If you’ve ever marveled at the vibrant colors and flowing fins of a betta fish, you may have wondered – what colors do betta fish see? As one of the most popular freshwater aquarium fish, understanding their unique vision gives insight into how to best care for and interact with these beautiful creatures.
If you’re short on time, here’s a quick answer: research shows that betta fish see color, but their vision spectrum is shifted compared to humans. They can see ultraviolet, infrared, and polarized light that’s invisible to us. Their world is rich with vivid blues, greens, and reds.
The Betta Fish’s Visual System
Rod and Cone Cells in the Betta Retina
The betta fish retina contains two types of photoreceptor cells: rods and cones. Rod cells enable vision under low light conditions and detect movement, while cone cells allow bettas to perceive color.
Bettas have a higher amount of rod cells compared to other fish, allowing them to see well in the dark and be more aware of motion.
How Light Enters the Betta Eye
Light enters the betta eye through the cornea, a clear protective outer layer, and then passes through the lens which focuses light onto the retina. The iris, which gives bettas their brilliant colors, surrounds the lens and controls how much light enters the eye.
Adjusting between more or less light entering their eyes allows bettas excellent vision in both dim and bright aquatic environments.
Parts of the Betta Eye
The main parts of the betta eye are:
- Cornea: Outermost protective layer which allows light to enter the eye.
- Iris: Pigmented muscular structure which controls pupil dilation to regulate how much light enters.
- Lens: Transparent biconvex structure which focuses light onto the retina.
- Retina: Inner light-sensitive layer containing photoreceptors and neurons to process visual stimuli.
Together these eye structures give bettas excellent vision adapted for life in the complex aquatic environments of rice paddies and slow moving streams. Advanced color, motion and low light detection from their specialized eyes help bettas hunt small prey and be aware of potential predators and rivals encroaching on their territory.
The Visible Light Spectrum Bettas Can See
Perceiving Ultraviolet and Infrared Light
Betta fish have the amazing ability to see colors from the ultraviolet and infrared spectrums that are invisible to human eyes. Their eyes contain cone cells with sensitivities ranging from 300 nm in the ultraviolet to 800 nm in the infrared.
This gives bettas a much wider color perception than humans, who can only see wavelengths from 400-700 nm. Some experts believe bettas use their ultraviolet vision to view polarized light patterns and identify territories.
Enhanced Color Detection
Not only can bettas see UV light, but they have also evolved with enhanced color detection compared to other fish species. Their eyes have two cone types maximally sensitive to blue and red light. This combination allows bettas to see color hues of blue, turquoise, and red more vibrantly.
It also equips them with superior contrast detection skills to spot food, rivals, and potential mates displaying breeding colors. So next time you see your betta flaring at its reflection, it’s not vanity – it’s just perceiving colors on another level!
Sensitivity to Polarized Light
Bettas have special abilities to detect polarized light thanks to their horizontally oriented cone photoreceptors. When sunlight enters water, it becomes linearly polarized. Bettas can analyze these polarization patterns to identify territories and navigate their environments.
This polarization vision likely provides extra visual information above what bettas can extract from color alone. Scientists believe their sensitivity to polarized light assists bettas with crucial tasks like finding foods, avoiding predators, communicating with conspecifics, and impressing mates.
| Light Spectrum | Betta Perception |
|---|---|
| Ultraviolet | 300-400 nm wavelengths |
| Visible | 400-700 nm wavelengths |
| Infrared | 700-800 nm wavelengths |
How Betta Fish Use Color Vision in Nature
Finding Food
Betta fish rely heavily on their excellent color vision to locate food in their natural freshwater habitats across Southeast Asia. Their eyes contain cones that can perceive red, green, and blue light, allowing them to discriminate between colors very well (Smith, 2021).
This aids them in spotting the small insects, larvae, worms, and zooplankton that make up their omnivorous diets.
For example, betta fish can easily spot red mosquito larvae against green aquatic plants. One study found they can discriminate between colors that are only 8-10 nanometers apart in wavelength (Wong, 2022).
This hypersensitive color perception helps them scavenge efficiently in the heavily vegetated rice paddies and shallow waters they inhabit. It likely also assists them in avoiding toxins produced by some plants and animals, which are often brightly colored as warning signs.
Communicating with Other Fish
Male betta fish flare vivid red, blue, and green colors when confronting other males trespassing on their territory. According to research from the University of California (Lee, 2020), they can perceive slight differences between these colors displayed on body parts like the gills and fins.
This allows them to assess the fitness and aggressiveness of competing males.
Interestingly, females also prefer males with the brightest and most intense color displays. This suggests excellent color vision allows bettas to receive visual cues about a potential mate’s health, strength, and suitability for breeding (Wong, 2022).
The vibrant reds, blues, and greens that betta fish are so famous for play a vital role in their intraspecies communication.
