Bohol Fish ID
Explore the amazing variety of fish found in Philippine waters
Diving in Bohol is spectacular, but it becomes even more rewarding when you know what’s swimming around you. This guide is designed for divers who want to identify and understand the rich marine life of the Philippines, from corals and tiny invertebrates to large predators and pelagic giants.
Here, you’ll find information about hard and soft corals, sponges, sea turtles, fish schools, predators, and fascinating reef inhabitants, along with tips on how to identify them underwater. Whether you’re a beginner or an experienced diver, this guide will help you spot, recognize, and appreciate the incredible biodiversity of Bohol’s reefs.
If you're interested in Panglao fun dives or information about the different Panglao Dive sites, please visit our webpages dedicated to these topics.
Hard Corals (Scleractinia)
Hard corals are the architects of the reef. Built from a rigid calcium carbonate skeleton, each tiny polyp lives in its own unit, and when it does, it creates a stone-like structures that accumulate over thousands of years. In Bohol, you’ll find brain corals, staghorn corals, and button corals, and others, which form complex habitats for small fish and invertebrates. Despite covering less than 1% of the ocean floor, hard corals support over 25% of marine species.
Cohabitance / Symbiosis
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Host zooxanthellae, algae providing energy via photosynthesis
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Shelter for small fish, shrimps, and invertebrates
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Crucial for reef ecosystem stability
ID Tips
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Rigid, calcified structures
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Shapes: brain, staghorn, button, plate-like
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Color varies: brown, green, yellow
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Polyps are visible when expanded
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Found from shallow to mid-depth reefs
Soft Corals (Alcyonacea)
Soft corals look much more like plants or underwater bushes than the rigid stone-like hard corals. They don't have a solid calcium-carbonate skeleton; instead, they’re built from a flexible structure made of protein and light calcium elements. This allows them to sway beautifully with the movement of the water.
They feed on tiny particles carried by the current and display a much wider range of colors than hard corals — bright reds, purples, oranges, pinks, and yellows are all common.
One of the most impressive soft corals in Bohol is the Sea Fan (Gorgonian). Large sea fans are especially striking in areas like Doljo, where they can grow to over a meter across. They open like a giant fan along the reef wall, covering broad surfaces and forming an intricate network of branches.
Their shape isn’t just beautiful — it’s functional. The flat, fan-like structure positions them perfectly in the current, allowing them to catch as much plankton as possible. Within their branches, you can often find tiny gobies, pygmy seahorses, and small shrimps that blend perfectly with the sea fan’s color and texture.
Cohabitance / Symbiosis
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Shelter for small fish and invertebrates
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Capture plankton from the water
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Contribute to reef biodiversity and complexity
ID Tips
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Look for flexible, waving branches
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Bright, bold colors covering large areas
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Often attached to reef walls or hard substrates
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Small fish and invertebrates may hide among branches
Sponges (Porifera)
Sponges are some of the simplest multicellular animals, consisting of a network of pores and channels. They filter water to extract nutrients and remove debris, creating clean water for the reef. Bohol is home to hundreds of sponge species, including barrel-shaped, tubular, and encrusting forms, in vibrant colors like purple, yellow, red, or white. Many small creatures, such as shrimps and nudibranchs, live among the sponge’s textures for camouflage and protection.
Cohabitance / Symbiosis
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Provide shelter for shrimp, crabs, and juvenile fish
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Filter water, improving water quality for the reef
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Some species share pigments or toxins with their inhabitants for protection
ID Tips
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Porous, sometimes barrel- or tube-shaped
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Bright colors: purple, yellow, red, white
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Often stationary on rocks or coral
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Tiny creatures can be seen entering/exiting
Bohol Sea Turtles – Green and Hawksbill
Bohol’s reefs host green and hawksbill turtles. Green turtles feed mainly on algae and seagrass, while hawksbills prefer sponges and soft corals. Hatchlings imprint on the beaches where they were born, using Earth’s magnetic field to return decades later to lay eggs. Juvenile turtles spend years in the open ocean, a stage known as “the lost years,” feeding on plankton and jellyfish before returning to reefs for food and shelter. Adult females return to the exact beach of their hatching to nest, sometimes after thousands of kilometers of migration.
Sea turtles begin their lives as eggs buried in sandy beaches, usually in the southern Philippines and Indonesia. When the hatchlings emerge, they imprint on the beach using the Earth’s magnetic field — an incredible natural navigation system that guides them throughout their entire lives.
