Hippaliosina imperfecta ( Canu & Bassler, 1928a )

Ramalho, Laís V., Taylor, Paul D., Moraes, Fernando Coreixas, Moura, Rodrigo, Amado-Filho, Gilberto M. & Bastos, Alex C., 2018, Bryozoan framework composition in the oddly shaped reefs from Abrolhos Bank, Brazil, southwestern Atlantic: taxonomy and ecology, Zootaxa 4483 (1), pp. 155-186 : 169

Hippaliosina imperfecta ( Canu & Bassler, 1928a)

( Fig. 5F )

Gephyrophora imperfecta Canu & Bassler, 1928a: 86 , fig. 1.

Hippaliosina imperfecta: Marcus, 1949: 26 , fig. 40; 1955: 306, figs 78, 79; Winston et al., 2014: 209, fig. 44; Almeida et al., 2015a: 5; Almeida et al., 2017: 303, figs 60, 61; Bastos et al., 2018: table 1.

Material examined. Abrolhos Bank, Bahia State, Brazil: MNRJ-Bry1343, Parcel dos Abrolhos, 4 m depth, February 2014, col. R. Moura, G. Amado-Filho & A. Bastos.

Short description. Encrusting colony with zooids hexagonal or polygonal; frontal wall granular with only small, rounded areolar pores. Orifice rounded distally and concave proximally with a pronounced pair of condyles. A pair of avicularia, occasionally only one, located latero-distally to the orifice, rostrum elongated and triangular. Ovicell not observed.

Geographic distribution. Bahia, Espírito Santo and Rio de Janeiro states, Brazil ( Marcus 1949, 1955; Winston et al. 2014; Almeida et al. 2015a; Almeida et al. 2017; Bastos et al. 2018).

Remarks. Hippaliosina imperfecta is characterized mainly by the paired avicularia (rarely one) with spearshaped rostra located latero-distally to the orifice. It resembles H. rostrigera ( Smitt, 1873) but differs in the size of the orifice (shorter in H. rostrigera ) and the shape/position of the avicularia (beginning above the orifice and with the rostrum slightly curved in H. rostrigera ).

Figures

FIGURE 5. Scanning electron micrographs of five bryozoan species. A, B. Stylopoma variabilis n. sp. A. Detail of a small fragment showing some zooids and an ooecium. B. Frontal view of one ooecium showing the crescent-shaped aperture and the fused and asymmetrical labellum. C–E. Stylopoma hastata n. sp. C. Detail of part of the colony showing zooids and different kinds of avicularia: small and triangular lateral oral avicularia, two large and spear-shaped interzooidal avicularia, and a giant elongated and curved avicularium. D. Detail of the distal part of a zooid showing the orifice with U-shaped sinus, small condyles, and a triangular lateral avicularium. E. Detail of a giant avicularium with curved, elongate rostrum. F. Hippaliosina imperfecta, detail of two zooids with a pair of elongate distal avicularia. G. Utinga castanea, detail of the colony showing zooids with different kinds of avicularia and ooecia with a pair of small avicularia. H. Arthropoma cecilii, detail of fertile and infertile zooids showing orifices, perforate frontal walls and smooth ooecia.