GB2023396A - A device for breeding snails and application thereof - Google Patents

Abstract

A device for breeding snails comprises at least one independent column of superimposed cells, each cell being provided with an inclined irrigation surface 8 and at least two boxes 7, the said irrigation surfaces being arranged one beneath the other and the said column having a top part which comprises means for supplying water to the said irrigation surfaces. <IMAGE>

Description

SPECIFICATION A device for breeding snails and application thereof The present invention concerns a device and an application for breeding snails.

The traditional collect of these animals is not sufficientto meet the considerably increased needs which necessitate to import from the large producing countries. A way had therefore to be found to palliate the shortage of the natural supplies and industrial breeding was then considered. To this end, it was proposed to multiply the "sticky surfaces" (along which the snails move) away from the ground by means of boards or large superimposed tables.

The major disadvantage in such a case, is that said surfaces can only be multiplied by two. Other problems also arise. It is necessary to prevent the snails from escaping, to bring them moisture and food both of which are essential to their growth, and also it is necessary to avoid breeding them in large numbers, which encourages the propagation of epidemics and hence mortality.

For a good profitability therefore, the sticky surfaces should be multiplied in a minimum space, whilst keeping small amounts of snails in a sealed moist enclosure.

It is the main object of the invention to solve this problem by proposing a device which fulfills the optimum requirements for breeding snails.

This object is attained with an independent column of superimposed cells, comprising at its upper part a water supply and inclined irrigation surfaces, arranged one above the other and kept moist by the said water supply, each cell being provided with its own irrigation surface and at least two boxes.

Preferably, the said irrigation surfaces of the middle cells slope down in alternate sequence of direction, so that the draining outlets of the said surfaces are aligned vertically in pairs; the said boxes intended for the layings of the snail eggs contain a substrate the approximate height of which varies between 3 and 5 cm and are made of a transparent material.

Said boxes preferably contain a substrate composed of fine soil preferably taken from the following group of products: running soil, vegetable seed ground, compost, river sand, and a moisture absorbing agent, preferably selected from the following group of products: perlite, vermiculite, turf.

They can be provided with a mirror placed at a slight distance from their bottom, in order to reveal and to count the eggs laid in the said substrate, and they can also comprise airvents.

Each cell further comprises at least one vertical door sealingly locked in horizontal grooves.

The device further comprises at least one incubating cell consisting of a box containing a substrate wherein the eggs, extracted from a laying cell are deposited, and of an upturned empty box, covering up the first box, the said empty box being preferably crossed in its centre by a tube containing a powdered food, which is used after the eggs have hatched. The said incubating cell preferably contains a substrate in which the approximate proportions of fine soil and absorbent are respectively one and two thirds, and a thin layer of substrate covers up the eggs; it can also contain turf only.

The invention also relates to the use of snail raising device, preferably applied to the Algerian Petits-Gris, Helix Aspersa, Lucorum or Pomatia, consisting in the following phases: - During the mating and laying period, the temperature inside the said cells is kept at between 15 and 18"C; - Eggs are periodically taken and placed in incubating boxes in which a temperature H is kept for X days, X and 8 being variables and proving the report XB = 18 x 21; - During the infantile growth phase for approximately two to four weeks after hatching, the newlyborns are kept in the said incubating cells and are fed through the tube;; - During the juvenile growth phase, the upturned empty tub composing the said incubating cell is removed and the young snails are fed every 2 to 3 days, the temperature inside the cell being kept at between 15 and 18"C.

The result of the present invention is a new product constituted by a device and its use for breeding snails.

The main advantage of the invention is to provide an independent unit giving a maximum of "sticky" surface (along which move the snails) per square metre of ground occupied, the height of said unit being preferably that of a man, and this, in the optimum conditions for snails reproduction and fattening, of moisture, temperature, luminosity, volume, area, so that the animal spends a minimum of energy and puts on the maximum of weight, with the lowest possible death rate.

The design of these cells has been studied so asto give the aforesaid advantages whilst keeping costs to a minimum; standard sizes have been chosen; the cells can be easily assembled and dismantled to make up units varying in numbers depending on the requirements.

Atranslucent or transparent material, depending on the parts, has also been chosen, to allow certain wave-lengths to go through, which wave-lengths have an effect on the faculties of reproduction or development, and on the weight put on.

The recorded results show the advantage of the invention from an economical point of view. One cell produces in average 1,800 adult snails with a mortality of 300, throughout the fattening period.

The invention finds its application in the industrial breeding of snails and in particular the breeding of Algerian Petits-Gris and Helix Aspersa, Lucorum or Pomatia.