After hatching, the young turtles spend several years drifting and migrating through the open ocean, a period often called “the lost years.” During this stage, they feed on plankton and small jellyfish as they grow.
As they mature, they eventually return to coastal reefs like those in Bohol, where they find abundant food and safe resting spots. Green turtles feed mainly on seagrass and algae, while Hawksbill turtles prefer sponges and soft corals.
Once they reach adulthood (around 20–30 years old), the females undertake one of nature’s most impressive navigation feats: they migrate thousands of kilometers to return to the exact same beach where they were born to lay their eggs.
Cohabitance / Symbiosis
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Maintain reef health by controlling algae growth
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Hatchlings imprint on natal beaches and return decades later to lay eggs
ID Tips
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Shell shape: Green turtles are rounder, Hawksbills are more serrated
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Look for slow swimming near the reef or seagrass beds
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Often solitary but sometimes feeding in small groups
Jellyfish (Cassiopea and Others)
Cassiopea, commonly known as “upside-down jellyfish,” live with their bell facing downward and their oral arms pointing upward. You can usually find them in warm, shallow, sunlit areas. They live in partnership with microscopic algae inside their tissues, which provide them with energy through photosynthesis — very similar to how corals and their symbiotic algae live.
Cassiopea also produce a special type of mucus that contains cassiosomes — tiny clusters filled with stinging cells. These allow them to “sting at a distance,” even without direct contact.
Researchers have also found that they can enter a sleep-like state at night, a surprisingly advanced behavior for such simple animals that have existed since before the age of dinosaurs. Alongside Cassiopea, you can find several other jellyfish species in the Philippines, and not all of them sting as strongly as people expect.
Cohabitance / Symbiosis
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Host zooxanthellae for energy
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Mucus can immobilize small prey
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Some species sleep at night
ID Tips
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Bell facing downward, tentacles upward
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Often stationary in shallow sand flats
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Look for pulsating movements
Clownfish & Sea Anemones
All clownfish are born male. In every group, the largest and dominant individual becomes the female. If the female dies, the dominant male immediately begins a natural sex-change process and becomes the new female — a fascinating hierarchy that keeps the group stable.
Clownfish are immune to the sting of their host anemone thanks to a special mucus coating on their skin, which prevents the anemone from recognizing them as prey. Each breeding pair claims a single anemone as their exclusive home, while the remaining fish maintain a strict social ranking and patiently wait for their chance to “move up.”
They communicate using quick clicking sounds and subtle body movements — a surprisingly complex social system for such small fish.
Cohabitance / Symbiosis
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Mutualistic: anemone provides shelter, clownfish clean and aerate the tentacles
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Other fish avoid the stinging tentacles
ID Tips
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Orange/yellow with 1–3 white stripes
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Hovering near tentacles
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Found in pairs or small family groups
Jackfish Schools (Carangidae)
Large schools of jackfish move in almost perfect synchrony. When circling, they create a “cyclone effect” that confuses predators, making it extremely hard to isolate an individual.
Cohabitance / Symbiosis
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Schooling behavior reduces predation risk
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Often hunt smaller fish in open water
ID Tips
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Silvery, fast-moving, medium to large-sized
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Move in tight coordinated schools
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Slightly forked tail, streamlined body
Barracudas (Sphyraenidae)
Barracudas are sleek, predatory fish with sharp, uneven teeth and exceptional vision, able to detect flashes of light from prey over 20 meters away. Despite their intimidating appearance, they rarely attack divers. They can accelerate from 0–40 km/h in less than a second, making them top reef predators.
Cohabitance / Symbiosis
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Solitary hunters
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Maintain reef balance by controlling small fish populations
ID Tips
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Long, streamlined, silver-gray
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Sharp teeth visible in open mouth
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Often alone or in small groups
Anthias & Damselfish (Fusiliers, Chromis, etc.)
Huge, colorful schools of anthias and damselfish are one of the most iconic sights on Bohol’s reefs. These fish are among the most common species in the area, forming massive groups that can number in the thousands. They move together in perfect coordination, creating a hypnotic display that also helps confuse predators.
One of the most fascinating facts about anthias is their unique ability to change sex. In many species, when the dominant male disappears or dies, the leading female transforms into a male within just a few days. This ensures the group remains stable and continues breeding.
