Corbuliporina crepida, Vieira, Leandro M., Gordon, Dennis P., Souza, Facelucia B. C. & Haddad, Maria Angélica, 2010

Vieira, Leandro M., Gordon, Dennis P., Souza, Facelucia B. C. & Haddad, Maria Angélica, 2010, New and little-known cheilostomatous Bryozoa from the south and southeastern Brazilian continental shelf and slope, Zootaxa 2722, pp. 1-53 : 14-15

Corbuliporina crepida n. sp.

( Figures 22–27 , Table 7 )

Material examined. Holotype. MZUSP 0 62, Rio Grande do Sul, Brazil, project GEDIP II, RV ‘Prof. Wladimir Besnard’, BT extra between Station 1710 (30o03’ S, 47o58’ W, 407 m) and 1711 (30o28’ S, 48o28’ W, 194 m); erect colony. Paratypes. MZUSP 0292–293, Brazil, project REVIZEE South SCORE, RV ‘Prof.

Wladimir Besnard’, station 6661; erect phase. MZUSP 0 294, encrusting and erect phase with ovicells (goldcoated). MZUSP 0 295, station 6665; erect phase. MZUSP 0 296, station 6666; encrusting and erect phase.

Diagnosis. Encrusting phase unilaminar, with erect bilaminar subcolonies arising from kenozooids; autozooids oblong to oval, with 9–13 pairs of costae; interzooidal avicularia helmet shaped; ovicell present only in erect phase, hyperstomial, with some pores.

Etymology. Latin crepida , alluding to the sandal-like appearance of the costate zooids.

Description. Encrusting phase unilaminar, about 0.5–7 mm diameter, with erect, bilaminar, fan-like branched phase up to 6 cm long, arising from tubular kenozooids at edge of encrusting portion. Erect phase comprising small subcolonies, irregularly elongate to subtriangular, 2–5 mm wide and 7–12 mm long, each budded from short tubular kenozooids; each erect subcolony giving rise to 1–4 new erect bilaminar subcolonies at distal edge. Autozooids oblong or oval; gymnocyst variably developed proximally but narrower or absent laterally. Costal field occupying greater part of zooid frontal (60–90% of length), formed by 9–13 pairs of costae, each briefly fused with adjacent costae just beyond mid-length and opposing costae fused along midline of zooid; 2–3 lumen pores, one in talon of costa, one at lateral fusion point, and sometimes a third near the midline. Orifice D-shaped, with a very short articulated spine at each distolateral corner. Avicularia present in encrusting and erect phases, more or less helmet shaped, with rostrum and opesia facing frontally and palate facing proximally; complete crossbar and single or paired frontal pore. Kenozooid with large oval pore usually present at marginal border of erect phase. Ovicells present in bilaminar phase, hyperstomial, closed by operculum of maternal zooid, with weak medial longitudinal suture; about 15–20 small ectooecial perforations, slit-like or drop-shaped; entooecium with small scattered pores.

Remarks. Corbuliporina n. gen. appears related to the Indo-Pacific genus Corbulipora MacGillivray, 1895 , with which it has a number of characters in common: two or more colonial growth phases, a zooidal gymnocyst that is variably developed proximally and narrow marginally, costal lumen pores, and interzooidal avicularia . The ovicell differs significantly between the two genera, however, being bifenestrate in Corbulipora and porous in Corbuliporina . The latter genus is characterized by helmet-shaped avicularia and the erect phase with marginal kenozooids with a large oval pore.

Bock and Cook (2001) noted that each growth phase in species of Corbulipora has distinct features, such as the shape of the subcolony and autozooid, the presence/absence of avicularia , kenozooids and ovicells. Despite the similar shape of the autozooid in both erect and encrusting phases, distinct characters are found among subcolonies of Corbuliporina crepida n. sp. ― erect phases are bilaminar and encrusting phases are unilaminar; the ovicells are present only in erect bilaminar branches.

Some fragments of the erect phase of C. crepida were collected during project REVIZEE, but only a few small encrusting portions were found, attached to shell fragments (MZUSP 0296).

Distribution. Brazil: off São Paulo and Rio Grande do Sul states, 147–258 m (present study).

Figures

FIGURES 22 – 27. Corbuliporina crepida n. gen. et sp., MZUSP 0 294 (paratype colony), off São Paulo, Brazil. 22, Encrusting colony with erect subcolony; 23, encrusting colony; 24, erect subcolony; 25, close-up of autozooid of encrusting colony with avicularia; 26, close-up of autozooid of erect subcolony; 27, ovicelled zooid in erecting colony.

Tables

TABLE 7. Measurements (in mm) of Corbuliporina crepida n. gen. et sp.

	n min–max	mean	SD
Autozooid length	20 0.741–1.013	0.916	0.062
Autozooid width	20 0.445–0.556	0.499	0.034
Frontal shield length	20 0.679–0.865	0.786	0.056
Orifice length	20 0.105–0.154	0.131	0.014
Orifice width	20 0.216–0.284	0.254	0.021
Avicularium length	20 0.216–0.340	0.260	0.035
Avicularium width	20 0.161–0.278	0.209	0.031
Ovicell length	8 0.395–0.432	0.404	0.012
Ovicell width	8 0.420–0.469	0.452	0.016