Identifying Sponges

Key to California Porifera (Page 058)

( From page 057 B) Sigmas either normal with moderate arch/curved back OR unusual with a thickening at the center of the shaft. Anisochelae of 1 or 2 size classes.
[A]
Sigmas either normal OR with a thickening at the center of the shaft.
Anisochelae of 1 size class.
cc058A.jpg
Mycale (Carmia) richardsoni Bakus, 1966
Sponge: Encrusting often wrapped around algae, hydroids etc to 1 cm thick. Consistency: compressible. Surface: hispid but feels smooth. Oscula: 1-2 mm diameter, the larger often elevated.
Color: Alive: yellow-rose to gold-beige.
Spicules: Megascleres: (1) Styles: 125 -173-186- 212 um. x 5 -7-8- 10 um. Microscleres: (1) Sigmas (often rare): 15 -19-20- 38 um. (2) Anisochelae: 15 -30-31- 38 um.
Skeleton: Dermal membrane above subdermal spaces. Ladder-like tracts to surface. Near their bases they tend to merge into a reticulation.
Distribution: Central, northern California.
Depth: Intertidal to deep water, 40 m.
Note: California specimens lack Sigmas with central thickening (some Pacific Northwest specimens do have these) and all spicule measurements are somewhat smaller than those of the type. This species and M. hispida (pg. 57A) are very similar and need to be thoroughly compared.
[B]
Sigmas normal only. No central thickening.
Anisochelae of 2 size classes.
Mycale (Carmia) richardsoni (Bakus)? n.var. [of Lee]
Sponge: Thin encrusting to 2-3 mm thick. Consistency: Rubbery. Oscula: abundant, 0.5-1.0 mm diameter.
Color: Alive: Yellow, buff to light brown..
Spicules: Megascleres: (1) Styles]: 96 -160-202- 381 um. x 4 -7-9- 12 um. Microscleres: (1)Sigmas-asymetrical: 19 -20-36- 44 um. (2) Anisochelae: 19 -23-26- 37 um. (3) Anisochelae-Note tooth on lower palm.: 36 -42-46- 59 um.
Skeleton: Ladder-like skeleton near surface only, otherwise a loose reticulation. Tracts thick.
Distribution: Central, Northern California.
Depth: Intertidal.
Note: This variety differs from M. richardsoni by having two size classes of Anisochelae, a limited ladder-like skeleton and thickened tracts. More comparisons of specimens from a wider geographic range are needed.
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