Phycopsis styloxeata, Lage & Carvalho & Menegola, 2013

Lage, Anaíra, Carvalho, Mariana De S. & Menegola, Carla, 2013, Two new species of Halichondrida (Demospongiae) and the first record of Phycopsis and Ciocalapata for Brazil, Zootaxa 3734 (2), pp. 292-300 : 294-295

Phycopsis styloxeata sp. nov.

Figure 2 A–F ; Table 1.

Holotype: UFBA 4209 - POR, Brazil, Bahia, Maraú, Camamu Bay, # Paciência de Fora , 13º54.675’S / 38º59.378’W, 18–22m depth, 23.x.2012, coll. C. Menegola & R. Guimarães.

Diagnosis. Phycopsis styloxeata sp. nov. is the only species of the genus possessing two categories of styles and one of oxeas.

Description. Sponge bushy-shape or cushion-shape, being 45 mm high and 53 mm wide, with branches ending in rough ascending conules. Microhispid surface, forming irregular ridges with grooves giving it a rough appearance. Consistency is soft, compressible and easy to cut. Various oscules scattered on top of projections with 1–2.5 mm in diameter. Color alive is red-orange and orange in spirit ( Figure 2A and B ).

Spicules. Megascleres: One category of oxeas and two of styles. Microscleres absent.

Oxeas ( Figure 2C ) abundant, smooth, curved to slightly straight with acerate ends, larger than styles; few sinuous shapes: 320–429.4–600 / 20–25.2–30 µm (length/ thickness).

Styles I ( Figure 2D ) abundant, smooth, robust, straight to slightly curved near the base, with pointed end and blunt base clearly defined: 250–350.4–420 / 20–27.8–30 µm (length/thickness).

Styles II ( Figure 2E ) smooth, thin, and curved near base, rarely sinuous, with pointed end and blunt base clearly defined: 205–285.8–350 / 7.5–8.9–12.5 µm (length/ thickness).

Skeleton. Specialized ectosomal skeleton absent. Choanosomal skeleton differentiated into the axial and extraaxial regions ( Figure 2F ). Axial skeleton condensed in multispicular upside bundles surrounded by scarce spongin. Extra-axial skeleton with 1–2 spicules projected laterally from the main bundles, giving a spiny surface. Near the apex the main bundles bifurcate toward the surface.

Ecology. Phycopsis styloxeata sp. nov. was collected from Camamu Bay in consolidated substrate (coral reefs) from a depth of 18– 22 m.

Etymology. The name styloxeata refers to the spicule set composed of styles and oxeas.

Distribution. Provisionally endemic from Camamu Bay, Maraú, Bahia, Brazil 18–22 m depth (NE Brazil)

Remarks. The genus Phycopsis contains seven valid species ( van Soest et al. 2013). Six of them are located in the Southern Pacific Ocean: Phycopsis epakros ( Hooper & Lévi, 1993) , P. fusiformis ( Lévi, 1967) and P. papillata ( Hooper & Lévi, 1993) from New Caledonia; and P. fruticulosa Carter, 1883 , P. hirsuta, Carter 1883 , and P. hispidula ( Ridley, 1884) in Australia. The remaining species has been observed in the North Atlantic Ocean: P. setosa ( Bowerbank, 1873) from United Kingdom.

Phycopsis styloxeata sp. nov. differs from the other described species of this genus due to the presence of two categories of styles, sometimes sinuous, and a single category of oxeas that is larger than styles (see Table 1). The new species differs from P. epakros and P. fusiformis in the absence of a specialized ectosomal skeleton and choanosome formed by an axial skeleton with ascending multispicular tracts and scarce spongin, and an extra-axial skeleton with 1–2 spicules laterally projected and no sinuous strongyles. P. epakros possesses a fleshy ectosome and a plumoreticulated choanosomal skeleton, with axial and extra-axial differentiation and fibers cored by multispicular tracts, including sinuous strongyles. P. fusiformis presents a thick ectosome with scattered plumose bundles of sinuous megascleres. As well as a collagenous membrane and a plumoreticulated choanosomal skeleton with a clear fibrous axial and extra-axial differentiation. Phycopsis fruticulosa , P. hirsuta , P. hispidula and P. setosa differ from Phycopsis styloxeata sp. nov. by the presence of only oxeas as megascleres.

Concerning the external morphology of the sponge, P. fruticulosa and P. hirsuta are distinguished by their stipitate, arborescent and branched shape; P. hispidula is erect, lobose and nodular with a leathery consistency; and P. setosa by its fan- branched shape with short stalks and a surface composed by numerous and long setae. Otherwise, Phycopsis styloxeata sp. nov. has a microhispid surface and soft elastic consistency, as well as a bushy or cushion-shaped body with projections starting from an unique basal portion, and ending in rough conules. Phycopsis papillata differs from the new species in the presence of a translucent collagenous dermal membrane, and possessing an axial skeleton with vestigial spicules, except near the surface. All these features are not observed in Phycopsis styloxeata sp. nov.

Figures

FIGURE 2. Phycopsis styloxeata sp. nov. (UFBA 4209-POR): (A) specimen in situ; (B) specimen in spirit; (C) Oxea; (D) Style I; (E) Style II; (F) Skeleton. Scale bars: A–B, 1 cm; C–D, 50 µm; E, 100 µm; F, 200 µm.