Hymedesmia (Hymedesmia) bonairensis

Dataset
New sciophilous sponges from the Caribbean (Porifera: Demospongiae): Rank
SPECIES: Published in
Van, Rob W. M. (2009): New sciophilous sponges from the Caribbean (Porifera: Demospongiae). Zootaxa 2107: 1-40, DOI: 10.5281/zenodo.187789

Classification

kingdom
Animalia: phylum
Porifera: class
Demospongiae: order
Poecilosclerida: family
Hymedesmiidae: genus
Hymedesmia: species
Hymedesmia bonairensis

description

Description. Thinly encrusting under coral rubble. Surface bumpy, provided with small areolae. Color an intense rich yellow (like egg yolk) or paler yellow; in alcohol it is greyish white. Consistency soft. Skeleton. Acanthostyles erect on the surface, tornotes loosely arranged in the ectosome. Densely scattered sigmas in all parts of the sponge. Spicules. Tornotes, acanthostyles in two size categories, isochelae in two size categories, sigmas in two size categories. Tornotes (Figs 13 A – B) thin, slim, with slightly unequal endings, one mucronate, the other oxeote, 179 - 192.6 - 213 x 1.5 - 2.1 - 2.5 µm. Large acanthostyles (Fig. 13 C), with blunt spines at the head, 144 - 176.1 - 207 x 4 - 5.3 - 6.5 µm; small acanthostyles (Fig. 13 D), 48 - 63.1 - 75 x 3 - 3.6 - 4.5 µm. Large sigmas (Fig. 13 E), shaped normally, 35 - 38.7 - 42 µm; small sigmas (Fig. 13 F), thin, shaped normally, 11 - 12.8 - 14 µm. Large arcuate isochelae (Fig. 13 G), with the shaft grooved on the outside, 17 - 20.6 - 24 µm; small isochelae (Fig. 13 H), with reduced side alae attached to the shaft over their entire length, 9 - 9.8 - 11 µm. Ecology. Under stones at shallow depth, 3.5 – 5 m.

discussion

Remarks. Among the species of Hymedesmia (Hymedesmia) known from Central West Atlantic waters, the new form stands out by the possession of sigmas, in two size categories. Elsewhere in the North Atlantic Ocean, approx. 15 species of Hymedesmia are known to possess sigmas, but only one species, H. ebria Alander (1937) from deep water fjord habitat (180 – 210 m) in northern Norway has a similar spicule complement of sharp-ending tornotes, two size classes of acanthostyles, more than one size class of chelae and two size classes of sigmas. However, the chelae of H. ebria occur in three sizes, the largest of which is clearly much larger (55 – 75 µm) than the largest chela in our new species. Further differences are the larger size of both sigma categories in Alander’s material (20 – 30 and 55 – 75 µm), and the larger size of both acanthostyle categories (350 – 425 and 125 – 145 µm).

etymology

Etymology. Named after the island of Bonaire, Netherlands Antilles.

materials_examined

Holotype. ZMA Por. 21065, Bonaire, Jachthaven, 12.162 ° N - 68.286 ° W, under rubble, 3.5 m, 30 - 06 - 1987, coll. R. Pennaerts & G. J. Roebers, # J. 07.07 - 103. Paratype. ZMA Por. 21066, same data as the holotype, coll. G. J. Roebers # 73. Additonal material (not belonging to the type series). Bonaire, Punt Vierkant, 12.116 ° N - 68.295 ° W, under rubble, 5 m, 1987, coll. G. J. Roebers, # G. 02 - 5.

Name

Homonyms: Hymedesmia (Hymedesmia) bonairensis