I’ll never forget the first time I found Azure, my beautiful blue betta, lying sideways at the bottom of his tank at 2 AM. My heart stopped. He was completely motionless with his eyes wide open. I rushed over, certain he was dead. But the moment I got close, he shot up and darted to the front glass like nothing happened. That’s when I realized – he was just sleeping.
If you’ve ever panicked seeing your betta fish sleeping in a weird position, you’re not alone. The question “do betta fish sleep?” comes up constantly, usually right after someone finds their fish lying motionless and assumes the worst.
Yes, betta fish do sleep, and they do it in some seriously strange ways. Let’s dive into everything about betta fish sleeping behavior, when they rest, and how to tell if your betta is sleeping or actually in trouble.
Quick Answer: Do Betta Fish Sleep?
| Question | Answer |
| Do betta fish sleep? | Yes, all fish need sleep to stay healthy |
| When do betta fish sleep? | Primarily at night (12-16 hours of darkness needed) |
| Do betta fish have eyelids? | No – they sleep with eyes open |
| Where do betta fish sleep? | Bottom of tank, on leaves, wedged in decorations, or floating at surface |
| How long do betta fish sleep? | 12-16 hours in short bursts throughout the night |
| Can you tell if betta is sleeping? | Yes – slower breathing, reduced movement, duller colors |
| Is it normal for bettas to sleep during day? | Yes – short power naps are completely normal |
Do Betta Fish Actually Sleep?
Yes, betta fish do sleep, just like every other fish species. Sleep is essential for their health, immune function, and energy conservation. However, betta fish sleep is very different from human sleep.
When we sleep, we enter deep REM (Rapid Eye Movement) cycles where we’re completely unconscious. Betta fish don’t experience this deep sleep. Instead, they enter a light resting state where their metabolism slows down but they remain somewhat alert to their surroundings.
Think of it like a light doze rather than deep sleep. This makes sense when you consider that in the wild, bettas need to stay aware of predators even while resting. Their survival instincts are still hardwired into their DNA, even after generations of captive breeding.
How Betta Sleep Differs From Human Sleep
Here’s what makes betta fish sleeping unique:
No eyelids: Unlike humans and most land animals, betta fish don’t have eyelids. This means betta fish sleep with their eyes open, which is why so many owners don’t realize their fish is resting. Only sharks have eyelids among fish species!
Light sleep only: Bettas don’t enter deep REM sleep. They remain in a state of restful inactivity where they can still sense danger and react quickly if needed.
Reduced but active breathing: Even when sleeping, bettas continue breathing through their gills. The breathing rate slows down significantly, but they must keep water flowing over their gills to extract oxygen.
Color changes: Many bettas actually change color when sleeping, appearing duller or faded. This is thought to be a defense mechanism to make them less visible to predators while vulnerable.
When Do Betta Fish Sleep?
Betta fish are diurnal, which means they’re most active during the day and sleep at night – just like humans! This makes them perfect bedroom companions since they don’t need bright tank lights at night.
Normal Betta Fish Sleep Schedule
Nighttime sleeping: Bettas do most of their sleeping at night when it’s dark. They need 12 to 16 hours of complete darkness each night to maintain healthy sleep patterns and circadian rhythm.
Daytime napping: It’s totally normal for bettas to take short power naps during the day. These naps usually last just a few minutes to an hour. If you see your betta resting during the day, don’t panic – he’s probably just recharging.
Individual differences: Every betta has a unique personality, and that includes sleep habits. Some are lazy and rest frequently throughout the day. Others are hyperactive and seem to never stop moving (but they do sleep at night when you’re not watching).
The Importance of Light and Dark Cycles
Betta fish need a consistent day/night cycle to regulate their sleep schedule. Here’s what you need to know:
Natural light is enough: You don’t need special aquarium lights to give your betta a proper sleep cycle. Ambient room lighting during the day and darkness at night work perfectly.
Turn off tank lights: If you do use aquarium lights, always turn them off at night. Bettas can’t sleep properly with bright lights on.
Avoid 24/7 lighting: Never leave lights on all the time. This disrupts their circadian rhythm and causes serious stress, which can lead to illness.
Darkness matters: Even in a lit room, try to minimize light exposure during nighttime hours. Cover the tank or move it away from bright lights if needed.