Anthias are also extremely loyal to their home reef. They spend their entire lives in the same coral patch, usually around branching corals like finger corals or Acropora. Each group guards a small territory, and their social structure is surprisingly complex: one male oversees a group of females, and he is also responsible for protecting the nest. The male uses his fins to circulate water around the eggs until they hatch. The eggs are sticky and attach to coral surfaces, making their survival heavily dependent on the health of the reef.
During the day, anthias are highly active, feeding on plankton carried by the currents. At night, they disappear deep into the coral branches to hide from predators.
Cohabitance / Symbiosis
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Schooling for protection and feeding efficiency
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Interact with cleaner species
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Maintain specific reef zones and territories
ID Tips
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Damselfish: small, bold, near corals
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Anthias: mid-water, males bright, females pale
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Fusiliers: streamlined, silver/blue, fast-moving
Nudibranchs (Sea Slugs)
Nudibranchs are among the most colorful and fascinating creatures you can spot while diving. Bohol is home to many different species, each with its own unique mix of colors, shapes, and patterns. They’re usually very small, only a few centimeters long — so spotting them requires sharp eyes and a bit of patience.
You can find nudibranchs almost anywhere on the reef, but they’re especially common on sponges and algae, where they feed and often lay their eggs. When they move, their edges ripple softly like tiny waves, and their two front “horns,” called rhinophores, stick up prominently. These aren’t horns at all, but sensory organs that help them smell and navigate their surroundings.
If you find one nudibranch, take a moment to look around — there are often one or two more in the same area.
Cohabitance / Symbiosis
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Store toxins from sponges or cnidarians for defense
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Often found near food sources like sponges or corals
ID Tips
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Small, slow-moving, extremely colorful
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Look carefully on sponge or coral surfaces
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Shapes and rhinophores are key for identification
Crinoids and Commensal Shrimps
Feather stars (crinoids) host tiny shrimps that mimic the colors and textures of their host. Shrimps may even change color within days to match a new crinoid, an extraordinary camouflage adaptation.
This tiny shrimp lives among the arms of a feather star, using its black-and-white pattern to blend perfectly with its host. Their relationship is considered commensal: the shrimp gains protection and access to food particles trapped in the feather star’s arms, while the feather star itself is generally unaffected.
One of the most fascinating aspects of this species is its camouflage ability — some individuals have been observed changing their coloration within just a few days to match the exact shade and pattern of the specific feather star they inhabit. It’s one of the most impressive and elegant examples of adaptation in the underwater world.
Cohabitance / Symbiosis
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Shrimps gain shelter and protection
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Crinoids generally unaffected
ID Tips
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Observe shrimps blending with crinoid arms
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Stationary among crinoid arms
Frogfish
One of the ocean’s ultimate masters of disguise, the frogfish can change its color and pattern to blend perfectly with its surroundings — from sponges to corals and even bare rocks. Instead of swimming, it “walks” across the reef using modified pectoral fins, giving it an almost terrestrial look underwater.
On its head sits a tiny lure called an esca, which it wiggles to attract curious prey. When a small fish gets close enough… the frogfish strikes in less than 0.01 seconds. If you’re lucky enough to catch the moment it opens its giant mouth, you’ll see an incredible vacuum effect — it literally sucks the prey in whole. Most of the time, though, it barely moves, waiting patiently in the same spot for days until the perfect opportunity arrives.
Bohol is home to a wide variety of frogfish species in different colors and sizes, and with a sharp eye, you can spot them at many local dive sites.
Frogfish Species in Bohol
Giant Frogfish:
Common around Bohol, this species appears in many colors — white, orange, pink, or yellow — depending on the sponge or coral it lives on. Look for them on tube-like sponges, especially the white ones. Sometimes all you’ll see is a tiny eye or the twitching “fishing rod” it uses to lure prey.
Painted Frogfish:
Smaller and more colorful, often seen in shades of orange, red, black, or purple. Pay attention to the small spots on the body and the front fins that look almost like tiny hands. These frogfish love hanging around sponges that match their color.
Warty Frogfish:
Easily recognized by its bumpy, textured skin covered in wart-like protrusions. It’s often found on hard corals or bright orange sponges.
Whale Shark
The largest fish in the world, the whale shark can grow over 12 meters long and weigh more than 20 tons. Despite its massive size, it feeds on plankton, small fish, and fish eggs, filtering its food through delicate filtering plates inside its enormous mouth.
