Why Won’t my Swordtail Eat?

For the past few days, I have been noticing an unusual behavior in my swordtails; they are not eating properly and whenever I open the tank to add food, the previous meal is already there, untouched and decaying.

So, why won’t my swordtail eat? Being an omnivorous fish, swordtail in your aquarium can eat processed fish food or natural plants but if it is rejecting the usual food, then it may be due to several factors like pregnancy, sickness, stress or overfeeding.

In this article, I’d like to put some light on the feeding nature of swordtails and discuss the reasons for their rejecting food and how to fix it.

Why aren’t my fish eating? (Video)

What does a swordtail eat?

The swordtail fish are basically omnivores. In wild, they feed on insects, invertebrates, plants, or algae. So, if you are keeping them in the home aquarium, then you have to make sure that they are getting their proper diet (similar to that which they require in the wild) to live a healthy and stress-free life. You can feed them two kinds of foods inside the aquarium

1: Natural food

They can be fed natural or live foods like:

  • Plants
  • Algae
  • Live worms like Fruit flies, mosquito larvae, bloodworms or daphnia etc. (they are available in frozen form as well)

Live plants or algae inside the tank would mimic and recreate the natural environment of the swordtails.

2: Processed food

As processed or frozen food options, you can feed them:

  • High-quality flakes
  • Blanched vegetables like zucchini medallions, shelled peas, broccoli etc. (Blanch the vegetables by boiling in water and let them cool down before putting them inside the tank.)

You need to feed them according to their habitual nature, make sure that you are adding an ideal mix of vegetation and protein inside the tank. These foods will ideally satisfy their diet needed to live an active life inside the aquarium.

Why does a swordtail stop eating?

A swordtail is capable of showing this unusual behavior to stop eating at all. Now there are many reasons why a swordtail is doing this. Following is the list of reasons that might be causing your swordtail to not eat at all:

  • Pregnancy
  • Over-eating
  • Sickness
  • Fear
  • Stress

Let’s move towards the description of the above-mentioned reasons and find out how to fix them

1.   Pregnancy

Almost all the live-bearing fish eat lesser than usual when they are near to giving birth. Swordtail fish exactly does the same. Starting with a disturbed eating behavior, it will eventually stop eating when it gets close to giving birth.

Check for the signs of pregnancy, which are a swollen belly and gravid spots on the abdomen of fish. If your not-so-hungry fish is pregnant, then it explains the behavior and you should move the fish to a separate breeding tank where it can have protection and privacy to give birth.

2.   Sickness

When a healthy and active swordtail suddenly stops eating, then it could be an alarm of sickness. To determine the condition of your fish, pay attention to its overall behavior. If the fish is staying at one corner of the tank, showing very small movement, swimming abnormally or appearing tired or listless then it is an indication of some health problem.

The sick fish may start to swim on one side of their body. Sometimes old fish do the same because of progression of age. After consulting with an expert, you can treat such illnesses.

3.   Stress

A stressed swordtail may reject the food due to its mood swings. But what causes stress among fish? Swordtail can get stressed by:

  • Poor tank conditions: If the tank water is not cycled regularly then the tank gets dirty and the level of ammonia increases which makes the fish anxious.
  • Temperature: A sudden and drastic change in the tank’s temperature can lead to stress in the fish.
  • Moving: If fish are moved from one tank to another frequently, then they get temporarily stressed, resulting in an eating disorder
  • Addition of new fish inside the tank: If new fish are added inside the tank, the swordtail may take some time to accept them. This can also result in behavioral change and fish can stop eating due to this.

You can control the stress on your swordtail by keeping them under ideal tank conditions and conduct water cleaning in regular intervals rather than conducting complete tank cleaning in a single go. Also, avoid adding extra fish inside the aquarium until you get a bigger tank for containing them properly.

By taking care of these little tank rules and parameters, you can keep your fish stress-free.

4.   Fear

Swordtail has a very peaceful nature. It neither creates nor accepts any kind of violence, so if your fish is frightened, then it might stop eating. It happens in a community tank where bigger fish frighten the smaller ones. If you are keeping different breeds of fish together, then make sure they are equal in size and get along with each other.

The swordtail fish can be kept with other live-bearing fish of the same size like platies, mollies or guppies. All these fish have similar behavior and size.

5.   Over-feeding

When you feed your swordtail, make sure you are adding a normal amount of food in the tank at a time. If you are adding more than the required food, then the fish would eat it all at once which results in overeating. An overfed fish might get sick and stop eating afterward. That’s why you should read the instructions on the food box carefully and add the recommended amount of food portion for one meal.

Fish can meet their dietary requirements in just five minutes of consuming. After that, remove the left-over food from the tank. It would prevent the food particles to break down inside the aquarium and affect the water quality. An even better option is to only drop in enough food for the fish that they can consume within 3-5 minutes so you would not have to clean the tank for left-over food.

Housing swordtails

The swordtail fish is more or less an average-sized fish but considering their active nature, they need a large-sized aquarium to live comfortably. A 10-gallon tank can accommodate just 1-2 swordtails inside it and if you want to add more fish, then you should increase the tank size accordingly. It is possible for the swordtail to jump quite high and out of the tank, so you must cover the tank surface with a lid at all times.

An improper housing can also lead the fish towards an eating disorder.

Related questions

Is it safe to put a pregnant swordtail in a breeding trap? It is suggested not to put a swordtail inside a breeding trap because keeping them in a narrow space might increase their stress levels. The risk of early birth increases due to such stress and this might cause complications in the birthing process. So, you can just move the pregnant fish to a separate tank where it can freely move around. Once the fry is born, you can move the mother back to its original tank to keep the fry safe as the adult swordtails can eat their own fry.

What is the proper amount to feed your swordtail? The only way to figure out the proper amount of food for your fish is to observe them. Add a little food first and watch your fish eating it. You can increase the amount of food depending on how much your fish eat but bear in mind to only drop in enough food which can be consumed within 3-5 minutes. Fish will often keep eating excessively as long as you provide them with food so keep a regular tab on the eating behavior of your fish.


Other sources

Leave a Comment