Mycale (Aegogropila) rubra, Cedro & Hajdu & Correia, 2013

Cedro, Victor R., Hajdu, Eduardo & Correia, Monica D., 2013, Three new intertidal sponges (Porifera: Demospongiae) from Brazil’s fringing urban reefs (Maceió, Alagoas, Brazil), and support for Rhabderemia’s exclusion from Poecilosclerida, Journal of Natural History 47 (33 - 34), pp. 2151-2174 : 2165-2170

Mycale (Aegogropila) rubra sp. nov.

Holotype

MNRJ 16270 (cross ref. EH–035), Ponta do Prego Reef (ca. 09 ◦ 31 ′ 48.76 ′′ S, 035 ◦ 35 ′ 29.44 ′′ W), Maceió ( AL, Brazil), intertidal, coll. E Hajdu, VR Cedro and MD Correia, 31 January 2010. Schyzoholotype, UFAL – POR 0605 .

Paratype

MNRJ 14050 , Riacho Doce Reef (09 ◦ 34 ′ 49 ′′ S, 035 ◦ 39 ′ 58 ′′ W), Maceió ( AL, Brazil) , intertidal, coll. V Cedro , 13 March 2010 .

Comparative material

Mycale (Aegogropila) americana van Soest, 1984 ( ZMA 4074, holotype). M. (A.) carmigropila Hajdu and Rützler, 1998 ( MNRJ 15602, 15679, Bocas del Toro, Panama – det. E. Hajdu). M. (A.) citrina Hajdu and Rützler, 1998 ( MNRJ 635, schyzoholotype). M. (A.) lilianae Carballo and Hajdu, 1998 ( MNRJ 381, holotype; formerly DZUSP 381).

Diagnosis

Mycale rubra sp. nov. is the only Tropical Western Atlantic Mycale (Aegogropila) with three categories of anisochelae, category two being 25–40 µm long, one of sigmas, two of toxas and no micracanthoxeas.

Description

Thinly encrusting fragile sponge, mostly 1–2 mm thick, c. 4 cm at its greatest diameter, surface smooth, with vein-like system of dermal canals ( Figure 2C ). Regular surface reticulation present, visible to the naked eye, albeit not as conspicuously so as in other co-occurring red sciophilous crustose Mycale , such as M. (A.) escarlatei Hajdu et al. 1995 and M. (Naviculina) diversisigmata van Soest, 1984 . Colour in situ orange-red, beige in ethanol. No oscula seen.

Skeleton. Ectosomal architecture from neatly reticulated Aegogropila pattern to undifferentiated Carmia -like arrangement of scattered spicules at various angles ( Figure 5A ), originating from the terminal brushes of the main skeletal tracts. Rosettes of anisochelae I seen here and there in ectosome. Both the latter and the sigmas appear more attached to the reticulation than free in interstices, where anisochelae II and III, as well as toxas, abound ( Figure 5B, C ). Choanosomal architecture (plumo)reticulated, consisting of ascending, variously interconnected paucispicular tracts of mycalostyles ending in terminal brushes in subdermal region.

Spicules ( Table 3). Megascleres. Mycalostyles, straight, slender, with rather discreet heads ( Figure 6A, B ). Length 194– 239.6 –249 µm, width 2.4– 3.1 –6.1 µm. Microscleres. Anisochelae I, head height nearly 60% of the whole spicule length, face view width nearly 40% of total length ( Figure 6C ). Height 44– 48. 6–55 µm. Anisochelae II, head height also nearly 60% whole spicule length, and face view width nearly 30% of the total length ( Figure 6D ). Height 14– 15.2 –17 µm. Anisochelae III, head height nearly 50% of whole spicule length ( Figure 6E ). Height 11.5– 12.6 –14 µm. Sigmas, single stout category, s-shaped ( Figure 6F ). Length 92– 93.1 –97 µm. Toxas I and II, deeply curved three times: I, length 128– 178.1 –243 µm; II, length 44– 63.2 –95 µm.

Ecology

Two specimens were found in our surveys of the sponge fauna of Maceió City’s coastal reefs. They occurred on the underside of a medium-sized coral boulder (holotype) and lining the shallow depressions underneath a rodolith (paratype).

Distribution

The species is a provisional Brazilian endemic, so far known only from its type locality (intertidal Maceió’s reefs – Riacho Doce, Figure 1B ; Ponta Prego, Figure 1D ).

