Trematooecia rotunda, Almeida & Souza & Menegola & Sanner & Vieira, 2014

Almeida, Ana C. S., Souza, Facelucia B. C., Menegola, Carla M. S., Sanner, Joann & Vieira, Leandro M., 2014, Taxonomic review of the family Colatooeciidae Winston, 2005 (Bryozoa, Cheilostomata), with description of seven new species, Zootaxa 3868 (1), pp. 1-61 : 53-56

Trematooecia rotunda n. sp.

( Fig. 34 , Table 7 )

Material examined. Holotype: UFBA 533 , Trematooecia sp. , A.C. Almeida det., Camaçari, Bahia, Brazil, 1994, 26 m. Paratype: UFBA 550 , Trematooecia sp. , A.C. Almeida det., Camaçari, Bahia, Brazil, 2000, 28 m. Additional specimens: UFBA 536 , Trematooecia sp. , A.C. Almeida det., Camaçari, Bahia, Brazil, 2002, 50 m ; UFBA 548 , Trematooecia sp. , A.C. Almeida det., Camaçari, Bahia, Brazil, 2002, 23 m.

Diagnosis. Encrusting Trematooecia with unilamellar colony and elevated elliptical avicularia on tubercles.

Etymology. Latin rotunda , circle, alluding to the rounded autozooids.

Description. Colony encrusting, unilamellar. Zooids hexagonal, becoming rounded-polygonal with increasing calcification, as long as wide, delimited by distinct grooves. Frontal shield heavily calcified, with a few frontal pseudopores and 8–15 marginal areolar pores. Primary orifice large relative to frontal shield, centered, more or less hoof-shaped, wider than long, with arcuate anter and broad concave poster delimited by 2 downcurved condyles at about one-third orifice length. Secondary orifice surrounded by 3–4 (often 4) solid tubercles that frequently bear an elliptical avicularium. Each autozooid with a large suboral tapering umbo. Suboral avicularium absent. Frontal avicularia small (0.043 –0.079 mm long, 0.043 –0.068 mm wide), elliptical, single (rarely 2), placed at proximal margin of zooid. Interzooidal avicularium large, rostrum obovate; calcified palate occupying more than half rostral length; foramen rounded. Ooecium subglobose, inclined toward zooid surface, often with 1–3 tubercles and a single avicularium; ectooecium with slit-like membranous area.

Remarks. Trematooecia rotunda n. sp. is distinguished from all congeners by the combination of unilamellar colony and avicularium-bearing tubercles. Related species with encrusting colonies and a slit-like membranous area in the ectooecium are T. clivulata and T. hexagonalis . Trematooecia rotunda n. sp. differs from T. clivulata in having a hoof-shaped primary orifice (transversely D-shaped in T. clivulata ) and obovate interzooidal avicularia (spatulate in T. clivulata ). Differences from T. hexagonalis include frontal shield punctuation (uniformly porous in T. hexagonalis ) and the obovate interzooidal avicularia (absent in T. hexagonalis ).

Distribution. Atlantic: Brazil.

Figures

FIGURE 34. Trematooecia rotunda n. sp. A, C, UFBA 533, holotype, Brazil; B, D–F, UFBA 550, paratype, Brazil. A, fragment of encrusting colony. B, zooids, some ovicellated. C, primary orifice and tubercle with elliptical avicularium. D, frontal and interzooidal avicularia. E, close-up of interzooidal avicularium. F, close-up of ovicelled zooid. Scale bars: A = 500 µm; B = 200 µm; C–F = 100 µm.