Turbicellepora papula Almeida & Larré & Vieira 2021, n. sp.

Turbicellepora papula n. sp.

(Fig. 3A–D)

urn:lsid:zoobank.org:act: CFEDDD01-F88A-4B8F-9137-6A903C2AB450

Material examined. Holotype: UFBA 874.1, 12°58’ S, 38°33’ W, Baía de Todos os Santos, Bahia, Brazil, coll. by Orane Alves, 1997. Paratypes: UFBA 1109.6, 13°45’ S, 38°50’ W, Camamu, Costa do Dendê, Bahia, Brazil, 30 m, coll. by LAMEB-UFBA, 2004; UFBA 1132.2, 16°07’ S, 38°29’ W, Banco Royal Charlotte, Costa do Descobrimento, Bahia, Brazil, 35 m, coll. by LAMEB-UFBA, 2004; UFPE 902, 4 º49’– 5º10’ S, 36º10’– 36º50’ W, Bacia Potiguar, Rio Grande do Norte, Brazil, coll. by Petrobras, 2009–2010. Additional specimens: UFBA 790.1, UFBA 791.1, 12°56’ S, 38°33’ W, Baía de Todos os Santos, Bahia, Brazil, coll. by Abílio Bittencourt, 1976; UFBA 1339.1, 13°53’ S, 39°59’ W, Camamu, Costa do Dendê, Bahia, Brazil, 18 m, coll. by LAMEB-UFBA, 2004.

Diagnosis. Turbicellepora with nodular (pimpled) frontal zooidal surface with few large marginal pores, oval primary orifice with shallow proximal rim, well-developed peristome around entire primary orifice and with single or paired avicularia with rounded rostrum, no interzooidal/vicarious avicularia, hyperstomial ovicells with ectooecium having more than 20 pseudopores.

Type locality. Baía de Todos os Santos, Bahia, Brazil.

Etymology. Latin papula, pimple, alluding to the zooidal surface with small, rounded tubercles.

Description. Colony encrusting, uni- to multilamellar, spot-like (Fig. 3A).

Autozooids raised distally, oval to polygonal (0.503–0.597– 0.719 mm long, n = 22, SD = 0.059 mm; 0.337– 0.461– 0.567 mm wide, n = 22, SD = 0.059 mm), irregularly organized, delimited by distinct grooves (Fig. 3B). Frontal shield heavily calcified, nodular and with warts, convex, raised distally, imperforated frontal, but with 6–10 large marginal areolar-septular pores (Fig. 3B). Primary orifice oval, large relative to frontal shield (0.145– 0.176– 0.215 mm long, n = 22, SD = 0.017 mm; 0.155–0.172– 0.198 mm wide, n = 11, SD = 0.013 mm), sunken in peristome, with arcuate distal edge and broad concave proximal border; condyles present, small, triangular, placed at proximal third of the orifice (Fig. 3C). Weak peristome elevated around entire primary orifice, or obscuring it, forming a complete tubular open rim (Fig. 3C).

Vicarious avicularia not seen. Latero-oral avicularia small (0.089–0.108– 0.127 mm long, n = 13, SD = 0.013 mm; 0.059–0.071– 0.088 mm wide, n = 13, SD = 0.010 mm), single or paired on peristomial rim; rostrum subtriangular almost elliptical, distally directed upwards, with pointed proximal rim; cryptocyst absent, elliptical opesia and complete crossbar (Fig. 3C, D).

Ovicell hyperstomial, with globular ooecium (0.230–0.255– 0.275 mm long, n = 5, SD = 0.015 mm; 0.268– 0.306– 0.366 mm wide, n = 5, SD = 0.024 mm); ectooecium with more than 20 pseudopores, opening just above the operculum (Fig. 3D).

Remarks. Most Turbicellepora species have interzooidal and suboral avicularia (e.g., Hayward 1978; Alvarez 1990; Denisenko 2016), thus they are easily distinguished from T. papula n. sp.

Among congeners, four other species also have spot-like colonies: Turbicellepora iarae Almeida, Souza, Menegola & Vieira, 2017 and Turbicellepora winstonae Vieira, Gordon, Souza & Haddad, 2010), described from the Brazilian coast; Turbicellepora coronopus (Wood, 1844), based on fossil material from the British Isles but also reported in the Mediterranean, E Atlantic and Europe (Hayward 1978); and Turbicellepora nodulosa (Lorenz, 1886), restricted to the cold, Arctic waters (Hayward 1978). Differences among T. papula n. sp. and T. iarae include the frontal calcification (nodular in T. papula n. sp. and smooth in T. iarae) and latero-oral avicularia (absent in T. iarae) (Almeida et al. 2017). Turbicellepora winstonae has a smooth frontal shield (nodular in T. papula n. sp.), a primary orifice with a V-shaped proximal sinus (slightly concave in T. papula n. sp.) and a secondary orifice with pointed tubercles (tubular in T. papula n. sp.). Finally, T. papula n. sp. is distinguished from T. coronopus and T. nodulosa by having a primary orifice with a broad concave proximal region (primary orifice with distinct sinus in T. coronopus and with shorter proximal region in T. nodulosa) and typically paired latero-oral avicularia (sub- and/or latero-oral and interzooidal avicularia in T. coronopus and a single latero-oral avicularium in T. nodulosa).

Another Brazilian congener is Turbicellepora brasiliensis Winston, Vieira & Woollacott, 2014, characterized by having flat colonies, distinct from the spot-like colonies of T. papula n. sp. Other differences include the shape of the autozooids (rectangular and flat in T. brasiliensis and oval to polygonal, raised distally in T. papula n. sp.), frontal calcification (faintly granular in T. brasiliensis and nodular and with warts in T. papula n. sp.) and laterooral avicularia (paired and not incorporated into the peristome in T. brasiliensis but single or paired and always embedded in the peristomial rim in T. papula n. sp.) (Winston et al. 2014).

Distribution. Western Atlantic: Brazil (Bahia and Rio Grande do Norte). Turbicellepora papula n. sp. encrusts hard substrata such as gravel grains and calcareous nodules; 18‒ 35 m.