I learned this the hard way with my first betta. I kept his tank light on constantly because I thought it looked nice. After two weeks, he became lethargic and stopped eating. The vet explained he was severely sleep-deprived. Once I started turning the lights off at night, he bounced back within days.
How Can You Tell If Your Betta Fish Is Sleeping?
Since bettas sleep with their eyes open and can rest in weird positions, figuring out if your betta is sleeping or dead can be tricky. Here are the telltale signs that your betta fish is sleeping:
8 Signs Your Betta Is Sleeping
- Reduced or No Movement
A sleeping betta will be completely still or moving very minimally. They won’t be actively swimming around the tank. However, you might see slight fin movements as they make micro-adjustments to stay in position.
- Slower Breathing Rate
Watch their gills and mouth carefully. Betta fish breathing slows significantly during sleep, becoming shallower and less frequent. They use less oxygen while resting, so this is totally normal. Dead fish don’t breathe at all, so if you see any gill or mouth movement, your betta is alive.
- Minimal or No Gill Flaring
Bettas are famous for flaring their gills to look impressive or intimidating. When sleeping, they cease gill flaring completely to conserve energy. If your betta’s gills are flat against their body and they’re motionless, they’re likely sleeping.
- Dull or Faded Color Appearance
This freaked me out the first time I saw it! Many bettas lose their vibrant coloration when sleeping, appearing washed out or dull. This color change is believed to be a natural camouflage mechanism – less vibrant colors make them harder for predators to spot while vulnerable.
The moment they wake up, the colors return to full vibrancy within seconds.
- Consistent Resting Position
Sleeping bettas usually settle into their preferred sleeping spot and position. They might stay there for extended periods (30 minutes to several hours). Each betta has favorite sleep positions – some sleep on their side, others float, some wedge themselves between decorations.
- Unresponsive to Stimuli
A sleeping betta won’t react immediately to movement outside the tank or shadows passing by. However, they’re light sleepers, so any loud noise, sudden light, or tapping on the tank will startle them awake. (Please don’t tap the tank – it’s incredibly stressful for them!)
- Eyes Remain Wide Open
Since bettas have no eyelids, their eyes stay open 24/7. Don’t use eye closure as an indicator of sleep. Instead, look for the other signs on this list.
- Hiding in Preferred Sleep Spot
Many bettas have a specific sleeping spot they return to every night. It might be a cave, behind a plant, on a leaf hammock, or wedged in a decoration. If your betta consistently goes to the same spot and becomes still, that’s their bedroom.
Where Do Betta Fish Sleep? (Weird Sleep Positions Explained)
If you think you’ve seen strange sleeping positions, you’re in for a treat. Bettas sleep in some of the weirdest, most alarming positions imaginable. Here’s where and how betta fish sleep:
Bottom of the Tank
Most common position: The majority of bettas sleep at the bottom of the tank. You’ll often see them resting with their head on the substrate and their tail floating up slightly, creating an L-shaped position.
On their side: Some bettas literally sleep on their side like they’ve fallen over. This looks absolutely terrifying but is completely normal.
Curled up: Others curl their body into a C-shape or spiral, which can make them look sick but is just a comfortable sleep position for them.
Why the bottom? In captivity, filter flow can push bettas around even with gentle current. By sinking to the bottom where water movement is minimal, they can rest without being swept across the tank. In the wild, bettas lived in nearly still rice paddies, so current bothers them even when sleeping.
Floating on Surface or Leaves
Here’s something that terrifies new betta owners: bettas can sleep while floating at the water surface or resting on leaves.
This is possible because bettas are anabantoids – they have a special organ called the labyrinth organ that allows them to breathe atmospheric air directly from the surface. They can actually rest on top of floating plants with part of their body out of the water!
My betta Celeste does this every single night on her floating Indian almond leaf. The first time I saw her, I thought she’d jumped out and died. Nope – just sleeping like a weirdo.
Betta hammocks (those suction cup leaves sold in stores) are specifically designed for this behavior. Many bettas love sleeping on them near the surface.
Wedged Behind Decorations
Bettas love to wedge themselves into tight spaces while sleeping:
- Behind the heater (my Azure’s favorite spot)
- Between rocks or driftwood
- Inside caves or decorative houses
- Tangled in plant roots
- Squeezed between the tank wall and decorations
This gives them a sense of security. In the wild, bettas would hide in dense vegetation to avoid predators while sleeping. The tighter the space, the safer they feel.
