spicule

views updated Jun 27 2018

spicule A small needle or spine, or a small, spiky, skeletal element. In Porifera (sponges), spicules form a skeletal framework supporting the soft, cellular mass. They exist in a variety of forms and are important in the identification and classification of species. An extensive nomenclature has developed through the use of these structures in poriferan taxonomy (e.g. they may be described as monoaxon, tetraxon, triaxon, hexaxon, polyaxon, megasclere, or microsclere). Spicules may be calcareous, siliceous, or of a fibrous material (spongin).

spicule

views updated Jun 08 2018

spicule (spik-yool) n. a small splinter of bone.

spicule

views updated May 29 2018

spicule A small needle or spine.

spicule

views updated May 08 2018

spicule A small needle or spine.

spicule

views updated May 23 2018

spicule A small needle or spine.