Mycale (Carmia) fungiaphila, Van & Aryasari & De, 2021

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 : 57-59

Mycale (Carmia) fungiaphila sp.nov.

Figs 35 a–d, 36a–f

Material examined. Holotype ZMA Por. 16645, Indonesia, Sulawesi, SW Sulawesi, Kudingareng Keke, depth not given, but presumably from shallow-water reef environment, SCUBA, coll. B.W. Hoeksema, field nr. 0206–01, 2 June 1997 (brown).

Description. Thinly encrusting sponge, covering and insinuating among the septae of a broken Fungia mushroom coral ( Figs 35 a–b). In preservation, surface is smooth, without visible openings. Size of several patches up to 2 x 3 cm in lateral expansion, several mm in thickness. Color brown in life, reddish brown in preservation. Consistency soft, easily damaged.

Skeleton ( Figs 35 c–d). Very lightly built, with thin megasclere tracts, 20–30 µm in diameter (4–6 spicules in cross section) running sinuously from the substratum towards the surface, where they fan out into brushes of single megascleres. Tracts are distanced from each other at 250–300 µm intervals. Between the tracts are shorter or longer (80–250 µm) bundles, 50–100 µm in thickness, of fusiform trichodragmas ( Figs 35 c–d), each about 75 x 5 µm (see below), running parallelly to the megasclere tracts or irregularly. There is no special ectosomal skeleton, the dermal membrane having numerous sigmas and few rosettes of anisochelae I (50–60 µm in diameter). The choanosomal tissue is darkly reddish brown.

Spicules ( Figs 36 a–f). Mycalostyles, two categories of anisochelae, sigmas, and fusiform trichodragmas.

Mycalostyles ( Figs 36a,a 1 ), straight, with well-developed rounded heads, comparatively short and thin, 187– 205.5 – 222 x 1.5– 1.8 – 2.5 µm.

Anisochelae I ( Fig. 36b ), comparatively narrow-shaped, with upper and lower alae well developed, free part of shaft 25–30% of total spicule length, little variation in size, 18– 22.1 – 27 µm.

Anisochelae II ( Fig. 36c ), reduced in overall development, with upper median alae longer than half the spicule length, 8– 10.8 – 14 µm.

Sigmas ( Fig. 36d ), thin (0.5–1.5 µm in thickness), asymmetrical, comparatively narrow-shaped, 37– 46.2 – 57 µm.

Trichodragmas ( Figs 36e,e 1 ,f), fusiform, faintly reminding of toxodragmas, but individual raphides sinuously curved but not toxa-shaped, 60– 74.2 –84 x 3– 4.7 – 6 µm. They are grouped in wide bundles, 50–100 µm in diameter, individually (80 µm long) or in longer sinuous structures (more than 250 µm long, cf. Fig. 35d ) running parallel to the choanosomal megasclere tracts.

Distribution and ecology. Indonesia, on shallow-reefs.

Etymology. The compound name is an adjective consisting of the words Fungia and –philus meaning ‘ Fungia -loving’ referring to the substratum, a dead specimen of the mushroom coral genus Fungia .

Remarks. The habitus of the new species is encrusting-insinuating in the grooves between the septae of a dead Fungia . Since there is only a single sample, we cannot be certain that the species is uniquely confined to this substratum. The outstanding features of the new species are the bundles of fusiform trichodragmas and the poorly developed megasclere tracts. The combined spicule characters of the specimen are unique among Mycale (Carmia) species of the region. No close relatives have been identified.

Mycale (Carmia) pulvinus Samaai & Gibbons, 2005 from the Atlantic coast of South Africa shows some superficial resemblance in spicule complement, but sizes and categories show significant differences and there are no toxodragma-like microscleres.

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 35. Mycale (Carmia) fungiaphila sp.nov., holotype ZMA Por. 16645 from Indonesia, a, overview of dead Fungia fragments bearing the specimen, b, detail of the same showing brown crusts (arrows) between the septae of the Fungia fragments (scale bar = 1 cm), c, light microscopic view of the spicules including the fusiform trichodragmas, d, light microscopic view of thick bundles of trichodragmas.

FIGURE 36. Mycale (Carmia) fungiaphila sp.nov., holotype ZMA Por. 16645 from Indonesia, SEM images of the spicules, a, mycalostyle, a1, details of mycalostyle, b, anisochela I, c, anisochela II, d, sigma, e, fusiform trichodragma, e1, detail of fusiform trichodragma, f, bundled fusiform trichodragmas.