CAREFUL MOTHERS 



lively little creatures are hatched ; the parent fish finds it so difficult 

 to breathe that she has to shift her brood to and fro in her mouth, 

 as we shift a mouthful of water when rinsing the mouth. When the 

 young fry are able to swim the mother blows them out, but in 

 moments of danger they instantly gather about her head ; she opens 

 her jaws, and all the little fishes, often to the number of fifty or 

 sixty, slip through the open door. Later, as they grow more venture- 

 some, she has to swim after her brood, in order to collect them in 

 the evening and protect them from the perils of the night. 



In the rivers of southern Brazil there is a great Silurid or Gat-fish, 

 locally known as the Bagre. The male fish takes the large eggs into 

 his mouth (they measure as much as a twelfth of an inch in diameter), 

 when the self-sacrificing creature is no longer able to eat; so that 

 dead fish have often been found with their 

 mouths full of dead fry. 



The Nandidae show peculiar devotion to 

 their eggs. The female, with her long oviposi- 

 tor, fastens the eggs in some convenient spot ; 

 the male, paddling with his fins, provides them 

 with fresh water ; but first any mud there may 

 be is cleared away from underneath, lest the 

 little fish, when they are hatched, should fall 

 into it and be stifled. Certain Plated Catfish 

 make a proper nest of grass-stalks, with an Fig. 20. — Salamander- 

 opening into the interior, and the Scaly ^^^' Lepidosiren 

 Salamander-fish or Lung-fish (Lepidosiren), in 



Brazilian the Pira m'boia, but known as the Lolach in the interior 

 (Fig. 20), digs holes a foot deep in the bottom of the Amazon and 

 its tributaries, which are reached by a horizontal passage often a 

 yard in length. Here the eggs are laid, and the male fish watches 

 them, and in order that he may breathe more readily he has de- 

 veloped tufted outgrowths on his fins. The Lung-fish is eel-like in 

 form, but it already represents a transition to the Batrachians, for 

 its swimming-bladder has begun to transform itself into a lung, and 

 enables the fish to take in air at the surface of the water. If the 

 stream dries up this lung-bladder enables the fish to survive buried 

 in the mud. 



Finally, there are fish which remove their eggs from the perils of 

 the pond or river, and hang them over the surface. In an aquarium 

 the male Pyrrhulina may be seen rising, with his mate, to the top 

 of the tank, when both fish leap into the air, and remain clinging 



275 



