Mycale (Aegogropila) cf. lilianae Carballo & Hajdu, 1998

(Fig. 23 A–L) (Tab. 10)

Examined material. Sample HK 3: Hawai’i, O’ahu Island, Hawai’i Kay, 1 m, 31 August 2003; sample HK 8: Hawai’i, Oahu Island, Hawai’i Kay, depth between 0.5–3m, 31 May 2007.

Comparative material: Mycale (Aegogropila) lilianae Carballo & Hajdu, 1998, paratypes MNRJ 296, MNRJ 369 (two slides).

Description. The sponge is very thin (about 1 mm) and completely envelops a colony of Carijoa riisei (Fig. 23 A), with the exception of anthocodiae that are free from the sponge cover. The examined specimens consist of several fragments of coral colonies, up to 8 cm long (Fig. 23 B). The surface is macroscopically smooth, but mycalostyles protrude from the surface making it microhispid. In situ red (Fig 23 A), beige in ethanol (Fig. 23 B).

Skeleton. The ectosome is well defined and consists of paucispicular tracts of mycalostyles (4–5 spicules) creating a reticulum with triangular or polygonal meshes (Fig. 23 C). Sigmas, toxas and anisochelae I in rosettes are located in the tracts, while anisochelae II and III are scattered in the tissue. Due to the extreme thinness of the sponge, the choanosome can not be clearly determined; nevertheless ascending tracts of mycalostyles, with sigmas and toxas are visible; these tracts run towards the surface making it hispid (Fig. 23 D).

Spicules. Straight mycalostyles slightly constricted beneath the elongated head (Fig. 23 E), 240 – 280 x 5 – 10 µm. Centrally the shaft is slightly swollen (Fig. 23 E). Sigmas “C” shaped, sometimes “S” shaped, in two size classes: sigmas I (Fig. 23 F), 92.5 – 117.5 x 5 – 11.5 µm; sigmas II (Fig. 23 G), 17.5–27.5 µm. Anisochelae palmate, in three size classes, similar in shape: anisochelae I (Fig. 23 H), 42.5–50 µm; anisochelae II (Fig. 23 I), 22.5–27.5 µm; anisochelae III (Fig. 23 J), 12.5–17 µm. Toxas in wide dimensional range (Fig. 23 K), 17.5–380 µm. Micracanthoxeas generally curved with numerous spines (Fig. 23 L), 5–10 µm. Refer to Tab. 10 for complete measurements.

Distribution and remarks. Brazil. Micracanthoxeas are present in six species of Mycale belonging to subgenera Aegogropila and Carmia (Carballo & Cruz-Barraza 2010): M. (C.) micracanthoxea Buizer & van Soest, 1977; M. (C.) urizae Carballo & Hajdu, 1998; M. (A.) bamfieldensis Reiswig & Kaiser, 1989; M. (A.) escarlatei Hajdu, Zea, Kielman & Peixinho, 1995; M. (A.) lilianae Carballo & Hajdu, 1998; M. (C.) hentscheli Hooper & Wiedenmayer, 1994 (see M. (A.) furcata). Among these, M. (A.) lilianae is the only species close to the Hawaiian specimens in the shape and size of the spicules. The study of the paratypes of M. (A.) lilianae confirmed that the Hawaiian and the Brazilian specimens are morphologically very similar. The measurements of spicules from Carballo & Hajdu (1998) are reported in Tab. 10.

In the type locality M. (A.) lilianae was also found living on C. riisei . It is unlikely that the Hawaiian and the Brazilian specimens are conspecific with such a disjunct distribution but in the absence of molecular evidence we can not elucidate their cryptogenic nature.