Cellaria subtropicalis, 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 : 11-12

Cellaria subtropicalis n. sp.

( Figures 12–16 , Table 5)

Material examined. Holotype. MZUSP 0 0 45, 14.vii. 1966, Angra dos Reis (Station 283), Ilha Grande, Rio de Janeiro, Brazil, 43 m (alcohol 70%). Additional material. MZUSP 0 279, Brazil, project REVIZEE South SCORE, RV ‘Prof. Wladimir Besnard’, station 6662. MZUSP 0 280, station 6787. MZUSP 0 281, station 6793.

Diagnosis. Colony erect, cylindrical, symmetrically bifurcated and jointed, with rhizoids on inner angle of axis; autozooids rhomboidal to hexagonal; crescentic opesia with a raised proximal rim and paired conspicuous condyles; distal rim of opesia with very small denticles; avicularia with a broadly subtriangular rostrum.

Etymology. Name alluding to the subtropical latitudes at which the species occurs.

Description. Colony erect, cylindrical, specimens 6–40 (holotype) mm long, about 0.6–1.3 mm diameter, symmetrically bifurcated, jointed, with rhizoids in inner angle of axis; colony attached by chitinous rhizoids at its base. Autozooids in alternating whorls of 6–16, rhomboidal to hexagonal, separated by raised ridges; cryptocyst concave and granular. Opesia crescentic, in distal half of autozooid; proximal rim convex and slightly raised, forming a rounded proximal lip. A pair of large rounded denticles placed in proximal corners of opesia, projecting forward; a few inconspicuous minute denticles at inner distal rim of opesia. Avicularia common, as large as autozooids; rostrum high-arched, occupying distal half of avicularium, with rounded mandible and stout, ridge-like mandibular pivots. Ovicell completely immersed, distal to maternal autozooid; its aperture semielliptical to subtriangular.

n min–max mean SD Autozooid length 20 0.321–0.389 0.359 0.018 Autozooid width 20 0.228–0.321 0.262 0.024 Opesia length 20 0.068–0.093 0.085 0.007 Opesia width 20 0.111–0.148 0.131 0.012 Avicularium mandible length 20 0.179–0.216 0.201 0.014 Avicularium mandible width 20 0.154–0.204 0.173 0.017 Remarks. This is the first formally characterized species of Cellaria in Brazilian waters. It is particularly distinguished by the shape of the rostrum of the vicarious avicularium. All colonies of C. subtropicalis in the REVIZEE South samples have broken branch tips where it is possible to see incipient bifurcation. One transverse section at the end of a colony shows two opposing circular zooidal walls separated by a calcareous wall; each of the opposing zooids has a few radial calcareous layers. The holotype specimen from Rio de Janeiro has unjoined basal internodes with regular branching, and rhizoids at its axis.

Distribution. Brazil: off Rio de Janeiro, São Paulo and Santa Catarina states, 43–151 m (present study).

Figures

FIGURES 12 – 16. Cellaria subtropicalis n. sp., MZUSP 0 45 (part of the holotype specimen), off Rio de Janeiro, Brazil. 12, Colony with bifurcation; 13, detail of the colony; 14, close-up of avicularium (left) and ovicelled zooid (right); 15, close-up of ovicelled zooid; 16, close-up of opesium, note the proximal condyles and the very small distal denticles at the inner rim of the opesia.