[General 1] Pointed structure, either part of or secreted by cell.

[General 2] Very thick, simple chaeta.

[Pteropoda] Lateral spines are lateral prolongations of the shell near the aperture corners. They differ in shape among species and are often bent dorsally. The caudal spine projects posteriorly, it is straight or bent and in some species discarded in the adult.
Cavolinia in ventral view
Diacavolinia in lateral view
Cuvierina detached protoconch

[Cephalopoda] The sharp spike-like extension on the posterior tip of the gladius or cuttlebone (Ce 1D).

[Crustacea] Sharp projections on the carapace or an appendage. They are usually inflexible and unarticulated, but the differentiation between setae, spines and tubercles is not always clear-cut.

[Pisces] A sharp projecting point; if referring to fins, a stiff unsegmented, undivided and unbranched element supporting a fin.

Alternative forms for Spine : Caudal fold, Caudal joint, Caudal septum, Caudal spine, Compare also: , Spines (pl.), [Cephalopoda] Rostrum, [Pteropoda] Caudal spine, [Pteropoda] Lateral spine, [p][/p], [p][/p], [p][/p].