The Relationship Between Interbrood Interval And Yolk Loading In A Generalized Poeciliid Fish, Poecilia-Latipinna
Abbreviated Journal Title
Interbrood intervals in the livebearing sailfin molly, Poecilia latipinna, were studied in laboratory experiments. Of the factors investigated, temperature was the most important in influencing interval length, with shorter intervals characteristic of females maintained at higher temperatures. However, even when temperature and food level were controlled, there was significant variation in interbrood interval. Pooled data from five experiments gave a non-normal distribution of intervals ranging from 26-50 d, with a mode of 33 and positive skewness. The results of a subsequent yolk-loading experiment conformed intuitively and statistically with the results of the interbrood interval studies, suggesting that most of the variation in interval length is explained by variation in the vitellogenic phase of the ovarian cycle. Most females completed egg maturation and fertilization 4-8 d after parturition, when the eggs had reached about 2.2 mm diameter. However, some females exhibited accelerated egg maturation while others were dramatically retarded. Females that are in poor condition following parturition appear to be slow in yolking the next clutch of eggs and, therefore, will have longer interbrood intervals. Interspecific comparisons reveal consistent differences in interbrood interval among some generalized poeciliids. Differences between the sailfin molly and the guppy, P. reticulata, are maintained across a broad temperature range. However, it is unclear whether the distinctions are due to differences in the yolk-loading period, the gestation period, or both. In general, species that are larger at birth have longer interbrood intervals.
Snelson, Franklin F. Jr.; Wetherington, Jeffrey D.; and Large, Helen L., "The Relationship Between Interbrood Interval And Yolk Loading In A Generalized Poeciliid Fish, Poecilia-Latipinna" (1986). Faculty Bibliography 1980s. 546.