Aaptos hajdui, Carvalho, Mariana De S., Da Silva, Suzane M. & Pinheiro, Ulisses, 2013

Carvalho, Mariana De S., Da Silva, Suzane M. & Pinheiro, Ulisses, 2013, Two new species of Aaptos (Demospongiae, Hadromerida) from Brazil (western Atlantic), Zootaxa 3750 (4), pp. 357-366 : 359-361

Aaptos hajdui sp. nov.

( Figure 2 , 3 A–B; Table 1 )

Type material. Holotype: UFPEPOR 62—Campaign BPOT 0 2, station 0 4 (Potiguar Basin, Rio Grande do Norte State, 04°37’31.7”S – 36°46’0.7”W), 70–101 m depth, coll. R/V ‘Astro Garoupa’, 14/V/2003.

Schyzoholotype: MNRJ 16684.

Paratypes: UFPEPOR 181—Campaign BPOT 0 3, station A3 (Potiguar Basin, Rio Grande do Norte State, 04°49´58.0”S – 36°12´12.0”W), 50 m depth, coll. R/V ‘Astro Garoupa’, 13/XI/2003.

Schyzoparatypes: MNRJ 16688.

Diagnosis. Aaptos with an ectosomal skeleton with subectosomal cavities, composed of styles forming a palisade at the surface and bouquets formed by strongyloxeas branching below the surface. Spicules are one category of strongyloxeas with telescopic or mucronate tips (occasionally rounded ends), 485–1475 µm in length and 6–30 µm thick; and one category of styles, 242–582 µm in length and 2.4–9.6 µm thick.

Description. Specimens are globular or sub-spherical (up to 9.7 cm in diameter, holotype; Fig. 2 A), with some incrustations of calcareous substrate. Oscules rounded, up to 1 mm in diameter, although only few are visible. Surface optically smooth, but microhispid. Consistency firm, almost incompressible. Color of the holotype is unknown and the paratype (UFPEPOR 181) is orange alive, turning dark gray, almost black after fixation in ethanol, with a light interior.

Skeleton. Ectosomal skeleton with subectosomal cavities and composed of styles forming a discontinuous palisade at the surface, in which the ends of the strongyloxeas are also present. Choanosomal skeleton with large tracts composed of strongyloxeas with a radial arrangement branching below the surface, forming bouquets ( Fig. 2 B,C). Collagen is present in a low density mainly within the ectosome throughout.

Spicules. Megascleres in two categories ( Tab. 1 ). Choanosomal strongyloxeas (with variations to styles; Figs. 2 D,E; 3)—smooth, straight or slightly curved, usually with telescopic or mucronate ends, with a wide size range: 485–1475 µm in length and 6–30 µm thick. Ectosomal styles ( Fig. 2 F)—smooth, straight, occasionally slightly curved: 242–582 µm in length and 2.4–9.6 µm thick. The distinction between strongyloxeas and styles is very subtle. Here, we consider strongyloxeas as fusiform or slightly fusiform and styles are isodiametric.

Etymology. The species is named after Prof. Dr. Eduardo Hajdu in recognition for his great contribution to our understanding of the systematic of sponges.

Distribution. Provisionally endemic from Potiguar Basin (Rio Grande do Norte State, north-eastern Brazil).

Ecology. Bryozoans and polychaetes were found associated to both specimens. This species occurs from 50 to 101 m depth, on rocky substrate.

Remarks. Aaptos hajdui sp. nov. approaches A. aaptos very closely. Overall morphology and spicule dimensions are similar. Both species differ though in some traits such as the presence of larger styles in the new species (up to 582 µm in length) and the occurrence of styles to subtylostyles in A. aaptos (sensu Schmidt, 1864; Kelly-Borges & Bergquist, 1994 and van Soest 2002). In addition, Kelly-Borges & Bergquist (1994) have examined the holotype and verified the presence of flexuous styles and subtylostyles, not observed in the new species.

Aaptos hajdui sp. nov. is considerably different from the other Brazilian species. Its smaller and thicker strongyloxeas and the presence of only one category of styles differentiate the new species from A. glutinans , which has strongyloxeas always larger than 925 µm and two categories of styles ( Tab. 2 ). Among the records of Aaptos from Brazil, only A. aff. aaptos sensu Mothes & Lerner (1994) is close to the new species in spiculation ( Tab. 1 , 2 ), except for the fact that it shows variations of styles to subtylostyles and tylostyles, a character not found in A. hajdui sp. nov.

