CHAP. 21.—WHY FISHES LEAP ABOVE THE SURFACE OF THE WATER.
There is a little animal,[1] in appearance like a scorpion, and
of the size of a spider.[2] This creature, by means of its sting,
attaches itself below the fin to the tunny and the fish known
as the sword-fish[3] and which often exceeds the dolphin in
magnitude, and causes it such excruciating pain, that it will
often leap on board of a ship even. Fish will also do the same
at other times, when in dread of the violence of other fish, and
mullets more especially, which are of such extraordinary swiftness, that they will sometimes leap over a ship, if lying cross-
wise.
1. This is, as Cuvier has remarked, a crustaceous insect of the parasitical
class Lernæa, which are monoculcus [and form the modern class of the
Epizoa]. Gmelin, he says, has called it "Pennatula filosa," though, in fact,
it is not a pennatula [or polyp] at all. As Dalechamps observes, its ap-
pearance is very different from that of a scorpion. Penetrating the flesh
of the tunny or sword-fish, it almost drives the creature to a state of
madness.
2. Aristotle, Hist. Anim. B. viii. c. 19. Appian also, in his Halieutics, B ii.,
makes mention of this animal. Pintianus remarks, that Athenæus, on reading this passage of Aristotle, read it not as "arachnes," but "drachmes;"
not the size of a spider, but the weight of a "drachma," or Roman denarius.
3. Or the emperor fish, Cuvier says, the Xiphias gladius of Linnæus.