On Top of Equipment
Some bettas develop hilariously specific sleep preferences:
- Perched on top of the filter intake
- Balanced on the thermometer
- Resting on the heater cord
- Propped against the air stone
My friend’s betta literally sleeps balancing on the edge of the filter outflow. It looks impossible, but he does it every night.
The Strangest Positions I’ve Seen
After years of keeping bettas and talking to other owners, here are some of the weirdest betta fish sleeping positions I’ve encountered:
- Nose-down, tail-up: Literally doing a headstand in the gravel
- Upside down: Belly-up floating (absolutely heart-attack inducing)
- Vertical sleeping: Floating straight up and down like a pencil
- The “dead leaf”: Floating sideways, swaying with any current
All of these are normal! As long as your betta wakes up when disturbed and shows other signs of health, these bizarre positions are just their preferred sleeping style.
How Long Do Betta Fish Sleep?
Betta fish need 12 to 16 hours of darkness per night to maintain healthy sleep patterns. However, they don’t sleep continuously like humans do.
Sleep Duration and Patterns
Night sleeping: Bettas sleep in short bursts throughout the night rather than one long sleep session. They might sleep for 30 minutes, wake briefly to check their surroundings, then go back to sleep.
Daytime naps: Many bettas take 5 to 30 minute power naps during the day. This is completely normal and not a sign of illness.
Total rest time: When you add up all the sleeping and resting periods, most bettas get about 8 to 12 hours of actual sleep per 24-hour period.
Individual variation: Lazy bettas might sleep 14 hours a day. Hyperactive bettas might only sleep 6 to 8 hours. As long as they’re eating well and behaving normally when awake, their individual sleep amount is fine.
How Much Darkness Bettas Need
The general rule is 12 to 16 hours of darkness per night. Here’s a simple schedule:
- Lights on: 8 AM to 8 PM (12 hours)
- Lights off: 8 PM to 8 AM (12 hours)
Or adjust based on your schedule:
- Lights on: 10 AM to 10 PM (12 hours)
- Lights off: 10 PM to 10 AM (12 hours)
The key is consistency. Bettas thrive on routine, so try to keep the same schedule every day.
Why Do Betta Fish Sleep in Strange Positions?
You might wonder why bettas don’t just sleep normally like other fish. There are several evolutionary and practical reasons for their weird sleep positions:
Survival Instincts
Despite being captive-bred for generations, bettas still have wild survival instincts. In nature, a sleeping fish is vulnerable to predators. By sleeping in hidden spots, wedged positions, or while staying near the surface (where they can breathe if buried), they increase their chances of survival.
Territorial awareness: Bettas are highly territorial. Even while sleeping, part of their brain remains alert for intruders. This light sleep state allows them to defend their territory quickly if needed.
Overcoming Water Flow
Modern fish tanks have filters that create water current. Even the gentlest flow can push a betta around while they’re trying to rest. By:
- Sinking to the bottom (where current is weakest)
- Wedging into tight spaces (anchoring themselves)
- Resting on solid surfaces (preventing drift)
Bettas solve the current problem and can sleep comfortably.
Labyrinth Organ Advantages
The labyrinth organ is a game-changer for betta sleeping habits. Since they can breathe air from the surface, bettas can:
- Sleep on floating leaves partially out of water
- Rest at the surface without struggling for oxygen
- Survive in low-oxygen environments while sleeping
This unique adaptation gives them sleeping options other fish don’t have.
Color Change for Camouflage
The color dulling when bettas sleep serves an important purpose. Bright, vibrant colors attract attention – exactly what you don’t want when you’re vulnerable and sleeping. By fading to duller tones, bettas become less noticeable to potential predators.
It’s like wearing camouflage pajamas!
How to Create the Perfect Sleep Environment for Your Betta
Want to ensure your betta gets quality rest? Here’s how to create an ideal sleep environment:
Turn Off Lights at Night
Tank lights: Always turn off aquarium lights when you go to bed. Set a timer if you tend to forget.
Room lights: If your betta tank is in a bedroom or living room, try to minimize light exposure at night. Even room lighting can disrupt their sleep if it’s too bright.
Screen time: Avoid positioning the tank where TV or computer screens will flash light into it at night.
