Identifying Sponges

Key to California Porifera (Page 081)

( From page 078 B) Heavy, dense reticulation. Often with rock-like consistency.
[A]
Oxeas of 1 size class, to 450 μm in length.
Oxea width to 30 μm.
Sponge lamellate.
cc081A.jpg
Xestospongia diprosopia (de Laubenfels, 1930)
Sponge: Lamellate, subspherical 1-4 cm thick. Consistency: hard, friable. Surface: superficially smooth with low, rounded protuberances, 5-15 mm high on oscular surface. Strongly hispid. Oscula: on one side only, 3 mm diameter and 15 mm apart over shallow, branching, cloacas. Non-oscular side with numerous ostia at least 10 μm in diameter.
Color: Dried: Pale drab.
Spicules: Megascleres: (1) Oxeas: 205 -296-352- 450 um. x 8 -10-23- 30 um.
Skeleton: Ectosome a tangential disordered network of spicule brushes. Choanosome highly dense, reticulate, network of short multispicular tracts interconnected by only a few oxeas or bundles of 4-6 oxeas. Meshes tend to be polygonal. Reticulation finer near surface.
Distribution: Central California.
Depth: Deep water, 500 m.
Note: Was Haliclona diprosopia.
[B]
Oxeas of 2 size classes, 115 - 200 μm; 240 - 260 μm.
Oxea width, 18 - 20 μm.
Sponge encrusting or erectly lobate.
Amphimedon trindanea (Ristau, 1978)
Sponge: Encrusting, 4-12 mm or erectly lobate 8 x 3 x 5 cm high. Consistency: firm and hard, slightly compressible. Surface: slightly hispid, somewhat conulose. Oscula: 1.5-5.0 mm in diameter, flush with surface and either in defined lineations or spread over surface.
Color: Alive and preserved: Dark brown to cinnamon.
Spicules: Megascleres: (1) Oxeas: 115 - 200 um. x 2 - 8 um. (2) Oxeas: 240 - 260 um. x 18 - 20 um.
Skeleton: No easily seen special ectosomal skeleton. Choanosome a reticulation of large multispicular tracts and spicules in confusion. Major tracts 100 - 160 μm wide. Meshes 200-800 x 100-400 μm. Interstitial Oxeas smaller than those in tracts.
Distribution: Central California.
Depth: Intertidal to 38 m.
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