JP3168223B2 - How to process fish eggs - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for treating fish eggs for producing fish seedlings.

[0002]

2. Description of the Related Art As a problem in breeding and managing hatched fish eggs such as salmon and trout, prevention of occurrence of water mold caused by aquatic fungi attached to dead eggs is an important issue. In fact, frequent disinfection with malachite green was carried out.

[0003]

Recently, however, the problem of carcinogenicity of malachite green has been pointed out, and its use has been banned. However, no new effective means has been found yet, and it is as soon as possible. At present, the emergence of an alternative safeguard is desired. In view of these circumstances, the present inventor has conducted various experimental studies on ozone having a bactericidal action. As a result, ozone is not very effective against aquatic fungi (genus Mizuki sp.) An object of the present invention is to provide a method for treating fish eggs which is effective for aquatic fungi without affecting hatching and in which the eggs are bred and managed.

[0004]

In order to achieve the above-mentioned object, the present invention provides a method for producing fish eggs at a saturated dissolved concentration of ozone in water of 6 days a day.
They are kept for more than an hour.

[0005] The concentration of ozone in the saturated solution in water varies depending on the water temperature. However, the water temperature for breeding and controlling fish eggs is 5 ° C to 20 ° C, and is about 0.1 to 0.2 ppm.

As a basis for performing the treatment of ozone for 6 hours or more per day in the present invention, the present inventor conducted an experiment on the relationship between the length of aquatic fungi in aerated ozone water and the aeration time per day. By performing aeration treatment for at least 6 hours per day as shown in FIG. 1,
It was confirmed that aquatic fungi can be suppressed to a degree that does not adversely affect the breeding management of fish eggs. In addition, the change in hatchability in ozone aerated water according to the content of dead eggs of chum salmon was measured, as shown in FIG. 2. Is based on the finding that the hatchability can be maintained at 75% or more.

[0007] Based on these new findings, the present invention treats fish eggs at a saturated dissolved concentration of ozone in water for 6 hours or more per day, thereby reducing dead eggs during breeding management of fish eggs with high-concentration ozone water. The present invention is intended to efficiently inhibit the occurrence and growth of attached aquatic fungi and improve the hatching rate of fish eggs.

[0008]

EXAMPLE The temperature of a circulating breeding aquarium having a size of 1.6 × 0.8 × 0.5 m was maintained at 13 to 17 ° C., and white salmon laid eggs (in a flowing water method by a standard method until the eye formation stage) were placed in water. 1kg (approximately 2000 tablets) is added, and 300mg of ozone
Per hour (saturated dissolved concentration: 0.12 ppm) was supplied for 8 hours per day, reared for 12 days, and hatched. The hatching rate was 94.4%.

FIG. 3 shows a specific embodiment of the present invention, in which ozone from an ozone generator 1 is dissolved in water in an ozone tank 4 by an ozone diffuser 3 via a washing tank 2. Water is supplied to the breeding aquarium 7 by the pump 5 via the filter tank 6 and is circulated by returning to the ozone tank 4 by the siphon tube 8.
Fish eggs are bred in a breeding aquarium 7 in a basket 9 or the like. In the figure, reference numeral 10 denotes an ozonolysis filter.

[0010]

According to the present invention, the generation and growth of aquatic fungi attached to dead eggs generated during the hatching and breeding of fish eggs can be simplified by treating them with a saturated dissolved concentration of ozone for 6 hours or more per day. By this means, the hatching rate can be improved by reliably suppressing the hatching, and fish seedling production can be carried out efficiently.

[Brief description of the drawings]

FIG. 1 is a chart showing changes in the length of aquatic bacteria in ozone aerated water.

FIG. 2 is a chart showing hatching rates of chum salmon in ozone aerated water according to dead egg content.

FIG. 3 is a front view of a breeding aquarium embodying the present invention.

Continuation of the front page (58) Fields investigated (Int. Cl. ⁷ , DB name) A01K 61/00 A01K 67/00 BIOSIS (DIALOG) JICST file (JOIS) WPIDS (STN)

Claims (1)

(57) [Claims] 1. A method of treating fish eggs, comprising treating fish eggs with a saturated dissolved concentration of ozone in water for 6 hours or more per day.