Whether land or sea animals are cleverer (27-30)

As for cleverness in attacking and catching prey, we may perceive subtle examples of it in many different species. The starfish,[*] for example, knowing that everything with which it comes in contact dissolves and liquefies, offers its body and is indifferent to the contact of those that overtake or meet it. You know, of course, the property of the torpedo[*]: not only does it paralyse all those who touch it, but even through the net creates a heavy numbness in the hands of the trawlers. And some who have experimented further with it report that if it is washed ashore alive and you pour water on it from above, you may perceive the numbness mounting to the hand and dulling your sense of touch by way of the water which, so it seems, suffers a change and is first infected.[*] Having, therefore, an innate sense of this power, it never makes a frontal attack or endangers itself; rather, it swims in a circle around its prey and discharges its shocks as if they were darts, thus poisoning first the water, then through the water the creature which can neither defend itself nor escape, being held fast as if by chains and frozen stiff.

The so-called fisherman[*] is known to many; he gets his name from his actions. Aristotle[*] says that the cuttlefish also makes use of this stratagem: he lets down, like a fishing line, a tentacle from his neck which is naturally designed to extend to a great length when it is released, or to be drawn to him when it is pulled in. So when he espies a little fish, he gives it the feeler to bite and then by degrees imperceptibly draws it back toward himself until the prey attached to the arm is within reach of his mouth.

As for the octopus’ change of colour,[*] Pindar[*] has made it celebrated in the words

To all the cities to which you resort

Bring a mind like the changing skin of the seabeast;

and Theognis[*] likewise:

Be minded like the octopus’ hue:

The colour of its rock will meet the view.[*]

[*]

The chameleon,[*] to be sure, is metachromatic, but not from any design or desire to conceal itself; it changes colour uselessly from fear, being naturally timid and cowardly. And this is consistent with the abundance of air in it, as Theophrastus[*] says; for nearly the whole body of the creature is occupied by its lungs,[*] which shows it to be full of air and for this reason easily moved to change colour. But this same action on the part of the octopus is not an emotional response, but a deliberate change, since it uses this device to escape what it fears and to capture what it feeds on: by this deceit it can both seize the latter, which does not try to escape, and avoid the former, which proceeds on its way. Now the story that it eats its own tentacles[*] is a lie, but it is true that it fears the moray and the conger. It is, in fact, maltreated by them; for it cannot do them harm, since they slip from its grasp. On the other hand, when the crawfish[*] has once got them in its grasp, it wins the victory easily, for smoothness is no aid against roughness; yet when the octopus has once thrust its tentacles inside the crawfish, the latter succumbs. And so Nature has created this cycle[*] and succession of mutual pursuit and flight as a field for the exercise and competitive practice of adroitness and intelligence.

We have, to be sure, heard Aristotimus[*] telling us about the hedgehog’s foreknowledge of the winds; and our friend also admired the V-shaped flight of cranes.[*] I can produce no hedgehog of Cyzicus or Byzantium,[*] but instead the whole body of sea-hedgehogs,[*] which, when they perceive that storm and surf are coming, ballast themselves with little stones[*] in order that they may not be capsized by reason of their lightness or be swept away by the swell, but may remain fixed in position through the weight of their little rocks.

Again, the cranes’ change of flight against the wind[*] is not merely the action of one species: all fish generally have the same notion and always swim against wave and current, taking care that a blast from the rear does not fold back their scales and expose and roughen their bodies. For this reason they always present the prow of their bodies to the waves, for in that way head first they cleave the sea, which depresses their gills and, flowing smoothly over the surface, keeps down, instead of ruffling up, the bristling skin. Now this, as I have said, is common to all fish except the sturgeon,[*] which, they say, swims with wind and tide and does not fear the harrowing of its scales since the overlaps are not in the direction of the tail.

The tunny[*] is so sensitive to equinox and solstice that it teaches even men themselves without the need of astronomical tables; for wherever it may be when the winter solstice overtakes it, in that same place it stands and stays until the equinox. As for that clever device of the crane,[*] the grasping of the stone by night so that if it falls, she may awake from sleep - how much cleverer, my friend, is the artifice of the dolphin, for whom it is illicit to stand still or to cease from motion.[*] For its nature is to be ever active[*]: the termination of its life and its movement is one and the same. When it needs sleep, it rises to the surface of the sea and allows itself to sink deeper and deeper on its back, lulled to rest by the swinging motion of the ground swell[*] until it touches the bottom. Thus roused, it goes whizzing up, and when it reaches the surface, again goes slack, devising for itself a kind of rest combined with motion.[*] And they say that tunnies do the same thing for the same reason.

Having just a moment ago given you an account of the tunny’s mathematical foreknowledge of the reversal of the sun, of which Aristotle[*] is a witness, I beg you to hear the tale of their arithmetical learning. But first, I swear, I must mention their knowledge of optics, of which Aeschylus[*] seems not to have been ignorant, for these are his words:

Squinting the left eye like a tunny fish.

They seem, indeed, to have poor sight in one eye. And it is for this reason that when they enter the Black Sea, they hug one bank on the right, and the other[*] when they are going out, it being very prudent and sagacious of them always to entrust the protection of themselves to the better eye. Now since they apparently need arithmetic to preserve their consociation and affection for each other, they have attained such perfection of learning that, since they take great pleasure in feeding and schooling together,[*] they always form the school into a cube, making it an altogether solid figure with a surface of six equal plane sides; then they swim on their way preserving their formation, a square that faces both ways. Certainly a hooer[*] watching for tunnies who counts the exact number on the surface at once makes known the total number of the shoal, since he knows that the depth is equal one to one with the breadth and the length.

Schooling together has also given the bonitos their name of amia [*] and I think this is true of year-old tunnies as well.[*] As for the other kinds which are observed to live in shoals in mutual society, it is impossible to state their number. Let us rather, therefore, proceed to examine those that have a special partnership, that is, symbiosis. One of these is the pinna-guard,[*] over which Chrysippus[*] spilled a very great deal of ink; indeed it has a reserved seat in every single book of his, whether ethical or physical.[*] Chrysippus has obviously not investigated the sponge-guard[*]; otherwise he could hardly have left it out. Now the pinna-guard is a crab-like creature, so they say, who lives with the pinna[*] and sits in front of the shell guarding the entrance. It allows the pinna to remain wide open and agape until one of the little fish that are their prey gets within; then the guard nips the flesh of the pinna and slips inside; the shell is closed and together they feast on the imprisoned prey.

The sponge is governed by a little creature not resembling a crab, but much like a spider.[*] Now the sponge[*] is no lifeless, insensitive, bloodless thing; though it clings to the rocks,[*] as many other animals do, it has a peculiar movement outward and inward which needs, as it were, admonition and supervision. In any case it is loose in texture and its pores are relaxed because of its sloth and dullness; but when anything edible enters, the guard gives the signal, and it closes up and consumes the prey. Even more, if a man approaches or touches it, informed by the scratching of the guard, it shudders, as it were, and so closes itself up by stiffening and contracting that it is not an easy, but a very difficult, matter for the hunters to undercut it.

The purplefish[*] lives in colonies which build up a comb together, like bees. In this the species is said to propagate; they catch at edible bits of oystergreen and seaweed that stick to shells, and furnish each other with a sort of periodic rotating banquet, as they feed one after another in series.