Trematooecia arborescens (Canu & Bassler, 1928) Almeida & Souza & Menegola & Sanner & Vieira, 2014

Almeida, Ana C. S., Souza, Facelucia B. C., Menegola, Carla M. S., Sanner, Joann & Vieira, Leandro M., 2014, Taxonomic review of the family Colatooeciidae Winston, 2005 (Bryozoa, Cheilostomata), with description of seven new species, Zootaxa 3868 (1), pp. 1-61 : 40-42

Trematooecia arborescens (Canu & Bassler, 1928) n. comb.

( Figs 25–26 , Table 6 )

Rhynchozoon arborescens Canu & Bassler, 1928b: 32 , pl. 7, figs 4–10. [Bahia and Rio de Janeiro, Brazil]

Rhynchozoon arborescens: Souza 1989: 502 . [Bahia, Brazil]

Cigclisula arborescens: Vieira et al. 2010a: 29 , figs 67–72. [Rio de Janeiro and São Paulo, Brazil]

Material examined. Lectotype: USNM 8565 (see Vieira et al. 2010a), Rhynchozoon arborescens, F. Canu & R. Bassler det., Bahia and Rio de Janeiro, Brazil . Additional specimens: NHMUK 1899.7.1.5283; NHMUK 1899.7 .1.5290, ‘ Lepralia adamitica’, G. Busk col., HMS ‘ Herald’, John Adams Bank ( Victoria Bank , Espírito Santo, Brazil) ; UFBA 527 , Trematooecia arborescens, A.C. Almeida det., Camaçari , Bahia, 14–38 m ; UFBA 553 , Trematooecia arborescens, A.C. Almeida det., Camaçari, Baía de Todos os Santos , Brazil ; UFBA 555 , Trematooecia arborescens, A.C. Almeida det., Camaçari , Bahia, 50 m ; MZUSP 0315 , Cigclisula arborescens, L.M. Vieira det., project REVIZEE South SCORE, RV ‘ Prof. Wladimir Besnard’, station 6662, Rio de Janeiro, 135 m ; MZUSP 0316 , Cigclisula arborescens, L.M. Vieira det., project REVIZEE South SCORE, RV ‘ Prof. Wladimir Besnard’, station 6674, São Paulo, 122 m ; MZUSP 0317 , Cigclisula arborescens, L.M. Vieira det., project REVIZEE South SCORE, RV ‘ Prof. Wladimir Besnard’, station 6678, São Paulo, 99 m.

Description. Colony erect, bilaminar, branching. Skeleton red. Zooids hexagonal to polygonal, generally longer than wide, delimited by slightly raised sinuous margins. Frontal shield heavily calcified, marginally punctured by 18–24 pores, smooth. Primary orifice large relative to frontal shield, elliptical, longer than wide, sunken, with an arcuate anter and deeply concave poster, separated by 2 proximolateral downcurved condyles. Secondary orifice surrounded by 4–6 low, blunt processes. Suboral, elliptical, laterally directed avicularium of 2 sizes, the smaller with smooth distal rostral margins, the larger with serrated distal rostral margins. Frontal avicularia small, elliptical with serrated distal rostral margins, often 2 per zooid, placed at zooidal margins. Interzooidal avicularia at colony margins, large, longer than wide, rostrum spatulate; calcified palate occupying more than half rostral length; foramen rounded. Ovicelled zooids larger than non-ovicelled zooids. Ooecium immersed, flattened hood; ectooecium granular with frontal semicircular to circular membranous area.

Remarks. Vieira et al. (2010a) transferred this species from Rhynchozoon Hincks, 1895 to Cigclisula based on the frontal shield, peristomial complex and ooecium, but comparison with C. occlusa , the type species of the genus, shows clear differences in the ectooecium compared to Trematooecia , to which genus R. arborescens must be transferred.

Large, erect species of Trematooecia have routinely been assigned to Cigclisula , including not only the example of C. arborescens ( Vieira et al. 2010a) but also C. verticalis ( Hageman et al. 1998, following Hastings 1932 and Harmer 1957) and C. gemmea ( Winston & Woollacott 2009) . However, both erect and encrusting colonies can be found in Cigclisula and Trematooecia . We argue that these two genera can be distinguished morphologically only by ooecial structure, hence the absence of fertile colonies may make species assignment difficult.

Uniquely in the genus, Trematooecia arborescens has immersed ooecia and short blunt processes around the secondary orifice. This species resembles T. gemmea and T. verticalis in having erect bilaminar colonies and a marginally punctured frontal shield, but differs in the immersed ooecium and an ectooecium with a frontal circular membranous area. Other differences between T. arborescens and T. gemmea are the secondary orifice (with solid tubercles in T. gemmea and low blunt processes in T. arborescens ). Trematooecia verticalis is distinguished by the absence of tubercles around the secondary orifice and lack of suboral avicularia.

Distribution. Atlantic: Brazil (Bahia to São Paulo).

Figures

FIGURE 25. Trematooecia arborescens (Canu & Bassler, 1928). A–D, USNM 8565, lectotype, Brazil. A, zooids at growing edge of branch. B, primary orifice. C, D, ovicelled zooids and tiny elliptical frontal avicularia. Scale bars: A = 500 µm; B = 100 µm; C, D = 200 µm.

FIGURE 26. Trematooecia arborescens (Canu & Bassler, 1928). A–D, UFBA 555, Brazil. A, entire erect colony. B, close-up of branch. C, D, zooids with tiny, elliptical frontal avicularia and spatulate interzooidal avicularia. E, ovicelled zooids. F, closeup of ovicelled zooids. Scale bars: A = 1 mm; B = 500 µm; C, E, F = 200 µm; D = 100 µm.