Site açılış tarihi: 27 Kasım 2012
Geçen ayki Günlük ort. ziyaret: ..254.(şub.2021)
Ay içinde en yüksek ziy sayısı: ..295
Geçen ayki ziyaretçi sayısı: . 7884
Toplam ziyaretçi sayısı: 716616

Kitaplar » AQUACULTURE » Carped Shell (Akivades ) Farming




 AKIVADES (SAND MUSSEL) BREEDING


Picture: Ready to market and packaged akivades.

     In the diet of humans, seafood fish are the leading ones. However, in many countries, shellfish are sought after and marketed at high prices. One of these creatures is Akivades, also known as sand mussels. Akivades is a valuable foodstuff in many European countries. Among these countries, especially Mediterranean countries come first. Spain, Portugal, France, Italy and Greece are the leading countries in terms of shellfish consumption. It is common for creatures such as oysters, mussels and akivades to be collected from nature and consumed.
        Due to the decrease in natural resources, interest in breeding has increased in recent years. Akivades can breed in polluted estuaries or in areas close to cities. It is getting harder day by day for Akivades to be sourced from natural resources. The collection of Akivades is generally done in three regions. The first of these is the production in areas where water is drawn from time to time due to tides. Excavations are carried out on the shores of the Atlantic Ocean, where tidal movements reach several meters. The second catchment areas are the places where the water depth is at most one meter. The sludge dug with a shovel is sifted through the sieve. This method is generally applied in the collection studies in the Gulf of Izmir. The third catchment zone is the areas where the water depth reaches 2.5 meters. Digging is done by diving in these areas or aquacades are collected with the help of long rods from the shovel. In depths not exceeding human height, collecting is done with shovel, sieve or overalls. These applications are usually done when the sea is still. These applications are difficult to do in rough and windy conditions. In this type of gathering, the collector wears overalls. The overall allows the picker to work in cold weather. The collector sieves the  sludge removed from the ground with a shovel. Some collectors use a two-layer sieve. The meshes of the first floor are 1.5-2 cm and the meshes of the second floor are 0.5 cm in two-storey sieves. The collector gives the akivades on the first floor. The forager grows small aquacades on the second floor and actually cultivates them. There are no special areas reserved for gatherers in Izmir Bay in our country. That's
why gatherers keep it a secret. In such a gathering practice, 3-15 kg of aquacades can be collected depending on the richness of the region. This amount decreases a little in the winter season.
 
 

 



Picture: Akivades are a luxury food, especially in France and Italy. Because they are expensive, they are served with their shells.

 

 
       In places deeper than 2-3 meters, akivades are collected by boat. A material called "Sara" is used in the process of collecting from the boat in Izmir Bay. This material is a 4-5
meter long pole. There is a comb at the end of the pole. There is also a net bag behind this comb. Akivdes are taken into a net bag with the comb at the end of the pole. Collectors look
at the bottom of the sea with a vehicle called "Mirror". In this way, they try to find the most suitable floor.
 
 



Picture: After collection of aquacades, aquacades smaller than the size to be marketed are taken into growing areas for controlled growth. In recent years, air can be supplied by a
compressor placed on a boat in the Gulf of Izmir.
 
      Description of the Type:
 
      There are many subspecies among the Veneripus (Tapes) species. The most common of these subspecies is Tapes Decussatus L. This type is very rich in nutritional value. Tapes
Decussatus is the species exported from the inner bay of Izmir. Apart from this genre, V.Pollustra is also commercially important, but marketed more cheaply. Rbomboides species
found in Portugal is produced in small quantities.
     

 

Tapes Philippinarum is the common type for breeding.

 

 
Geographical Distribution: 
 
Akivades are spread over a very large area in the world. They span from the 12th degree latitude to the 61st degree latitude. From Senegal to Norway. It is also available on the south and west coasts of England. They are not found in the North Sea except Norway and Denmark. It is common in all mediterranean countries. It is widespread on the coasts of the
Atlantic Ocean and the English Channel. In our country, İzmir Bay is the region where it is produced the most. It is a widespread species around Mersin, places where phytoplankton reproduction is good and Çanakkale.
 
