Timea tylasterina, Van, Rob W. M., 2017

Van, Rob W. M., 2017, Sponges of the Guyana Shelf, Zootaxa 1, pp. 1-225: 180-181

publication ID

http://doi.org/ 10.5281/zenodo.272951

publication LSID

lsid:zoobank.org:pub:6D68A019-6F63-4AA4-A8B3-92D351F1F69B

persistent identifier

http://treatment.plazi.org/id/03A80010-77E4-FF18-FF14-A24E949DFD32

treatment provided by

Plazi

scientific name

Timea tylasterina
status

sp. nov.

Timea tylasterina  sp. nov.

Figures 112View FIGURE 112 a –e

Material examined. Holotype RMNH Por. 9776, Suriname, ‘ Luymes O.C.P.S. II’ Guyana Shelf Expedition, station I115, 7.21°N 54.8617°W, depth 81 m, triangular dredge, 24 April 1969GoogleMaps  .

Description. ( Fig. 112View FIGURE 112 a) Thin ecrustation cementing calcareous rubble. Surface optically smooth. Size about 2 cm 2, consisting of dispersed patches. Color (in alcohol) whitish to greyish.

Skeleton. Thin single tylostyles arise from the substratum erect or in small diverging groups, protruding barely beyond the surface. Microscleres form a dense mass at the base of the sponge.

Spicules. ( Figs 112View FIGURE 112 b –e) Tylostyles, tylasters.

Tylostyles ( Figs 1 12View FIGURE 1View FIGURE 2View FIGURE 3View FIGURE 4View FIGURE 5View FIGURE 6View FIGURE 7View FIGURE 8View FIGURE 9View FIGURE 10View FIGURE 11View FIGURE 12 b,b1), thin, slightly curved, with rather elongated tyle, sometimes subapical, 204– 292 –388 x 2 – 3.2 –4 µm.

Tylasters in two categories, (1) larger ( Figs 112View FIGURE 112 c), with 8–10 thick, truncated, smooth rays each ending in a crown with 3–7 conical spines, 13– 14.1 –15.5 µm, and (2) smaller ( Figs 112View FIGURE 112 d), with 7–11 short truncated rays each ending in a profusedly spined crown often consisting of double circles of spines, 7– 8.4 –10 µm. A few middle-sized tylasters ( Fig. 112View FIGURE 112 e) occurred with thinner rays, presumably juveniles of the large tylasters.

Distribution and ecology. Guyana Shelf, on sandy bottom at 81 m depth.

Etymology. The name refers to the tylasters.

Remarks. Among the many (13) species of Timea  recorded from the Central West Atlantic, there are no descriptions matching all aspects of the above described material. Using Leite et al. ‘s (2015) key to the Timea  species of the Tropical West Atlantic the new species keys out as Timea stenosclera Hechtel, 1969  . There are indeed several similarities with this species, originally described from Barbados: thin optically smooth encrustation, small sized tylostyles, loose arrangement of megascleres, and two categories of asters. However, the large asters of T. stenosclera  are oxyspherasters of up to 25.9 µm (average 19.7 µm) whereas the large asters in the present species are tylasters of up to 15.5 µm. The small asters of T. stenosclera  are ‘euasters’ (drawn as thin-rayed oxyasters) of up to 11.8 µm (average 9.7 µm), whereas the small asters in the present species are tylasters with squat, profusedly ornamented rays, 7–10 µm in size.

The asters of the new species on paper appear similar in shape and size to those of Timea perastra ( De Laubenfels, 1936)  (as Halicometes  ), but the tylostyles of that species may be up to 1888 µm long.

RMNH

National Museum of Natural History, Naturalis

Kingdom

Animalia

Phylum

Porifera

Class

Demospongiae

Order

Hadromerida

Family

Timeidae

Genus

Timea