CATDOLL : CATDOLL: The crucian carp I bought today had a lot of yellow egg-like objects (light yellow) around its gills and even in the fish meat. What are those things?

1. The crucian carp I bought today has a lot of yellow egg-like objects (light yellow) around its gills and even in the fish meat. What are those things?

Yes, it is a parasite, a sporozoan. Follow-up question: Can this fish be eaten? Answer: No!

2. What is the disease with a lot of mud in the gills of crucian carp?

Gill rot.

Gill rot is mostly caused by parasitic infestation or bacterial infection, so there are two types of gill rot: parasitic gill rot and bacterial gill rot.

(1) Parasite-induced gill rot: The pathogen is ringworm or wheelworm. They cross-infect each other, causing obvious swelling of the gills and difficulty in opening the gill cover. In severe cases, the gill filaments are partially ulcerated, exposing the gill cartilage, making it difficult for the fish to breathe and eventually die. Prevention and control methods: 0.5-0.8 grams of crystal trichlorfon can be used, put in 10 kilograms of water, and soak the diseased fish for 10-15 minutes. You can also use 0.2 grams of crystal trichlorfon, 0.2 grams of copper sulfate, and 0.2 grams of iron sulfite, mix them in 10 kilograms of water, and soak the diseased fish for 10-15 minutes. Or you can use 0.2-0.3 grams of crystal trichlorfon dissolved in water, sprinkle it in 1 ton of feed water, and use the medicine 1-2 times a week to effectively kill parasites in the water.

(2) Bacterial gill rot: The pathogen is Saprolegnia. The gill filaments of the diseased fish are severely damaged and lose a lot of blood. The gill filaments turn white. In severe cases, flocculent hyphae adhere to the gills. The mortality rate is very high. Prevention and control methods: 50 grams of salt and 50 grams of baking soda can be mixed in 10 kilograms of water and the diseased fish can be soaked for 15-20 minutes. You can also use 0.7 grams of malachite green, put it in 100 grams of water, and soak the diseased fish for 15-30 minutes.

(3) Myxosporean gill rot: The pathogen is myxosporean. Many grayish-white spots or cysts visible to the naked eye will appear on the gill filaments, which grow from small to large and damage the fish gills. Once the cysts rupture, countless spores enter the feed water and re-invade the gills of healthy fish. The gill filaments lose blood and cause large-scale deaths. Gill rot caused by myxosporean is relatively rare. Prevention and control methods: Use the juice soaked in the bark of a three-year-old maple poplar tree, absorb an appropriate amount, put it in ten kilograms of water, and soak the diseased fish for 5-10 minutes.

You can also use 150 grams of ammonia water, put it into 10 kilograms of water, and soak the diseased fish for 5-10 minutes. Repeated use of the medicine will be effective.

(4) Myxococcus gill rot: The pathogen is myxococcus. The gill filaments of diseased fish are ulcerated and covered with a lot of white mucus. In severe cases, the gill filaments are corroded into small holes, the cartilage is exposed, and the mortality rate is very high. Prevention and treatment methods: 1-2 grams of furazolidone can be used, dissolved in 10 kilograms of water, and the diseased fish can be soaked for 15-20 minutes. High-concentration salt water can also be used to soak the diseased fish for 15-20 minutes. You can also use 11.5% concentration of chloramine 0.05 grams and 0.2 grams of furazolidin, mix them and put them in 10 kilograms of water. Multiple use of the medicine has a good effect.

3. There are white particles on the gills of crucian carp. Can this fish be eaten?

Yes, it is a male fish. Male fish have small white spots on their front fins and gill covers, which are called "star chasing". Female fish do not have them.