acantho-, acanth-, -acanth, -acanths, -acanthid, -acanthous

(Greek: used either as a prefix or as a suffix; pointed appendages; spine, spiny; thorn, thorny)

coelacanthid
cystacanth
decacanthous
Having ten spines.
diacanthous
Having two spines.
diatragacanth
eoacanthocephala
heteracanth
Having the spines of the dorsal and anal fins alternately broader on one side than the other.
heteracanthous
In ichthyology, having the spines of the dorsal and anal fins alternately broader on one side than the other.
hexacanth
Having ten spines.
homacanth
Having the spines of the dorsal and anal fins situated symmetrically.
ichthyoacanth
Sharp-pointed fish fins.
ichthyoacanthotoxin, ichthyoacanthotoxism
1. The venom secreted by venomous fishes, in connection with stings, spines. or “teeth”.
2. Any poison produced by the spines, stings, or teeth of a fish.
keratoacanth
Metriacanthosaurus
A “moderately-spined lizard” from Late Jurassic southern England. Named by British paleontologist Cyril A. Walker in 1964.
monacanthid
With one row of ambulacral spines, as certain starfish, sea urchins, etc.

Ambulacral spines refer to any of the radial areas of echinoderms along which run the principal nerves, blood vessels, and elements of the water-vascular system.