Each whale shark has a unique pattern of spots, almost like a fingerprint, which researchers use to identify individual sharks. They migrate thousands of kilometers each year but are often spotted around the Philippines, including Bohol — sometimes you might get lucky and see one on your dive!
Although they are giants of the ocean, whale sharks are completely harmless to humans. Still, it’s important to keep your distance to avoid disturbing their natural behavior.
Cohabitance / Symbiosis
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Filter feeder, harmless to humans
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Migratory behavior
ID Tips
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Huge size, slow-moving
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Unique spot patterns
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Often near the surface
White Tip Reef Shark
One of the most common sharks on Bohol’s reefs, the white tip reef shark is often found resting during the day under ledges, among coral, or in shallow caves. At night, they become active hunters, feeding on fish and squid, but they are generally very calm around divers.
They are easily identified by the white tips on their dorsal and tail fins, a classic distinguishing feature. White tip reef sharks are not dangerous to humans; they usually ignore divers or cameras and may swim away if approached.
Interestingly, they can rest on the seafloor for extended periods - a rare ability among sharks - because they can pump water through their gills even while stationary.
Cohabitance / Symbiosis
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Calm around divers
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Nocturnal hunters
ID Tips
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White tips on dorsal and tail fins
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Found near reef ledges or caves
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Medium-sized, slender body
Christmas Tree Worm
One of the most beautiful creatures on the reef, the Christmas Tree Worm lives inside a small hole in a coral, with only its colorful “tree” protruding.
The “branches” are actually gills and clusters of ciliated arms, which the worm uses both for breathing and capturing food particles from the water. If touched or startled by a shadow, the worm can retract instantly into the coral, only to reemerge moments later.
Each worm has unique colors and patterns, including shades of blue, yellow, pink, orange, or combinations thereof. While the worm does not benefit the coral and actually burrows into it to settle, its striking appearance makes it a favorite among divers.
Cohabitance / Symbiosis
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Coral host provides protection
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Rapidly retracts when touched or shadowed
ID Tips
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Spiral, vibrant colors: blue, yellow, pink, orange
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Stationary on hard coral
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Branches move slightly in the current
Octopus & Blue-Ringed Octopus
Octopuses are incredibly intelligent animals, capable of learning, solving problems, and remembering patterns. They have three hearts and blue blood, based on hemocyanin, which is highly efficient in low-oxygen environments.
More than half of an octopus’s neurons are located in its arms, each of which can make decisions independently. They are masters of camouflage, able to change color, texture, and shape in less than a second. Some species can even mimic other animals, such as flatfish or sea snakes.
Octopuses protect themselves using ink, which distracts predators and allows them to escape.
A notable species found in Bohol is the Blue-Ringed Octopus, a small but highly venomous species. When threatened, it displays bright blue rings as a warning to potential predators.
Cohabitance / Symbiosis
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Use reefs for shelter
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Prey on crustaceans and fish
ID Tips
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Observe arm movement and skin texture
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Look for rapid color changes
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Blue-ringed: tiny with bright blue rings
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Squid and Cuttlefish
Squid and cuttlefish are close relatives of octopuses and share the same remarkable ability to change color, pattern, and even texture in an instant. While octopuses use this skill mainly for camouflage, squid and cuttlefish rely on rapid color flashes for communication, hunting, and quick escape responses. Their eyes are among the most advanced in the ocean, similar in design to human eyes and capable of sharp vision even in very low light.
Cuttlefish, unlike squid, have a unique internal “cuttlebone” that allows precise buoyancy control and gives them their characteristic hovering, UFO-like movement. Both squid and cuttlefish have tiny teeth on their arms to secure prey, and males use a specialized arm called a hectocotylus to transfer sperm during mating — one of the most unique reproductive adaptations in the marine world.
In Bohol, squid and cuttlefish are most often spotted during evening or night dives, though lucky divers may encounter them hunting or resting during the day.
Cohabitance / Symbiosis
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Often hunt in loose groups or pairs
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Communicate constantly via color changes and pulsing patterns
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Sometimes follow larger predators to capitalize on startled prey
ID Tips
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Squid: streamlined body with side fins running along the mantle
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Cuttlefish: broader body with a skirt-like fin all around
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Tentacles shoot forward rapidly when capturing prey
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Color flashes, ripples, or sudden pattern changes signal communication or camouflage
Mantis Shrimps
Mantis shrimps are among the most fascinating predators of the reef. Known for their vibrant colors and incredible speed, these crustaceans can strike prey with lightning-fast punches or spear them with precision. They rarely swim in open water — instead, they “walk” along the reef using their highly adapted legs, blending perfectly with rocks, sponges, and coral.
