Cliona amplicavata Rützler, 1974

(Tab. 1–2, 5; Fig. 8A–H)

Studied material. MNRJ 20511, Arraial D’Ajuda (16°29.861′ S, 39°4.068′ W, Porto Seguro, BA, Brazil), intertidal, coll. Leite D., 20 th March 2019 .

Description. Alpha growth stage, ca. 5 cm in maximum diameter, with circular oscular and ostial papillae, mostly 1–3 mm in diameter. Color in vivo light-yellow, and beige in fixative (Tab. 5; Fig. 8A).

Skeleton. Overall confused and in low density, except in papillae, where tylostyles form a dense felted layer in inhalant papillae and a palisade in oscular papillae, (Figs. 8B–D). Several colored rounded cells throughout the ectosomal (mainly) and choanosomal regions (Fig. 8E).

Spicules. Megascleres (Tab. 5; Figs. 8F–H): tylostyles, slightly curved, pronounced, usually subterminal head, 160‒244.0‒302 x 3‒7.0‒10 µm. Microscleres (Tab. 5; Fig. 8H): raphides, slightly curved, 67‒91.0‒113 µm.

Distribution. Previously Bermuda (Ŗtzler 1974), Mediterranean (Spain — Rosell & Uriz 2002), Greater Caribbean (Western Carib.— Ŗtzler et al. 2014; Southern Gulf of Mexico— Ugalde et al. 2015), Pacific Central America (Costa Rica, Nicaragua — Pacheco et al. 2018). New record—Southwestern Atlantic (Costa do Descobrimento, BA, Brazil).

Ecology. Excavating limestone substrate under boulders amidst abundant silted filamentous organisms, mostly algae, hydroids and bryozoans.

Remarks. The species had already been collected in the southwestern Atlantic (Brazil), but had not been formally described (Dr. C.V. Leal, unpubl. res.). Data presented here perfectly match previous descriptions of the species. Its in situ appearance is virtually indistinguishable from the commoner at Costa do Descobrimento, C. aff. celata (Tab. 5).