Heteromeyenia Potts, 1881

Pinheiro, Ulisses, Calheira, Ludimila & Hajdu, Eduardo, 2015, A new species of freshwater sponge, Heteromeyenia barlettai sp. nov. from an aquarium in São Paulo, Brazil (Spongillida: Spongillidae), Zootaxa 4034 (2), pp. 351-363 : 352-357

Genus Heteromeyenia Potts, 1881

Synonymy. For synonymy see Manconi & Pronzato (2002).

Diagnosis. Spongillidae with encrusting body shape. Choanosomal skeleton an irregular network of paucispicular parallel fibres and undefined secondary tracts. Sparse spongin. Megascleres and microscleres acanthoxeas. Gemmules free in the sponge body. Foramen circular, tube short or long, with or without filiform extensions. Gemmular theca tri-layered with gemmuloscleres radially embedded. Gemmuloscleres in one or two categories: birotules and pseudobirotules (sensu Batista et al. 2007).

Type Species: Spongilla baileyi Bowerbank, 1863 (by subsequent designation; De Laubenfels 1936).

Heteromeyenia barlettai sp. nov.

Type locality. Aquarium in São Paulo, São Paulo State, Paraná Basin, Brazil.

Type specimens: Holotype. UFPEPOR 1728. Paratypes: UFPEPOR 1729 and UFPEPOR 1730 (collected together with the holotype).

Diagnosis. Sponge encrusting to slightly massive, with megascleres and microscleres acanthoxeas; only one category of birotule gemmuloscleres, with exclusively smooth rotules, radially inserted in outer and pneumatic layers (theca) of the gemmule.

Description of holotype. UFPEPOR 1728 is encrusting measuring 6 cm 2. Colour is creamy white in vivo, without colour change after preservation in ethanol. Megascleres acanthoxeas (250–280.3–310 / 8.8–9.9–12.5 µm), microscleres acanthoxeas (63–76.6–88 / 3.8–5.0–6.3 µm), gemmuloscleres birotules (58–61.1–68 / 5–5.6–7.5 / 17.5–18.0–20 µm), gemmules scattered throughout the sponge body (396–488–600 µm in diameter) ( Table 1).

Description. Sponges encrusting to slightly massive, 3–5 mm thick, 3 cm wide. Surface hispid with tubular and translucent oscules. Colour creamy white in vivo, without colour change after preservation in ethanol ( Fig. 1 ).

Consistency soft to fragile. Megascleres acanthoxeas (235–279.9–332 / 8.1–9.7–12.5 µm), slightly curved, with conical microspines scattered in the median portion ( Fig. 2 a,b). Microscleres acanthoxeas (63–78.3–106 / 3.8–5.3– 6.4 µm), straight to curved, entirely spined with a variable number of spines, usually more abundant and larger in the median portion of the shaft. Spines can be straight or curved, curved ones are simple and occur mainly towards the center of the spicule; straight ones are simple (rarely) or compound (predominantly), occur in the center of the spicule. The compound spines have a bouquet-like structure, where the primary spine supports the secondary ones ( Fig. 2 c,d). Gemmulosclere birotules ( Fig. 2 e) (58–62.9–71 / 5.0–6.6–9.7 // 16–18.5–23 µm), radially inserted in the theca of gemmules; shaft with conical spines (simple or compound) ( Fig. 2 f). Rotules are smooth, circular, convex and identical, with microspines on their margins, inserted perpendicularly, erect or recurved in either direction ( Fig. 2 g). Gemmules (396–488–600 µm) rare, small, spherical, scattered throughout the sponge body ( Fig. 3 a). Foramen short, with rosette-like collar from some gemmuloscleres radially inserted. Gemmular theca trilayered, well developed, with irregular spaces, gemmuloscleres radially inserted in the pneumatic layer, inner layer with compact spongin, outer layer irregularly outlined ( Fig. 3 b,c).

Species/ Specimens Locality Megasclere Microscleres Acanthoxea

Acanthoxea

Holotype (UFPEPOR 1728) SP, Brazil 250–280.3–310 / 63–76.6–88 / 8.8–9.9–12.5 3.8–5–6.3

Paratype (UFPEPOR 1729) SP, Brazil 245–280–332 / 64–76.9–87 / 8.1–9.6–11.3 4.8–5.3–6.4 Paratype (UFPEPOR 1730) SP, Brazil 235–279.3–319 / 64–81.3–106 / 8.1–9.5–9.7 4.8–5.7–6.4

continued.

