Mycale (Mycale) aff. grandis ( Gray, 1867 )

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 : 129-134

Mycale (Mycale) aff. grandis ( Gray, 1867) ‘white’

Figs 82 a–f, 83a–e, 84a–h, 85, 86, Table 7

Material examined. ZMA Por. 08554, Indonesia, Sulawesi, SE Sulawesi, Take Karlarang , 6.45°S 121.2083°E, reef, depth 8 m , SCUBA, coll. R. W.M. van Soest, Indonesian-Dutch Snellius II Expedition stat. 147, field nr. 147/ III/01 , 27 September 1984 (grey-white) ; ZMA Por. 08996, Indonesia, Sulawesi, SE Sulawesi, Tukang Besi Islands , SW of Taipabu, 5.9333°S 123.975°E, reef slope, depth 15–30 m , SCUBA, coll. R. W.M. van Soest, Indonesian-Dutch Snellius II Expedition stat. 044, field nr. 044/ V/02 , 11 September 1984 (white) ; ZMA Por. 14549, Indonesia, Sulawesi, North Sulawesi, North East Bunaken Island , 1.6376°N 124.7647°E, steep slope, depth 35 m , SCUBA, coll. B.W. Hoeksema, SYMBIOSPONGE project, field nr. 98/NS/MAY10/BH/103, 10 May 1998 (white) ; ZMA Por. 17384, Indonesia, North Sulawesi, SW Siladen Island, 1.6167°N 124.7833°E, depth 15 m , SCUBA. coll. N.J. de Voogd, field nr. MD11 /170502/049, 17 May 2002 (white, yellow inside) ; ZMA Por. 18757, Thailand, Trad, Chang Island , S of Ko Mark, 11.786°N 102.4873°E, fringing reef, depth 3 m , SCUBA, coll. Sumaitt Putchakarn, field nr. CHAD–08, 19 November 2001 ; RMNH Por. 3699, Indonesia, Sulawesi, North Sulawesi, SW Bunaken Island, Alung Banua , 1.618°N 124.7583°E, depth 20 m , SCUBA, coll. N.J. de Voogd, field nr. MD07 /150502/NV049, 16 May 2002 (white, yellow inside) ; RMNH Por. 5434, Indonesia, Halmahera, Ternate, Tarau , 0.8417°N 127.3772°E, depth 10 m , SCUBA, coll. N.J. de Voogd, Ternate-Halmahera Expedition stat. TER.17, field nr. TER.17/021109/ NV185, 2 November 2009 (white) ; RMNH Por. 6595, Indonesia, Sulawesi, North Sulawesi, Lembeh Strait, Tanjung Nanas Island , 1.46097°N 125.2266°E, depth 15 m , SCUBA, coll. N.J. de Voogd, field nr. LEM33/170212/NV283, 17 February 2012 (white) .

Description ( Figs 82 a–f, 83a, 84a). Thickly encrusting to massively lobate epilithic sponges, with punctate smooth surface, white colored in life, white-beige in preserved condition. Size often considerable ( Fig. 83a ), up to 20 x 15 cm in lateral expansion, up to 10 cm thick. Oscules in life may be up to 1 cm in diameter, contracted in preservation to a few mm. Consistency firm, hard, barely compressible.

Skeleton ( Figs 83 b–e). Choanosomal skeleton plumoreticulate with thick spicule tracts of up to 1.5–2 mm diameter dividing towards the surface into tracts of 300–600 µm diameter. Main tracts are irregularly connected by thinner tracts of approximately 200–600 µm. Spicule tracts closely to the surface are echinated by individual anisochelae I, these are not crowded and do not form rosettes. Meshes of the choanosomal skeleton are up to 6 mm in size, which causes the punctate aspects of live specimens. Ectosomal skeleton is a tangential layer of confused single intercrossing megascleres. Anisochelae are distributed individually or in small groups along the subectosomal tracts. Trichodragmas are scattered throughout the sponge, often in great numbers.

