106 NATURAL HISTORY OF AMIA CALVA LINN^US. 



by more than one fish. It is therefore likely that in this species also, under 

 normal conditions, the female merely assists in building the nest, but that when the 

 eggs have been laid the male assumes- eharge. In all other nest-building teleosts 

 there is no pair of fish. 



The nest belongs to an individual male and has been constructed by him in 

 advance of the spawning. Females subsequently approach the nest or are urged 

 to it and the eggs are laid. The relation between the sexes at this time may be 

 described as a promiscuous polygamy. The spawning activities centre about the 

 males which build and defend individual nests. The female spawns in the first 

 nest that she,' comes into and may subsequently spawn in others. The male, after 

 receiving into his nest the eggs of one female, may receive those of a second, often 

 after a considerable interval. After the spawning is completed the females are no 

 longer seen near the nests. The males may then continue to guard the nests, and 

 in some cases they guard also the young brood. I have observed nest-building by 

 the excavation of the gravel or sand by the male in advance of spawning in Amia 

 and in the following teleosts: Semotilus atromaculatus, Campostoma anomalum, 

 Eupomotis gibbosus, Micropterus dolomieu, Micropterus salmoides (see also Lydell, 

 :02). Kent ('73) has reported nest-building of the same sort by the male in advance 

 of spawning in Labrus mixtus and Cantharus lineatus. Leunis ('83) places Gobius 

 niger and Cyclopterus lumpus in the same category. Brehm ('92) adds Cottus gobio 

 and Nemachilus barbatula. I have been unable to examine the original accounts 

 in the cases cited by Leunis and by Brehm. Guitel ('92, '95) has described the 

 habits of Gobius minutus and of Gobius ruthensparri, the males of both of which 

 excavate nests in the sand beneath shells and guard them in advance of spawning 

 and afterward. Guitel ('93 ) has also described the habits of Blennius sphynx and 

 of Blennius montagui, the male of the first of which occupies cavities in rocks 

 and guards them in advance of spawning and subsequently, while the male of the 

 second species uses cavities beneath stones and guards them both before and after 

 spawning. In none of the cases described by Guitel is the female present at the 

 nest except while spawning or during the manoeuvres preliminary to it. The 

 description given by Guitel ('93 a ) of the habits of Clinus is not accessible to me. 



In fifteen of these cases the nests are excavations of the bottom. The care of 

 the male may cease when the eggs have been laid (Semotilus, Campostoma), may 

 be continued until they are hatched (Eupomotis), or may follow the young fish 

 until they are well grown (Amia, Micropterus). 



In addition we have two cases in which the male accumulates material for the 

 construction of the nest, Gasterosteus (Coste, '48, and others) and Colisa vulgaris 



