Conescharellina bocki, 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 : 42-44

Conescharellina bocki n. sp.

( Figures 104–109 )

Material examined. Holotype. MZUSP 0 371, Brazil, project REVIZEE South SCORE, RV ‘Prof. Wladimir Besnard’, station 6693. Paratypes. MZUSP 0 372, Brazil, project REVIZEE South SCORE, RV ‘Prof. Wladimir Besnard’, station 6693. MZUSP 0454–478, station 6693. Additional material. MZUSP 0 373, Brazil, project REVIZEE South SCORE, RV ‘Prof. Wladimir Besnard’, station 6661. MZUSP 0 374, station 6675. MZUSP 0 375, station 6693.

Diagnosis. Colony regularly conical; narrow apical end pointed, lacking clear areas of origination of rhizoids; antapical end somewhat concave, with a central depression owing to the way the zooids and their peristomes project outwards and upwards radially from the colony centre.

Etymology. Conescharellina bocki n. sp. honours Philip E. Bock for his many contributions to bryozoology, especially the invaluable Bryozoa Home Page.

Description. Colony more or less regularly conical, tending towards elongate and bullet-shaped, up to 7.2 mm long and 4.5 mm widest diameter. About one third to a half the length of the colony with open orifices, the remainder occluded by calcification; orifices arranged roughly quincuncially such as not to be in regular longitudinal or diagonal rows. The narrow apical end pointed, lacking clear areas of origination of rhizoids except for an apical foramen in some colonies. Scattered tiny areolar-septular pores and small circular avicularia present, the latter with a crossbar and ligula. Antapical end of colony somewhat concave, with a central depression owing to the way the zooids and their peristomes project outwards and upwards radially from the colony centre; more or less circular in overall outline or somewhat oval owing to lateral flattening. Peristomes somewhat tubular, variable, either symmetrical with one avicularium more prominent than the others and a descending ridge below it, or asymmetrical with all peristomial avicularia (2 or more) prominent and projecting equally, each with a crossbar and tiny columella. Older peristomial orifices with a slightly convex closure plate, with 1 or more avicularia on the rim. Primary orifice concealed at bottom of peristome, with a straight, broad, proximal margin; operculum transversely oval with a thin sclerite around its entire margin to the position of the small proximolateral condyles of the orifice; an occlusor muscle insertion on each side distolaterally. Ovicell inconspicuous, visible as a slight bulge at the base of the zooidal peristome on its apical side, the ectooecium smooth, completely concealed by secondary calcification like that of the zooidal surface, opening just above the primary orifice.

Remarks. The differences between this and the preceding species have already been commented on in the remarks under C. cookae . These two species constitute the first known species of Conescharellina in Brazilian waters ( Vieira et al. 2008). Some 32 nominal Recent species already exist, all from the Indo-Pacific. Antapical ends of the colonies of both species support small infertile colonies of Aulopocella americana ; this species requires a hard surface for larval settlement and conescharellinids provide that in the soft-bottom environment where these species co-exist.

Previously, monotypic Sphaerulobryozoon d’Hondt, 1981 was the only known genus of Atlantic conescharellinid, described off northeastern Brazil ( Vieira et al. 2008), and also known from a single colony collected in REVIZEE samples from southeastern Brazil (Station 6675, MZUSP 0376).

Distribution. Brazil: off São Paulo and Santa Catarina state, 147–517 m (present study).

Figures

FIGURES 104 – 109. Conescharellina bocki n. sp., off São Paulo, Brazil (REVIZEE station 6693). 104, Colony; 105, antapical end of colony; 106, ovicelled zooid; 107, autozooids with some peristomial avicularia and kenozooids; 108, close-up of orifice; 109, close-up of kenozooid.