486 PARENTAL CARE AMONG FRESH-WATER FISHES. . 



to Castelnaii, a medium length of about 8 feet (2.50 meters), and 

 one of that size is said to weigh about 330 pounds (150 kilograms). 

 Occasionally, however, a much greater size is attained. Schomburgk 

 " was assured by the inhabitants of the Rio Negro that they have 

 caught some 15 feet long and of 12 to 13 arrobas (410 pounds) 

 weight." These accounts are obviously discrepant. If a fish 8 feet 

 long weighs 330 pounds, one 15 feet long, having the same pro- 

 ]-)ortions, v^ould weigh nearly, if not quite, a ton. Undoubtedly 

 Castelnau exaggerated the weight of a fish 8 feet long; Schomburgk 

 more nearly approximated the truth by attributing to a fish " C to 7 

 feet " long a Aveight of "" not less than 150 pounds.". 



The natives claim that the mother takes charge of the eggs and 

 Avatches over them with great care, protecting them especially against 

 the male, who seeks to devour them. " The voung," it is further as- 



PiG. 71. — Tlie Pirarucu i Aniixiiiiia yigas). Head enlarged. After Valenciennes. 



serted, " are protected by the mother for some time after they leave 

 the eggs," and they " swim generally over her head." 



Both Castelnau and Schomburgk record this liclief of the natives, 

 but it is i:)robable they Avere misled by preconceived notions and 

 knoAvledge of what birds do. It is likely (but not absolutely certain) 

 that the male takes charge of the eggs, as in the case of most fishes. 



The pirarucu was ascertained by Agassiz (18()8) to be '' found 

 almost everywhere " in the Amazon Valley and to be " the most im- 

 portant fish of the river, that Avhich, as food, corres])onds to cattle 

 for the population along the banks." Castelnau records (1855) that 

 its flesh, supplemented by that of the manatee, serves to feed the 

 numerous " nations " of that part of the Avorld. Essentially the same 

 conditions persist to the jjresent time. '" AVhen fresh it is excellent, 

 and the bell}- nearly all fat," and it is tlie l)elly that is held in great- 

 est esteem. It is not alone as a fresh fish, however, that it is used. 



