Breeding in the natural environment
Breeding in the natural environment takes place at the company’s production site in Audenge.
The pools replicate natural pools in every detail, with a peaty bottom and an abundance of aquatic plants. The peaty bottom enables the leeches to bury themselves whenever it gets too hot or too cold. The presence of aquatic plants oxygenates the water and protects the leeches, who like to hide among them. Leeches like to settle on the large leaves of the water-lily, which also act as a protection against strong sunlight during the summer. The aquatic grass islands in the middle of some of the pools, as well as the peaty beaches along the edge of the pools have been incorporated to encourage the depositing of cocoons. The basins and their surrounds are regularly maintained to prevent them being overrun with vegetation and make it easier to manage the sites.
Just like the structure of the pools, water quality is an important factor in breeding. A pH close to neutral, good bacteriological quality, water free of chemical fertilisers, regular water changes and a constant water level, particularly at the point of reproduction, appear to be essential environmental conditions for annelids. Leeches deposit their cocoons in a humid environment but level with the water. If the water level rises, therefore, there is a risk that the cocoons could drown. It is for this reason that each pool is equipped with a system to manage the supply of water. The water comes from a wellbore. RICARIMPEX has an independent laboratory carry out regular checks on the quality of the pool water. The pools are supplied by wellbore water.
The natural pools are exposed to the prevailing weather conditions; the leeches thus follow changes in the light and temperature conditions within the environment. In the natural environment, the reproduction period varies depending on the climate but generally begins at the start of spring and can last until the start of winter.
As far as feeding within the natural environment is concerned, leeches eat the wildlife naturally present in the pools (Amphibians, Amphibian eggs, insect larvae). The natural biotope therefore enables leeches to find the food they require to survive. For health reasons (decaying corpses, proliferation of predators) and in order to optimise control of the annelids’ diet, no additional food is provided at this stage of production.
Harvesting is carried out using relatively fine taut mesh nets. The leeches that are fished are then sorted by size in the Eysines laboratory. Leeches that are too small to be sold are fed in the laboratory until they are big enough for market. Leeches categorised as “Belle Moyenne” (Good Average), weighing between 1 g and 1.8 g are placed in a storage unit ready for sale. Leeches categorised as “Grosse Moyenne” (Large Average) are either placed in a storage unit for sale or – in the majority of cases – used for reproduction.