Exechonella, Canu & Bassler in Duvergier, 1924

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 : 159

Exechonella sp.

( Fig. 2E )

Material examined. Abrolhos Bank, Bahia State, Brazil: MNRJ-Bry1375, Parcel dos Abrolhos, 4 m depth, February 2014, col. R. Moura, G. Amado-Filho & A. Bastos.

Description. Small encrusting fragments comprising a few zooids ( Fig. 2E ). Autozooids rhomboidal, longer than wide, separated by deep fissures; frontal wall convex, perforated by large circular pores surrounded by a smooth flat collar. Orifice almost quadrate, as wide as long; condyles, avicularia, kenozooids and ovicells not observed.

Geographic distribution. Abrolhos Bank, Bahia State ( Bastos et al. 2018; present study).

Remarks. Due to the poor preservation and difficulty of obtaining colonies from the inner core, this specimen can be identified only to genus level. According to Cáceres-Chamizo et al. (2017), two species of Exechonella are confirmed to occur in Brazilian waters: E. brasiliensis Canu & Bassler, 1928a , described from the Bahia coast ( Canu & Bassler 1928a; Vieira et al. 2008), and E. vieirai Cáceres-Chamizo et al. 2017 , described from Alagoas and Bahia states ( Vieira et al. 2008; Winston et al. 2014; Almeida et al. 2015a).

Figures

FIGURE 2. Scanning electron micrographs of six bryozoan species. A. Steginoporella magnilabris, part of the colony showing the shape and disposition of the autozooids. B. Labioporella tuberculata, part of the colony with some autozooids. C, D. Crassimarginatella winstonae n. sp., general view of the colony with autozooids and one avicularium. E. Detail of the colony showing an interzooidal avicularium. E. Exechonella sp., general view of a colony fragment. F. Reptadeonella bipartita, general view of colony part showing some autozooids with elliptic orifice, median avicularium and ascopore. G, H. Celleporaria atlantica, detail of some zooids showing orifices, and suboral avicularia on umbos. H. Detail of an autozooid showing an avicularium at the base of the umbo.