treatment provided by
Grantessa woerheidei sp.nov.
Material examined. Holotype, RMNHAbout RMNH Por. 9586, Saudi Arabia, Jeddah , near Thuwal, Abu Gishaa, 22.255194°N 39.025639°E, depth 12 m, scuba, coll. N.J. de Voogd, field nr. THU06/JED081, 9 November 2014.GoogleMaps
Description. Extremely ‘hairy’ sycon-like ovoid sponge ( Figs 66a–bView FIGURE 66), whitish in situ, light beige in preservation. Size 2 cm high, 0.5 cm in diameter (1 cm if protruding diactines are included). Consistency compressible but firm.
Aquiferous system. Syconoid.
Skeleton. ( Figs 66c–fView FIGURE 66) Articulate, with radiating structure following the syconoid aquiferous system. The wall of the sponge is pierced almost for its entire thickness by long giant diactines, and these protrude beyond the surface for a considerable distance. From the periphery to the atrial cavity there is first a thin cortical layer of small triactines, overlying a layer of pseudosagittal triactines, with the unpaired and short paired actine tangential to the surface and the long paired actine directed inwards. Next, the choanosomal skeleton ( Figs 66c–dView FIGURE 66) consists of aligned tracts of sagittal tubar triactines with the unpaired actines directed outwards and the paired actines similarly aligned parallel to the cortical and atrial surfaces. Below this, the subatrial skeleton is formed by triactines similar to the tubar triactines but with unpaired actines elongated, also directed outwards. Finally, the atrial skeleton is formed by the basal triadiate system of tetractines, with their apical actines protruding far into the atrial cavity ( Fig. 66dView FIGURE 66). Although there is not a separate fringe, the oscular opening is surrounded by protruding diactines ( Fig. 66eView FIGURE 66) even longer than those of the main body, and these also form bundles, which give the opening a star-like appearance. The oscular rim is strengthened by rows of triactines ( Fig. 66fView FIGURE 66)
Spicules. ( Figs 67a–gView FIGURE 67) Diactines, triactines, pseudosagittal triactines, tetractines.
Giant diactines ( Figs 67a,aView FIGURE 67 1View FIGURE 1), long, straight, varying in thickness from trichoxea-like thin diactines to thickly fusiform longer and shorter spicules, with endings varying from thinly sharply tapering to lance-shaped, those protruding from the main body 700– 2791 –4900 x 4 – 25.8 –33 µm, the oscular diactines are at least 6–7 mm x 3–20 µm.
Triactines of the oscular rim ( Fig. 67bView FIGURE 67), sagittal, rather strongly recurved, only a few could be measured, actines 70–130 x 7–10 µm.
Triactines of the cortical skeleton ( Figs 67cView FIGURE 67), slightly sagittal, actines 62– 111 –145 x 5 – 7.6 –9 µm.
Pseudosagittal triactines ( Figs 73dView FIGURE 73), of variable shape but always clearly distinct from other triactines by having all actines of different length and usually partially curved, unpaired actines 86– 112 –132 x 5 – 6.2 –7.5 µ, long paired actines 92– 189 –244 x 5 – 6.0 –7.5 µm, short paired actines 36– 48 – 65 x 5 – 5.7 –7 µm.
Tubar triactines ( Figs 67eView FIGURE 67), sagittal, equiangular, unpaired actines 110– 124 –146 x 5 – 7.6 –11 µm, paired actines 84– 125 –193 x 5 – 7.1 –10 µm.
Subatrial triactines ( Fig. 67fView FIGURE 67), sagittal, equiangular, with unpaired actine longer than paired actines, measuring 195– 223 –285 x 5 –7.7–11 µm, paired actines 63–110–132 x 4 – 6.4 –10 µm.
Atrial tetractines ( Figs 67gView FIGURE 67), with slightly curved actines, often with apical actines longest; unpaired actines 102– 134 –186 x 4 –5.6–8 µm, paired actines 99– 144 –180 x 4 –5.3–7 µm, apical actines 46– 155 –345 x 3 – 5.3 –10 µm.
