A trab is structural element within a sponge formed by the fusion of dendroclones. In the Anthaspidellidae, when spicules (usually dendroclones) connect at their tips to form a ladder-like structure, trabs may be formed. Oxeas are sometimes employed in the central rod. Trabs have a feather-like structure, or may form rods. Trabs are usually regularly spaced, usually at sub-millimetric intervals.
More at: Trab