Placospongia ruetzleri Van Soest, 2017

Mácola, Rosa & Menegola, Carla, 2021, A new species of Placospongia Gray, 1867 (Porifera, Demospongiae, Placospongiidae) and new record of P. ruetzleri van Soest, 2017 from Northeast, Brazil, Zootaxa 5072 (1), pp. 12-22 : 16-18

Placospongia ruetzleri Van Soest, 2017

( Fig. 3 ; Tab. 2 )

Placospongia ruetzleri Van Soest, 2017: 173 , figs 108 a–g.

Material examined. UFPE POR 1462 , Cabo de Santo Agostinho , Praia Enseada dos corais, 8º19’0.34’’S – 34º56’51.92’’W, Pernambuco State, Brazil, intertidal zone, June 3rd, 2011, coll. Pinheiro, U.

UFBA 769 , Itacimirim, Camaçari, 12°36’40.28”S – 38°02’26.06”W, Bahia State, Brazil, 1982, coll. Peixinho, S. ; UFBA 2991 , Baía de Camamu, Ilha da Pedra Furada , 13º53’35’’S – 38º59’58’’W, Bahia State, Brazil, intertidal zone, May, 2009, coll. Fernandez, J. & Santos, G. ; UFBA 1571 , Arembepe, Camaçari, - 12º47’00’’S – 38º11’00’’W, Bahia State, Brazil, intertidal zone, 0–1 m deep, January 12th, 1997, coll. Peixinho, S. ; UFBA 633 , Porto da Barra , Salvador, 13º00’06’’S – 38º32’00’’W, Bahia State, Brazil, <10 m deep, September 30, 1984, coll. Nunes, M.

Description. Encrusting sponges (Based on UFBA 769 measurements: Fragment 1: 36.51 mm length x 14.83 mm width, 5.10 mm thickness, fragment 2: 28.56 mm length x 22.88 mm width, 4.10 mm thickness; fragment 3: 25.99 mm length x 19.71 mm width, 3.53 mm thickness), covered by smooth and rigid cortical plates separated by contractible grooves ( Fig. 3A ). Brown color in life. Firm consistency, non-compressible sponges. Oscules not observed.

Skeleton. Cortex with densely packed selenasters. Choanosome with bundles of tylostyles disposed outwards, arising from a basal or a central axis of selenasters, providing support to cortex. Selenasters in different developmental stages, acanthomicrorhabds, and spirasters dispersed in the choanosome ( Fig. 3B ).

Spicules. Megascleres. Tylostyles in two size categories, straight with spherical tyles, hastate and blunt ( Fig. 3E ) or mucronate ( Fig. 3H ) ends in both. Tylostyles I ( Fig. 3C ), larger (530–912.3–1150µm/12.5–16.5–20µm); tylostyles II ( Fig. 3F ), smaller (190–300.5–540µm/7.5–11.4–15µm). Microscleres. Bean-shaped to oval or sometimes spherical selenasters ( Fig. 3I ) (47–67.3–77µm/33–55.5–70µm). Irregular spirasters ( Fig. 3J,K ), with twisted shaft presenting one or two spiral turns, rays bifurcate or with tuft concentrated in the ends (8–13 rays), with shorter and longer secondary rays and spines. Microspined rays disposed sparsely, exclusively at the convex side ( Fig. 3J ) or densely in throughout the spicule ( Fig. 3K ), with two terminal clusters and rays in central region (13–19–23µm/3– 3.7–6µm). Acanthomicrorhabds abundant ( Fig. 3L ), with straight or slightly sinuous shafts (6–9.7–13µm/2–2.9– 4µm).

Substratum, depth range and ecology. Encrusting rocky substratum in the intertidal zone, or subtidal to <10 m deep.

Distribution. Southwest Atlantic. Originally described from Suriname and the Guyana Shelf ( Van Soest, 2017). In the present study, it is recorded for the first time from Brazil: Pernambuco State (Cabo de Santo Agostinho, Praia Enseada dos Corais), Bahia State (Camaçari: Northern coast, Todos os Santos Bay: Salvador, Praia Farol da Barra: central region and Baía de Camamu: Ilha da Pedra Furada).

Remarks. P. ruetzleri was originally described from the Guyana shelf, in French Guyana and was reported from Florida, Jamaica, Grenada, Colombia and NE Brazil ( van Soest, 2017). However, this Brazilian record was considered doubtful due to insufficient information ( van Soest, 2017). In the present study, we confirm its occurrence to northeastern Brazil.

In Suriname, this species was found in sandy bottom and in murky waters with muddy bottom at 25–34 m depths, the occurrence of sponges in this type of substrate is considered rare ( van Soest 2017). Brazilian species of P. ruetzleri are recorded for intertidal reef environments, composed by sandy sediments at 0–10 m depths .

Although the specimens from Brazil and from Suriname come from environments with distinct features (high turbid waters, and muddy bottoms in Suriname), the samples of these two regions contain the same spicular categories, with presence of unique spirasters with spines disposed exclusively at the convex side of the microsclere. In the Brazilian specimens, here described, the spirasters can be sparsely spined or, more rarely, densely spined.

Figures

FIGURE 3. Placospongia ruetzleri (UFBA 769). (A) Preserved specimen; (B) Skeleton architecture (C) Tylostyle I; (D) Tylostyle I head; (E) Blunt ends of tylostyle I; (F) Tylostyle II; (G) Tylostyle II head; (H) Mucronate ends of tylotyle II; (I) Selenaster; (J) Streptaster; (K) Spiraster; (L) Microrhabd. Scales: A = 1 cm; B = 50 μm; C, F = 100 μm; D, E, G, H, I = 10 μm; J = 5 μm; K, L = 2 μm.