Thalamoporella floridana Osburn, 1940

Vieira, Leandro M., Almeida, Ana C. S. & Winston, Judith E., 2016, Taxonomy of intertidal cheilostome Bryozoa of Maceió, northeastern Brazil. Part 1: Suborders Inovicellina, Malacostegina and Thalamoporellina, Zootaxa 4097 (1), pp. 59-83 : 77-79

Thalamoporella floridana Osburn, 1940

( Figs. 37–39 )

Thalamoporella gothica var floridana Osburn, 1940: 378 , pl. 5, figs. 42–43. [ Puerto Rico] Thalamoporella gothica var floridana: Maturo, 1957: 40 , fig. 35. [ USA: North Carolina] Thalamoporella gothica var prominens: Marcus, 1937: 53 , pl. 10, fig. 25A, pl. 11, fig 25B. [ Brazil: São Paulo] Non Thalamoporella Rozeri var. C ( prominens ) Levinsen, 1909: 183. [ Australia]

Thalamoporella gothica var prominens: Marcus, 1938: 23 , pl. 4, fig. 10A–B. [ Brazil: São Paulo] Thalamoporella floridana: Winston, 1982: 126 , pl. 126, fig. 41. [ USA: Florida]

Thalamoporella floridana: Chaney et al., 1989: 348 , figs 6a–b. [ USA: South Carolina and Florida] Thalamoporella floridana: Soule et al., 1999: 32 , figs. 48–50. [Caribbean and USA: Florida] Thalamoporella floridana: Vieira et al., 2008: 21 . [ Brazil: São Paulo]

Material examined. UFBA 1598, UFPE 0 22, UFPE 0 79, Sobral sewer outfall, Maceió, Alagoas, Brazil, 9º40'45" S, 35º45'01" W, intertidal, on hydroids, coll. 11 August 2007 by L.M. Vieira & M.D. Correia.

Description. Colony encrusting, multiserial, forming bilaminar patches attached to artificial structures, hydroids and algae. Autozooids arranged multiserially, alternating, rectangular, 0.469–0.655 mm (0.537 ± 0.048) long and 0.235–0.371 mm (0.286 ± 0.032) wide, separated by distinct grooves. Cryptocyst granular and porous, occupying almost the entire zooidal length; two large rounded unequal opesiules, with usually only one (rarely two) descending into the basal wall, with insertion about half of zooid width. Polypide tube and opesiules depressed. A single small pore in the distal third of the basal wall. Aboral rounded tubercles present on either side of orifice. Aperture wider than long, 0.142–0.191 mm (0.167 ± 0.013) long and about 0.185 mm wide, arcuate distally and slightly ridged proximally, with tiny condyles. Interzooidal avicularia shaped like a gothic arch, about 50% of the autozooid length, 0.185–0.309 mm (0.256 ± 0.035) long and 0.099–0.148 mm (0.121 ± 0.013) wide, rostrum about 0.170 mm long with an acute tip, opesia widely open, and a small cryptocyst (about 0.080 mm long). Spicules in the form of calipers, about 0.030–0.130 mm wide. No ovicells observed.

Remarks. Three species of Thalamoporella are known from Brazil: Thalamoporella falcifera ( Hincks, 1880) , Thalamoporella floridana Osburn, 1940 and Thalamoporella evelinae Marcus, 1939 ( Vieira et al. 2008; Almeida et al. 2015b). Other specimens from Rio Grande do Norte (NE) and Bahia were reported only as Thalamoporella sp. ( Machado & Souza, 1994; Almeida et al. 2015b). As previously noticed by Soule et al. (1999), specimens named as T. falcifera by Marcus (1937) may represent a distinct species because they lack avicularia (common in and characteristic of T. falcifera ), have spicules in the form of compasses and calipers ( T. falcifera has only compasses), and have numerous ovicells (unknown in T. falcifera ). The absence of avicularia and the presence of ovicells distinguishes T. falcifera sensu Marcus (1937) and T. evelinae from T. floridana .

Thalamoporella floridana is characterized by avicularia shaped like a gothic arch, spicules that consist mainly of calipers (compasses are rare), and by the absence of ovicells. Specimens reported as T. gothica var. prominens from São Paulo ( Marcus 1937) resemble those here figured in regard to the avicularia (when present) and zooidal shape, but material analyzed by Marcus is distinct in having compass spicules, absent in specimens from Alagoas and rare in material from the USA ( Winston 1982). The specimens from São Paulo ( Marcus 1937, 1938) were reassigned to T. floridana by Vieira et al. (2008). Thalamoporella prominens ( Levinsen, 1909) , which is absent in the Brazilian coast, is distinguished from T. floridana by its large avicularia, about 0.400– 0.430 mm long. The avicularia in specimens from Alagoas are slightly shorter than those of specimens from the USA and the Caribbean, and we believe the size difference may reflect local environmental conditions.

Distribution. Thalamoporella floridana is found in Western Atlantic, from the United States (North Carolina) to southeast Brazil. This is the first record of the species in Alagoas.

Figures

FIGURES 36 – 39 Species of Thalamoporellina from Maceió, Maceió, Alagoas, Brazil; 36, Steginoporella magnilabris, UFPE 0 82, Meirim, Maceió, Alagoas, Brazil, group of zooids, with A-zooids (small) and B-zooids (large); 37 – 39, Thalamoporella floridana, UFPE 0 79, Sobral, Maceió, Alagoas, Brazil; 37, group of zooids and one interzooidal avicularium; 38, close-up of orifice; 39, close-up of internal wall with some spicules (calipers).