Effect of photoperiod on ovarian maturation in Cheirodon interruptus (Teleostei: Characidae)

GARCÍA ID; PLAUL SE; TORRES D ; DEL FRESNO PS ; MIRANDA LA; COLAUTTI DC

BRAZILIAN JOURNAL OF BIOLOGY

INT INST ECOLOGY

Lugar: SAO CARLOS, SP; Año: 2019 vol. 79 p. 669 - 677

1519-6984

AbstractCheirodon interruptus is a ubiquitous small characid that inhabits the Pampean region and commonly used as bait.Its vast market is supplied from the wild population causing a significant environmental impact. In this study, we assessthe effect of photoperiod on ovarian maturation in order to evaluate its potential as a tool to manipulate reproductionunder artificial conditions. Four treatments in triplicate (light: dark, L: D) were tested: 24L: 0D, 12L: 12D, 0L: 24D anda progressive photoperiod corresponding to the daily photoperiod increments in wild during winter-spring transition,accelerated three times. The experiment was conducted for 45 days. Gonadosomatic index (GSI), oocyte mean diameter,vitellogenic oocyte proportions, plasma estradiol concentrations (E2), condition factor (Kn) and standard length wereestimated. Values of mean GSI, oocyte diameter, vitellogenic oocyte proportions and E2 concentration were maximumin the progressive treatment indicating vitellogenesis stimulation. In turn the same parameters were minimum in the24L: 0D, revealing the vitellogenesis inhibition. This study showed that photoperiodic regime play an important rolein the onset of ovarian maturation in C. interruptus.