Clathrina rodriguesensis, Van & De, 2018

Van, Rob W. M. & De, Nicole J., 2018, Calcareous sponges of the Western Indian Ocean and Red Sea, Zootaxa 4426 (1), pp. 1-160 : 46-50

Clathrina rodriguesensis sp.nov.

Figures 24a–e , 25a–g , 26a–d , 27a–d

Material examined. Holotype, RMNH Por. 11694, Mauritius, Rodrigues, Mourouk Ebony, Castel Rock , 19.7648°S 63.4626°E, depth 12 m, scuba, coll. N.J. de Voogd, field nr. ROG108, 19 October 2016.

Paratypes, RMNH Por. 11624, Mauritius, Rodrigues, Passe Baladirou , 19.6683°S 63.46307°E, depth 12 m, scuba, coll. N.J. de Voogd, field nr. ROG025, 16 October 2016 ; RMNH Por. 11662, Mauritius, Rodrigues, Passe Baladirou , 19.6683°S 63.46307°E, depth 12 m, scuba, coll. N.J. de Voogd, field nr. ROG069, 18 October 2016 ; RMNH Por. 11670, Mauritius, Rodrigues, Passe Baladirou , 19.6683°S 63.46307°E, depth 12 m, scuba, coll. N.J. de Voogd, field nr. ROG077, 18 October 2016 ; RMNH Por. 11671, Mauritius, Rodrigues, Passe Baladirou , 19.6683°S 63.46307°E, depth 12 m, scuba, coll. N.J. de Voogd, field nr. ROG078, 18 October 2016 ; RMNH Por. 11705, Mauritius, Rodrigues, Passe Baladirou , 19.6683°S 63.46307°E, depth 8 m, scuba, coll. N.J. de Voogd, field nr. ROG119, 20 October 2016 ; RMNH Por. 11710, Mauritius, Rodrigues, Passe Saint François , 19.69893°S 63.5005°E, depth 15 m, scuba, coll. N.J. de Voogd, field nr. ROG124, 20 October 2016 .

Additional specimens. ZMA Por. 11282, Seychelles, Amirantes, Desroches Atoll, SW rim, 5.7167°S 53.6167°E, depth 5–30 m, scuba, coll. M.J. de Kluijver, field nr . NIOP-E stat. 774/01, 30 December 1992; ZMA Por. 12096, Seychelles, Amirantes , St. François Atoll, Île Bijoutier, 7.0833°S 52.7333°E, reef, outer slope, depth 6–18 m, scuba, coll. R.W.M. van Soest, field nr . NIOP-E stat. 792/12, 5 January 1993.

Description. In situ, the species forms a massively encrusting cormus ( Figs 21a–d , 22a–b ) consisting of relatively wide tubuli (approximately up to 2–3 mm in diameter), which are nevertheless closely anastomosed, showing little differentiation in tubule-width. The cormus may be also flatly encrusting over a larger area ( Fig. 23a ) with loosely anastomosing tubuli showing a tendency to be arranged ladder-like, with longitudinal main tubuli and interconnecting secondary thinner tubuli. The main tubuli frequently end in an oscule, often slightly erected above the cormus ( Figs 22a–b ). Lateral size considerable, 20 x 15 cm or more, thickness 1–4 cm. Color white with blueish or greyish tinges in situ, white or pink ‘on deck’ ( Figs 21b , 22c,e , 23b ), in preservation they become pale beige ( Figs 21c , 22f : Rodrigues specimens) or brown ( Fig. 24a : Seychelles specimens). The latter have possibly become brown by exposure to algae or other sponges, as their in situ color was noted as blueish white. Size of preserved fragments up to 10 x 5 x 4 cm. Consistency firm.

Aquiferous system. Asconoid.

Skeleton. Tubule walls multi-layered, densely crowded in most specimens ( Figs 21d , 22d , 23c ), but less dense in one of the Seychelles specimens ( Fig. 24b ).

Spicules. ( Figs 21e , 22g , 23d , 24c–d ). Triactines only, but occasional fragments of trichoxea-like spicules were observed (not shown).

Triactines, robust, with conical actines, measuring 97– 169 –225 x 11 – 18.2 –22 µm in the Rodrigues specimens. The two Seychelles specimens which we believe to belong to this species have actines respectively 93– 159 –198 x 11 – 17.4 –21 µm (ZMA Por. 11282) and 111– 164 –204 x 13 – 17.8 –21 µm (ZMA Por. 12096) ( Figs 24c–d ). The actines in all these specimens are conical

Distribution and ecology. Rodrigues, Seychelles, on reefs, 5–30 m depth.