Biology of the Species:

       There are many subspecies in Veneripus species. The most common of these species is Tapes Decussatus. We have said this before. Tapes Decussatus has a thinner shell than other species. They can be easily buried in sand with their siphons that act as feet. Their lives continue in the sand continuously. They can intake and give water through the hole they opened in the sand. While making this water intake, they meet both their oxygen needs and their nutritional needs. The siphons they use in water exchange are not long, so they are not buried deep in the sand. Mature ones are generally buried to a depth of 5-10 cm. Smaller ones have less burial depth. They do not leave their place and stay in the same place until they die. For this reason, production will be more efficient if they like their place while breeding.

      Below are the differences between the two most recognized species.

 Tapes Decussatus

- Blunt with prominent back.
- Siphons separate
- The shell is thin and without resistance
- Inner shell is white in color
 
Tapes Philippinarum
 
- The back is less blunt
- Siphons are not separate
- The shell is thick and durable
- Inner shell purple and violet color

 



 Tapes Philippinarum is a successfully grown artificially. It is also called the Japanese Akivades. The ideal temperature for the Japanese Akivades is 18-25 degrees. Ideal salinity is

32-40%. Older individuals are more successful in terms of being able to endure different conditions. Japanese Akivades are resistant to temperature and salinity drop.           Tapes Decussatus species cannot survive if the salinity drops below 20%. For this reason, farming should be done far from river mouths.

Akivades are separate sexual creatures. The end of the spring season and the beginning of the summer season are the spawning periods. Fertilization takes place outside. Larvae become 0.7-0.8 mm in size after the pelagic period. Then they are buried in the sand. Akivades prefer to live on hard, sandy and muddy ground. The ground should contain lots of organic matter. If the water depth is around 0.40-1 meters, the collection process becomes easier. Compare with kidonya and cikcik (Venus Gallina) in terms of the ground they live in.
Kidonya prefers more sandy floors. The ground structure is softer. Akivades live in mud, which is slime-like black and contains organic substances. Vangola lives in clean sand, whose sand can be dispersed easily. Tools have been developed to collect Vangolas that live in the depths of the ground. These tools allow living things to come out of the sand by squeezing water cannons. Creatures that come out of the sand are transferred to a bag. Aquacades cannot be collected by the same method since they are buried in mud.
 
 



Picture: Tapes Philippinarium puppies bred in a hatchery.
 

     Akivades settle on the ground when they are 7-8 mm in size. They grow rapidly and reach 10-12 mm in length within 3-4 months. The rings in their shells can be looked at   when determining the age of akivades. This does not give exact information. They can be sold when they reach 3-4 cm in length. It is stated in foreign sources that it will take 2-4 years to reach 3-4 cm in height. They can reach a maximum length of 7-8 cm. As a result of a study, an individual weighing 26 grams, 3,69 cm in length and 5,45 cm in width was found in the Izmir region. It has been observed that they reach 3 cm in 3 years and 5 cm in 6 years in the natural environment in Europe. Small sizes are faster to grow in both species.

Breeding
   
      There are two stages in akivades cultivation. The first step is to find or produce offspring. The second stage is to bring the puppies to the size to be marketed in a suitable environment.
       Akivades settle on the ground when they are 7-8 mm in size. They grow rapidly and reach 10-12 mm in length within 3-4 months. The rings in their shells can be looked at when
determining the age of akivades. This does not give exact information. They can be sold when they reach 3-4 cm in length. It is stated in foreign sources that it will take 2-4 years to reach 3-4 cm in height. They can reach a maximum length of 7-8 cm. As a result of a study, an individual weighing 26 grams, 3,69 cm in length and 5,45 cm in width was found in the İzmir region. It has been observed that they reach 3 cm in 3 years and 5 cm in 6 years in the natural environment in Europe. Small sizes are faster to grow in both species.

