§ 3 



SEXUAL CYCLE OF LEBISTES RETICULATUS 



I 29 



To summarize we may say that in this viviparous fish the 

 sexual cycle is regulated by (a) co-ordinated ovular growth, 

 followed by internal fertilisation, and care of the foetuses 

 with the aid of an embryotrophe secreted by the calyx nutri- 

 cius, and (b) intensive corpus luteum formation (pre-ovula- 

 tion corpora lutea), which is often supported by luteinisation 

 of the calyx granulosa. It is probable that sexual-activity may 

 occur in spring as well as in autumn. 



§ 3. THE SEXUAL CYCLE OF LEBISTES RETICULATUS 



Jaski (1938) described the macroscopically visible estrous 

 cycle of the viviparous Cyprinodgnt Lebistes reticulatus, 

 which is characterized by a typical attitude, the "elevation- 

 position" (Figs. 87 and 88). At 28° C the cycle lasts from 

 4 to 6 days. Jaski succeeded in closely analysing the rhythm 

 of the elevation-positions by the daily measurement of the 



Fig. 87. Virgin female Lebis- 

 tes without elevation; above: 

 swimming; below: in rest. 

 (Thesis JASKI). 



Fig. 88. Virgin Lebistes females 

 with elevation. Above: swim- 

 ming; centre and below: two 

 animals with different eleva- 

 tion, in rest (JASKI). 



