Nevianipora floridana ( Osburn, 1940 )

Ramalho, L. V., Muricy, G. & Taylor, P. D., 2009, Cyclostomata (Bryozoa, Stenolaemata) from Rio de Janeiro State, Brazil, Zootaxa 2057, pp. 32-52 : 41-43

Nevianipora floridana ( Osburn, 1940)

( Figs 3D, 6A–E)

Diaperoecia floridana Osburn, 1940: 331 ; Osburn 1947: 5.

Nevianipora floridana: Buge 1979: 229 ; Taylor 2001: 583.

Material examined. Arraial do Cabo : MNRJ-051, Forno beach, 14 November 2002, collector L. V. Ramalho and G. Muricy, depth 5 m. MNRJ-192, Boqueirão , 3 January 2003, collector L. Granthom, depth 5 m. MNRJ- 193, Forno beach (Restaurante Flutuante), 30 September 2003, collector L. V. Ramalho, depth 1 m. MNRJ- 055, Forno Harbor (quebra-mar), 6 September 2003, collector L. V. Ramalho, depth 1 m. MNRJ-050, Pedra Vermelha (Cabo Frio Island), 27 February 2003, collector L. V. Ramalho, depth 5 m. MNRJ-194, Forno Harbour , 7 September 2003, collector L. V. Ramalho, depth 6 m.

Comparative material: Nevianipora milneana: NHM 86.3.6.44–46; NHM 11.10.1.143, Madeira.

Description. Colony large (3–3.5 cm), white, dichotomously branched ( Fig. 6A), unjointed, with branches 514–(674)–970 µm wide. Kenozooidal struts arising from dorsal sides of branches. Autozooids tubular, apertures arranged in non-connate series of 4–5, opening on frontal side of branches, peristome elevated (267–(380)–453 µm long x 133–(143)–160 µm wide), gently curved; aperture circular (99–(106)–109 µm diameter). Median zooids slightly shorter, located a little lower in zooidal series; lateral autozooids with much longer peristomes than others ( Fig. 6B). Distance between autozooidal series (without peristomes) 388–(477)–776 µm. Frontal wall with abundant small pseudopores and transverse wrinkles ( Fig. 6B–C). Dorsal side with tiny pseudopores and small constrictions or horizontal wrinkles ( Figure 6D). Gonozooids located immediately below branch bifurcations, occupying frontal median region of branch; irregularly shaped, narrow proximally and dilated distally, elongate-pyriform in outline ( Figs 3D, 6E); ooeciopore not terminal, flattened and laterally elongated, 68–(81)–97 µm long x 204–(207)–213 µm wide, normally located near autozooidal aperture; ooeciostome directed slightly towards proximal region of colony ( Fig. 3D). Small pseudopores scattered over gonozooid surface ( Fig. 6E).

Remarks. Two species of Nevianipora are known from Brazil: N. floridana and N. rugosa ( Osburn, 1940) , the latter recorded from Pernambuco (Recife) to Bahia states (Caravelas) by Buge (1979). The Rio de Janeiro material of N. floridana differs from N. rugosa , which has colonies that grow parallel to the substratum and fewer autozooids disposed in very irregular transverse series.

The species N. milneana (d’Orbigny, 1839) has more autozooids in each series (6–7) and wider branches (950–1300 µm). Nevianipora borgi Buge, 1979 has wider branches (900–1250 µm), a larger ooeciostome (310 µm) and autozooidal apertures (210–300 µm).

The material from Rio de Janeiro differs from N. floridana as redescribed by Buge (1979), which has a slightly larger maximum distance between autozooids. It also differs from the fossil specimen of N. floridana described by Taylor (2001), in which the ooeciopore is less transversely elongated. These differences are small, however, and can be interpreted as reflecting within-species variability.

Nevianipora floridana was recorded from Bahia ( Salvador and Caravelas) and São Paulo (Santos) states by Buge (1979). This is the first occurrence of this species in Rio de Janeiro State, closing a gap in its distribution in Brazil. Buge (1979) collected colonies at 38 m and 97–100 m depth. The colonies studied here were collected in much shallower waters varying from two to seven metres deep.

Ecology. Colonies were found associated with sponges and ascidians. They are fouled by the gymnolaemate bryozoans Amathia sp. and Catenicella uberrima (Harmer, 1957) and colonized by small ophiuroids.

Geographic distribution. World: Western Atlantic (Florida, Gulf of Mexico, Porto Rico, Venezuela, and Santa Helena) ( Buge 1979). Brazil: Bahia ( Salvador and Caravelas) and São Paulo (Santos) ( Buge 1979). Rio de Janeiro State: Arraial do Cabo (Forno beach, Forno Harbor, Boqueirão, and Pedra Vermelha).