Spicules ( Figs 83e , 84 b–h, 85). Mycalostyles, three/four categories of anisochelae, two categories of sigmas, trichodragmas.

Mycalostyles ( Figs 84b,b 1 ), usually curved, with heads elongate and with faintly developed neck, pointed often mucronate or bluntly rounded, 444– 571.3 –660 x 10– 15.2 – 21 µm.

Anisochelae I, in most specimens divisible in two overlapping size categories which also have subtle different shapes, here dubbed anisochela Ia and Ib.

Anisochelae Ia ( Figs 84c , 85 ), usually exceeding 100 µm in length, with characteristic, strongly developed upper alae standing off from the shaft; upper alae are often sharply pointed, especially the lateral ones, but more rounded rims are not infrequent; shaft straight until just above the lower alae, where the lateral alae are positioned slightly higher along the shaft than the median alae; rims of the lower lateral alae are rounded, median lower alae are broad and the rims may be somewhat irregular in outline; sizes variable among specimens, 96– 112.5 – 147 µm.

Anisochelae Ib ( Fig. 83e ), more or less of the same shape as anisochela Ia , but with shorter shaft. This causes the spicule to look slightly different due to changed proportions of upper alae; the spicule is often rare, but can always be found and may occasionally be more common than anisochelae Ia; size variable, 56– 73.2 – 84 µm.

Anisochelae II ( Figs 84d,d 1 ), robust, with free part of shaft short (on average 15% of spicule length), with upper alae long (average 60% of spicule length), curved slightly inwards, rims rounded, median upper alae often grooved; lower alae well-developed, median lower alae with rounded rim or tending to form a bluntly pointed rim; spicule may be rare or more common; size 24– 28.1 – 36 µm.

Anisochelae III ( Figs 84e,e 1 ), with dominant upper alae (40–60% of spicule length), with lower alae reduced to stick-like extension of the shaft, lacking any bladed extensions laterally or medially, with prominent spur on the distal part of the spicule; size 14– 16.3 – 21 µm.

Sigmas I ( Fig. 84f ), thin, on average 2 µm in thickness or less, usually slightly asymmetrical, size 41– 57.3 – 73 µm.

Sigmas II ( Fig. 84g ), thin, on average 1 µm in thickness, similar in shape to sigma I, but slightly more incurved, size 14– 17.5 – 22 µm.

Trichodragmas ( Fig. 84h ), fusiform shape, size 27– 65.3 –92 x 9– 10.1 – 12 µm.

Distribution and ecology ( Fig. 86 ). In our material, most specimens were limited to northeastern Indonesia, usually in deeper reef parts; one specimen was collected in Thailand. Shallow reefs down to 35 m.

Remarks. One of us (NJdV) collected specimens from the type locality ( Ternate, Indonesia) of Thiele’s Mycale armata , and these were white. It is thus tempting to assume that Thiele’s species could be valid as distinctly different in color from Mycale (Mycale) grandis . However, there is no definite evidence that Thiele’s material was white, so we adopt here the assumption that it probably was red as most of the specimens we examined were red if live color was reported. The white form is apparently more rare and has a more restricted distribution, known from Indonesia and Thailand, but so far not reported from elsewhere.

We could find no consistent spicular difference with red/orange colored members of the species (see Table 7). To emphasize this, we compared in Fig. 85 anisochelae Ia of six red specimens + the Mycale armata type of which no color was known (upper row), with anisochelae Ia of four white specimens (lower row), and found them to be clearly similar to one another. Compare also spicule packages of Figs 79 , 80 and 84 . In the field, the two are easily recognized by the white vs the red color and presumably also the more cryptic occurrence of the red form, but it is indeed remarkable that the spiculation does not reflect these differences. A potential parallel is found in West Atlantic Mycale (Mycale) laevis ( Carter, 1882) , which is known to occur in orange and white forms ( Loh et al. 2012). Mycale (Mycale) crassissima (cf. above) also occurs in a wide range of live colors, including reddish, purplish and whitish or yellow-white shades. Color differences may be less distinctive then presumed at first glance. A further reason for us to choose to name the white form also M. (M.) grandis (with ‘aff.’ to acknowledge the differences), is because there is no information on the color of earlier synonyms of M. (M.) grandis ( Esperia pellucida Ridley, 1884 , Esperia indica Carter, 1887 and Mycale armata Thiele, 1903 ), each of which might compete with any new name proposed.