      Akivades Breeding by Gathering Pups from the Natural Environment in Portugal. Portugal- Argarviarn is rich in akivades. Useful studies have been carried out in this
region for aquaculture. We can name the cultivation in this region as semi-intensive production. Because feeding in production is not possible due to the characteristics of the
living creature. Aquaculture is carried out on the coastal lanes where tidal movements occur. The individuals used in breeding are generally collected from nature. In recent years,
artificially produced offspring are also used in breeding. The babies collected from the nature are left to the breeding places quite often. Due to the frequency of this practice, development
is slow. Since the desired rate of harvest is available, slow development does not cause any problems. The producers constantly check the development in the place of production. When the desired size is achieved, the collection process begins. In controlled production, living things can reach bigger paint compared to those collected from nature. Therefore, controlled production can be efficient and profitable.
Since everyone has the opportunity to collect akivades in natural areas, akivades do not have the opportunity to mature enough. People who hunt in these environments hunt even
smaller than the legally permitted hunting sizes. Due to such reasons, very few individuals can reach the desired height. It is possible to expect individuals to reach the desired height in
controlled production areas. Also, farming in controlled production areas is healthy to protect  the lives of living things. Another advantage of this production method is that while a certain number of living things are being reared, the same number of living things can produce more weight. In Portugal, sand mussels are highly sought after and expensive to market. It is one of the most demanded dishes in many restaurants. It is a product that is exported to France and Spain. 
 
 



Image: Hoses that enable Akivades to exchange water
 
GEOGRAPHICAL SITUATION
 
      In Portugal, akivades are very common on the coasts between Faro and Tayira. Many businesses have been established on these coasts. Many of these businesses have achieved  success. There are further businesses located approximately 3-5 km from the city of Fuseta.
      The long and shallow sea strip on the south coast of the Algarie is an important place as the natural beds of the akivades. This coast, which is naturally protected from storms by an island, is very suitable for akivades to survive. A storm is not desired in a region where akivades are studied. Waves in the sea caused by a storm can lift the mud on the ground and
then cause the mussels to drift. It is also important for the freshness of the water that there are channels between the island and the coast that will provide water flow.
     The areas where the sand mussels are settled are shallow enough to be exposed during the Med-Jazira. High efficiency can also be obtained on the coasts where water is not
absorbed at all. Even more efficient production can be made here because the mussels that are constantly under water will show continuous development. When the air gets hot in very
shallow places, overheating of the water can cause deaths.
Med-Jazira: In this region, the highest 2.40 meters, the lowest 1.30 meters Med-Jazira is seen.
      Water temperature: In the Atlantic Ocean in the southern regions of Portugal, the water temperature is around 15-20 degrees in summer and around 12-14 degrees in winter.
However, near the island, this temperature can rise to 20-24 degrees in summer, and may drop to 10 degrees in winter. The tides that occur in the middle of the day in the summer cause
sudden changes in the water temperature. This situation acts as a warning about ovulation. Salinity: Salinity is between 35% and 31.8%. However, as a result of some very strong rains, this rate may decrease up to 30%. It is even known to decrease up to 20%. However, since these regions are somewhat arid, there is not much danger in this regard.
 
     Pollution: The places where the clams are grown are generally very clean in terms of water. However, there is contamination in some places close to the city. The official offices regarding the controls carried out in the country do not allow the establishment of businesses in places where contamination may occur. Especially places with city sewers are avoided. Portuguese generally eat akivades meat by frying or boiling it. However, since it is eaten raw in France, aquacades produced in polluted waters can be harmful.
 



Picture: A shallow sea area used for the production of Akivades.

LEGAL MATTERS

     All seas in Portugal belong to the state. The areas where the sand mussels can be collected are restricted by the state. The regions where natural hunting can be done and the
people working are registered with the state. 
 
     The registrations and transactions made by the state can be listed as follows: 
 
- Men and women who work in this job and are over 14 years old
- Natural clam deposits
- Licenses given to the person who rents a certain area and hunts there
- Licenses given that a particular area can be used for breeding purposes
- Permits issued for regions where sand mussels are temporarily stocked