Darkness duration: Aim for at least 12 hours of complete darkness. 16 hours is even better for optimal rest.
I use a basic timer plug for my betta tanks. Lights turn off automatically at 9 PM and back on at 9 AM. This consistent 12-hour cycle keeps all my bettas on a healthy sleep schedule.
Provide Hiding Spots
Bettas need places where they feel secure enough to sleep. Add these to your tank:
Live or silk plants: Large, broad-leaved plants like Amazon swords or anubias make perfect sleeping spots. Always use silk artificial plants, never plastic – plastic plants can tear delicate betta fins.
Betta hammocks: These suction-cup leaves are specifically designed for bettas to rest on near the surface. Most bettas love them!
Caves and decorations: Provide at least one hiding spot like a cave, hollow log, or decorative house where your betta can retreat.
Floating plants: Species like water sprite, frogbit, or dwarf water lettuce create natural resting spots at the surface.
Driftwood: Provides both hiding spots and natural tannins that bettas love.
The more options your betta has, the better they’ll sleep.
Maintain Stable Water Temperature
Temperature stability is crucial for healthy sleep patterns.
Ideal range: Keep water between 76°F and 82°F (24-28°C). The sweet spot is 78°F (25.5°C).
Use a heater: Even in warm climates, use an aquarium heater to maintain stable temps. Temperature fluctuations stress bettas and disrupt sleep.
Avoid cold water: Water below 76°F slows betta metabolism dramatically. They become lethargic and may appear to sleep excessively, but this is actually temperature shock, not healthy sleep.
Check nightly: Tanks in cold rooms can lose several degrees at night. Make sure your heater compensates for this.
Reduce Noise and Vibrations
Bettas are light sleepers and can be disturbed by:
- Loud music or TV
- Footsteps near the tank (if on a unstable surface)
- Slamming doors
- Other pets pawing at the tank
Best practices:
- Place the tank on a stable, sturdy surface
- Keep it away from high-traffic areas
- Lower music/TV volume at night
- Keep other pets away from the tank
Never tap on the tank glass to wake your betta. This is extremely stressful and can cause lasting fear responses.
Add Floating Plants or Betta Hammock
As mentioned, many bettas love sleeping near the surface. Give them that option:
Betta leaf hammock: The classic suction cup leaf. Place it 1 to 2 inches below the water surface in a calm area of the tank.
Floating plants: Natural options like Amazon frogbit, red root floaters, or dwarf water lettuce provide perfect sleeping platforms.
Wide-leafed plants: Planted or floating plants with large leaves (water sprite, anubias) give bettas multiple resting height options.
Keep a Consistent 12-16 Hour Dark Cycle
Consistency is key for healthy sleep. Bettas thrive on routine.
Same schedule daily: Turn lights on and off at the same times every day, even on weekends.
No all-nighters: Don’t keep lights on all night occasionally. This disrupts their circadian rhythm.
Natural seasonal changes okay: If you use natural room lighting, gradual seasonal changes (slightly longer days in summer) are fine. Just avoid dramatic day-to-day changes.
Vacation planning: If you’re away, use timers to maintain their schedule or ask your fish-sitter to keep consistent lighting times.
Creating optimal sleep conditions for your betta is one of the best things you can do for their long-term health. Well-rested bettas have stronger immune systems, better colors, and live longer lives.
Betta Sleeping vs Dead: How to Tell the Difference
This is the question that sends new owners into panic mode. Your betta is lying on its side, eyes open, completely still. Is it sleeping or dead?
Check for Gill Movement
Living betta: Gills will show slow, rhythmic movement as the fish breathes. The breathing is much slower during sleep but still visible if you watch carefully.
Dead betta: No gill movement at all. The gills remain completely still.
How to check: Watch the gill covers (opercula) on both sides of the head. Even the slightest flutter means your betta is alive.
Look for Slow Breathing
Living betta: The mouth may show very subtle opening and closing as they draw water across the gills. It’s slow during sleep but present.
Dead betta: The mouth stays frozen in one position with no movement.
How to check: Look for any mouth movement, even tiny. Sometimes you’ll only see it every 5 to 10 seconds during deep rest.
Observe Mouth Movement
Beyond breathing, check mouth positioning:
Living betta: Mouth may be slightly open or closed, but the position may change slightly as they breathe.
Dead betta: Mouth is typically frozen open or closed in a rigid position.
