A no less wonderful pedestrian is the Hassar (_Doras costata_), a South American fish, that marches over land in search of water, travelling a whole night when the pools dry up in which it commonly resides. It projects itself forwards on its bony pectoral fins, by the elastic spring of the tail, exerted sidewise, and in this manner proceeds nearly as fast as a man will leisurely walk. The strong scuta or bands which envelop its body must greatly facilitate its march, in the manner of the plates under the belly of serpents, which are raised and depressed by a voluntary power, in some measure performing the office of feet. The Indians say justly that these fishes supply themselves with water for their journey. If they find the pools and rivers everywhere dried up, they bury themselves in the mud, and fall into a kind of asphyxia or lethargy, till the rainy season recalls them again to life.
The hassar is also remarkable for a parental affection, almost unexampled among fishes. Sir Richard Schomburgk relates that it not only builds a complete nest for its spawn but also watches over it with the utmost vigilance till the young brood comes forth. In April, this marine artist begins to build his little dwelling of vegetable fibres, among the water-plants and rushes, until it resembles a hollow ball, flattened at the top. An aperture corresponding to the size of the mother leads into the interior. The parental affection of the fish is shamefully misused by man for its destruction. A small basket is held before the opening; then the nest is slightly beaten with a stick; and, furious, with extended fins, whose sharp points are able to inflict a painful wound, the poor hassar darts into the fatal basket.
[Illustration: SUBAQUEOUS LIFE--STICKLEBACKS AND NEST.]
This plate represents a group of fifteen-spined sticklebacks busily employed in making their nests. To the left is seen a curious piece of marine architecture, mentioned by Mr. Couch, the well-known ichthyologist. A pair of sticklebacks had made their nest "in the loose end of a rope, from which the separated strands hung out about a yard from the surface, over a depth of four or five fathoms, and to which the materials could only have been brought, of course, in the mouth of the fish, from the distance of about thirty feet. They were formed of the usual aggregation of the finer sorts of green and red sea-weed, but they were so matted together in the hollow formed by the untwisted strands of the rope that the mass constituted an oblong ball of nearly the size of the fist, in which had been deposited the scattered assemblage of spawn, and which was bound into shape with a thread of animal substance, which was passed through and through in various directions, while the rope itself formed an outside covering to the whole."