Mycale (Aegogropila) cavernosa Bergquist, 1965

Van, Rob W. M., Aryasari, Ratih & De, Nicole J., 2021, Mycale species of the tropical Indo-West Pacific (Porifera, Demospongiae, Poecilosclerida), Zootaxa 4912 (1), pp. 1-212 : 28

Mycale (Aegogropila) cavernosa Bergquist, 1965

Figs 15 a–h

Mycale cavernosa Bergquist, 1965: 170 , figs 23a–c.

Mycale (Aegogropila) cavernosa ; Hajdu et al. 1995: 7.

Material examined. USNM 23703 , small fragment of the holotype, Palau Islands , 1.75 miles NE of Ngabadangel, depth 30.6 m, coll. Coral Fish Project Expeditions, stat. 125, 24 August 1955 .

Summary description. The lobate single specimen of 20 x 5 x 1.5 cm is broken in two finger-shaped fragments ( Figs 15a,a 1 ). The fragments are greyish white, no life color is known. The surface is characteristically folded, probably due to shrinking. Surface skeleton is of the aegogropila-type ( Fig. 15b ), with thin tracts 4–38 µm in diameter (1–8 spicules in cross section) delimiting triangular meshes of up to 400 µm in widest dimension. The choanosomal skeleton is plumoreticulate with notable spongin cementing the tracts, with in the interior stout spicule tracts (90–185 µm in diameter), thinning out towards the surface (20–50 µm in diameter), where there are spicule brushes carrying the tangential surface skeleton. Spicules ( Figs 15 c–h) mycalostyles ( Fig. 15c ) (Bergquist: 262– 306 –351 x 4– 4.2 – 8 µm), remeasured 273– 330.7 –391 x 4– 5.9 – 7.5 µm, anisochelae I ( Fig. 15d ) (if proper, not mentioned by Bergquist) 39–60 µm, anisochelae II ( Figs 13e,e 1 ,e 2 ) (Bergquist 29–33– 40 µm), remeasured 28– 33.4 – 36 µm, anisochelae III ( Fig. 15f ) (Bergquist 11– 13.5 – 15 µm), remeasured 11– 13.7 – 16 µm, sigmas I ( Figs 15g,g 1 ) (Bergquist 92– 97.5 – 105 µm), remeasured 96– 99.4 – 104 µm, sigmas II ( Fig. 13h ) (Bergquist 19– 23 – 26.5 µm), remeasured 21– 24.2 – 26 µm. No additional microscleres, and no rosettes of anisochelae were observed.

Distribution. Known only from the Palau Islands.

Comments. We were able to make some slides and a SEM stub, and confirmed Hajdu et al. ’s (1995: 7) discovery of anisochelae I in low quantity and with reduced shape. These were not mentioned by Bergquist, so it remains somewhat uncertain whether they are proper. The anisochelae II are similar to those of M. (Ae.) sulevoidea . We consider the present species as doubtfully valid, because toxas were sometimes rare in some specimens of M. (Ae.) sulevoidea . If the anisochelae I mentioned above are proper to the sponge, there is an outside possibility that M. (Ae.) cavernosa will prove to be a junior synonym of M. (Ae.) sulevoidea , but lack of toxas precludes this conclusion.

Figures

FIGURE 1. A. Numbers of available specimens for the present study from the collections of the Naturalis Biodiversity Center distributed over Indo-West Pacific Marine Ecoregions (MEOWS, cf. Spalding et al. 2007). B. Ditto for type specimens and additional specimens from other institutions consulted for this study.

FIGURE 2. Mycale (Aegogropila) gravelyi Burton, 1937, ZMA Por. 07864 from Ambon Bay, Indonesia, a, habitus encrusting on coral rubble (arrows) (scale bar = 1 cm), b–f, SEM images of spicules, b, mycalostyle, b1, details of mycalostyle, c, anisochela I in side view, d, anisochela II, d1, anisochela II enlarged, e, anisochela III, e1, anisochela III enlarged, f, sigma I.

FIGURE 13. Mycale (Aegogropila) sulevoidea (Sollas, 1902), SEM images of spicules of ZMA Por. 17808 from Kenya, a, mycalostyle, a1, details of mycalostyle, b, anisochela I in lateral view, c, anisochelae II in lateral view, d, anisochela III, larger spicule in front view, d1, smaller spicule in lateral view (all anisochelae in same magnification), e, sigma I, f, sigma II, g, toxa.

FIGURE 15. Mycale (Aegogropila) cavernosa Bergquist, 1965, holotype (fragment) USNM 23703 from Palau, a, habitus of fragment available to us (scale bar = 1 cm), a1, holotype and paratype in USNM (photo L.E. Becking), b, light microscopic view of ectosomal skeleton, c–h, SEM images of the spicules, c, mycalostyle, d, anisochela I (not detected and mentioned by Bergquist (1965) but presumed to be proper), e, anisochela II in side view, e1, anisochela II in front view, e2, anisochela II in back view, f, anisochela III (all anisochelae in same magnification), g, sigma I, g1 thin sigma I, h, sigma II.