Why Is My Angelfish Twitching? (5 Ways To Fix This)

Disclosure: When you purchase something through my affiliate links, I earn a small commission. As an Amazon Associate, I earn from qualifying purchases.

Observing angelfish, usually peaceful fish, abruptly twitching and jerking their bodies can be quite alarming. That’s certainly what I thought when I first saw this behavior in my fish tank.

Through time, I’ve come to understand that twitching in angelfish has various reasons, each with specific solutions.

In this piece, I’ll guide you through the reasons behind angelfish’ shaking and show you how to address it efficiently.

Let’s dive straight into it.

What Is Twitching in Angelfish?

Twitching in angelfish is often a sign of distress or illness; it’s a behavior where they exhibit rapid, jerky movements or shudders.

While occasional, brief twitching can happen in healthy fish due to minor irritants or sudden changes in their environment, consistent or severe twitching is not normal and usually indicates a problem.

I’d advise closely monitoring the water quality and the fish’s overall health if you notice twitching, as it could be a sign of issues like parasitic infections or poor water conditions.

What Causes Twitching in Angelfish?

Several factors can cause your angelfish to twitch. Here’s what you should know:

1. Parasitic Infections

Parasitic infections, such as Ich or other parasites, can cause twitching in angelfish as these organisms irritate or invade the fish’s body.

This irritation leads to spasmodic movements as the fish tries to dislodge the parasites.

  • Irritation: Parasites like Ich cause severe itching and discomfort, leading angelfish to twitch in an attempt to relieve the irritation.
  • Physical Distress: The parasites can physically damage the fish’s skin and gills, causing twitching due to pain and discomfort.
  • Identification Tip: Look for small, white spots on the skin, fins, and gills, which are a common sign of parasitic infections like Ich.

2. Poor Water Quality

Poor water quality, including high levels of ammonia or nitrites, can stress angelfish, leading to neurological and physical responses like twitching.

Toxins in the water affect the fish’s nervous system and overall health.

  • Toxicity: High ammonia or nitrite levels in the water can lead to neurotoxicity, causing nervous system issues and resultant twitching.
  • Stress Response: Poor water quality can induce stress, weakening the fish’s immune system and leading to erratic movements.
  • Identification Tip: Regular water testing for ammonia, nitrite, and pH levels can indicate poor water quality; look for any deviation from optimal parameters.

3. Nutritional Deficiencies

A lack of essential nutrients in the diet can cause health problems in angelfish, including twitching.

This is often due to a lack of vitamins or minerals crucial for nerve and muscle function.

  • Muscle Weakness: Deficiencies in key nutrients can lead to muscle weakness or spasms, manifesting as twitching.
  • Nerve Function: Essential vitamins and minerals are crucial for proper nerve function; deficiencies can cause neurological symptoms like twitching.
  • Identification Tip: Examine the diet for variety and balance; lack of color vibrancy and slow growth can also indicate nutritional deficiencies.

4. Stress

Stress, whether from overcrowding, aggressive tank mates, or environmental changes, can trigger twitching in angelfish as a stress response.

This is a reaction to the discomfort or fear caused by stressful conditions.

  • Fight or Flight: Stress triggers a fight-or-flight response, leading to erratic movements like twitching.
  • Hormonal Changes: Stress can cause hormonal imbalances, affecting the fish’s behavior and causing twitching.
  • Behavioral Changes: Observe for skittishness, hiding, or aggression, which are common signs of stress in angelfish.

Also Read: Stress In Angelfish

5. Neurological Disorders

Neurological disorders, though less common, can cause twitching in angelfish. These could be due to genetic issues, injuries, or infections affecting the brain or nerves.

  • Brain Function Impairment: Any impairment in brain function due to disorders can lead to involuntary movements or twitching.
  • Nerve Damage: Damage to nerves, possibly from injury or infection, can disrupt normal muscle control, causing twitching.
  • Sudden Onset: A sudden onset of unusual behaviors, such as imbalance or disorientation, can indicate a neurological issue.

How Do You Treat a Twitching Angelfish?

If your angelfish continuously twitching and shaking its tail, follow these steps:

1. Medication for Parasitic Infections

Treating parasitic infections in angelfish requires specific medications to target and eliminate parasites. Correct diagnosis is key to select the right treatment and avoid harm to the fish.

  • Medication Choice: Opt for copper-based treatments or formalin for parasites like Ich, ensuring compatibility with angelfish; avoid overdosing as it can be toxic. My recommendation: Fritz Mardel Coppersafe (link to Amazon).
  • Dosage and Duration: Strictly adhere to the prescribed dosage, often involving a treatment course over 5-7 days to cover the parasite’s life cycle.
  • Isolation of Infected Fish: Quarantine infected fish in a separate tank to prevent spreading; this also allows for targeted treatment and close monitoring.
  • Tank Treatment: Treat the entire tank if infection is widespread; this may include multiple treatments spaced a few days apart to eliminate all parasites.

Also Read: Angelfish Diseases

2. Improving Water Quality

Good water quality is essential for the health of angelfish. Regular monitoring and maintenance can prevent and treat twitching due to environmental stress.

  • Regular Water Changes: Conduct 20-25% water changes weekly; this helps reduce ammonia and nitrite levels and replenishes essential minerals.
  • Water Testing: Test water parameters weekly using a reliable test kit; aim for ammonia and nitrite levels at 0 ppm, and nitrates below 20 ppm. After extensive research, I picked this API Freshwater Master Test Kit (link to Amazon).
  • Filter Maintenance: Clean and maintain the aquarium filter monthly to ensure efficient toxin removal and stable water conditions.
  • Temperature Control: Keep the water temperature stable, ideally between 76-82°F, as fluctuations can stress angelfish.