Etymology. The name refers to the type locality, the island of Rodrigues, east of Mauritius.

Remarks. We provide ample illustrations of this new species to demonstrate the habitus variability. Spicules are closely similar in all above-mentioned specimens.

Partial 28S sequences of seven specimens collected at Rodrigues and two Seychelles specimens grouped in a separate clade (cf. Fig. 2A ) at high bootstrap value, apparently not closely related to the other Western Indian Ocean Clathrina .

Australian and Indonesian Clathrina heronensis Wörheide & Hooper, 1999 is close in color and spicule size and shape, but its habitus is flatly encrusting and it has thinner tubuli (1 mm) than the present material. An Indonesian specimen identified as C. heronensis was sequenced and found to share a clade with lower bootstrap value with the present material in the molecular tree of Fig. 2A. A separate analysis of the sequences of both species in a trimmed alignment with length of 395 sites showed a difference of eight sites between C. heronensis and C. rodriguesensis sp.nov.

Figures

FIGURE 2. Maximum-likelihood tree based on analysis of sequences of the partial 28S gene (C2–D2 region, comprising 442 sites) of Western Indian Ocean Calcinea newly generated by the Naturalis Biodiversity Center and sequences additionally obtained from GenBank, the Sponge Barcode Project and from Oliver Voigt (München) from the Red Sea, Indonesia, Australia, and a few sequences from other parts of the world, to demonstrate the affiliation of the compared species. Please note that Arturia sequences do not appear in the same clade, indicating Arturia is non-monophyletic. Numbers at the root of clades are bootstrap values of 1000 replicates. Since the high number of sequences were difficult to read in detail, we subdivided the present tree in three detailed sections 2A, 2B, and 2C.

FIGURE 21. Clathrina rodriguesensis sp.nov., holotype RMNH Por. 11694, from Rodrigues, a, in situ (photo N.J. de Voogd), b, on deck (scale bar = 1 cm), c, preserved (scale bar = 1 cm), d, light microscopic image of the cormus, e, SEM images of the spicules.

FIGURE 22. Clathrina rodriguesensis sp.nov., paratypes from Rodrigues, a–d, RMNH Por. 11662 (ROG025), a, in situ on the reefs (photo N.J. de Voogd), b, detail of a, c, on deck photo of the same, (photo N.J. de Voogd) d, light microscopic image of part of the cormus of the same, e–g, RMNH Por. 11662 (ROG069), e, on deck photo, f, preserved specimen of the same, g, SEM images of the spicules of the same.

FIGURE 23. Clathrina rodriguesensis sp.nov., paratype RMNH Por. 11670 from Rodrigues, a, habitus in situ (photo N.J. de Voogd), b, habitus on deck, c, light microscopic images of the tubuli network, d, SEM images of the spicules.

FIGURE 24. Clathrina rodriguesensis sp.nov., specimens from the Seychelles, a, habitus of ZMA Por. 11282, preserved specimen (scale bar = 1 cm), b, light microscopic image of skeleton, c, SEM images of spicules, d, ditto of ZMA Por. 12096.

FIGURE 25. Clathrina maremeccae sp.nov., holotype RMNH 9662 from Saudi Arabia, Jeddah, a, habitus on deck (photo N.J. de Voogd), b, light microscopic image of the cormus, c, SEM images of triactines.

FIGURE 26. Clathrina repens sp.nov., a, in situ habitus of holotype RMNH Por. 10161 from the Maldives, a1, in situ habitus of a second specimen (not collected) (photos N.J. de Voogd), b, preserved holotype (scale bar = 1 cm), c, light microscopic image of one of the tubuli, d, SEM images of the spicules.

FIGURE 27. Clathrina aff. pulcherrima (Dendy, 1891), a, habitus of preserved specimen from Mozambique Channel W of Madagascar (scale bar = 1 cm), a1, detail of head with row of oscules on the rim, b, light microscopic image of skeleton of the basal part of the head, showing aligned parasagittal spicules, c–e, SEM images of the spicules, c, equiradiate triactine with thin actine, d, ditto with thick conical actines, e, various shaped parasagittal triactines.