Other characteristics of the invention will become more obvious on reading the following description of an embodiment, reference being made to the accompanying drawings, in which: - Figure 1 is a cross-sectional view of a column of cells according to the invention; - Figure 2 is a longitudinal section of the said column shown in Figure 1, in a plane crossing the irrigation surfaces and their outlets; - Figure 3 is a longitudinal section of the said column crossing the boxes where the different stages of the breeding method have been shown.

Figure 1 shows a column of cells which is inde pendent and sealed, where we shall hereinafter conventionally designate (by way of non-restrictive example only), A, the back face, and B, the front face.

The column is divided vertically into two parts: a "moist" part occupied by superimposed irrigation surfaces 8, and a "dry" part occupied by boxes 7, which are also superimposed. The moist part is normally the mating place and the dry part is the laying place.

For a better permanent moisturing of the column, a water supply is provided at the top part 2 where a pipe, coming from source E and leading to a drip 10, allows the continuous spraying of the surfaces 8.

Preferably, said surfaces slope down in alternate sequence of direction as shown in longitudinal section in Figure 2. The path taken by the water is as shown by the arrows. The drip is situated at the top part, beneath the lid 2, as far as possible of the outlet 9 of the highest surface and it is then obvious that the path followed by the stream of water describes a zigzag and is thus the longest, ensuring a maximum rate of hygrometry. Moreover, the moist part is preferably situated above the water outlet 11. Another advantage of this superimposition of the irrigation surfaces is that the basins 8 are kept clean. These basins are where the animals deposit their excrements. It suffices then to send a stronger stream of waterthan the drip, into the top basin 8, to ensure the cleaning of all the basins and the discharge through 11.

Preferably, the "dry" part is composed, for each cell, of two boxes 7, situated on the same level. The level of the bottoms of said boxes 7 is higher than the level of the basin 8 of the same cell, illustrated in this embodiment. This arrangement should not be considered as an essential feature, but rather as an accessory one.

In the embodiment shown by way of a nonrestrictive example, each column is composed of six cells. It is constituted of two vertical sides 1 covered by a lid 2, and of six horizontal cross-members. Said cross-members form an angle piece 3 provided with a top (11') and lower (12) slotting permitting to lock the back doors 13 and to ensure the tightness of the column. A certain clearance is allowed in the groove 12 to release the door 13 from the slotting 11' by raising said door and pivoting it about a horizontal axis as shown by the arrows. The basins 8 then become accessible as well as the drawers which can be pulled towards the face B through the doors 14.

The possibility of locking the doors tightly is very important, first to maintain the hygroscopic rate necessary to a good development of the snails, and second to prevent the snails from escaping, the snails being known to try, at night time, to lift the said doors.

The same locking-by-slotting principle is applied to the doors 14 of the front face A. For each cell, the "dry" part comprises a horizontal plate 5, going from one vertical side 1 to the other. In the embodiment shown here, said plate comprises two rectangular recesses 6 which correspond to the dimensions of the sliding boxes 7, resting on guides 15 adjoining the horizontal plates and parallel to the sides 1. Said plates 5 comprise a bend 4, on the side of the front face B, to receive the upper part of the door 14 which is locked in position by the same slotting system as described previously for the back face A.

Thus a tightness is ensured which prevents the animals from escaping. The lid 2 ensures further tightness.

A preferred embodiment proposes to equip the back (13) and front (14) windows with vent holes of different diameters, depending on the size of the snails contained in the cells.

In order to prevent the small animals from escaping a variant embodiment proposes to place a kind of mosquitoe net, to coverthese holes.

The materials preferred are white translucid plastics, usable with foods, for all parts with the exception of the lid and the boxes which are made from a transparent material. The reason for this choice is to let the light through into the cells and also to be able to see the eggs deposited in the boxes. In addition, radiations are known of a wavelength favorable to spermatogenesis in adults and to growth in young snails. Such effects are obtained by a colouring of the plastic used.

For information, it is pointed out that wavelengths varying between 4,500 A and 4,900 A encourage mating and that wavelengths of 6,250 A speed up the maturity of the gonads.

Also noted is the influence of the height of each cell on the results obtained. Preferably, and following experimental tests, the heights selected for each cell is between 15 and 35 cm. And preferably also, the heights selected for the columns correspond to the height of a man.

The boxes contain a substrate. For those boxes which receive the eggs, the substrate has a height corresponding to the length of the snail's neck, i.e.

between 3 and 5 cm. Thus it is possible to see the eggs which are at the bottom of the box. To make it easier to count these eggs, a mirror 16 is provided in the egg boxes, which mirror is placed at a distance, beneath the bottom of the box.

