This paper reports reproductive parameters for 9 female grey-cheeked mangabeys kept in a captive colony over a 17-year period. Birth seasonality has shown a consistent trend towards an autumn peak. Oestrous cycles had an average length of 31.2 days: however 'short-cycle' (29.9 days) and 'long-cycle' (37.7 days) groups could be discriminated. Gestation was 175 days, with little variability. Vari...

The reproductive cycle in anurans may be either continuous or discontinuous. These differences may be connected to seasonal climate changes and/or to anthropic activity. Forty adult male individuals of the Dendropsophus minutus species were collected during one year, in the municipality of Chapada dos Guimarães (Mato Grosso, Brazil). The testicles were studied under light and transmission elect...

Catamenial epilepsy is defined as a pattern of seizures that changes in severity during particular phases of the menstrual cycle, wherein estrogens are proconvulsant, increasing the neuronal excitability; and progesterone is anticonvulsant, enhancing GABA-mediated inhibition. Thus, changes in serum estradiol/progesterone ratio throughout a normal reproductive cycle bring about an increased or d...

As the number of fish reproduction studies has proliferated, so has the number of gonadal classification schemes and terms. This has made it difficult for both scientists and resource managers to communicate and for comparisons to be made among studies. We propose the adoption of a simple, universal terminology for the phases in the reproductive cycle, which can be applied to all male and femal...

Some pesticides may interfere with the female hormonal function, which may lead to negative effects on the reproductive system through disruption of the hormonal balance necessary for proper functioning. Previous studies primarily focused on interference with the estrogen and/or androgen receptor, but the hormonal function may be disrupted in many more ways through pesticide exposure. The aim o...

To investigate the role of endogenous opioid peptides (EOP) in the inhibitory control of LH secretion in the ram, the acute effects of naloxone (opioid antagonist) on episodic LH secretion were measured in rams at different stages of a reproductive cycle induced by treatment with melatonin. Groups of SCGx rams (functionally pinealectomized) and pineal intact rams were housed under long days (16...

Bivalve molluscs such as Perna perna display temporal cycles of reproduction that result from the complex interplay between endogenous and exogenous signals. The monoamines serotonin, dopamine and noradrenaline represent possible endocrine and neuronal links between these signals allowing the molluscs to modulate reproductive functions in conjunction with environmental constraints. Here, we rep...

Many conditions affect the reproductive health of the beef herd, including nutrition, bull fertility, and environmental stresses. Perhaps none have the potential to create more significant losses than infectious diseases. Infectious diseases affecting reproduction can create losses all throughout the reproductive cycle by decreasing ovulation rates, fertilization rates, embryonic survival rates...

Many conditions affect the reproductive performance of the beef herd, including nutrition, bull fertility, and environmental stresses. Perhaps none have the potential to create more significant losses than infectious diseases. Infectious diseases affecting reproduction can create losses throughout the entire reproductive cycle by decreasing ovulation rates, fertilization rates, embryonic surviv...