PARENTAL CARE AMONG FRESH-WATER FISHES. 487 



Great numbers are salted and cured, and it is the object of a consider- 

 able connnerce. 



THE HETRROTIS. 



The best account of the nesting habits of any Osteoglossoidean has 

 been given by the late J. S. Budgett, Avho visited Africa in 1!)00 for 

 the purpose of studying the life histories of some of that con.tinent's 

 remarkable fishes. Like the arapaima, Ileterotis is so distinct from 

 all other forms that it has been set aside as the type of an independent 

 famil}'. AMiile it agrees Avith the arapaima and the Osteoglossids as 

 to the characters already indicated, it has a rounded belly, the dorsal 

 shorter than the anal, the ventrals submedian, the postorbitals con- 

 tinuous in an even curve with the suborl)itals, the mouth small, and 

 the branchiostegal rays in reduced number (seven or eight). The 

 princii)al characters, hoAvever, are skeletal modifications, especially of 

 the bones of the back of the skull, and, more than all, of the exocci])i- 

 tal bones, which furnish larire accessorv condvles for the first vertebra. 



72. — The Ileterotis (llLtcrutia nilutlcus). After A'alenciennes. 



The only known Ileterotis, II. niJotleii.s, is a large fish, occasionally 

 even attaining a length of 3 feet or more. A good idea of it may be 

 obtained from the accompanying figure. 



The heterotis makes a very large circular nest, and, indeed, in some 

 of the swamjDs of west Africa which Budgett visited, one of the most 

 striking features was " the presence of numbers of enormous nests," 

 which looked like '' miniature lagoons," and which j^roved to be those 

 of Heteroth niloticiis. The " nests measured four feet in diameter 

 and were made in about two feet of water." The walls were " about 

 eight inches thick at the top and compact, being made of the stems of 

 the grasses removed by the fish from the center of the nest." The 

 floor Avas " the SAvamp-bottom, and Avas made perfectly smooth and 

 bare." 



Budgett once had the good fortune to see a '* fantang "' (such is 

 the natiA^e name of the heterotis) make a nest, and tells hoAv it Avas 

 done. " Tt Avas circling round and round the Avall of its nest, every 

 uoAv and then throAving its tail upwards and outAvards, tossing on to 

 the toj) of the Avail the debris from the inside of the nest. Thus it 

 toiled on until the Avail reached the surface of the water and Avas com- 

 plete. When the nest Avas finished the Avater it contained was per- 



