Looking for Kauai reef fish? From the state fish humuhumunukunukuapua'a to rare butterflyfish, here's what you'll see snorkeling our reefs - with the best spots to find them.
Shoots! Every time I take friends snorkeling around Kauai, the same thing happens - they pop their head up after five minutes, pull out their snorkel, and go "What WAS that?!" pointing at some colorful fish that just cruised by. I get it - our Kauai reef fish are like nothing you've seen anywhere else, and honestly? Learning what you're looking at makes the whole experience way more amazing 🐠
After years of snorkeling these reefs (basically my office at this point), I've put together this guide to help you identify the fish you'll actually see around Kauai. No scientific textbook stuff - just the real deal on what's swimming around our islands and where to find them.
Let's start with the celebrity - the humuhumunukunukuapua'a (yeah, I can say it fast now, but took me months when I first moved here). Most people call it the "humuhumu" or just "reef triggerfish" to save their tongue 🤙
Here's what makes this fish special:
I see these guys all the time at Poipu Beach Park - they're pretty chill unless you get too close, then they'll grunt at you and swim off. They're not shy, just have boundaries, you know?
The yellow tang is probably the first fish you'll notice - they're literally sunshine yellow and swim in groups. These guys are herbivores, so you'll see them grazing on algae all day. They're especially thick at Tunnels Beach on the North Shore.
Fun fact: Yellow tangs can change their color at night to a darker shade with a white horizontal stripe. First time I saw that, I thought it was a different species!
This one's a showstopper - looks like it swam straight out of an aquarium (or Finding Nemo if we're being real). Here's how to spot them:
The Moorish idol is sacred in Hawaiian culture - it's said to bring good luck. I always feel blessed when I spot one during a morning snorkel.
Kauai has over 20 species of butterflyfish, but here are the ones you'll definitely see:
Longnose Butterflyfish (Lauwiliwili) - Bright yellow with a black mask and a seriously long nose. They use that nose to pick tiny invertebrates out of coral crevices. Super common at Anini Beach.
Raccoon Butterflyfish - Named for the black mask over their eyes. They're curious and will often check you out while you're snorkeling.
Threadfin Butterflyfish (Kikakapu) - Orange with a black spot and threadlike extensions from their dorsal fin. These are usually in pairs - butterflyfish mate for life, which is pretty sweet 💕
Wrasses are everywhere on Kauai reefs, and they're fascinating to watch:
Hawaiian Cleaner Wrasse (Hinalea) - Small, blue and black striped fish that run "cleaning stations" where bigger fish line up to get parasites removed. It's like watching an underwater car wash!
Christmas Wrasse - Green body with red and white markings (hence the holiday name). Males and females look completely different, which threw me off at first.
Bird Wrasse - The males have an elongated snout that looks like a bird's beak. They're fast swimmers and hunt for small fish and crustaceans.
You'll hear parrotfish before you see them - they make this loud crunching sound as they bite chunks of coral to eat the algae. They literally poop sand (those white sandy beaches? Yeah, fish poop). The males are usually bright blue-green, and they can change colors throughout their life.
Pufferfish (o'opu hue) are adorable until they feel threatened - then they puff up like a balloon. The porcupinefish takes it further with spines that stick out when inflated. I've never seen one fully puffed in the wild (and I don't want to stress them out), but they're super cute swimming around normally.
Don't freak out - moray eels look scary but they're actually pretty chill. They hide in reef crevices with their mouths open (that's how they breathe, not a threat display). Just don't stick your hands in dark holes and you're good. The yellowmargin moray is the most common one around Kauai.
North Shore (Summer Months)
South Shore (Year-Round)
East Shore
⚠️ Always check current conditions before heading out. When in doubt, don't go out! 🌊
Real talk - regular sunscreen is killing our reefs. The chemicals (especially oxybenzone and octinoxate) bleach coral and mess with fish reproduction. Hawaii banned these ingredients in 2021, but you still need to make sure you're using reef-safe sunscreen.
Look for:
I use Raw Elements or Stream2Sea - both work great and don't leave you looking like a ghost. You can also just wear a rash guard and skip sunscreen on your body altogether.
I know it's tempting, but feeding reef fish is actually harmful:
Just watch and enjoy - the fish are doing their thing, and that's way cooler than turning them into water beggars. Trust me, they're more interesting when they're acting natural.
If you're lucky, you might spot some of these less common Kauai reef fish:
Hawaiian Lionfish - Not aggressive like their invasive cousins in the Caribbean. Ours are native and beautiful with flowing fins.
Hawaiian Turkeyfish - Similar to lionfish, with dramatic spines. Usually hiding under ledges during the day.
Manta Rays - Not technically reef fish, but occasionally cruise by reef areas. Seeing one is pure magic ✨
Spotted Eagle Rays - Graceful swimmers with white spots. I've seen them at Tunnels a few times - always makes my day.
Morning snorkels (7-10am) are primo for several reasons:
Late afternoon (3-5pm) can also be good, especially in summer when the water's calm. Just avoid midday - that's when the fish are chilling in the shade and you probably should be too 😎
After thousands of hours in the water, here's what I've learned:
Move Slowly - Fish spook easily. Calm, gentle movements let you get closer for better views.
Look Under Ledges - That's where the shy fish hang out during the day. Eels, lionfish, and sleeping parrotfish all love dark spots.
Watch the Sand - Stingrays, flounder, and other bottom dwellers blend in perfectly. Look for eye bumps or outline shapes.
Early Morning = Cleaner Stations - This is when fish line up to get cleaned by wrasses and shrimp. It's like watching a nature documentary live.
Bring an Underwater Camera - Even a waterproof phone case works. You can identify fish later using apps or guides.
Want to level up your fish knowledge? Here's what I use:
These Kauai reef fish depend on healthy coral ecosystems. Here's how to be a good reef visitor:
The reefs around Kauai are special, and they need our protection. Every time you snorkel responsibly, you're helping preserve this underwater paradise for future generations.
Here's my final advice after years of exploring Kauai's reefs: Don't rush it. I see tourists trying to check off every beach in one trip, spending 20 minutes in the water, then moving on. Pick one or two spots, spend real time there, and actually watch the fish. You'll see behaviors and interactions that most people miss.
The humuhumunukunukuapua'a protecting its territory, the cleaner wrasse running its station, the parrotfish munching coral and pooping sand - this is the real show. These Kauai reef fish aren't just pretty decorations; they're living, breathing creatures with personalities and behaviors that'll blow your mind if you take the time to observe 🌺
And honestly? Once you start recognizing individual species, you can't stop. You'll become that person pointing at fish and calling out their names. Welcome to the club 🤙
Questions about where to snorkel or what fish you saw? Chat with me at https://alohakai.ai - I'm always happy to talk about our underwater neighbors!