The constitution of this substrate should enable a moisture to be retained without the water running freely. This is important in order to prevent the eggs cracking from osmosis. A preferred composition is fine soil, such as for example running soil, seed vegetable ground, river sand or compost, with a moisture absorbing agent such as vermiculite, perlite or turf, which latter can also be used on its own.

The boxes are preferably provided with vent holes, for example on the periphery of the bottom such as shown in 17 in Figure 3.

During incubation, a mini-cell, so-called incubating cell, is used, which consists of two boxes, one containing a substrate preferably composed as follows: one third of fine ground, two thirds of abso rbent, in order to ensure the retention of moisture for three weeks, and in which are placed the eggs, the second box, empty and upturned, covering up the first one. A perfectly closed-in area is thus obtained which encourages incubation. Such a mini-cell is shown in Stage (3) of Figure 3. Another possible substrate composition is turf on its own.

Preferably, a thin layer of soil of 1 cm at the most, covers the eggs in that cell.

A food supply device is provided preferably in the centre of the upper box, and consisting of a pipe 18 extended by a cone 19 arriving on a plate 20. A minimum of movement is thus required from the newly-borns who can have moisture and food without spending too much energy. This helps them to put on a maximum amount of weight in a cell which ensures the optimum reduced volume for this phase.

One advantage of such a device is that no specific equipment is required at each stage of the process.

The same boxes, in the same cells, are used for all ages.

The invention also relates to a special method for breeding snails, using preferably the aforesaid equipment.

It is known that the normal cycle of reproduction of snails consists in the four following phases: hibernation from October to January, mating and laying in the spring, slowed down life in summer and laying and mating season in the autumn.

The present application does away with the hibernation phase, by acting on those parameters which are essential to the development of the snails and which are: temperature and hygrometry. Preferably, this method has been tested on the Algerian Petits-Gris, HelixAspersa, Lucorum and Pomatia.

It was observed that the determining factors in such a breeding are in particular: the densities of mating, of laying, of infantile growth, of juvenile growth, the death rate, and the height of the cell.

These have governed the choice of the elements hereinabove described, as well as the characteristics of the present method. The different phases of the raising method in one column, are fictitiously illustrated in Figure 3. Indeed, the conditions not being necessarily the same, in particular where the laying and the incubation are concerned, the incubating cells should preferably be placed in anothercol- umn than the one where the laying and mating take place, for example. If the incubation takes place in the same column as the laying, then it will suffice to cause X to vary so that with 15 < 0 < 1 8 C, X0 = 18 x 21.

In 1, in the boxes containing the substrate such as described hereinabove, the laying preferably takes place at a temperature varying between 15 and 1 8 C.

Said temperature is kept inside the columns, and outside it is cooled by - 2"C by ventilation for 2 mins.

A condensation is then obtained on the walls of the cells, from which condensation the snail will drink.

Said snail will thus have a minimum way to go to find the water it needs. In parallel the mating will take place in the "moist" parts of the irrigation surfaces, in the same operational conditions and in the same cell 1. Such reductions of the outside temperature by -2 C compared with the temperature inside the cells are experimentally determined when the need is felt to cause a moisture on the walls of the cells.

In 2, the eggs are selected and deposited periodically (about every fifteen days). To this effect, they are counted in the boxes situated in 1 due to the transparent bottom of these boxes and possibly also to the mirrors 16.

Statistics show that there are about 100 to 200 eggs in average per laying. Preferably, lotto 12 layings are taken for each incubation box. The minicells and the substrate of preferential composition described hereinabove are used and the eggs are deposited therein, spaced apart so that they do not eat one another.

The eggs are then covered with a small layer of soil. The newly-born should only have a minimum path to go through (s1 cm).

In 3, the minicell is constituted. A temperature of 0 C is kept therein for X days, X and 0 being the variables determined by the relation X.O = 21 x 18.

The infantile period comes immediately after incubation and lasts between two and four weeks approximately after the eggs have hatched. It takes place in the same minicell with the feeding means described hereinabove, at a temperature varying between 150 and 18"C.

Food in powder form is fed through the device 18, 19, 20 as described hereinabove. The food distribution is progressive and is localized in a central point, requiring from the newly-borns a minimum of energy. Moreover, the vents 17, provided on the periphery, give the necessary ventilation, and the condensation which is created on the walls inside the minicell gives an adequate moisture to the population of eggs enclosed therein. An identical increase of weight is recorded for all the newlyborns at the end of this phase. The advantage of a restricted space is for example to reduce to a minimum the energy spent for feeding.