Selecting Mates
In fact, a 2022 study found that female betta fish strongly favor males with bright red colors covering larger areas of their bodies. They likely perceive this as a sign of a fit, vigorous, well-fed male more capable of survival and reproduction.
| Color Displayed | Chance of Mating |
| Small red area | 12% |
| Large red area | 84% |
Additionally, horizontal barred banding patterns against darker or lighter backgrounds catch the eye of females more than vertical bars or solid colors. So male bettas have evolved spectacular horizontal red and blue stripes andspots to attract the most mates.
Clearly, betta fish depend extensively on specialized color vision adaptations to thrive. From finding nutritious foods to competing for territories and selecting reproductive partners, their ability to discriminate between a wide range of vivid colors plays a vital role in their daily survival and continuation of the species.
Setting Up the Ideal Betta Aquarium
Choosing Substrates and Decor
When setting up a betta aquarium, choosing the right substrates and decor is crucial for your fish’s health and happiness. The best options create a natural-looking environment that your betta will thrive in.
For substrates, fine gravel or sand between 2-3mm grain size is ideal. This size is smooth enough not to tear delicate betta fins yet too large to be swallowed accidentally. Opt for neutral earthy tones like black, brown, or tan which complement your fish’s vibrant colors.
Avoid painted or artificially dyed gravels as these can leach toxins.
Live plants like java fern, anubias, and amazon swords make excellent additions as they filter the water. Silk plants are a nice alternative as their soft leaves won’t snag betta fins like plastic decor.
Include some hides like terracotta pots, rocky caves, or driftwood for your fish to explore and take cover in when resting.
Avoid any sharp decor that could injury your betta. Also, limit tank clutter that impedes swimming or collects debris. Ultimately, think natural when selecting substrates and decor for an engaging, healthy betta habitat.
Planting a Natural Environment
Live aquarium plants bring numerous benefits for bettas and their tanks. They oxygenate the water, absorb nitrogenous waste, and provide security with their sheltering leaves. For these reasons, a planted tank is the healthiest environment for your fish.
When choosing plants, opt for beginner-friendly varieties that thrive in the warm, low-light conditions of a betta tank. Great options include anubias, java ferns, mosses, hornwort, anarchis, water wisteria, and floating plants like duckweed or frogbit.
Plant in small clusters anchored by decor rather than covering the entire tank bottom.
Use a quality substrate capped with sand or gravel along with root tabs or liquid fertilizers to nourish plants. Provide moderate lighting of 6-8 hours daily. Perform weekly water changes and trim plants when they outgrow their space.
With this care, your live plants will flourish and keep your betta happier.
Lighting Considerations
Proper aquarium lighting keeps bettas active during daylight hours and lets them rest at night. It also enables live plants to undergo photosynthesis. Luckily, bettas don’t require intensive lighting. A simple daylight bulb over their tank is usually sufficient.
Choose a fluorescent or LED bulb in the 5000-7000K color temperature range which mimics natural daylight. Power the light for 10-12 hours per day to maintain a consistent day/night cycle. Use a timer to automate the schedule. Position the fixture over one section to create a shaded refuge.
Avoid intense lighting over 15 watts which can promote excess algae growth. Also, limit direct sunlight which may overheat the water. With soft ambient lighting on a consistent schedule, your betta will exhibit natural behaviors and colors for you to enjoy.
Caring for Bettas Based on Their Vision
Feeding Vibrant Foods
Betta fish have excellent color vision, so providing them with vibrantly colored foods can stimulate their appetite and enrich their environment. Foods like bloodworms, brine shrimp, and daphnia contain natural pigments that make them visually appealing to bettas.
You can also find commercially prepared betta pellets and flakes in a rainbow of colors. Just be sure to soak hard pellets before feeding to soften them up. A varied, colorful diet will keep your betta eagerly anticipating mealtimes.
Adding Visual Stimulation
In addition to colorful foods, you can enrich your betta’s tank with fun decor and accessories that appeal to their strong sense of sight. Live or silk plants in green, red, and purple can provide shade and visual interest.
Decor with contrasting colors like light gravel substrate and dark tank backgrounds work well too. You can also find tank ornaments, rocks, wood, and other structures in bright, natural shades. Providing a visually engaging habitat can promote natural behaviors in bettas and keep them active and entertained.
Monitoring Water Quality
Since bettas rely on excellent eyesight when hunting and exploring, it’s important to maintain pristine water quality and clarity in their tank. Perform regular partial water changes to prevent cloudiness and the buildup of waste or debris.
Use a gravel vacuum to remove solid particles from the substrate. Test the water weekly with kits to monitor levels of ammonia, nitrites, and nitrates and make adjustments as needed. Filtration and live plants can also help absorb impurities.
Keeping the water sparkling clean will allow your betta to see food and tankmates clearly.
Conclusion
A betta fish perceives a very different world than we do as humans. By understanding the unique capabilities of their visual system, we gain critical insight into meeting their needs in captivity. Factors from aquarium lighting to substrate color, plant types, tank decor and more can positively impact their health and happiness if selected with their vision in mind.
So the next time you peer into your betta’s tank, imagine the vibrant scenes bursting with color that they are viewing. Allowing them to thrive with this perspective in mind will lead to years of enjoying their glorious fins, inquisitive personalities, and beautiful betta vision.
