Therenia dianae Ramalho & Moraes, 2021

Ramalho, Laís V., Moraes, Fernando C., Salgado, Leonardo T., Bastos, Alex C. & Moura, Rodrigo L., 2021, Bryozoa from the reefs off the Amazon River mouth: checklist, thirteen new species, and notes on their ecology and distribution, Zootaxa 4950 (1), pp. 1-45 : 20

Therenia dianae Ramalho & Moraes n. sp.

( Fig. 9E–G )

Material examined. Holotype: MNRJBRY-1431: Brazil, Amapá state (Sta #3, 03°35.4267’N – 049°07.6028’W), 90 m, on rhodolith, 26 September 2014, collected by Fernando Moraes & Rodrigo Moura (NHo Cruzeiro do Sul ).

Etymology. Named after Diana Vieira Canabarro Savi, daughter of the first author.

Diagnosis. Autozooidal frontal shield perforate by tiny pseudopores; orifice almost circular with a pair of rectangular condyles. Single avicularium, somewhat oval, variably broader at the distal end, with a thick rim, without columella and somewhat twisted. Ovicell usually immersed, except at the colony border, frontally formed by a flat, smooth, crescentic and broad gymnocystal band.

Description. Colony encrusting, multiserial, unilaminar. Autozooids polygonal, longer than wide [L 550–655– 737 (SD 50, N 13); W 414–472– 530 µm (SD 35, N 15)]; frontal shield flat, perforated by tiny and closely-spaced pseudopores, sometimes lacking from the proximal orificial region; 4–5 larger marginal areolar pores widely spaced ( Fig. 9E–G ). Orifice wider than long [L 103–119–130 (SD 9, N 13); W 123–148– 168 µm (SD 13, N 13)], almost circular, with a deeply immersed shelf along the distolateral margin, a small U-shaped sinus proximally and a pair of rectangular condyles almost as long as the proximal margin ( Fig. 9G ); distolateral orifice border in autozooid with a thickened calcified rim ( Fig. 9E–G ). Avicularium [L 120–162–187 (SD 19, N 20); W 107–135– 170 µm (SD 19, N 17)] single, proximolateral to orifice, right or left placed at the distal end of an elongate and perforated cystid, somewhat oval, variably broader at the distal end, with a very thick (variable) rim; crossbar complete, thick, without columella and somewhat twisted ( Fig. 9F, G ). Ovicell more visible in the zooids placed at the edge of the colony, usually immersed in other parts; ooecial surface smooth, frontally formed by a flat, smooth, crescentic and broad gymnocystal band ( Fig. 9F, G ); aperture closed by zooidal operculum.

Remarks. Berning et al. (2008) revised the genus Therenia David & Pouyet, 1978 and distinguished it from Escharina Milne Edwards, 1836 and Herentia Gray, 1848 mainly by the pseudoporous frontal shield, the greater number and smaller size of communication pores along the vertical walls, and the asymmetrical and usually twisted avicularium crossbar. Canu & Bassler (1928a) and Marcus (1955) identified some specimens from Rio de Janeiro and Espírito Santo states ( Brazil) as Therenia porosa ( Smitt, 1873) , but Berning et al. (2008) noted that those specimens have broader sinus and different condyles and are likely to represent an undescribed species. These Brazilian specimens also contrast with T. dianae Ramalho & Moraes n. sp. by the broader sinus, smaller condyles, smaller avicularium with a less developed rim.

Therenia porosa described from Florida ( Winston 2005) differs from the new species in having smaller oval avicularium (L 100; W 80 µm on average), without a well developed rim and such a distinct cystid, and orifice with robust condyles. Therenia rosei Berning et al., 2008 also resembles T. dianae Ramalho & Moraes n. sp., but has larger frontal pseudopores, wider sinus, thickened rim framing the distolateral orifice margin, and oval to kidneyshaped avicularium rostrum.

Figures

FIGURE 9. A–D. Thornelya atlanticoensis Ramalho & Moraes n. sp. (Holotype MNRJBRY-1452). A. Colony with both ovicellate and non-ovicellate zooids. B. Autozooids showing orifice with spines, and lateral avicularia. C. Unbleached colony showing zooids with long spines. D. Fertile zooid showing lateral avicularia and ovicell bearing a small avicularium. E–G. Therenia dianae Ramalho & Moraes n. sp. (Holotype MNRJBRY-1431). E. Colony edge with several fertile and infertile zooids and large avicularium. F. Detail of zooids showing orifices with a small sinus, and avicularia. G. Detail of an ovicellate zooid. Scale bars: A, E, 500 µm; B, C, 250 µm; D, 100 µm; F, G, 200 µm.