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15 JUNE 2016 : 28 000 juveniles are born in the mark of the Giant Pearl Mussel LIFE project !

For a month, the LIFE team has been collecting and filtering the water of the diferent basins and cylinders to collect hthe juveniles of Giant Pearl Mussel having unhooked from the sturgeons' gills. In this month, 18 000 juveniles of Giant Pearl Mussel have been counted ! These juveniles are today bred in troughs and will remain inside for several years so that they can acquire forces and handle a reintroduction without being weakened.


 
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21st MAY 2016 : FIRST JUVENILES 

The first Charente juveniles unhooked from the sturgeons'gills !

This saturday 21st of May, the first juveniles of Charente unhooked from the sturgeons' gills : We can count 7 ones alive at this stage. After being collected, they were put in a trough in which they will stay for several years in order to build up their strenght  and be able to be reintroduced in the environment.
 

Different types of maintenance are carried out for the scientifics to study the evolution of juveniles according to their environment:


          - A first trough contains natural sediments from the Creuse not sterilized with every kind of granulometry, as well as water from the Vienna no treated in circulation.

          - Two other troughs will contain sediments from a sandpit. These sediments with sand dominance are sterilized and steamed, and contain water from the Vienna filtered with cotton wool,  UV and coal.
 

                    Breeding through                                            Trough filtration                                         Hopper preventing the juveniles
                                                                                                                                                                     to pass by the filtration system          

                                             
 


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APRIL 2016 :


Emission of glochidias by  specimens of Charente Giant Pearl Mussel


The first specimens of Charente Giant Pearl Mussel  issued glochidias in the beginning of April, the other ones followed only days after. It has to be noted the temporary difference in the emission of the specimens of Creuse who issued glochidias a couple of weeks later than the Charente mussels.

Several issued glochias were however not viable. The infestations started with viable specimens of glochidias.




Infestations

The sturgeons were put in contact with the glochidias issued by the Giant Peal Mussels (witish substance visible on the foto on the left) in a little container; so that these ones can hook to the sturgeons' gills.

 
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MARCH 2016 : The first Giant Pearl Mussel arrived ! March being the fertility period of the Giant Pearl Mussels, 20 specimens were collected in Charente and Creuse to collect their glochidias (larvas) and start the breeding processus. 200 little sturgeons, the most known host fish of the Giant Pearl Mussel, also arrived in the laboratory (Drill water Hatchery, Guyenne), for the larvas to encyst on their gills during their first month, as it happens in the nature.



      20 Mussel collected in Charente                  5 Mussel collected in Creuse                                         Sturgeons
                      
                   Esturgeons en acclimatation à leur bassin - mars 2016               
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FEBRUARY 2016 : The construction of the laboratory being delayed because of the animal regulation, the LIFE team found we had to find a transitional solution to host the fishes and mussels for 2016: the installation of the laboratory in the barn attached to the university site of Chinon:
 
The site attached barn, previously warehouse for the boats of the university was cleaned and modified to meet the standards, by the LIFE team, and then equipped to receive sturgeons and Giant Pearl Mussels.


Cylinders for the sturgeons breeding
The conic cylinders were created according to the specific regulation for the maintenance and experiment, in order to be able to contain 20 fishes and collect the juveniles (young mussels) once they unhooked from the sturgeons' gills.



 




Breeding basins
The adjacent basins were elaborated specifically for the LIFE Giant Pearl Mussel project. The first one is a water tank to provide water to the different basins and cylinders hosting the fishes. The B1 and B2 basins will host the sturgeons at their arrival in the laboratory.
 











Filtres
 
Every cylinder is equipped with two filters to control the quality of the water. The first one, blue, is a 90 microns cartridge filter to prevent the mussel from being realeased in the external filters.

 The second one, in black, hidden under the cylinder on the picture is made up of 4 filtration baskets:
 
FIRST BASKET : The first basket is an organic filter full of balls on which the "good bacterias" will fix. These bacterias enable the decomposition of the toxic elements contained in the water of the aquarium in chimical elements with low toxicity.

SECOND BASKET : The second basket contains cotton wool to enable the filtration of the finest particles contained in the cylinders water.

THIRD BASKET : Filtration foams and active coal are the components of the third basket. They aim at absorbing the toxic substances by avoiding their rejection in the water.

FOURTH BASKET: The fourth basket contains two levels of filtration foam, bigger than the cotton wool, together with a level of cotton wool. These filters ensure the good ecological balance of the sturgeons water and therefore enable a good growth of the mussels. 
 




Electrical panel of the animal facility

 
The animal facility is electrically powered with an electrical panel. In case of a loss of energy supply, the electrical panel is connected to a power generator with an automatic actuating mechanism.
                     
   

Power generator
                    


Alarm system

 
Finally, to improve the security of the filtration of the animal facility, this one is connected to an alarm system enabling a continuous moritoring of the oxygen and temperature in all the basins of the animal facility. It also enables the emission of an alert message to the LIFE team in case of a fall of the planned rates in oxygen. 
 
 
The animal facility of Chinon is now ready to welcome mussels and sturgeons !
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JANUARY 2016 
: The earthmoving work for the construction of the breeding laboratory in Chinon has started ! We will soon be able to welcome sturgeons and the mussels currently bred in Banyoles.


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May 2015:
The first baby mussels are born!

Our mussels farm in the Banyoles station witnessed the birth of the first Giant Pearl Mussel juveniles of our project! About 7000 juveniles have been counted. However the mortality rate being very high during the first months of a mussel, we cannot currently state on the exact figure of juveniles still alive.

The size of these ones (about 200μm once collected) and the growth being really slow, it makes the count difficult once the juveniles are bred in artificial channels. 

17 APRIL 2015 : Reimplantation of the 10 individuals collected on the 18 March 2015 in their area of origin: in Charente on the “site of Port d’Envaux ».
 
Figure 3 : Grande Mulette réimplantée en Charente ©P.Jugé
18 MARCH 2015 : Collection of 10 individuals in Charente on the « site of Port d’Envaux » to send them in Spain (in the Banyoles CES in Catalonia, Giant Pearl Mussel reproduction and breeding station – Figure 4). These individuals are collected to take their glochidias (larvas) and to infest some 60 Siberian sturgeons raised in the Spanish study center. This infestation is part of a natural reproduction process of the Giant Pearl Mussel which requires a development phase on the host fish gills. On the 10 collected specimens, only one had glochidias.
 
Grande mulette de Charente, conservées en Espagne le temps de recueillir les glochidies ©P. Jugé
15 MARCH 2015 : Collection of 4 Giant Pearl Mussel individuals in the Creuse river on the Rhonne station to measure, weigh and mark them. The presence of ovas was checked on all the mussels, and 2 of them had fertilized ovas. The weight of the collected specimens was about 450 grams. Once the analyses have been made, the 4 individuals of Margaritifera auricularia were relocated in their original position.