At the end of this phase of infantile growth, the upper box which is used as the lid of the minicell is removed and placed next to the first box, under the same support as shown in 4.

The volume in the cell is thus increased without the animals having to be handled or moved.

Then, the phase of juvenile growth starts. The food is placed on the support plate between the two boxes, in 21 for example, preferably every two or three days, the temperature inside the cell being kept at between 15 and 18"C.

Claims (23)

1. A device for breeding snails comprising at least one independent column of superimposed cells, wherein the said column comprises, at its upper part, a means for supplying water to the inclined irrigation surfaces, which are arranged one above the other and which are moistened by the said water supply, each cell having its own irrigation surface and at least two boxes.

2. A device as claimed in claim 1 wherein the said irrigation surfaces of middle cells slope down in alternate sequence of direction, so that the draining outlets of the said surface are aligned vertically in pairs.

3. A device as claimed in any one of claims 1 and 2, wherein the said boxes intended for the laying of snails eggs contain a substrate which is between 3 and 5 cm high approximately.

4. A device as claimed in any one of claims 1 to 3, wherein the said boxes contain a substrate com posed of fine soil preferably selected from the follo wing group of products: running soil, vegetable seed ground, river sand, compost, and a moisture absorbing agent, preferably selected from the follo wing group of products: perlite, vermiculite, turf.

5. A device as claimed in any one of claims 1 to 4, wherein the said boxes are provided with a mirror arranged at a slight distance from the bottom of said boxes in order to reveal and count the eggs con tained in the said substrate.

6. A device as claimed in any one of claims 1 to 5, wherein the said boxes are made from a transparent material and comprise air vents.

7. A device as claimed in any one of claims 1 to 6, wherein the said boxes are mounted to slide on horizontal cross-members.

8. A device as claimed in any one of claims 1 to 7, wherein each cell comprises at least one vertical door sealingly locked in position in horizontal slottings.

9. A device as claimed in any one of claims 1 to 8, comprising at least one incubating cell consisting of a box containing a substrate wherein the layings are deposited, after being removed from a laying box, and of an empty upturned box covering up the first box.

10. A device as claimed in claim 9, wherein the said incubating cells contains a substrate of which the approximate proportions of fine soil and absorbent are one third and two thirds respectively.

11. A device as claimed in any one of claims 9 and 10, wherein a layer of soil 1 cm thick at the most covers up the said layings.

12. A device as claimed in any one of claims 9 to 11,wherein the said incubating cell is used for the infantile growth of the newly-borns and wherein a tube containing food in powdered form crosses through the empty box in its center.

13. A device as claimed in any one of claims 1 to 12, wherein the upper part of the column is made from a transparent material and wherein the other faces are made from a translucent material.

14. Application of the device such as claimed in any one of claims 1 to 13, wherein a temperature of between 15 and 18"C is kept inside the said cells throughout the mating-laying period.

15. Application as claimed in claim 14 wherein the temperature outside the said mating-laying cells is cooled down by -2"C compared with the temperature inside said cells thereby creating a condensation on the walls of the said cells.

16. Application as claimed in any one of claims 14 and 15 of the device such as claimed in any one of claims 9 to 12, wherein the eggs laid are taken up periodically and deposited in incubating boxes where a temperature of 0 is kept for X days, such that X0 = 18 21.

17. Application as claimed in claim 16, consisting in covering up the said eggs with a layer of soil 1 cm thick at the most.

18. Application as claimed in any one of claims 16 and 17, wherein the eggs are deposited in the said incubating boxes every 15 days approximately.

19. Application as claimed in any one of claims 14 to 18, which further comprises an infantile growth phase over approximately two to four weeks after hatching, and wherein the newly-borns are kept in the said incubating cells, which are crossed through by a feeding tube, preferably in their centre.

20. Application as claimed in any one of claims 14 to 19, which further comprises a juvenile growth phase wherein the empty top box which constitutes the incubating cell is removed and the young snails are fed every 2 or 3 days, the temperature inside the sard cell being kept at between 15and180C.

21. Application as claimed in any one of claims 14 to 20 wherein Petits-G ris of Algeria, Helix Aspersa, Helix Lucorum, Helix Pomatia are bred.

22. A device substantially as hereinbefore described and illustrated with reference to the accompanying drawings.

23. An application of the device such as hereinbefore described and illustrated with reference to the accompanying drawings.