Clathrina luteoculcitella Wörheide & Hooper, 1999

Van, Rob W. M. & De, Nicole J., 2018, Calcareous sponges of the Western Indian Ocean and Red Sea, Zootaxa 4426 (1), pp. 1-160 : 42-43

Clathrina luteoculcitella Wörheide & Hooper, 1999

Figures 18a–f , 19a–e , 20a–e

Clathrina luteoculcitella Wörheide & Hooper, 1999: 868 , figs 5A–E

Clathrina aff. luteoculcitella ; Van Soest & De Voogd 2015: 13, figs 6a–d.

Material examined. RMNH Por. 11623, Mauritius, Rodrigues, Passe Baladirou, 19.6683°S 63.46307°E, depth 12 m, scuba, coll. N.J. de Voogd, field nr. ROG024, 16 October 2016; RMNH Por. 11641, Mauritius, Rodrigues, Mourouk Ebony, Castel Rock, 19.76203°S 63.46273°E, depth 10 m, scuba, coll. N.J. de Voogd, field nr. ROG044, 17 October 2016; RMNH Por. 11659, Mauritius, Rodrigues, Mourouk Ebony, Castel Rock, 19.76203°S 63.46273°E, depth 10 m, scuba, coll. N.J. de Voogd, field nr. ROG063, 17 October 2016; RMNH Por. 11686, Mauritius, Rodrigues, Passe Baladirou, 19.6683°S 63.46307°E, depth 12 m, scuba, coll. N.J. de Voogd, field nr. ROG094, 18 October 2016; RMNH Por. 11687, Mauritius, Rodrigues, Mourouk Ebony, Castel Rock, 19.7648°S 63.4626°E, depth 12 m, scuba, coll. N.J. de Voogd, field nr. ROG101, 19 October 2016; RMNH Por. 11703, Mauritius, Rodrigues, Passe Saint François, 19.69893°S 63.5005°E, depth 15 m, scuba, coll. N.J. de Voogd, field nr. ROG117, 20 October 2016; ZMA Por. 17438, Oman, Muscat, Ras al Khayran, on rocks, 23.75°N 58.75°E, (depth not recorded, but shallow), scuba, coll. O. Eerland, field nr. 02/IO/ DEC08 /OE/006, 6 December 2002; ZMA Por. 10223b, Seychelles, Mahé, NE coast, Cap Maçons and Anse de Forbans, 4.7667°S 55.5167°E, depth 0–6 m, snorkeling, coll. R.W.M. van Soest, field nr. NIOP-E stat. 612, 12 December 1992.

Description. Cushion-shaped masses of tightly anastomed tubuli ( Figs 18a–e ). Tubuli thin, 0.2–0.4 mm in diameter. Numerous prominent oscules much wider than individual tubuli are visible on the upper side on in situ images (e.g. Fig. 18a ). Color beige or orange-brown in situ, dirty white or pale beige ‘on deck’, ( Fig. 18f ), pale beige in preserved condition. Consistency soft. Sizes up to 6 x 3 x 3 cm, individual tubuli 0.2–0.3 mm in diameter. The specimen from Oman had white live color, the Seychelles specimen was of unknown life color; both are pale beige ( Fig. 20a ) in preserved condition.

Aquiferous system. Asconoid.

Skeleton. ( Figs 19a–b , 20b,d ) Thin tubules with the walls single-spicule layered, not very dense. Spaces between the tubuli small, 0.1–0.5 µm.

Spicules. ( Figs 19c–e , 20c,e ) Triactines equiangular equiradiate, with small conical actines; some broken trichoxeas ( Fig. 19d ).

Measurements of the actines of the triactines in three of the specimens from Rodrigues show a very limited variation:

RMNH Por. 11641: 69– 99 x 6.5–9.5 µm

RMNH Por. 11659: 72– 94 x 6–9 µm

RMNH Por. 11687: 74– 93 x 6 –9.5 µm

Overall, sizes are 69– 99 x 6 –9.5 µm (n= 50).

Few broken trichoxeas are found in one of the specimens.

Triactines of the Oman specimen ( Figs 20c ) are slightly larger, 72– 95.6 –108 x 6.5– 9.4 –12 µm (n=25); those of the Seychelles specimen ( Fig. 20e ) are similar to the Rodrigues specimens: 71– 84 – 96 x 7 – 8.6 –9.5 µm (n= 25).

Distribution and ecology. Rodrigues, Oman, Australia, Indonesia, on reefs at 0–15 m depth.

Remarks. The identification of the Rodrigues specimens with C. luteoculcitella is based on morphological and molecular characters. The species is distinct by its cushion-shaped mass of tightly meshed tubuli in combination with prominent oscules and small conical-actined triactines. Partial 28S sequence data point towards close relationship with Indonesian specimen ZMA Por. 0 8657 assigned to Clathrina luteoculcitella (cf. Van Soest & De Voogd 2015) and the Northeast Australian holotype of the species in the Sponge Barcode Project database. Together they form a sisterclade to a clade containing specimens of C. rowi (see Fig. 2A ). Clathrina rowi is morphologically distinct from C. luteoculcitella as the cormus is more loosely organized and has different color. As reported above, the two show small but consistent molecular differences.

Likely members of C. luteoculcitella from Oman and the Seychelles have also a tightly meshed cormus and small spicules. The sequence of the Oman specimen matches closely with those of Rodrigues and Indonesian specimens of that species. However, the in situ color was noted as white, so some doubt is in order. The Seychelles specimen was very small and no sequence could be obtained, but what information we obtained makes membership of this species likely. We provide separate illustrations of the various specimens to support our conclusion that all are assumed to be conspecific.

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 18. Clathrina luteoculcitella Wörheide & Hooper, 1999, habitus of various specimens from Rodrigues (all photos N.J. de Voogd), a, RMNH Por. 11641 (ROG044) specimen in situ, b, second specimen in situ of the same sample, c, RMNH Por. 11687 (ROG101) in situ, d, RMNH Por. 11703 (ROG117) in situ, e, RMNH Por. 11623 (ROG024), f, RMNH Por. 11641 specimen a on deck (scale bar = 1 cm).

FIGURE 19. Clathrina luteoculcitella Wörheide & Hooper, 1999, from Rodrigues, skeleton and spicules, a–b, light microscopic images of the tubuli network, a, RMNH Por. 11687, b, RMNH Por. 11641, c–e, SEM images of spicules, c, triactines of RMNH Por. 11687, d, fragment of rare trichoxea of RMNH Por. 11687, e, triactines of RMNH Por. 11641.

FIGURE 20. Clathrina luteoculcitella Wörheide & Hooper, 1999, a–c, ZMA Por. 17438, from Oman, a, preserved habitus (scale bar = 1 cm), b, light microscopical image of the tubuli reticulation, c, SEM images of the spicules, d–e, ZMA Por. 10223b, from the Seychelles, d, light microscopic image of the cormus, e, SEM image of triactine.