    In the past, the area given to one person for breeding was 1500 m 2 . But this area is scarce nowadays. For this reason, there have been attempts to establish a larger production
area by combining 2-3 regions rented by a few people in recent years. With the new regulations, this limit has increased to 5000 m 2 . However, there are also businesses that
produce in larger areas. For example, these enterprises, which are 35-50 decares, appear as belonging to more than one person in the state records. But they operate as a single business.
      The boundaries of the area reserved for aquaculture are indicated with piles. But the pole gaps are wide enough to pass the boat. Thus, sea transportation is not obstructed.
According to the law, collecting mussels can only be done during the day. It is forbidden to use digging machines. It is thought that this may be allowed in the future. It is
necessary to be careful about this. Because it is possible to deteriorate the floors in the production with digging tools.
2 cm long offspring are used for production. 3cm is generally preferred in domestic markets. If it is to be exported, 3,5 cm is preferred. Anyone can pass through the production
areas by boat and motorboat. It is forbidden for the person who owns the region to put any
restrictions in this regard.

    ACIVADES CULTIVATION IN PORTUGAL

   

    PREPARATION OF THE PRODUCTION AREA

First, the boundaries of the area where the brood will be left are determined with stakes or floating balls. If the area is uneven, it is brought to a smooth state. The area is
cleaned, stones and herbs are removed. A rake is used for this. Shovel and digging can also be used when needed. All of these studies are done with human power.

PUPPY COLLECTION FROM NATURAL AREAS

In Portugal this is done by licensed workers. As mentioned earlier, collection is done when the water is drawn, as tidal events are quite high on the Atlantic coast. People dealing
with aquacades in our country can buy small sized puppies that are called under the sieve and are not exported. You can walk to the close ones from the collection areas in Portugal. You can go to distant places by boats. Workers often use wooden boats of their own. These are 4-5 meters long and 1-1.5 meters wide. Their depth is around 50-70 cm. Some of them are motorized while others move with the help of a shovel. When a worker goes to the collection area, he can work for about 3-4 hours as long as the water tides allow. The collection is done with a hand ladle called "Faca de mariscar". It has a handle made of a tree 15cm tall. This tool is 18-20 cm long and 12 cm wide. Its front face and corners are oval.
Collected cubs are generally 2 cm in length. Sometimes some small ones can also be packed together. Those shorter than 1,5 cm are never collected. Depending on the richness of the environment, 3-4 kg of fry can be collected in 3-4 hours of work. Workers deliver the puppies they collect to the breeder as soon as they return. Breeders classify the puppies they take according to the size. They sort out the ones that are suitable for marketing and send them to the market without waiting. The juveniles are released into the sea when the water level is low.

 




 Picture: (Top): Laying a net on the water surface in Akivades production areas.

(Bottom) Tank layout set outside and in which akivades juveniles are placed.
 

 This process is done from the boat by hand or with a shovel. Or the puppies that are placed in the production area in piles are distributed around by hand or with a shovel. The number of puppies to be placed in each 1 m 2 varies according to the size of the puppies. Normally, 500-1000 pieces are left per m 2 . Within 25-30 minutes, the cubs immediately enter the ground. The next day, it is checked whether the babies enter the sand or not by going to the area again. Dead cubs or those who have not been able to enter the sand are collected.

Some may come across a stone or hard ground and therefore may not be able to enter the ground. Puppies that cannot enter the sand may die after a short time. It is vital that these be collected and redistributed.

Puppies left in the park are kept until they are of marketable age. The offspring with an average of 2 cm reach 3-3,5 cm in a year after 2.5-3 years. The offspring left as 2cm are
harvested at least 3 years later. The production area is checked frequently. If grass and moss accumulate on the area, they are cleaned. The enemies of the sand mussel are followed. (Starfish, crab, etc.)

AKIVADES HARVEST

Harvesting is done as stated in the previous brood collection practice. However, collecting is easier because mussels are very common in these areas. The collected sand
mussels are first separated in size. Large sized ones are marketed. Those who cannot reach the marketable paint are left back to the production areas. 

 




  Picture:(Left) In an akivades growing area, post-harvest ground cleaning is done. All dead crusts are removed.

(Right): Aquavades and other shellfish are kept in clean water to purify them from germs before being marketed. During this period, they are exposed to ultraviolet rays. Disinfection can also be performed using chemicals that are not harmful to health. This process is called depuration.