Species/ Gemmuloscleres Gemmules Specimens Birotulate Pseudobirotulate

Holotype (UFPEPOR 1728) 58–61.1–68 / – 396–488–600

5–5.6–7.5 // 17.5–18–20

Paratype (UFPEPOR 1729) 58–64.6–71 / – – 6.4–7.5–9.7 // 16–18.9–23

Paratype (UFPEPOR 1730) – – –

Ecology. According to the aquarium owner, Mr. Fernando Barletta, an ideal condition for the development of these sponges is a pH 7.5 or higher. But when the specimens are subjected to lower pH (acidic conditions), the sponges produce gemmules and die. The sponges prefer the lentic sites in the aquarium, and can be found at leaves and roots of aquatic plants, crevices of woods, and the plastic filter, but not on the stones.

Etymology. The chosen specific name honors Fernando Barletta, the owner of the aquarium whose curiosity permitted the discovery of the new species.

Remarks. Batista et al. (2007) redefined the genus to allocate Heteromeyenia cristalina , which has only one category of gemmulosclere, differing from all other congeners that have two categories. Thus, by sharing this character, H. cristalina is the species most similar to H. barlettai sp. nov. However, the new species differs from H. cristalina by its gemmuloscleres which have smooth rotules, in contrast to the rotules of H.cristalina that are entirely covered in microspines. Futhermore, there are differences in the pattern of spination of the shaft of gemmuloscleres. Heteromeyenia barlettai sp. nov. has spines that are predominantly compound, against predominantly simple spines observed on the shafts of gemmuloscleres of H. cristalina . Although Batista et al.

(2007) did not describe compound spines, these can be observed in SEM images of gemmuloscleres (see Batista et al. 2007; Figs. 21–22). Another difference derives from the sizes of the spicules, as the megascleres, microscleres and gemmuloscleres of H. cristalina are larger than those of the new species (Table 1,2).

. latitenta ( Potts, 1881) (1) PensII˅anIª' USA 265–285 / 8–11 85 –100 / 2–3 50 –55 60–78 –

. stepanowii (Dysbowsky, 1884) (1) Czechoslovakia, 180–310 / 8–11 78 –88 / 2–3 58 –65 75–88 430–520

Germany, Poland,

Russia, China,

Japan, New South

Wales

. tentasperma ( Potts, 1880) (1) Wisconsin, USA 260–280 / 7–10 75 –80 / 2-3 50 –55 65–72 420–450

. tubisperma ( Potts, 1881) (1) Canada 190–230 / 7–10 85 –90 / 2-3 40 –48 60–70 500–550

. barlettai sp. nov. (5) SP, Brazil 235–279.9–332 / 63–78.3–106 / 58–62.9–71 / – 396–488–600

8.1–9.7–12.5 3.8–5.3–6.4 5–6.6–9.7 // 16–18.5–23

REFERENCES: (1) Penney & Racek (1968); (2) Batista et al. (2007); (3) Kilian & Wintermann-Kilian (1976); (4) Weltner (1895); (5) current work.

The natural environment of Heteromeyenia barlettai sp nov. is unknown. The macrophytes of the aquarium came from fish farm tanks near the Guarapiranga Reservoir, one of the main water sources for the city of São Paulo. The aquarium water was collected from the same reservoir. Probably, the gemmules were carried by the water or came attached to the macrophytes.

Figures

FIGURE 1. Heteromeyenia barlettai sp. nov. in situ. (a) H. barlettai sp. nov. (Holotype. UFPEPOR 1728) adhered to a leave of the macrophyte (Microsorum pteropusi). (b) H. barlettai sp. nov. adhered to a leave of the macrophyte (Vallisneria nana). (c) H. barlettai sp. nov. adhered to a root of the macrophyte (Pistia stratiotes). Scale bars: a – c 4 mm.

FIGURE 2. Scanning electron microscopy images of spicules of the holotype (UFPEPOR 1728) of Heteromeyenia barlettai sp. nov. (a) Megascleres: acanthoxeas. (b) Detail of the shaft of a megasclere. (c) Various shapes of acanthoxea microscleres. (d) Detail of the shaft of microscleres. (e) Various shapes of birotule gemmuloscleres. (f) Detail of the shaft of gemmuloscleres. (g) Detail of the rotules of gemmuloscleres. Scale bars: a 100 µm, b 10 µm, c, e 30 µm, d, f, g 5 µm.

FIGURE 3. Scanning electron microscopy images of gemmules of the holotype of Heteromeyenia barlettai sp. nov. (UFPEPOR 1728). (a) Gemmule. (b) Foramen of gemmule. (c) Well developed, tri-layered gemmular theca. Scale bars: a 300 µm, b, c 50 µm.