Test With Gentle Stimulation (DON’T Tap Tank!)
If you’re still not sure after checking breathing, you can gently test if they’re alive:
DO:
- Turn on the room light (if it was dark)
- Gently wave your hand outside the tank
- Drop a pellet of food near them (feed time usually wakes them)
- Very gently touch the tank (not banging, just a soft touch on the side)
DON’T:
- Tap or bang on the glass
- Shine bright flashlights directly at them
- Poke them with a net
- Shake the tank
A sleeping betta will wake up and react within a few seconds to a few minutes. A dead betta won’t respond at all.
Color Changes Are Normal When Sleeping
Remember, color dulling during sleep is normal! Many bettas:
- Lose vibrancy in their colors
- Develop pale or washed-out appearance
- May show stress stripes (pale horizontal bars)
This does NOT mean they’re dead or dying. It’s natural camouflage behavior. The colors return within seconds to minutes after waking.
When to Actually Worry
Your betta might genuinely be dead or dying if:
No gill movement for several minutes of observation
Rigid body that doesn’t move at all when you gently create current near them
Cloudy or sunken eyes (dead fish develop cloudy eyes)
Strong smell coming from the tank (decomposition)
Floating at surface belly-up for extended periods AND not breathing (some bettas float on their back while sleeping, but they’ll still breathe)
No response to any stimulation including feeding time
I’ve had several scares where I was certain my betta was dead, only to have them wake up and act like nothing happened. The key is always to check for breathing – if they’re breathing, they’re alive!
Common Betta Sleep Problems and Solutions
Sometimes bettas develop sleep issues. Here’s how to identify and fix them:
Sleeping Too Much (Lethargy)
Signs:
- Sleeping most of the day and night
- Barely moving even when awake
- Resting at the bottom constantly
- Not interested in food
Common causes:
Cold water: Check temperature immediately. Bettas become lethargic below 76°F. This isn’t healthy sleep – it’s temperature shock.
- Solution: Add or adjust heater to maintain 78°F
Illness: Diseases like fin rot, ich, or internal parasites cause excessive sleeping.
- Solution: Check for symptoms like clamped fins, white spots, bloating. Treat accordingly or consult a vet.
Poor water quality: High ammonia or nitrites cause stress and lethargy.
- Solution: Test water parameters. Perform immediate water change if needed. Cycle the tank properly.
Stress: New tank, aggressive tank mates, or constant disturbances cause depression-like symptoms.
- Solution: Reduce stressors, provide hiding spots, remove aggressive fish.
Old age: Senior bettas (3+ years) naturally sleep more as they age.
- Solution: This is normal. Ensure comfortable resting spots and pristine water quality.
Not Sleeping Enough (Hyperactivity/Stress)
Signs:
- Constant swimming, even at night
- Pacing or glass surfing
- Erratic, frantic movements
- Flaring constantly
Common causes:
Lights left on: Tank or room lights prevent sleep.
- Solution: Ensure 12 to 16 hours of darkness nightly. Use timers.
Reflections: Seeing their reflection makes bettas think there’s an intruder.
- Solution: Reduce reflections by lowering light intensity or backing the tank away from reflective surfaces.
Tank too small: Less than 5 gallons causes stress and prevents normal behavior.
- Solution: Upgrade to at least 5 gallons, ideally 10+ gallons.
No hiding spots: Without secure areas, bettas can’t relax enough to sleep.
- Solution: Add plants, caves, and decorations immediately.
Tank mates: Other fish may be harassing your betta.
- Solution: Remove aggressive tank mates or separate the betta.
Restless or Erratic Sleep
Signs:
- Waking frequently throughout the night
- Changing sleep positions constantly
- Swimming in circles before settling
- Gasping at surface while resting
Common causes:
Poor water quality: Ammonia, nitrites, or low oxygen cause restlessness.
- Solution: Test water. Perform 50% water change if parameters are off. Add air stone if oxygen is low.
Current too strong: Filter flow disrupts rest.
- Solution: Baffle the filter outflow or switch to gentler filtration.
Constipation or bloating: Digestive issues cause discomfort.
- Solution: Fast for 24 hours, then feed a blanched, peeled pea. Reduce feeding amount.
Parasites: Internal parasites cause discomfort and restlessness.
- Solution: Look for stringy white poop, lethargy, or loss of appetite. Treat with anti-parasitic medication.
