of the tail. These movements, which may extend over several days, enable it to pass from one 

 river to another. The related aspredinids have a curious way of ensuring the incubation of 

 their offspring, the care of which reverts to the females. The skin of their bellies becomes soft 

 and spongy before spawning and as soon as the eggs are expelled and fertilised, they lie on them 

 in such a way that they become incrusted in their soft abdomens. Small pits are formed in 

 the skin, and in these the eggs are enclosed until they hatch. 



All who have read Jules Verne will be aware that descending the Amazon is not without 

 its risks. Furthermore, he has not described all of the dangers. A native recklessly venturing 

 into the waters of the great river may be cut into pieces by the piranhas (Serrasalmo). Like 

 the terrible tiger-fish of African rivers they are characins and are even fiercer than this species. 

 Crowds of them live together in shoals and they travel with amazing speed when they have 

 scented blood, even if this has come from far away. With their sharp-edged teeth they can cut 

 a man into shreds. 



If the foolhardy man has escaped the bites of piranhas, he may get electric shocks from the 

 electric eels (Gymnotus eledricus) or trembladores. According to travellers, these discharges 

 may be strong enough to stun a horse. They are eel-shapel fishes without a dorsal fin, but 

 there is a very long anal fin. The electric organs are carried in the very long tail and consist 

 of two masses of tissue running longitudinally under the lateral line. 



Our unfortunate Brazilian may be more insidiously attacked by candirus (Stegophilus 

 insidiosus and Vandellia cirrhosa), small cat-fish of the family Trichomycteridae. They are 

 rather less than 2 inches in length and have become parasites of the larger cat-fishes, gliding 

 about within their gill chambers, infiicting wounds and sucking the blood. But they can also 

 enter the urinary organs of bathers, doubtless during micturition. If surgical attention is not 

 speedily given, the candirus enter the bladder and set up fatal infiammation. 



But less harmful creatures live in the Amazon, such as the toothed-carps (cyprinodonts), 

 which are attractive fishes well enough known to amateur aquarium keepers. They are vivi- 

 parous and coupling fishes, the sexes being readily distinguishable. As well as having more 

 brilliant colours, the males carry a conical papilla in front of the anus. This priapium is directed 

 to the right or left and there are bony appendages for holding on to the female. In some spe- 

 cies ( A liable ps letrophlhabnus ) , the female has a special scale (foriculum) concealing the genital 

 pore and an opening is left at one of the sides. Coupling is then carried out laterally and a 

 male with a priapium pointing to the right must pair with a female having a left-handed opening 

 to the foriculum. In addition to these sexual peculiarities Anableps, the " four-eyed " fish, 

 has a special visual device. Connective tissue divides each eye into two parts, the upper being 

 adapted for aerial vision and the lower for seeing under water. When poised at the surface 

 the fish can then watch for flies as well as for aquatic creatures. 



The Amazon basin is the land where the cichlid fishes originated and where they abound. 

 Moreover, when a group of fishes becomes isolated in a watercourse they quickly become modi- 

 fied, like the trout of European rivers. The most beautiful of the Brazilian cichlids is the well- 

 known angel-fish (Pierophyllum scalarc), which has a shape very like that of some coral fishes. 

 Its flattened body extends upwards and downwards into high fins. The general colouration 

 is light in shade with large black vertical stripes, these colours matching this superb fish with the 

 upright stems of the aquatic plants, among which it moves in a slow and stately fashion. In 

 these surroundings we once more meet with a lung-fish and osteoglossids. The lung-fish, Lepi- 

 dosiren paradoxus, swims in swamp waters beneath the plants, carefully avoiding the caymans, 

 which are greedy for its flesh. Occasionally it rises to the surface to breathe in a little pure air. 

 At the dry season it hollows out a tunnel and blocks up the end of its shelter with a clay plug, 

 perforated by small round holes. When the dried-up pools are once more covered with water 

 it resumes an active life. The nests are horizontal passages about a yard long, excavated in 

 the mud. The male guards the eggs and his care never fails, for he is even able to breathe in 

 stagnant waters by means of red filaments on the pelvic fins, which form accessory gills. The 

 osteoglossid companions of Lepidosiren are among the largest fishes. The arapaima can exceed 

 a length of 15 feet and weigh more than 400 pounds. 



Across the Brazilian landscape with its luxuriant equatorial forest vegetation the immense 



139 