MARKETING OF ACIVADES

For marketing, they must be at least 3cm tall. In Portugal, 3cm tall ones are reserved for domestic marketing while those 3.5cm and longer are reserved for export. Generally, 75-
125 sand mussels weigh 1kg. Mussels are shipped in packages or boxes. They are transported to distant places by train or trucks. 
      Some manufacturers may not want to sell their products right away. They keep these floating mussels in water for a while. They do this by keeping the mussels in the sand.

  
CULTIVATION RISKS

    If it rains a lot and the salinity in the water falls below 21%, deaths are often experienced.


ENEMIES AND DAMAGES

    Very small clams have a lot of enemies. The larger the mussels, the less enemies they have.

Picture: Akivades in reproductive stage

 Haemotopus ostraffics and Numenius arguota, a type of sea bird, can eat the offsprings by breaking their shells easily. They can only harm juveniles close to the surface. Fish such as

Myle dbates uquillo and Sparus auratus (sea bream) can only eat offspring near the surface. The main enemies of sand mussels are sea stars. (Astropecten bispinosus A. aurantiacus and Marthasterias glaeriolis). Some types of crab can also be harmful. Crabs can only kill small-sized babies. Producers frequently check the production area to avoid such situations, but they do not take any other measures.

DISEASES AND PARASITES

     Occasionally, deaths with unknown cause can be seen. Sometimes the mussels can be seen leaving the ground in masses. This situation can occur for many reasons. No virus has been detected so far. For example, mass deaths occurred in 1971-1972 and the cause is unknown, but is thought to be due to Redtide. The spore Haplosporidium topedis has been
seen in mussels, but it has not been proven that this is what caused the deaths. However, it has been found to delay sexual development. Widespread microbes of Bucephals Hoimeana have been observed on sand mussels (Venerupis Pullastro), but no damage has been found on the Algarvian coasts.

  
Controlled Offspring Production and Breeding in France

    A successful breeding study is being carried out in France on the Tapes philippimrum species called Japanese Akivades. The reason why the Japanese Akivades are preferred for breeding is that the cultivation of this species is much easier than the cultivation of the Tapes Decussatus species. They are easier to transport and are more durable. Japanese Akivades have a high ability to evaluate foods and they grow rapidly. The cultivation of Tapes Decussatus species has also increased in recent years.


 

 





 

Picture: Akivades juveniles 3-4 mm in size produced by human control and containers used in production.

 

The first stage in breeding is breeding supply. There is no problem in this regard. If desired, individuals can be obtained from the natural environment or from the breeding areas
to give eggs and progeny. Some companies that breed Japanese Akivades choose individuals they will use as breeders and keep them in an environment with a water temperature of around 10 degrees. A few individuals are sacrificed and the gonads are examined to determine whether the breeders have reached maturity. In addition, the water with the breeding
individuals is constantly examined and eggs are searched. If an egg is found, this indicates that sexual activities are taking place. The circulation order is established in the tanks where
the rootstocks are kept. If fed with mixed algae, maturation is accelerated. Aquacades can lay eggs twice a year, in the spring and autumn seasons. Aquacades kept for spawning are taken in water at a temperature of 20 degrees depending on the season and subjected to fattening. Where these creatures are kept, there is sand on the ground where akivades can shelter. A special feeding method is applied in an environment where the temperature is 20 degrees. These individuals are fed by giving phytoplankton produced in different ponds. Commonly used planktons: Dunaliella Primolecta, Monochrysis Lutheri,
Fsochrysis Galbana, Pseudcisochry-Sisparadoxa, Thalassiosina Pseudorana, Sklectonema Costratum, Chaetoceras Calcitrans and Platynonas Succicctn. With proper care and feeding,
akivades become capable of giving eggs within 30-40 days.
Thermal shock method is used to obtain eggs. For this purpose, rootstocks are first taken to the environment with a temperature of 10 degrees. The water medium is glass. By
providing 50 degrees of water circulation around the container, the water in the container is heated slowly. When the water temperature reaches 26-28 degrees, akivades begin to lay
eggs. Some males release some sperm before females lay eggs. This situation does not cause any situation in the production process. If three thermal shocks fail, the water in the container is replaced with clean and filtered sea water, this time at 14-15 degrees. A second thermal shock is applied. Generally, if individuals are well selected, they will release eggs after this second shock. For fertilization to occur, akivades can be milked manually. Fertilized eggs in 1 liter capacity containers undergo

Microscopic examination. Then, the eggs are drained with 40 micron strainers and transferred to the production tanks. In these tanks, the water is around 20 degrees. 
Water passed through 5 micron strainers is used in the tanks. A rich feeding process is made with the phytoplankton grown outdoors. 
      By applying the aforementioned method, year-round production enterprises have been established.

