Meaning: facing away from the axis of an organ or organism; "the abaxial surface of a leaf is the underside or side facing away from the stem"
Meaning: belonging to or on or near the back or upper surface of an animal or organ or part; "the dorsal fin is the vertical fin on the back of a fish and certain marine mammals"
Just as the pike's attack is at its height, the Rasper suddenly raises his twelve-spined dorsal fin.
For the present the whole flock keeps to the bottom, darting along with dorsal fin erect, the stiff spines bristling menacingly.
A little later a whirlpool appears on the seething water, and he catches a glimpse of a dorsal fin with the hinder point missing.
And to think that Heaven should at last reward him for his magnanimity! For the mark on the dorsal fin showed distinctly that this fish had been in his hands before.
All at once the van slips away from the rest, and the latter have to exert themselves to catch up, twisting and turning their tails, and unfurling the stiff sail of their dorsal fin.
By this time she weighs about eighteen pounds, and measures the length of a grown man's leg from hip to heel; her dorsal fin measures more than two hand-breadths, and it would take a large hand to span her back.
Almost immediately there was a furious splashing, and by the aid of the glass I distinctly saw the dorsal fins of several sharks darting here and there among them, whilst over the glassy surface of the water a shriek or two came faintly towards us.
He is still in the pike's throat, and cannot get away, for he has his twelve stiffest dorsal spines bored into his enemy's palate; and the more he worries and works with his dangerous opponent, the deeper and more firmly do the spines fix themselves.