Remarks

There were only six species of Mycale (Aegogropila) previously reported from the Tropical western Atlantic ( Table 3). Only three of these have toxas, namely M. (A.) arndti van Soest, 1984 , M. (A.) escarlatei and M. (A.) lilianae . Mycale (A.) arndti may have four categories of anisochelae and has sigmas in three size categories, which render it quite distinct from the new species. This is further realized by the anisocleistochelae shape of its anisochelae IV ( Hajdu & Rützler 1998) and rather smaller and shallower curved toxas when contrasted with categories present in the new species. Mycale (A.) escarlatei differs by its duck-bill shaped anisochelae II, much smaller toxas and possession of micracanthoxeas ( Hajdu et al. 1995). Mycale (A.) lilianae is surely the closest to the new species, as both share the occurrence of deeply curved toxas widely variable in length ( Carballo & Hajdu 1998). The characters judged here to support both species’ validity are the relatively larger anisochelae II, and the absence of a second much smaller category of sigmas, as well as of any micracanthoxeas in the new species.

Concluding remarks

Although the pressure of various human activities has intensified on northeastern Brazil’s coastal reefs over the last few decades ( Leão & Kikuchi 2005; Correia & Sovierzoski 2008), new species are still hidden in crevices and nearly every sciophilous habitat in these areas. Furthermore, in spite of extensive dredging conducted off these

(Continued)

M. (A.) citrina Hajdu and 339– 382.4 –456/ I, 32– 45.5 –48 s, 70– 74.9 –79 Lemon-yellow/Caribbean Rützler, 1998 holotype 8– 8.6 –9 II, 19– 21.6 –24 III, 13– 13.1 –14

population sensu Hajdu 339–477/7–11 I, 32–54 s, 69–88 and Rützler (1998) II, 18–26 III, 12–15

M. (A.) escarlate i Hajdu 249– 296.8 –350 I, 34– 39.6 –46 sI, 57– 67.4 –77 Crimson-red/Caribbean

et al. 1995 II, 24– 29.4 –33 sII, 20– 30.4 –39 and Brazil

III, 13– 12.5 –14 tI, 55– 66.5 –92

tII, 6– 14.8 –23

m, 3–4

M. (A.) lilianae Carballo 238– 255.7 –283/ I, 36– 40.2 –46 sI, 77– 86.7 –97 Light-yellow and

and Hajdu, 1998 4.1–6 II, 19– 21.4 –24 sII, 14.4–18 yellow-orange/ Brazil

III, 11– 14 – 17 t, 58– 117.9 –307

m, 6–13

reefs in the 1960s ( Calypso – Boury-Esnault 1973) and 2000s (Project REVIZEE – Muricy et al. 2006), such intertidal species were apparently not collected. Although it is possible that species such as those reported here, as well as Mycale (M.) alagoana Cedro et al., 2011 , will show up as soon as these collections are fully described, the former ( Boury-Esnault 1973) and ongoing study of those (e.g. Pinheiro et al. 2007; Vieira et al. 2010) has not yet revealed them, so the possibility cannot be ruled out that the intertidal or shallow subtidal fauna of sponges has an endemic component that needs enhanced conservation efforts, with the goal of preserving what remains, and permitting the likely discovery of additional sciophilous taxa.

Figures

Figure 1. Map showing South America and Brazil, with Alagoas state in black (upper left), an expanded Alagoas state with Maceió city in black (upper middle), and the collecting localities off Maceió ((A) Piscina dos Amores; (B) Riacho Doce; (C) Ponta do Meirim; (D) Ponta do Prego).

Figure 2. In situ photographs of the new species described in this study. (A) Plakina coerulea sp. nov. (holotype, MNRJ 14295 at Piscina dos Amores); (B) Rhabderemia meirimensis sp. nov. (holotype, MNRJ 14275 at Ponta do Meirim); (C) Mycale (Aegogropila) rubra sp. nov. (paratype, MNRJ 14050 at Praia do Francês). Scale bars: 1 cm.

Figure 5. Mycale (Aegogropila) rubra sp. nov. (holotype, MNRJ 16270). (A) Tangential section of ectosomal skeleton; (B, C) detail of ectosome showing abundant microscleres (a1, anisochelae–I; a2, anisochelae–II; a3, anisochelae–III; r, rosette; s1, sigmas–I; s2, sigmas–II; t, toxas). Scale bars: A, 100 µm; B, C, 50 µm.

Figure 6. Mycale (Aegogropila) rubra sp. nov. (holotype, MNRJ 16270). (A) Mycalostyle; (B) detail of mycalostyle base; (C) anisochelae I in oblique side view (top) and oblique face view (bottom); (D) anisochelae II (left, face view; middle, face view of young spicule; right, face view); (E) anisochelae III (side view); (F) sigma; (G) toxa I (both halves slightly overlaid); (H) toxa II. Scale bars: A, C–H, 20 µm; B, 50 µm.