      The larvae hatched from the eggs undergo change within 48 hours. During this period, counts are made and the amount is determined. Homogeneity is provided in one liter sampling
containers for counting. Then, 100 cm 3 sample is studied and an estimation is made. Larvae production is carried out in tanks that can vary between 5-10 tons. In some production areas, arming can be done in smaller tanks. In the first days, a circulation system is provided to help change the water in the tank once a day. The temperature is tried to be kept between 25-28 degrees. The water given and discharged is passed through 5 micron strainers, preventing the larvae from escaping and entering foreign creatures from the outside. The previously mentioned phytoplankton are used in nutrition. Cultivating various phytoplankton species and choosing different phytoplankton within two to three days
increases the chance of success in aquaculture. It is beneficial to feed different species, as each species has different nutritional values. The water temperature in phytoplankton
production areas should be around 20 degrees. Phytoplankton can be produced in containers and tanks of various weights, from 10 liter containers to 8-100 ton tanks.
 
It is very important to follow the development while breeding. Thus, it can be understood whether there is a malfunction during the development, whether the feeding is sufficient and effective. Feeding can be done by giving a certain amount of forage water every day. In addition, feeding can be done by draining 50-80% of the water in the environment and replacing it with forage water. The development process can be examined by taking samples in each water filtration process. It is useful to make a count every two or three days. Whether there is a disease or not can be understood through these counts. Until the 12th day, the larvae can reach 60-160 microns in size. Measurements are made by measuring the anterior and postarior axes under a microscope. At the end of larval development, metamorphosis is completed. If the offspring are not transferred to a suitable environment after this period, deaths begin to increase. Those who cannot undergo metamorphosis die. It is normal to have at least 40% death by this time.

 

 LARVAL PERIOD

 Larvae that undergo metamorphosis can only reach 1 mm in size within 1-6 months. The water in the growing tanks can be circulated through the sand filter. The use of water by providing circulation ensures successful results during cultivation. When the larvae reach 2 mm in height, the plankton variety given can be reduced to two. The feeding process can be simplified by applying mixed feeding. When the larvae reach 2 mm in size, they are transferred to specially designed tanks and breeding continues. In breeding, akivades offspring try to feed in an environment with 20-40 thousand algae per millimeter. 

     In general, the water temperature should not exceed 25 degrees during the growing period. The salinity ratio should be between 20-28%. Ventilation should be well regulated.
Issues related to water conditions such as pH, ammonia, nitrite and nitrate should be followed. In some studies, it has been observed that the increase in the number of larvae to
10,000 per liter does not affect the development status. Keeping the temperature around 25 degrees is very important for a healthy development period.