Most betta sleep problems stem from poor water conditions or temperature issues. Always check these first before looking for more complex problems.
Frequently Asked Questions About Betta Fish Sleep
Do betta fish sleep with their eyes open?
Yes, betta fish sleep with their eyes wide open because they don’t have eyelids. Only sharks have eyelids among fish species. This makes it difficult to tell when bettas are sleeping just by looking at their eyes. Instead, watch for reduced movement, slower breathing, and duller colors as signs of sleep.
Can I wake my betta fish?
You can wake your betta, but you shouldn’t do it unnecessarily. Bettas are light sleepers and will wake if disturbed, but constantly waking them causes serious stress. Never tap on the tank glass – this is extremely stressful and can cause lasting fear responses. Only wake your betta if you need to check if they’re alive or for emergency medical treatment. Normal feeding time will naturally wake them without added stress.
Is it normal for bettas to sleep during the day?
Yes, daytime sleeping is completely normal for betta fish! Many bettas take short power naps throughout the day, usually lasting anywhere from 5 minutes to an hour. As long as your betta is active and responsive during normal waking hours, eating well, and showing no signs of illness, daytime napping is just part of their individual personality. Some bettas are naturally lazy and rest more than others.
How many hours of darkness do bettas need?
Betta fish need 12 to 16 hours of complete darkness each night to maintain healthy sleep patterns and circadian rhythm. The standard recommendation is a 12-hour light/12-hour dark cycle, but 14 to 16 hours of darkness is even better. Consistent lighting schedules are crucial – turn lights on and off at the same time every day. Never leave lights on 24/7 as this causes severe stress and sleep deprivation.
Why does my betta change color when sleeping?
Color change during sleep is a natural defensive mechanism. In the wild, bright colors attract predators – exactly what a sleeping fish wants to avoid. By dulling their colors or showing pale stress stripes while sleeping, bettas become less visible to potential threats. This camouflage behavior is completely normal. Colors return to full vibrancy within seconds after waking up. If colors remain dull even when awake, this indicates stress or illness.
Conclusion
Yes, betta fish absolutely do sleep, but they do it in ways that can seem bizarre or alarming to new owners. From sleeping sideways at the bottom of the tank to floating on leaves with their eyes wide open, bettas have mastered the art of weird sleep positions.
The key things to remember about betta fish sleeping:
Bettas are diurnal – they sleep at night and are active during the day, just like us. They need 12 to 16 hours of darkness each night for healthy sleep patterns.
Sleep looks strange – Bettas sleep with eyes open, often in odd positions like on their side, curled up, or wedged into decorations. As long as they’re breathing and wake when disturbed, these positions are normal.
Create good sleep conditions – Turn off lights at night, provide hiding spots and resting areas, maintain stable temperature at 78°F, and keep consistent day/night cycles.
Check breathing to tell if alive – If your betta looks dead, check for slow gill and mouth movement. Sleeping bettas breathe slowly but steadily. Test with gentle stimulation, never by tapping the glass.
Understanding how bettas sleep is crucial for their health and your peace of mind. A well-rested betta is a healthy betta with a strong immune system and vibrant colors.
If you want to learn more about proper betta care or need help setting up the ideal betta tank, check out our other comprehensive guides. Your betta will thank you with years of healthy, happy life!
References
- National Sleep Foundation – “Do Fish Sleep?” – sleep.org – Comprehensive research on fish sleep patterns and behaviors.
- Wikipedia: Siamese Fighting Fish – “Betta Behavior and Sleep” – wikipedia.org – Scientific documentation of betta sleep positions and characteristics.
- AquariumSource – “Do Betta Fish Sleep? The Real Answer” (2025) – aquariumsource.com – Detailed analysis of betta sleep cycles and patterns.
- HubPages Animal Sciences – “How and When Do Betta Fish Sleep?” (2024) – hubpages.com – Evidence-based guide to betta sleeping behavior.
- A-Z Animals – “Do Betta Fish Sleep? 8 Ways You Can Tell Fish Are Asleep” (2023) – a-z-animals.com – Scientific breakdown of sleep indicators in bettas.
- Aquarium Store Depot – “How Do Betta Fish Sleep? When and Where” (2024) – aquariumstoredepot.com – Research on betta sleep duration and environmental factors
