Response of the ovary in the catfish, Heteropneustes fossilis (Bloch), to various combinations of photoperiod and temperature

Abstract

Responses of the ovary of the catfish, Heteropneustes fossilis, to various regimes of photoperiod and temperature, were studied during the different periods of the annual ovarian cycle. During the preparatory and post-spawning periods moderate temperatures of 25 degrees C and above, regardless of photoperiod, were more favorable for the formation of yolky (stage III) oocytes than coller temperatures (below 23 degrees C). Even under conditions of continuous dark or light, ovarian development occurred as a function of warm temperatures. Gravid ovaries were maintained beyond the spawning period only with a temperature of 30 degrees C, photoperiod notwithstanding. Nevertheless, moderate or cool temperatures did not prevent the ovarian regression that occurred by the first week of October in the post-spawning period. Regulation of ovarian activity at least in part by an endogenous circannual rhythm appears possible.

Environmental correlate of the testicular events in a major carpCatla catlain an annual reproductive cycle

“…Statistical analysis of the data revealed that the annual testicular cycle in the Indian major carp C. catla is positively correlated with the annual photoperiodic cycle. Similar features were also observed in both the temperate (de Vlaming 1975;Borg 1982;Borg et al 1987;Okuzawa et al 1989;Bornestaf et al 2001) and tropical (Vasal & Sundararaj 1976;Garg & Jain 1984;Srivastava & Singh 1993;Singh & Joy 1998) long day breeding fishes.…”

“…The influences of temperature on the testicular activities of teleosts have been postulated for many temperate as well as tropical species of fish. The rate of gonadal recrudescence in tropical fishes has shown positive correlation with an increase in ambient temperature and photoperiod (Vasal & Sundararaj 1976;Garg & Jain 1984). In the course of present study, following winter solstice the water temperature was noted to have increased gradually from January to June along with a gradual increase in daylength.…”

Thermal tolerance and preference of the Indian catfish Heteropneustes fossilis

“…It may well be that some fishes maintain themselves at temperatures optimal for growth and reproduction. Studies of Vasal & Sundararaj (1976) have indicated that temperatures around 30" C regardless of photoperiod induce precocious ovarian recrudescence in the catfish, H. fossilk. Moreover, the ambient water temperature in the natural habitat during the prespawning period (MayJune) is around 28" to 30" C and this water temperature accentuates ovarian recrudescence to ensure that fishes become gravid to be able to spawn in the monsoon season.…”

Influence of the daily distribution of light on reproduction in the barbel, Barbus barbus (L.)

“…Gasterosteus acufeutus L. (Baggerman, 1972(Baggerman, , 1985, Fundulus heteroclitus L. (Day & Taylor, 1984) or Oryzias latipes Schlegel (Chan, 1976), through night interruption experiments. In Heteropneustes fossifis (Bloch), Vasal & Sundararaj (1975) were able to determine the duration of the photo-inducible phase. More recently, Duston & Bromage (1 986) used a resonance procedure to demonstrate the circadian aspect of such a rhythm in Oncorhynchus mykiss (Walbaum).…”