"Half dead in the bolding stage"
This sentence reveals the heartache of so many people in the aquatic products industry
The mandarin fish, with its delicious meat and rich nutrition, is known as the "gold of water". However, the mortality rate of mandarin fish during the juvenile stage is often as high as 50% to 70%, causing heavy losses to countless farmers.
Today, after a deep analysis of dozens of successful cases, we have summarized the five major survival barriers for mandarin fish fry and the corresponding secrets to breaking through.
Challenge One: Opening bait
The "first bite of food" for mandarin fish fry is extremely important, but there are many problems:
Natural baits (water fleas, rotifers) are nutritious but their supply is unstable
Artificial feed is convenient but has poor palatability
Live bait (such as wheat ear fish, etc.) has a high risk of carrying diseases
Solution:
"Three-stage Feed Transition Method"
Opening period (3-10 days of age) : Cultivate high-density rotifers and feed with egg yolks
Transition period (10-20 days of age) : Live feed should be disinfected before feeding
Domestication period (after 20 days of age) : Gradually incorporate artificial feed
Challenge Two: Water quality Management
The mandarin fish fry have overly sensitive requirements for water quality: they need high dissolved oxygen (>5mg/L) but are afraid of strong water flow; they prefer clear water but a lack of algae will lead to a shortage of feed organisms.
Solution:
The golden combination of "micro-flow + biological regulation" :
Install a slow-flow aeration system (waterwheel aeration machine is the best)
Supplement EM bacteria weekly to maintain the balance of the algal flora
The water temperature should be controlled at 25-28℃ (with a fluctuation of less than 2℃ per day).
Difficulty Three: Self-harming behavior
The inherent "big eater" nature of mandarin fish leads to mutual eating when the size difference exceeds 30%, and the self-harm rate surges in a state of hunger, creating a vicious cycle
Solution:
The "Four Unifications" management rule:
Uniform specifications: Regular screening and grading
Uniform density: <500 tails /m³ in the initial stage, <200 tails /m³ in the later stage
Uniform feeding: 6 to 8 times a day to ensure satiety
Uniform lighting: Maintain a light intensity of 2000-3000lux
Challenge Four: Disease Prevention and Control
Three fatal diseases during the roughening period:
Iridovirus disease of mandarin fish (mortality rate >90%)
Trichoplasmosis (high secondary infection rate)
Enteritis (caused by inappropriate feed)
Solution:
"Prevention first, precise strike" strategy:
Vaccine immersion (such as inactivated vaccine for mandarin fish hemorrhagic disease)
Take a salt water bath twice a week (3‰ concentration, 10 minutes each time)
Mix and feed probiotics (a combination of lactic acid bacteria and yeast)
Challenge Five: Stress Response
The stress response of mandarin fish fry is often overlooked, but it is a hidden killer:
A water change temperature difference of more than 3℃ may cause large-scale deaths
Direct exposure to strong light can cause food intake to stop
Solution:
"Five-degree Management Method"
Temperature: The temperature difference between water changes is ≤0.5℃
Light intensity: Avoid direct sunlight
Dissolved oxygen content: Maintain at 5-6mg/L
Ph: 7.0-7.8
Salinity: Maintain 2-3‰
Although it is difficult to roughen mandarin fish fry, as long as you master the correct methods and skills, you can turn the difficult into the easy and make your mandarin fish farming business thrive.