Rhizaxinella clava ( Schmidt, 1870 )

Van, Rob W. M., 2017, Sponges of the Guyana Shelf, Zootaxa 1, pp. 1-225 : 189-190

Rhizaxinella clava ( Schmidt, 1870)

Figures 119 a–d

Axinella clava Schmidt, 1870: 61 .

Rhizaxinella clava ; Alvarez et al. 1998: 15; Rützler et al. 2009: 297.

Material examined. RMNH Por. 9925, Suriname, ‘ Luymes O.C.P.S. II’ Guyana Shelf Expedition, station M97, 7.3083°N 54.1667°W, depth 130 m, Agassiz trawl, bottom coarse sand, 16 April 1969 .

Description. Stalked sponge ( Fig. 119 a) with oval main body ( Fig. 119 a1). Total length of specimen 8 cm, body 12 mm high, 8 mm in diameter, stalk approximately 1.5 mm in diameter. Color pale brown in alcohol. Stalk optically smooth, main body microhispid. Oscule (now closed) apical on a slight elevation. Consistency of main body compressible.

Skeleton. The skeleton of the stalk consists of aligned long styles, penetrating the main body, where intermediate sized styles fan out and carry erect brushes of smaller tylostyles.

Spicules. ( Figs 119 b–d) Styles, tylostyles.

Long styles ( Figs 1 19 b,b1), straight, no visible tyles, longest spicules overlapping and intergrading with the intermediate styles ( Figs 119 c,c1) of the main body, overall sizes 814– 1334 –1936 x 10–15.4–22 µm.

Small tylostyles ( Figs 119 d,d1) of the surface brushes, straight, style-like but with a faint subterminal tyle or constriction, 186– 323 –474 x 3 – 5.2 –7 µm.

Distribution and ecology. Guyana Shelf, Gulf of Mexico, coarse sand bottom at 130 m depth.

Remarks. This is the second record of the species, after Schmidt’s (1870) description from the Gulf of Mexico (see Alvarez et al. 1998: 15).

So far, no type specimen of this species has been positively identified and redescribed. A possible type specimen has been recently found in the BMNH collection (Ms Emma Sherlock in litteris), labeled ‘ Cometella gracilior n.g. n.sp. Alligator Reef, BMNH 1939:2:10:45 (sp) MCZ Exchange (MCZ 8130)’. It has the shape of Schmidt’s pl. IV fig. 9, and in all probability is not ‘ Cometella gracilior ’ (= Asbestopluma (A.) gracilior , see above), but possibly the type of Rhizaxinella clava .

Figures

FIGURE 1. Map of the northeast coast of South America showing the Guyana Shelf with 200 m depth contour and in the inset the area covered by the Dutch HMS ‘ Snellius’ O. C. P. S. 1966, HMS ’ Luymes’ O. C. P. S. II 1969, and HMS ‘ Luymes’ Guyana Shelf 1970 expeditions. Arrows indicate predominant current direction. Map courtesy of www. prima. com (map collection Free Edition).

FIGURE 2. Overview of stations on the Guyana Shelf made by the Dutch HMS ‘ Snellius’ O. C. P. S. 1966, HMS ’ Luymes’ O. C. P. S. II 1969, and HMS ‘ Luymes’ Guyana Shelf 1970 expeditions (black dots), with numbered stations where sponges were obtained. Details for each station are provided in the text with each described sponge species.

FIGURE 3. Chondrilla caribensis Rützler, Duran & Piantoni, 2007, RMNH Por. 9816, a, habitus (scale bar = 1 cm), b, SEM image of spherasters.

FIGURE 4. Chondrosia collectrix (Schmidt, 1870), RMNH Por. 9338, a, habitus (scale bar = 1 cm), b, light microscopic image of cross section of peripheral region.

FIGURE 5. Aplysina caissara Pinheiro & Hajdu, 2001, RMNH Por. 9340, a, habitus (scale bar = 1 cm), b, light microscopic image of skeleton of pithed fibers.

FIGURE 6. Aplysina cauliformis (Carter, 1882), RMNH Por. 9340, a, habitus of two specimens (scale bar = 1 cm), b, light microscopic image of skeleton of pithed fibers.

FIGURE 7. Aiolochroia crassa (Hyatt, 1875), RMNH Por. 9819, a, habitus (scale bar = 1 cm), b, light microscopic image of skeleton of pithed fibers.

