Metrarabdotos aff. jani Winston, Vieira & Woollacott, 2014

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 : 161-163

Metrarabdotos aff. jani Winston, Vieira & Woollacott, 2014

( Fig. 3A )

aff. Metrarabdotos jani Winston et al., 2014 : p. 198, fig. 38.

Material examined. Abrolhos Bank, Bahia State, Brazil: MNRJ-Bry1345, Parcel dos Abrolhos, 4 m depth, February 2014, col. R. Moura. G. Amado-Filho & A. Bastos.

Short description. Fragments of encrusting colonies with zooids disposed quincuncially. Frontal wall tuberculate with large and almost circular areolar pores. Secondary orifice circular with a small U-shaped sinus; a simple, elongated and curved avicularium present lateral to the orifice. Ovicell not observed.

Geographic distribution. Bahia, Espírito Santo and Rio de Janeiro states ( Canu & Bassler 1928a; Marcus 1955; Santana et al. 2009; Winston et al. 2014; Almeida et al. 2017; Bastos et al. 2018; present study).

Remarks. Winston et al. (2014) described Metrarabdotos jani from Rio de Janeiro State and mentioned two characteristic features of the ovicell: the absence of pores on the ooecial surface and the presence of more than a single line of areolar pores. The specimens from Abrolhos are very similar to M. jani but no ovicells have been observed. Since the main diagnostic taxonomic features are the ovicells, we identify the studied material as M. aff. jani .

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Figures

FIGURE 3. Scanning electron micrographs of four bryozoan species. A. Metrarabdotos aff. jani, detail of some autozooids showing orifice with small, slit-shaped sinus and lateral, elongate avicularium. B. Metrarabdotos sp., general view of the fragment showing some autozooids with almost circular orifice and a pair of lateral distal avicularium. C–G. Parasmittina distincta n. sp. C. General view of a fragment showing autozooids with two oral spine bases and different kinds of avicularia: shoe-shaped, triangular and elongate. D. General view of a fragment showing autozooids with almost circular orifice, large lyrula, three or four oral spine bases and shoe-shaped avicularium. E. Detail of orifice showing four oral spine bases, large anvil-shaped lyrula and prominent condyles. F. Detail of two autozooids with two and three distal oral spines and short and large triangular lateral avicularium. G. General view of a fragment showing autozooid with two oral distal spines, lyrula and a putative ooecium. H. Parasmittina abrolhosensis n. sp., general view of a fragment showing some autozooids with different kinds of avicularia, orifice circular with three to four oral spine bases and tall and narrow lyrula.