Sycon

Rützler, Klaus, Piantoni, Carla, Van, Rob W. M. & Díaz, Cristina, 2014, Diversity of sponges (Porifera) from cryptic habitats on the Belize barrier reef near Carrie Bow Cay, Zootaxa 3805 (1), pp. 1-129 : 102

Sycon sp.

Synonymy and references. Scypha ciliata (Fabricius) : de Laubenfels (1950): 143, fig. 63. Sycon ciliatum (Fabricius) : Rützler (1986): 126, fig. 45, pl. 4: 7.

Material. USNM 1229162, Carrie Bow back reef near crest, underside of Acropora palmata coral rubble, 0.3 m; K. Ruetzler col. 23 Apr 1974. USNM 1229163, Carrie Bow Cay, south back reef, lower surface of platy coral rubble, 1 m; K. Ruetzler col. 17 Aug 2012.

External morphology. Vase-shaped, thickest in the middle, syconoid aquiferous system, 14 mm tall, 4 mm diameter, one apical atrium of 2 mm diameter, crowned by oxeas. Firm but fragile, white in color.

Skeleton structure. Oxeas and sagittal tetractines surround the atrium, oxeas, triactines and tetractines make up the choanoskeleton.

Spicules. Dimensions are difficult to determine from this small sample, as many spicules are broken. Oxeas I: 300– 1600 x 2–6 µm; oxeas II: 430– 1950 x 8–20 µm; triactines, regular or sagittal, with two actines bent backward toward the third (which may be longer), at varying degree; actine dimensions: 60–180 x 5-13 µm; tetractines, many sagittal, with paired actines straight or bent in various directions; actine dimensions: 50–140 x 5–10 µm.

Ecology. Observed in most cryptic habitats, undersides of shallow rubble to forereef caves, 0.5– 30 m.

Distribution. Reported from many locations in the northern Atlantic.

Comments. Records from outside the northern Atlantic region are considered doubtful or not valid (van Soest et al., 2013b). A more focused study of Sycon species (and many other Calcarea) from the tropical western Atlantic is most desirable.