Salinity and density in rearing Goby

The study of the effect of salinity on the rearing of goby fish from 10 to 45 days old was carried out at An Nghia Fisheries Station, under the Department of Fisheries of Ho Chi Minh City. Ho Chi Minh City, An Thoi Dong Commune, Can Gio District, Ho Chi Minh City.
Goby (Oxyeleotris marmorata Bleeker 1852) freshwater fish of high economic value. Currently, in addition to natural living they are artificially raised for the purpose of economic. However, in the process of rearing goby goby, there are still many difficulties, obstacles on breeds, food, farming techniques and diseases, of which the most difficult problem is goby breeding. Although successful in the production of Goby breeds, the survival rate was low, especially the period after deposition of the yolk until 30 days of age (31.9%). Recognizing the advantages of this species, it can survive in brackish waters where salinity ranges from 4 to 15 per thousand and less prone to ulcer syndrome, compared to culture in pure fresh water.
Therefore, this study was conducted with the aim of raising the survival rate as well as improving the growth rate of Goby, especially the period from 10 to 45 days of age by determining salinity and rearing density. suitable.
Experimental arrangement
Experiment 1: Surveying the effect of salinity on the rearing of Goby
10 - 45 days of age: fish are 10 days old, stocked with salinity for each treatment, in NT 2, 3 and 4: 3 days increased by 5 ppt until the salinity of each treatment was reached.
- Treatment 1 (NT1): 0 ppt salinity
- Treatment 2 (NT2): Salinity of 5 ppt-
- Treatment 3 (NT3): Salinity 10 ppt
- Treatment 4 (NT4): Salinity of 15 ppt
Experiment 2: Surveying the effect of density on raising Goby at salinity of 10ppt
Phase 3 - 30 days old
- Treatment 1 (NT1): 5 animals / L
- Treatment 2 (NT2): 10 animals / L
- Treatment 3 (NT3): 15 individuals / L
- Treatment 4 (NT4): 20 individuals / L,
Period of 30-45 days old
- Treatment 1 (NT1): Density 150 individuals / m2
- Treatment 2 (NT2): Density 200 individuals / m2
- Treatment 3 (NT3): Density 250 individuals / m2
- Treatment 4 (NT4): Density 300 individuals / m2.
Experimental results show that raising gobies during the period of 10 to 45 days old in an environment with a salinity of 10 ppt is the most suitable, the fish reared in this treatment have the highest growth rate and weight. At the same time, the survival rate of this treatment reached the highest value (NT3) reaching 92.37% while the 0 ppt treatment (NT1) had the lowest survival rate of 14.60%, followed by 5 ppt (NT2) is 51.43% and at 15 ppt (NT4) is 86.80%.
In the period of 3 - 30 days of age, Goby fingerlings with density of 15 individuals / L reach the highest economic efficiency.
In the period of 30-45 days of age, at the density of 150 individuals / m2 (NT1), the highest growth with the length and weight were 23.9 mm and 252.0 mg, followed by the treatment with Density of 200 fish / m2 (NT2) with length and weight are 23,3 mm and 249,2 mg, respectively.
The survival rate of fish in the period of 30 - 45 days of age showed quite high results, ranging from 71.8 to 92.6%. In which, NT4 treatment (71.8%) was lowest and different from the other treatments. The remaining treatments were NT1 (92.6%), NT2 (91.0%), NT3 (84.4%) were correlated to catch each other, although NT1 and NT3 were completely different.
Here NT1, even though the results are the best and higher than NT2, but because the difference is not significant with NT2, we choose NT2 treatment as the best treatment because the economic value is higher (200 birds / m2 compared to 150). fish / m2). Therefore, when nursing gobies from 3 - 30 days old, they should be stocked at a density of 15 fish / L and in the period of 30 - 45 days of age, they should nurse 200 fish / m2 to bring the best economic value.
Updated on 23-12-2019
According to Science and Technology Journal of Agriculture and Forestry.