Aaptos hajdui sp. nov. is also different from the three species known from the Caribbean. In A. bergmanni and A. duchassaingi strongyloxeas are always smaller than 950 µm (see Table 2 ). There are no measurements reported of oxeas and styles of A. pernucleata (Carter, 1870) , but the presence of oxeas and the black color easily differentiate it from the new species.

Other species of the genus ( A. alphiensis Samaai & Gibbons, 2005 ; A. ciliata (Wilson, 1925) ; A. confertus Kelly-Borges & Bergquist, 1994 ; A. globosum Kelly-Borges & Bergquist, 1994 ; A. horrida (Carter, 1886) ; A. kanuux Lehnert, Hocevar & Stone, 2008 ; A. laxosuberites (Sollas, 1902) ; A papillata (Keller, 1880) ; A. robustus (Plotkin & Janussen, 2008) ; A. rosacea Kelly-Borges & Bergquist, 1994 ; A. tentum Kelly-Borges & Bergquist, 1994 ; and A. vannamei de Laubenfels, 1935) possess other kinds of megascleres in their spicule set, such as oxeas, tylostyles and/or subtylostyles, thus also differing from the new species.

A. aaptos sensu Moraes (2011) I. 1000–1725 x 5–17 St: 182–303 x 2–4 Atol das Rocas, Brazil

II. 220–490 x 4–10

A. aaptos sensu Solé-Cava et al. 1064 –1322– 1522 x 17 –34.2–47 St: 250–319–425 x 3–6 – Guarapari, Espírito Santo

(1981) 11.5 State, Brazil

Figures

FIGURE 2. Aaptos hajdui sp. nov. A. Holotype (UFPEPOR 62). B. Choanosomal skeleton. C. Detail of the ectosomal skeleton, showing the bouquets near the surface and the ectosomal cavities. D. Strongyloxeas. E. Telescopic and mucronate tips of the strongyloxeas. F. Styles. Scale bars: A = 5 cm. B, C = 500 µm. D = 100 µm. E, F = 50 µm.

FIGURE 3. Distribution frequency of the size-classes of the strongyloxeas of Aaptos hajdui sp. nov. (A. UFPE POR 62; B. UFPE POR 181) and A. potiguarensis sp. nov. (C. UFPE POR 45; D. UFPE POR 46). (n = 100). x-axis size in microns; y-axis frequency in number of spicules per size class.

Tables

TABLE 1. Spicule measurements of Aaptos hajdui sp. nov. and Aaptos potiguarensis sp. nov. Smallest length – mean length – largest length / Smallest width – mean width – largest width, in micrometers.

Specimens	Strongyloxeas	Styles
Aaptos hajdui sp. nov.
UFPEPOR 62—holotype	649–1076.7–1475 / 10–19.7–30	252–342.7–524 / 2.4–3.4–7.2
UFPEPOR 181— paratype	485–896.9–1445 / 6–13.2–20	242–378.8–582 / 2.4–6.0–9.6
Aaptos potiguarensis sp. nov.
UFPEPOR 45—holotype	301–793.7–1562 / 8–20.6–43	220–350–590 / 3.7–7.4–11
UFPEPOR 46—paratype	301–779.1–1484 / 8–23.5–41	300–405–520 / 2.5–5.5–7.5

TABLE 2. Comparative table of spicular measurements of the species of Aaptos of the western Atlantic. Measurements are expressed in µm, as minimum – mean – maximum length / width value whenever available. n. r., not reported. Data are from original descriptions, unless stated otherwise. Legend: St, style; S, subtylostyle; T, tylostyle; O, oxeas.

Species	Strongyloxeas	Ectosomal spicules	Distribution
A. aaptos Schmidt, 1864	I. 1053–1911 x 12–31 II. 490–955 x 10–23	St–S: 135–230 x 1–5	Mediterranean Sea, NW Atlantic
A. aaptos sensu van Soest & Stentoft (1988)	1000–1400 x 10–30 (styles, occasionally oxeotes)	St: 180–260 x 2–4 (occasionally sinuous)	Barbados
A. aaptos sensu Kelly-Borges & Bergquist (1994)	I. 1053–1502–1911 x 12–29–31 II. 490–705–955 x 10–16–23	St: 364–388–509 x 5–7–8 S: 270–318–354 x <1	Mediterranean Sea, Algiers
A. aaptos sensu Soest (2002; lectotype)	I. 1500–1900 x 12–45 II. 750–1000 x 10–25	St –S: 135–230 x 1–5	Mediterranean Sea