Hamacantha (Vomerula) agassizi Topsent, 1920,

Van, Rob W. M., 2017, Sponges of the Guyana Shelf, Zootaxa 1, pp. 1-225: 127-128

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/03A80010-7729-FFD3-FF14-A1BD95E1FC3E

treatment provided by

Plazi

scientific name

Hamacantha (Vomerula) agassizi Topsent, 1920
status

 

Hamacantha (Vomerula) agassizi Topsent, 1920 

Figures 78View FIGURE 78 a –d

Hamacantha agassizi Topsent, 1920: 11  , fig. 2a; Van Soest 1984: 143, fig. 56.

Material examined. RMNH Por. 9849, Suriname, ‘ Luymes O.C.P.S. II’ Guyana Shelf Expedition, station M97, 7.3083°N 54.1667°W, depth 130 m, bottom coarse sand, 16 April 1969GoogleMaps  .

Description. Thickly to massively encrusting soft sponge ( Fig. 78View FIGURE 78 a), growing together with other encrusting sponges, hydroids and serpulids. Size of fragmented specimen approximately 14 x 10 x 1 cm. Color in alcohol orange-brown. Surface irregularly lobulate, with detachable surface membrane spanning large subdermal spaces.

Skeleton. At the surface there is a tangential reticulation of intercrossing thin megasclere tracts, 25–40 µm (3–7 spicules) in diameter, with many microscleres interspersed. The surface skeleton is carried by plumose spicule bundles, at their base wide (230–350 µm) and with many spicules included, subdividing and thinning out (100–150 µm) towards the surface.

Spicules. ( Figs 78View FIGURE 78 b –d) Styles, diancistras, sigmas.

Styles ( Figs 78View FIGURE 78 b,b1), straight or curved lightly, smooth, slightly fusiform, 361– 405 –438 x 6 – 7.3 –9 µm.

Diancistras ( Figs 78View FIGURE 78 c), in adult condition with fimbriae (razor-surfaces) only extensive at the apices and just below the notches (keyhole-like openings), middle part of shaft rounded; in presumed immature spicules they are elongate sigma-like without clear keyholes; size of mature spicules 119– 125 –147 µm (width approximately 40 µm), size of immature spicules 108– 124 –134 µm.

Sigmas ( Figs 78View FIGURE 78 d,d1), rounded, with one of the apices bird-beak shaped, 11– 12.4 –16 µm.

Distribution and ecology. Guyana Shelf, Gulf of Mexico, Jamaica, 130–151 m depth. Erroneously reported from the Azores by Van Soest (1984) (p. 144).

Remarks. The specimen agrees closely in shape and spiculation with previous descriptions by Topsent (1920) and Van Soest (1984). A second Hamacantha  ( Vomerula  ) species occurring in the Central West Atlantic, H. (V.) tenda ( Schmidt, 1880)  differs in possessing toxas and lacking sigmas [(cf. Topsent 1920 (p. 9), and Hajdu 2002 (p. 667)]. The sizes of the megascleres and diancistras of that species are distinctly larger than those of H. (V.) agassizi  .

RMNH

National Museum of Natural History, Naturalis

Kingdom

Animalia

Phylum

Porifera

Class

Demospongiae

Order

Poecilosclerida

Family

Hamacanthidae

Genus

Hamacantha

Loc

Hamacantha (Vomerula) agassizi Topsent, 1920

Van, Rob W. M. 2017
2017
Loc

Hamacantha agassizi

Van 1984: 143
Topsent 1920: 11
1920