Diapause

Temporary interruption of embryonic development. Among the “annual” cyprinodontidae, whose eggs resist drying, one can observe one or more diapals, the last interrupting when the egg is again in the water.

Diapause is a physiological phenomenon that occurs in certain animal species and consists of a temporary suspension of growth and development. This can manifest in different ways, such as a reduction in food consumption, a decrease in physical activity, a modification of the shape or color of the body, or a decrease in sensitivity to external stimuli.

The diapause is generally triggered by environmental factors, such as variations in temperature, brightness or humidity. It can also be triggered by hormones or genetic factors.

In the world of aquarophilia, diapause is often observed in insect and frog species, but it can also occur in other aquatic animals, such as fish and crabs.

Diapause is generally considered to be an adaptive survival strategy which allows animals to adapt to unfavorable environmental conditions, such as drought, cold or shortage of food. It allows them to break their development until the conditions are again favorable to their survival.

In the case of fish, the diapause can be triggered by variations in temperature or oxygen level of the water. In frogs, it can be triggered by the length of the day or by temperature variations.

It is important to note that diapause is not a state of sleep or hibernation. Diapause animals are always aware and can react to external stimuli, but they have simply slowed down their metabolism and development.

Diapause can be a temporary or permanent phenomenon, depending on species and environmental conditions. In some cases, the diapause can last several months or even several years.

In the aquariophilia, it is important to know the species subject to diapause and take this aspect into account when creating and maintaining an aquarium. Indeed, it is important to maintain environmental conditions favorable to the survival and development of animals, and not to disturb their diapause cycle inappropriately.