DISEASES

      It is known that Epizootin disease can cause serious damage in the production of Akivades larvae and cause 100% death. For this reason, it is necessary to be knowledgeable
and precautionary in the production of shellfish, including akivades. A good disinfection process should be applied and the materials to be used should be thoroughly cleaned before
starting production. When any disease develops, treatment can be provided by adding antibiotics and sulfamide drugs, equivalent to 2-3 mg per liter every day.
      Two methods are applied for the rearing of larvae exceeding 2 mm in length. One of them is that the development process is done in a closed environment, inside tanks. The second is that they are taken to outdoor pools and raised. (Tanks whose bottom is covered with 4 or 6 mm grids) These tanks can be rectangular or circular. Water circulation is
provided in these tanks. Some new feed water is added continuously. The water exit from the pipes is made after passing through the screened screen.
      As a second method, offspring are transferred outside in cages. In the park prepared for such situations, a fine net is placed on the ground that aquacades cannot pass. Feeding is
planned to be sufficient for a limited area. If feeding is not enough, it is useful to add plankton. During the cultivation in tanks, the tanks are covered and necessary measures are
taken to prevent the growth of foreign algae.
      In some manufacturing enterprises, a mesh with eyes 2 mm in size is stretched on both sides of a frame made of wood, size 50x50 or 50x100. Around 10,000-30,000 puppies are placed in this cage. These cages are transported to pools or private locations to continue the rearing process. Since aquacades cultivation was considered later than oyster cultivation, the cultivation method in cages was inspired by oyster cultivation. Crates should be shaken from time to time in order to prevent residue settlements that may occur inside the crates. In order to ensure a good water circulation, foreign materials that may accumulate on the mesh surface over time should be cleaned regularly. In some cultivations, these crates are hung in the pool. 
      The water temperature should be around 18-20 degrees in the breeding environment. Although it is easy to obtain this heat in inner tanks, it is difficult to achieve this condition in
outdoor aquaculture. In terms of oxygen level, there is usually no problem in cold weather. In hot weather, the sieves may become clogged and oxygen levels may be lacking. In this period, salinity ratio of 12-30% does not cause any problem for Japanese Aquiwaters.
     In aquaculture in the sea and coasts, the salinity rate is completely dependent on nature and it is not possible
to control it. Various measures can be taken in indoor aquaculture. In outdoor cultivation, it is possible to increase salinity as a result of evaporation due to summer season and decrease salinity due to rain.

       It would be beneficial to continuously add clean sea water to prevent the troubles that may be caused by such situations. In order to prevent sudden changes in the sea from causing
a change in the pool conditions, sea water is first collected in a pool and transferred from there to the production site.
       Losses may occur due to various reasons in the offspring production process. Since Akivades breeding is one of the new applications, studies and knowledge on diseases are limited. Instead of treating the diseases, it is useful to take preventive measures before the disease occurs. Taking care of cleanliness, paying attention to feeding, ensuring optimal water conditions, and being careful about density will ensure a healthy progress of the breeding process. The growth of filamentous algae in the environment can cause oxygen deficiency. In  case of uncontrolled growth of algae, cleaning should be applied. Considering all these, periodic control and cleaning planning is vital. 
       One of the most harmful creatures in offspring production is a type of crab that we can call the green crab. (Carcinus Maenas) The green crab that can settle in the corners of the
crates can cause great damage in the aquaculture done in the crates. If conditions are good at this stage of breeding, the survival rate may increase to 90-100%.
Growth rate should be followed carefully during this period. For this purpose, random samples are made in periods and the development is controlled. If there are those who show
different development in terms of height, it is useful to classify all of the individuals.
     Studies have determined that the development difference in offspring obtained from different individuals is related to the gonad development found in the parents. For this reason, it is
normal to see offspring of different sizes in each breeding. At the end of this period, individuals over 4mm in length are expected to be obtained. The most important issue in aquacades breeding is that the juveniles reach 4 mm in height. Marketing of puppies is done according to size. The price of a 2mm-over-period offspring is 0.04 francs, a 4mm larva's price is 0.11 francs. Large individuals are expensive, encouraging breeders to have 2mm sized puppies.