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 79. Mycale (Mycale) grandis (Gray, 1867), red colored specimens, a–c, light microscopic images of skeleton of RMNH Por. 2896 from Singapore, a, tangential ectosomal skeleton, b, cross section of peripheral choanosomal skeleton, c, spicule tract ‘echinated’ by anisochelae I, d–k, ZMA Por. 07979 from Indonesia, SEM images of spicules, d, mycalostyle, d1, details of mycalostyle, e, anisochela Ia, f, anisochela Ib, g, anisochela II, h, anisochela III, i, sigma I, j, sigma II, k, trichodragma.

FIGURE 80. Mycale (Mycale) grandis (Gray, 1867), red colored specimens, ZMA Por. 11157 from the Seychelles, a, preserved habitus on coral fragment (arrow) (scale bar = 1 cm), b–j, SEM images of spicules, b, mycalostyle, b1, details of mycalostyle, c, anisochela Ia, d, anisochela Ib, e, anisochela II, e1, ditto enlarged, f, anisochela III, f1, ditto enlarged, g, sigma I, h, sigma II, i, long trichodragma, j, short trichodragma.

FIGURE 82. Mycale (Mycale) aff. grandis (Gray, 1867), white colored specimens, habitus in situ, a, ZMA Por. 14549 from N Sulawesi, Indonesia, b, detail of same, c, RMNH Por. 3699 from N Sulawesi, Indonesia, d, RMNH Por. 6595 from N Sulawesi, Indonesia, e, detail of same, f, ZMA Por. 18757 from Thailand.

FIGURE 83. Mycale (Mycale) aff. grandis (Gray, 1867), white colored specimens, a, preserved habitus of ZMA Por. 14549 from N Sulawesi, Indonesia (scale bar = 1 cm), b–e, light microscopic images of skeleton from ZMA Por. 08996 (b,e) and RMNH Por. 6595 (c–d) both from Indonesia, b, cross section of peripheral skeleton, c, cross section of choanosomal skeleton, d, tangential ectosomal skeleton, e, peripheral skeletal tracts with ‘echinating’ anisochelae Ib.

FIGURE 84. Mycale (Mycale) aff. grandis (Gray, 1867), white colored specimen, RMNH Por. 5434 from Ternate, Indonesia, a, preserved habitus (scale bar = 1 cm), b–h, SEM images of spicules, b, mycalostyle, b1, details of mycalostyle, c, anisochela Ia, d, anisochela II, d1, enlarged anisochela II, e, anisochela III, e1, enlarged anisochela III, f, sigma I, g, sigma II, h, trichodragma.

FIGURE 85. Mycale (Mycale) grandis (Gray, 1867), comparison of anisochelae Ia to demonstrate similarity of red and white specimens. Upper row red specimens, lower row white specimens; at the upper right, anisochela I of holotype of Mycale armata Thiele, 1903, ZMB 3157 (= Mycale (M.) grandis) of which no live color is known, and the holotype of Oxymycale strongylophora De Laubenfels, 1954 (= Mycale (M.) grandis’red’).

FIGURE 86. Mycale (Mycale) grandis (Gray, 1867) s.l., approximate distribution of specimens studied (red and open squares) and literature records (pink dots). Squares and dots may represent several close collecting localities. Solid red squares = M. (M.) grandis ’red’, open squares = M. (M.) aff. grandis ‘white’.