Mycale (Aegogropila) furcata Calcinai, Bavestrello, Bertolino, Pica, Wagner & Cerrano, 2013, n. sp.
Creators: name: Calcinai, Barbara
name: Bavestrello, Giorgio
name: Bertolino, Marco
name: Pica, Daniela
name: Wagner, Daniel
name: Cerrano, Carlo
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Animalia
Porifera
Demospongiae
Poecilosclerida
Mycalidae
Mycale
Mycale furcata

description: Mycale (Aegogropila) furcata n. sp.
(Figs. 25 A–F; 26A–F; 27) (Tabs. 11; 12)
Holotype material. MSNG 56265: sample Bugor 307: Indonesia, North Sulawesi, Siladen Island, Siladen Barat, depth not stated, January 2007.
Paratype material. MSNG 56266: sample Bugor 332: Indonesia, North Sulawesi, Siladen Island, Siladen Barat, depth not stated, January 2007. MSNG 56436: sample Bugor Onong: Indonesia, North Sulawesi, Siladen Island, Siladen Onong, depth not stated, 27 January 2007
Comparative material: holotype of Mycale (Carmia) hentscheli Hooper & Wiedenmayer, 1994, new name for Mycale macilenta var. australis Hentschel, 1911 ZMB Por 4402 (see van Soest et al. 2011 for details) (Fig. 26 G- N).
Diagnosis. Mycale (Aegogropila) furcata n. sp. is characterised by two categories of sigmas, the larger one often with one bifurcate extremity, by two categories of chelae and by toxas similar to raphidotoxas.
Description. Very thin encrusting sponge, about 1 mm thick, covering the axis of a colony of Paratelesto rosea (Fig. 25 A, B) up to the bases of anthocodiae (Fig. 25 C). Surface macroscopically smooth but microhispid due to the mycalostyles of the choanosomal tracts. Consistency soft. In some areas transparent, branching canals converging towards elevated oscules. In situ whitish or transparent, with the red colour of the octocoral visible underneath (Fig. 25 A–C). White in ethanol (Fig. 25 B, C). The holotype consists of a small colony of P. ro s ea about 16 cm long, and of two detached fragments (Fig. 25 A, B); the paratype is a colony of about 13 cm that is reproductive and contains numerous larvae (Fig. 25 C).
Skeleton. Ectosomal skeleton of tangential mycalostyles organized in tracts and connected by single mycalostyles (Fig. 25 D, E); numerous scattered microscleres. Choanosomal skeleton of plumoreticulate tracts of mycalostyles running towards the surface where they open in fans, making it hispid (Fig. 25 F). Anisochelae I arranged in rosettes over the tracts, beneath the surface. All microscleres are scattered in the tissue.
Spicules. Mycalostyles generally straight with a slight constriction beneath the head and with hastate tips (Fig. 26A), 140 – 190 x 2 – 3.7 µm. Anisochelae in two size classes as confirmed by Bhattacharya analysis (Figs. 26B, C; 27; Tab. 11). The smaller extremity frequently bears fused alae with a space in between. Anisochelae I, more numerous, with the frontal ala shorter than the dorsal one (Fig. 26B), 17.5–35 µm; anisochelae II with the smaller extremity characterised by a short tooth on the small, frontal ala (Fig. 26C), 10–17.5 µm. Numerous intermediate forms are present. Sigmas numerous, “C” or “S” shaped in two size classes: sigmas I often with one bifurcate extremity (Fig. 26D), 52.5 – 87.5 x 2 – 5 µm; sigmas II very thin (Fig. 26E), 25–36 µm. Toxas very similar to raphidotoxas, with a slight central flexion, variable in length but in a single size class (Fig. 26F), 51–222.5 µm. Refer to Tab. 12 for complete measurements.
Remarks. The species of the subgenus Aegogropila that are similar to this new species for their spicular complement are M. (A.) lilianae (Carballo & Hajdu, 1998), M. (A.) escarlatei Hajdu, Zea, Kielman & Peixinho, 1995 and M. (A.) plumosa Hoshino, 1981. M. (A.) lilianae and M. (A.) escarlatei were described from the Brazilian coasts, while M. (A.) plumosa is known from Japan. Mycale (A.) lilianae has longer and thicker mycalostyles, anisochelae in three classes, toxas of classical shape and micracanthoxeas (Tab. 10). Mycale (A.) escarlatei differs from the new species in spicule dimensions and in the presence of micracanthoxeas; mycalostyles are longer (254–350 µm), anisochelae are in three categories and toxas (in two categories) are shorter (up to 77 µm). Mycale (A.) plumosa has longer and gently sinuous mycalostyles (215 – 278 – 310 x 4 – 6 – 7 μm), as well as three categories of sigmas (sigmas III, 10 μm). The species belonging to the subgenus Carmia (as it is considered likely polyphyletic (van Soest & Hajdu 2002b)) were also compared to this new species. In particular M. (C.) macilenta (Bowerbank, 1866), M. (C.) hentscheli Hooper & Wiedenmayer, 1994 and M. (C.) tasmani Bergquist & Fromont, 1988 show the spicular complement close to the new species (with subtylostyles and anisochelae in two or three size classes, sigmas in two size classes and a single category of toxas). Mycale (C.) macilenta and M. (C.) tasmani have bigger mycalostyles (198–265 μm and 175–242 μm in length, respectively) and sigmas I (85–102 μm and 65–104 μm in length, respectively). The comparison with the holotype of M. (C.) hentscheli (Fig. 26 G–N) highlighted differences in the shape of sigmas II and toxas, and in the length of mycalostyles (232–306 μm). SEM observations revealed the presence of micracanthoxeas in M. (C.) hentscheli (about 4 μm long) (Fig. 26 N), which had not been reported by previous authors.
Etymology. Named after the bifurcate extremities of sigmas.
description: Published as part of Calcinai, Barbara, Bavestrello, Giorgio, Bertolino, Marco, Pica, Daniela, Wagner, Daniel & Cerrano, Carlo, 2013, Sponges associated with octocorals in the Indo-Pacific, with the description of four new species, pp. 1-61 in Zootaxa 3617 (1) on pages 41-42, DOI: 10.11646/zootaxa.3617.1.1, http://zenodo.org/record/248150