FIGURE 8. Chelonaplysilla americana sp. nov., a, habitus of holotype RMNH Por. 9812 (scale bar = 1 cm), b, light microscopic image of surface sand grain reticulation.

FIGURE 9. Igernella notabilis (Duchassaing & Michelotti, 1864), RMNH Por. 9337, a, fragments (scale bar = 1 cm), a 1, one of the fragments enlarged (scale bar = 1 cm), b – c, light microscopic images, b, peripheral skeleton, c, horny spicule.

FIGURE 10. Ircinia felix (Duchassaing & Michelotti, 1864), a, habitus of RMNH Por. 9333 (scale bar = 1 cm), b, habitus of RMNH Por. 9936 (scale bar = 1 cm), c – d, light microscopic images of skeleton of RMNH Por. 9904, c, cross section, d, filaments.

FIGURE 11. Dysidea etheria De Laubenfels, 1936, a, habitus of RMNH Por. 9353 (scale bar = 1 cm), b. light microscopic image of cross section of skeleton of RMNH 10510.

FIGURE 12. Callyspongia (Callyspongia) cf. pallida Hechtel, 1965, a, habitus of RMNH Por. 9894 (scale bar = 1 cm), a 1, habitus of RMNH Por. 9900 (scale bar = 1 cm), b, light microscopic image of surface skeleton of RMNH Por. 9894, c – c 1, SEM images of skeleton of RMNH Por. 9900, c, surface skeleton, c 1, detail of c, d, SEM image of oxeas.

FIGURE 13. Callyspongia (Callyspongia) scutica sp. nov., a, habitus of holotype RMNH Por. 9874 (scale bar = 1 cm), a 1, detail of branches of a (scale bar = 1 cm), b, habitus of paratype RMNH Por. 9968 (scale bar = 1 cm), c, SEM images of oxeas of holotype RMNH Por. 9874.

FIGURE 14. Callyspongia (Callyspongia) scutica sp. nov., holotype RMNH Por. 9874, a – d, SEM images of skeleton, a, overview of surface with oscule, b, cross section of branch, c, detail of ‘ double’ surface skeleton, d, cross section of peripheral skeleton, e – f, lightmicroscopic images of skeleton, e, surface skeleton showing unispicular spicule network, f, cross section of choanosomal skeleton showing rectangular reticulation of paucispicular fibers.

FIGURE 15. Cladocroce guyanensis sp. nov., a, habitus of fragmented holotype RMNH Por. 9826 (scale bar = 1 cm), b, light microscopic image of surface skeleton, c, SEM images of oxeas.

FIGURE 16. Haliclona (Gellius) sp. aff. flagellifera (Ridley & Dendy, 1886), a, habitus of RMNH Por. 9783 (scale bar = 1 cm), b, light microscopic image of surface skeleton of ditto, c – e, SEM images of spicules of RMH Por. 9921, c, oxea, d, flagellated sigma, e, sigma.

FIGURE 17. Haliclona (Haliclona) epiphytica Zea & De Weerdt, 1999, a, habitus of RMNH Por. 9970 (scale bar = 1 cm), b – c, light microsocpic images of skeleton, b, surface skeleton, c, cross section, d, SEM images of oxeas.

FIGURE 18. Haliclona (Haliclona) cf. implexiformis (Hechtel, 1965), a, habitus of RMNH Por. 9989 (scale bar = 1 cm), a 1, of RMNH Por. 9835 (scale bar = 1 cm), b – b 1, light microscopic images of skeleton, b, b, surface skeleton, b 1, cross section, c, SEM images of oxeas.

FIGURE 19. Amphimedon nanaspiculata (Hartman, 1955), a, habitus of RMNH Por. 9876 (scale bar = 1 cm), a 1, of RMNH Por. 9985 (scale bar = 1 cm), b – c, light microscopic images of skeleton, b, surface skeleton of RMNH Por. 9896, c, cross section of RMNH Por. 9985, d, SEM image of oxea.

FIGURE 119. Rhizaxinella clava (Schmidt, 1870), a, habitus of RMNH Por. 9925 (scale bar = 1 cm), a 1, detail of body of RMNH Por. 9925, b – d, SEM images of the spicules, b, long style from the stalk, b 1, details of b, c, intermediate style from the body, c 1, detail of c, d, small ectosomal (sub-) tylostyle, d 1, details of d.