measured specimen #2, BIOTA Stn 211; VMNH 70032, BIOTA Stn 205.

Supplementary video. http://cifonauta.cebimar.usp.br/taxon/celleporina-abstrusa/

Etymology. From Latin abstrusus, hidden, concealed.

Diagnosis. Colonies encrusting sand grains or shell fragments, zooids semi-erect to erect with thick-rimmed and circular peristomes; frontal shield smooth with few marginal pores, plus 2–4 pores on peristome. Orifice with rounded anter, narrow condyles and shallow V-shaped sinus. Avicularia absent.

Description. Encrusting colony form varies from uniserial runners on narrow grains to multiserial expansions where space permits. Zooids are semi-erect to erect, distal halves rising as a thick-rimmed circular peristome. Frontal shield smoothly calcified, but with a few marginal pores visible. There may be 2–4 additional pores upon the upper rim of the thick peristome. Primary orifice comprising rounded anter with smoothly calcified distal rim, long, narrow condyles, and a shallow V-shaped sinus. No avicularia. The small membrane-covered skeletal foramina on the peristomial rim may take the place of the avicularia seen in larger Celleporina species. Ooecium circular in outline with two layers, a smooth ectooecial rim surrounding a broad inner layer, with a few small pseudopores where the two layers meet; ovicell opens into distal part of peristome, well above the operculum. Polypides with 8–9 translucent white tentacles.

Remarks. Fresh colonies clearly show the combination of characters: erect heavily calcified zooids with few marginal pores, sinuate primary orifice encircled by a distinct thick-rimmed peristome, and a subrounded ovicell with a broad tabula. Celleporina species can have very small colonies, although they are often nodular. Like many other sand-grain species, most of the specimens we found were worn and abraded; living or recently dead colonies were a minority.

Distribution. São Paulo state, Brazil.

Figures

FIGURE 22. Celleporina abstrusa sp. nov.: A, colony attached to an irregular sand grain. B, group of zooids, showing thick erect peristomes. C, zooids at growing edge of colony. D, close up of primary orifice within its peristomial collar. E, an ovicelled zooid adjacent to the ancestrula. Scale bars: A, 0.5 mm; B, E, 0.2 mm; C, 0.1 mm; D, 0.05 mm.

Tables

TABLE 20. Measurements (in mm) of Celleporina abstrusa sp. nov..

	Lz	Wz	Lo	Wo	Lov	Wov
N	18	18	18	18	3	3
Mean	0.416	0.307	0.108	0.095	0.150	0.198
SD	0.037	0.039	0.009	0.011	0.027	0.031
Min	0.360	0.234	0.090	0.072	0.126	0.180
Max	0.504	0.414	0.126	0.108	0.180	0.234