BREEDING UP TO MARKETING SIZE

   Aquacades can reach market size in marine areas. Areas to be used for this purpose are  required to have a less muddy floor. There should be no sewer openings in the environment
that may be harmful to health. Sufficient space should be available for settlements and other facilities. It is desirable to have social facilities such as electricity and water and to avoid road problems. Arrangement of 1000 m2 areas for breeding is a wide application. Based on the tide times of the growing area, care should be taken to ensure that the ground is under water even when the water is at its lowest. Transplantation should be done in the spring season as much as possible. Thus, individuals will be able to reach the desired height at the end of the summer season. 4-5 mm length will be sufficient for the sowing process. The development periods of creatures that can eat Akivades cubs are July and August. Until these months, the development and crusting of aquacades will help protect them from external influences. The number of juveniles to be left in a unit area is decided according to the food situation in the environment. Surrounding the area where the planting process will be applied, collecting the crabs in the region and raking the ground will increase the chance of success. It is a normal rate to apply 100-200 sowing processes per m2. After the transplantation process is applied, it is necessary to clean the environment regularly, to control the harmful creatures and to follow the development. If the area where the sowing process is applied is in contact with the sea and the water flow is good, a maximum of 200 sowing can be made per square meter. If the opposite of this situation is present, a maximum of 40 -100 sowing can be applied per m2. In the table below, some of the results determined on the development of akivades are given. In France, spreading nets suitable for the ground are sold when applied with the help
of a tractor. It is useful to follow the water quality continuously after planting. It may be difficult to follow this in the outdoor environment, but it is possible to take some precautions
by controlling the water inlet and outlet in the production areas.
      Information about diseases and ways to prevent them is limited. For this reason, there is not much that can be done to prevent diseases during the growing period. Overgrowth of
algae in production areas can lead to a lack of oxygen, so it will be healthy to clean algae regularly. Growth should be monitored continuously during the growing period. For this
purpose, it is possible to determine the development situations by sampling. In this way, the amount of available product in the whole area can be estimated. Crabs can often lead to death. For this reason, it should be paid attention that there is no crab under or above the net while planting. Early planting and a small amount of gravel on the ground will reduce crab damage. The rate of deaths may vary from one production to another. The important thing here is the skill of the breeder and his interest in the subject. Growth stops during the winter months.
     This is important for aquacades that enter the winter months in small sizes. Individuals who are weaker during the winter months are more likely to die. At this point, it is understood once again that early sowing is important. 
With net laying, harvesting takes place by removing the net. In the cultivation without the use of net, the harvest is done with the help of a shovel. The sludge taken with a shovel is
washed in the sieve. In our country, akivades harvest is usually done in this way. A practical and mechanical method for harvesting akivades has not been discovered. There are no
effective measures against algae and predators. Cleaning is done when it is desired to deal with algae and predators. There are no definite findings about the optimal frequency during the transplantation process. Extensive research should be conducted on these issues.

EFFICIENCY OBTAINED IN ACIVADES CULTIVATION IN FRANCE

There are large companies that generally produce puppies in France. The leading companies among these companies are SATMAR, AQUAMARE, APASUB. These companies produce between 20 and 100 million offspring per year. The number of businesses that buy and raise these puppies is also quite high. In the smallest of these enterprises, 5-10 tons of marketable products are grown annually. Great care is taken when deciding on breeding regions in France. The region where breeding will be done is examined from all angles.
In studies conducted in France,
 
a period of 800-1200 days is needed from egg to marketing. 
30-40 days: Sexual maturation period
2nd day: Egg intake
30-50 days: Metamorphosis period
30-180 days: 2mm height at 300-600 microns post larval stage
30-90 days: from 2mm to 6mm length
600-800 days: the period from 5-6mm to 35mm and larger marketing size

It takes between 800 and 1200 days to reach the marketable 35 mm height from the egg, depending on many factors. (Seasonal changes, cultivation method, feed possibilities,
frequency of sowing process, etc.) Also, if sowing is done in shallow areas where tidal incident develops differently, development will be late. Because when the water is withdrawn, it is not possible to take feed. Akivades consumption increases during vacation times. During these periods, growers have the opportunity to market their products at the highest price by shipping their products to
the market. Through breeding, it is possible to deliver products to the market at any time. For this reason, the possibility of farming to be more profitable will increase.
      In France, sea production is permitted by the state. In recent years, attempts have increased in the production of aquacades in some swampy areas. The handling of cultivation
in such places has contributed to the development of these regions. Fishermen and tourism professionals oppose to aquaculture in some areas.

     Akivades are marketed alive in France as well as in all European countries. Marketing length is 35 mm or more. Coarse products are marketed more expensive. Frozen aquacades are also available, but they are cheaper in price. Consumers attach importance to the freshness criterion when purchasing akivades.




Picture: (1) The facilities established for the production of Akivades are not very large. It is only necessary to be patient and careful during the breeding process.

(2) A hatchery where crustacean larvae are produced and breeder aquacades

(3) The containers used in the production of Akivades cub are very simple and easily available.