Also Read: Angelfish Water Parameters

3. Balanced Diet Enriched with Essential Nutrients

A balanced diet is critical for the overall health of angelfish. It prevents twitching and other health issues related to nutritional deficiencies.

  • Varied Diet: Include a mix of high-quality flakes, pellets, frozen, and live foods to provide a range of nutrients; avoid overfeeding.
  • Supplemental Vitamins: Add vitamin supplements to the diet, especially if using primarily dry foods, to ensure a well-rounded nutrient intake. My recommendation: Seachem Nourish (link to Amazon).
  • Feeding Frequency: Feed adult angelfish 2-3 times a day, giving only as much food as they can consume in 2-3 minutes to prevent overeating.
  • Quality of Food: Choose reputable food brands and check for high protein content and the inclusion of essential vitamins and minerals.

Also Read: How To Feed Angelfish

4. Stress Reduction Strategies

Reducing stress is vital for the health and well-being of angelfish. Stress can lead to twitching and other health issues.

  • Adequate Tank Size: Ensure a minimum tank size of 20 gallons for a single angelfish, adding 10 gallons for each additional fish to prevent overcrowding.
  • Environmental Enrichment: Provide plenty of hiding places with plants and decorations to create a secure environment for the fish.
  • Stable Routine: Maintain a consistent feeding and lighting schedule to avoid stressing the fish with sudden changes.
  • Peaceful Tank Mates: Choose tank mates carefully; avoid aggressive or overly active fish that can stress angelfish.

For example, here are some peaceful fish that can live with angelfish:

  • Neon Tetra (Paracheirodon innesi)
  • Harlequin Rasbora (Trigonostigma heteromorpha)
  • Corydoras Catfish (Corydoras spp.)
  • Bolivian Ram (Mikrogeophagus altispinosus)
  • Gourami (Trichogaster spp.)
  • Cardinal Tetra (Paracheirodon axelrodi)
  • Honey Gourami (Trichogaster chuna)

On the other hand, aggressive fish that generally can’t live with angelfish include:

  • Oscar (Astronotus ocellatus)
  • Jack Dempsey Cichlid (Rocio octofasciata)
  • Red Devil Cichlid (Amphilophus labiatus)
  • Green Terror (Andinoacara rivulatus)
  • African Cichlids (Various species from the Cichlidae family)
  • Tiger Oscar (Astronotus ocellatus ‘Tiger’)
  • Flowerhorn Cichlid (Hybrid cichlid, various varieties)

Also Read: Angelfish Tank Mates

5. Veterinary Consultation for Neurological Assessment and Treatment

If neurological issues are suspected, professional assessment and treatment are necessary. This ensures accurate diagnosis and appropriate care.

  • Expert Diagnosis: Consult a veterinarian specializing in fish to get a precise diagnosis; they may perform tests like skin scrapings or biopsies.
  • Specialized Treatment: Follow the veterinarian’s treatment plan, which may include medications or changes in care specific to the neurological condition.
  • Monitoring Progress: Keep a close eye on the fish’s behavior and health following treatment to ensure improvement or identify any further issues.
  • Ongoing Care: Post-treatment, continue providing optimal care, including water quality management and stress reduction, to support long-term health.

What Else Can Indicate That an Angelfish Is Stressed?

Stressed angelfish often exhibit changes in behavior and physical appearance that are quite noticeable.

These signs are the fish’s way of responding to unfavorable conditions in their environment, signaling a need for attention and care.

  • Loss of Appetite: A stressed angelfish may eat less or refuse food altogether, which is a stark contrast to their normally hearty appetite.
  • Color Fading: Stress can lead to a noticeable fading or dulling of the angelfish’s vibrant colors, making them appear less bright and healthy.
  • Hiding Behavior: If an angelfish is spending more time hiding than usual, especially during feeding times, it’s a clear sign of stress or discomfort.
  • Erratic Swimming: Stressed angelfish might swim erratically or dart around the tank, which is unusual for their typically graceful swimming style.

Also Read: Angelfish Swimming Erratically

How to Prevent Your Angelfish from Twitching in the Future

Preventing shaking or twitching in angelfish involves creating a stable, healthy environment and regularly monitoring their well-being.

These steps reduce stress and address potential health issues before they escalate into more serious problems.

  • Consistent Water Quality: Maintain a stable water temperature between 76-82°F and keep ammonia and nitrite levels at 0 ppm, with nitrates under 20 ppm.
  • Regular Health Checks: Observe your angelfish daily for signs of stress or illness, including changes in behavior, appearance, and feeding habits.
  • Balanced Nutrition: Feed a varied diet that includes high-quality flakes, pellets, and occasional live or frozen foods to ensure all nutritional needs are met.
  • Stress-Free Environment: Create a peaceful tank setup with ample space, hiding places, and compatible tank mates to reduce stress and promote well-being.

Also Read: Angelfish Making Bubbles


For quick readers, here’s a short summary:

  • Twitching in angelfish is often a sign of distress or illness, indicating possible problems like parasitic infections or poor water conditions.
  • Causes of twitching include parasitic infections, poor water quality, nutritional deficiencies, stress, and neurological disorders, each requiring specific attention.
  • Treating twitching in angelfish involves addressing the underlying cause, whether it’s through medication for parasites, improving water quality, or providing a balanced diet.
  • Stress reduction and maintaining a stable, healthy environment are crucial for preventing twitching and ensuring the well-being of angelfish.
  • Regular monitoring of angelfish for signs of stress or illness and creating a stress-free environment can prevent future occurrences of shaking or twitching.