8 Ways On How To Prevent Catfish Fry Mortality

A lot of people have been asking questions and are eager to find reasonable answers to why they record fry mortality almost every time in their catfish farm. Well, there are several reasons why newly hatched fish die. In today’s post, we will look at some of the causes of catfish fry mortality and how you can reduce mortality in catfish fry.

We had earlier published content on the causes of catfish mortality which was basically for general knowledge, but we will focus only on the newly hatched (fries) in this post. Before we look into how to prevent catfish fry mortality let’s find out what leads to the mortality itself.

What Is Catfish Fry?

Catfish fry are the newly hatched catfish. They are small, just a few millimeters long, and have a yolk sac attached that provides them with nutrients until they can start feeding on their own.

Basically, they are called fries between 7-10 days when they have not developed to the point where they are capable of feeding themselves. Catfish fry are very delicate and vulnerable at this first stage.

Causes of Catfish Fry Mortality

What causes catfish fry mortality? What are the factors that could cause mortality in fish fry? These questions and many more will be answered in this part of the post.

Many catfish farmers face the challenge of fry dying in their nursery ponds. This can be frustrating and can happen to any catfish species, be it clarias, or hybrids. Some of the possible reasons these happen are as follows:

Inadequate Preparation of the Pond

Fish farmers’ inability to prepare their nursery posts before hatching has been one of the major causes of fry mortality in most farms.

It’s often noticed that farmers, particularly newcomers, are eager to stock up quickly, sometimes overlooking crucial preparation processes. This eagerness might stem from their excitement about anticipated profits or simply from a lack of knowledge in the initial stages.

Before introducing each batch of fries into a new pond, you should clean the pond horoughly. This precaution is necessary in case there are algae, ammonia, or decayed feces from prior harvests.

The standard protocol involves diligently preparing the pond by washing and neutralizing any substances that could potentially harm your catfish fries, even before the hatching process commences.

When using newly purchased tarpaulin ponds or newly built concrete ponds, they may contain chemicals from their production, posing potential risks and acting as death traps for your fish.

What do you do at this stage? Thoroughly wash these ponds with either salt or dried leaves and allow them to dry completely before making use of them.

Feeding on the First Day

Newly hatched catfish fry with a transparent or whitish sack under their belly. If you have observed this without understanding why it is there, tell us how you felt in the comment box below.

These sacks serve as a source of food for the fry in their early days. Their body absorbs the nutrients contained in the sack to support their initial growth and development. Therefore, feeding them while these sacks are still visible can lead to overfeeding, which could be a major cause of catfish fry mortality.

To prevent overfeeding at this initial stage, it is recommended to allow the fries to absorb the nutrients from the sack for at least the first 24 hours before offering any additional food.

We’ve previously discussed the implications of overfeeding in our article on the causes of catfish mortality, so be sure to see that for further information.

Uncovered Ponds

The reason for having your ponds 80% covered and netted is to maintain a dark atmosphere in the pond and to prevent flies, lizards, birds, etc. from feasting on them.

You may ask why the dark environment? If newly hatched fish are exposed to direct sunlight that early, it could cause blindness to many of them. Now you understand.

Overstocking

We cannot stop talking about the danger of overstocking on this website. Since the catfish fries are tiny, does overstocking the pond mean anything? The answer to that question is Yes.

There are different sizes of ponds and wisdom demands that you know the capacity of your pond before you stock.

Our guide on stocking density of catfish in concrete ponds and plastic tanks will show you the mathematics of stocking. To prevent catfish mortality, especially at the fry stage, you must first understand how to do proper stocking.

Remember that few weeks after you have stocked, they will start growing and the space will choke them leading to most of them dying.

Starvation

By the time the fries absorb the sack we talked earlier, you need to start feeding them at least three (3) times daily. The essence is for them to have enough nutrients to start growing.

You should not overfeed do not mean that they should starve. Starvation increases the rate of mortality. So, if you still wonder why your catfish fries are dying after meeting other conditions, then is time to revisit how you feed them.

Pond Size

Does pond size matter in catfish fry management? YES. This is why it is advisable to use a nursery pond when raising your fries.

Nursery ponds are usually 3 feet in depth which is best for fries. The general idea is not to let the water in the pond exceed above 3 feet. At the fry stage, the fish finds it difficult to swim around any depth that is more than 3 feet.

Inbreeding

Inbreeding as we had explained in the previous posts is the mating of relatives or the mating of fish that are closely related.

Hatching male and female fish that are of the same parents is inbreeding. Research has shown that inbreeding affects the immune system functions of the fish, decreases fish growth, reduces fertility, and finally results in mortality. It also increases the right of deformity in the fish.

Here is a breakdown of the effects of inbreeding:

• Reduced immune system: Inbreeding can lead to less genetic diversity, making fish more susceptible to diseases and parasites.
• Slower growth: Fish from inbred parents may grow slower and have a smaller overall body size.
• Lower fertility: Inbred fish may have difficulty reproducing, producing fewer eggs or sperm, or having a higher rate of infertility.
• Increased deformities: Inbreeding can lead to higher rates of birth defects and abnormalities in the fish.
• Higher mortality: All these factors combined can contribute to a higher mortality rate among inbred fish.

Summary of How to Prevent Catfish Fry Mortality

Here are some guidelines to ensure the successful rearing of catfish fries:

1. Thoroughly wash and dry your pond(s) to eliminate any harmful bacteria that could threaten the newly hatched fish.
2. Refrain from feeding the fries for the initial 24 hours after hatching to prevent overfeeding.
3. Regularly monitor their growth to determine the appropriate time to begin sorting, thus minimizing the risk of cannibalism.
4. Avoid overstocking your pond, as overcrowding can lead to stress and subsequent mortality among the fries.
5. Feed the fries appropriately to prevent starvation, a significant cause of catfish fry mortality. Understanding the feeding regimen is essential for their well-being.
6. Utilize nursery ponds for growing your fries, as they are smaller and easier to manage, providing a conducive environment for the fry’s development.
7. Maintain the water level in the pond at a maximum of 3 feet. Newly hatched fish cannot swim beyond or below this depth.
8. During the hatching process, refrain from using male and female fish that are closely related, as this can increase the likelihood of losing your catfish fries.

Final Note

There are other reasons why catfish fries die that we may not have discussed in this post. Kindly use the comment section or box to tell us the ones you know that you feel should have been included in the post.

However, there are benefits of catfish farming, so do not lose your passion due to losses you might have experienced.

Ammonia, nitrite, water quality, and temperature imbalance are other factors that cause catfish fry mortality. The eight suggestions above on how to prevent catfish fry mortality will go a long way in solving the problem of mortality in our various farms.

Do you think that broodstocks immaturity could be a cause? Tell us what you feel.

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