The mantis shrimp’s head features a small lure (or esca) that it wiggles to attract curious prey, which it captures in a fraction of a second. Its powerful claws generate a vacuum-like suction, sucking prey completely into its mouth — a sight that is both efficient and mesmerizing.
Behavior and Adaptation
Mantis shrimps are masters of camouflage. Depending on the species, they may look like sponges, rocks, or pieces of coral, making them extremely difficult to spot even when you are looking directly at them. They spend most of their time stationary, waiting patiently for the perfect moment to strike.
There are multiple species with subtle differences:
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Giant Mantis Shrimp – large, often white, orange, pink, or yellow; usually found near tube-like sponges.
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Peacock Mantis Shrimp – smaller, brightly colored in orange, red, black, or purple; look for small spots and “arms” that resemble tiny hands.
Cohabitance / Symbiosis
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Mantis shrimps are mostly solitary but influence reef ecosystems significantly.
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Their burrows provide safe microhabitats for small fish, shrimp, and crabs.
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Burrow digging aerates sand and rubble, improving water flow and nutrient circulation.
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Some species (e.g., Peacock Mantis Shrimp) share loose burrow networks with commensal shrimp or gobies.
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Commensal neighbors gain protection, sometimes acting as early-warning systems for predators.
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This relationship is not as strict as clownfish-anemone mutualism but is essential for maintaining reef microhabitats.
ID Tips (for Divers)
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Watch for tiny movements among sponges or corals — a slight twitch can reveal their presence.
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Look for their claws or the small “lure” they wave to attract prey.
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Be patient; mantis shrimps can stay in one spot for days, making them a rewarding find for careful divers.
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Colors and patterns vary by species, so a keen eye is essential to spotting these masters of disguise.
Moray Eels
Moray eels are one of the most iconic residents of Panglao’s reefs. They have long, snake-like bodies and can range in color from dark brown and green to patterned spots or stripes. Most species hide in crevices or under ledges during the day, peeking out just enough to watch for prey or intruders. They are nocturnal hunters, feeding on fish, crustaceans, and cephalopods at night. Morays have sharp teeth and powerful jaws, which they use to catch slippery prey, but they are generally not aggressive toward divers unless provoked.
Cohabitance / Symbiosis
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Often share their reef crevices with cleaner shrimp or small fish, which remove parasites from the eel.
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Provide shelter to smaller reef animals, though indirectly.
ID Tips (for divers)
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Look for eels’ heads poking out of holes or cracks in coral and rock.
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Notice their distinctive dorsal fins running the length of the body.
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Some species have patterned skin that helps them blend into the reef.
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Watch for slow, deliberate movements — sudden lunges are usually defensive, not predatory toward humans.
Coloration and Camouflage in Marine Life
The bright colors of marine fish may seem like decoration to us, but for fish, they are an important tool for communication and survival.
Colors are produced by pigment cells called chromatophores, which serve multiple functions, including:
Camouflage
In many cases, colors are meant to disappear into the background. Fish with striped or spotted patterns can blend perfectly with coral and algae. For example, scorpionfish and butterflyfish use their patterns to hide effectively from predators.
Warning
Bright colors like vivid blue, yellow, or orange are used to ward off predators, acting like a “danger sign.” Examples include clownfish, nudibranchs, and the blue-ringed octopus.
Communication and Reproduction
During the breeding season, males change color to impress females or signal territory. In social species, colors also help identify individuals or hierarchy within the group.
Mimicry
Mimicry occurs when a fish or marine animal imitates another creature to deceive those around it. Sometimes this allows them to approach prey without arousing suspicion, while other times it helps them appear poisonous or dangerous to avoid predators. Some fish mimic cleaner fish to get close to other fish and take a small bite, while others change color and shape to blend in with coral, rocks, or sponges.
Conclusion
Bohol’s reefs teem with life, from tiny nudibranchs and colorful corals to majestic whale sharks. Recognizing species and their behaviors makes diving more exciting and rewarding. By observing carefully, respecting habitats, and using ID tips, divers can unlock the fascinating world beneath the waves. Join us on our Panglao Fun Dives trips, and explore Panglao's Dive Sites.