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

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

heteracanth (adjective) (not comparable)
Regarding fish having the spines of the dorsal and anal fins alternately broader on one side than on the other: Dick found some information regarding hateracanth fish with an unsymmetrical layout of spines on their dossal and anal fins which were broader on one side than on the other side.
heteracanthous (adjective) (not comparable)
In ichthyology, having the spines of the dorsal fin asymmetrical: Some fish have an unpaired median fin on their backs that are heteracanthous in that the spines are alternately broader on one side than the other.
hexacanth (adjective) (not comparable)
Concerning an organism having six larval hooks: Eucestoda, known as a hexacanth tapeworm, is a flatworm whose larvae have six posterior hooks on their heads and live in the digestive system of a vertebrate.
homacanth (adjective) (not comparable)
Descriptive of a fish having the spines of the dorsal fin situated symmetrically: Samantha found out that the median fin spines on the back of a fish are lined up in a parallel fashion, and such fish are termed homacanth.
ichthyoacanth (s) (noun), ichthyoacanths (pl)
A sharp-pointed fish fin: Some fish can be very dangerous because they possess ichthyoacanths which are quite needlelike.
ichthyoacanthotoxin (s) (noun), ichthyoacanthotoxins (pl)
The venom secreted by a venomous fish: Certain vicious and hostile fish can use their spines or "teeth" to emit ichthyoacanthotoxin, a poison which can be deadly.
ichthyoacanthotoxism (s) (noun), ichthyoacanthotoxisms (pl)
A poisoning arising from an injury caused by the sting or by the spines of a mephitical fish: In the aquarium at the zoo, Sam could see the big venomous fish known for the ichthyoacanthotoxism it could cause if it wounded a person.
Metriacanthosaurus (proper name)
A genus of the metriacanthosaurid dinosaur: Metriacanthosaurus refers to the extinct moderately-spined lizard from the upper Oxford Clay of England which lived about 160 million years ago. The British paleontologist Cyril A. Walker named this genus Metriacanthosaurus in 1964.
monacanthid (s) (noun), monacanthids (pl)
Regarding an organism with one row of ambulacral spines: Examples of monacanthids are certain starfish and sea urchins.

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.

myriacanth (adjective), more myriacanth, most myraicanth
A reference to that which has numerous, or countless, spines or spine-like growths: In the fantasy book Kitty was enjoying, she read about a myriacanth creature with innumerable spikes on its back and neck!
myriacanthous (adjective), more myriacanthous, most myriacanthous
Descriptive of an organism having numerous spines, or sharp points: Certain fishes, like rays, in the genus Myriacanthus are myriacanthous because they typically have a myriad of knifelike points.
notacanthous (adjective), more notacanthous, most notacanthous
Concerning a creature with spines on its back: In the fantasy story Jeremy was reading, there was a big notacanthous insect crawling along, with many thorny projections on top of its back!
oligacanthous (adjective), more oligacanthous, most oligacanthous
Characterizing flora having very few spines on stems or leaves: Outside in the garden, Mary discovered an oligacanthous plant with sharp-pointed tips on its foliage growing close to her plot of vegetables
oxyacanthine (s) (noun) (no pl)
An alkaloid as part of the chemical composition in the leaves and roots of the common barberry: Besides oxyacanthine being part of the make-up of the bark of the barberry branches, there is also berberine, lentil, and palmitine.
oxyacanthous (adjective), more oxyacanthous, most oxyacanthous
In botany, flora having sharp spines: Agatha learned in her botany class at college that oxyacanthous plants possessed a structure exhibiting sharp thorns.