Distribution and ecology. Saudi Arabia, Red Sea, from shallow-water reef overhangs.
Etymology. Named after Professor Gert Wörheide, München, to acknowledge his important contributions to Calcarea systematics.
Remarks. On paper this species appears close to Southeast Australian Grantessa hirsuta ( Carter, 1886) (originally as Hypograntia ), as redescribed by Dendy (1893a) and Burton (1963: 461). Unfortunately there are no images of this species published so far. From the description it is clear that it is a small cylindrical sponge (about 2 cm high) with hispid surface and apical fringe. However, the details provided by the latter two authors show several distinct differences with our new species: (1) the diactines protruding from the surface are given as 500– 1000 x 14 µm, against up to 7000 x 35 µm in our specimen, (2) the apical actines of the atrial tetractines are given as up to 100 x 6, against up to 345 x 10 µm in our specimen, (3) the articulated skeleton is described as being irregular, whereas our specimen has a very regular tubar skeleton. The lack of differentiation in the various kinds of tri- and tetractines provided in these descriptions makes it hard to be certain of the value of these differences. At least, the length of the diactines and the atrial apical actines provide quite a different aspect in the skeletal structure. The geographic distance and temperature discrepancy between temperate SE Australian waters and the tropical Red Sea adds a further argument for specific distinctness.
There is a possibility that our new species was previously recorded from the Gulf of Aden by Burton (1959) under the name Grantessa sycilloides ( Schuffner, 1877) . We reexamined Burton’s specimen (Murray Expedition station 24, nr 538) in 2004 and from our notes found this to be close in spiculation: giant diactines protruding from the surface, cortical skeleton of small triactines, an articulate main skeleton of pseudosagittal and sagittal triactines, and atrial skeleton of tetractines. In alcohol the specimen was brownish, shaggy. It is certainly unlike Sycortis sycilloides Schuffner, 1877 , as this is largely smooth and does not have atrial tetractines. Schuffner’s species could be a junior synonym of Sycettusa stauridia (see below), but this remains undecided.
The genus Grantessa is large. In our recent paper on Indonesian Calcarea, in which we described two new species, we discussed most of the species occurring in the Indo-West Pacific. We refer to this paper (pp. 82–86) for the more distantly distributed species. The two Indonesian species ( G. borojevici Van Soest & De Voogd, 2015 and G. tenhoveni Van Soest & De Voogd, 2015 ) are clearly distinct from G. woerheidei sp.nov. in having a smooth surface (with only small diactines in the cortical region) and both comprise coalescent groups of individuals. Additionally, they differ in details of their spiculation. The small diactines mentioned for the Indonesian species also occur in the widespread, smooth-surfaced G. intusarticulata ( Carter, 1886) (originally as Hypograntia ) and the South African G. rarispinosa Borojević, 1967 . The latter two species lack tetractines. G. ramosa ( Haeckel, 1872) (originally as Sycandra ) as described by Borojević (1967, p. 204) from South Africa forms a group of coalescent individuals and has sagittal triactines with long swollen unpaired actines and tetractines likewise with swollen apical actines. No other Grantessa species are known from the region.
We obtained a partial 28S sequence of this specimen. In our Calcarea phylogeny of Fig. 3View FIGURE 3, which included a Grantessa cf. intusarticulata sequence downloaded from the Sponge Barcode Project, Grantessa woerheidei sp.nov. ended up in a mixed larger clade quite close to Indonesian Uteopsis argentea ( Poléjaeff, 1883) , away from Grantessa cf. intusarticulata . In a trimmed alignment of three identical Uteopsis argentea sequences and one Grantessa woerheidei sequence of 428 sites, only 5 sites were found to be different, indicating that the two are inexplicably close. Voigt et al. (2012) already found that the family monophyly of Heteropiidae could not be retrieved resulting in two Heteropiidae groups separated by some Jenkinidae . Clearly, more taxa are needed to sort out the relationships of Grantessa .
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