Identifying Sponges

Key to California Porifera (Page 262)

( From page 259 B) Hypodermal Pentactins are NOT all smooth or granulated; some are ornamented with thorns.
[A]
Mean Discoctaster diameter is greater than 200 μm.
cc262A.jpg
Rhabdocalyptus nodulosus Schulze, 1899
Sponge: Tubular, thin-walled, with veil of Diactins and Pentactins.
Color: Not recorded.
Spicules: Megascleres: (1) Principal Diactins: 8.7 -17.1- 26.2 mm. (2) Thick Diactins: 16 -23- 30 mm. (3) Hypodermal Pentactins (tangential ray): 5.0 -5.7- 6.5 mm. Mesoscleres: (1) Dermal Stauractins (ray): 84 -119- 179 um. (2) Dermal Pentactins (tangential ray): 71 -149- 199 um. (proximal ray): 66 -127- 200 um. (3) Gastral Hexactins (ray): 101 -136- 195 um. Microscleres: (1) Oxyhexactins (diameter): 65 -104- 144 um. (2) Oxyhemihexasters (diameter): 71 -118- 146 um. (3) Discoctasters (diameter): 177 -267- 331 um.
Skeleton: Entirely composed of loose spicules.
Distribution: Southern California.
Depth: Deep water.
Other Data from Holotype USNM 7576.
Tabachnick's 2002 proposed move of Rhabdocalyptus to a subgenus of Acanthascus is not followed here.
[B] GO TO PAGE 263
Mean Discoctaster diameter is NOT greater than 200 μm.
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