Unlock the Secrets of Fish Identification – Part 2 Behavior

Ever wonder where fish hang out in the ocean? Are they hiding under the sand, lounging on the seafloor, or cruising the open water? Fish don’t just live anywhere – they have their favorite spots! In this blog, we’ll dive into the fascinating world of fish behavior, from their different swimming styles to their unique hunting tactics. Whether they’re blending into the sand like a flounder or schooling in massive groups like surgeonfish, each fish has its own way of making the ocean their home. So, let’s take a deep dive, starting from the bottom, and explore how fish interact with their underwater world. Ready to swim along? Let’s go!

Water column – where is the fish positioned in relation to the seafloor? Does it bury under sand, rest on the bottom, hover near objects, or swim freely in the water column? Let’s start at the bottom and work our way up.

There are several families of fish that live on and under the substrate, such as flounder, stingray, stargazers, jawfish, garden eels, and lizardfish. These fish are not built for speed, they rely on camouflage, burying themselves under sand, or hide in burrows.

A mottled jawfish peaking out from its burrow in the sand

brown garden eels in their burrows in the sand

a sand stargazer that has been lifted to the surface of the sand

Moving up to fish that will be associated with the seafloor, but don’t go under it, families of fish such as goatfish, flying gurnards, batfish, gobies, blennies, dragonets, scorpionfish, and hawkfish. These fish typically rely on camouflage and can have some odd body shapes.

a shortnose batfish flashing a lure to attract smaller prey fish

a yellow goatfish with barbels looking for food on the seafloor

a flying gurnard over the seafloor

Higher in the water column are fish that aren’t associated with the seafloor, but hang out around structure for protection, families such as butterflyfish, angelfish, snappers, and groupers. Many of these fish will have disruptive coloration to help them blend in with their backgrounds.

a foureye butterflyfish hiding behind fire coral

a bigeye snapper hiding under a ledge

white-spotted filefish in a crack in the reef

Some fish prefer to live in the water column, they tend to be faster and hunt their prey items (sharks, tuna, dolphinfish, mackerel). A few fish live just under the surface of the water and hope not to be noticed while they are so close the surface (needlefish) or have elongated pectoral fins that can act as wings (flying fish) so that they can glide out of the water to escape predators!

a dolphinfish, or mahimahi, swimming in the open ocean

three tarpon in the water column

needlefish just under the water's surface

Solitary vs schooling – when you see a new fish, pay attention to if it is solitary or if it prefers to school. Look closer to see if the fish prefers to be in pairs, if it hangs out with a different species, or if it schools with only other members of the same species.

a red grouper over a seagrass bed

a goldentail moray peaking out from a crack in the reef

a Caribbean reef shark swimming by the reef

Most larger predators are solitary like sharks, groupers, and barracudas, although they can school.

Some fish will hang out with other species, such as remora and bar jacks. Butterflyfish are usually found in pairs. Other fish prefer to school with only similar species, such as grunts, snappers, squirrelfish. Some fish will school, but only with members of the same family, you will commonly see large schools of surgeonfish, made up of blue tang, ocean surgeonfish, and doctorfish. Some fish just believe in safety in numbers and will hop in with whatever fish are nearby.

a sharksucker remora on a green sea turtle

a bar jack shadow feeding with a Southern stingray

a pair of foureye butterflyfish

a school of French grunts

a school of surgeonfish, blue tang and doctorfish

a school of Southern sennet and mackerel scad

How it swims – pay attention to the way that the fish is swimming, does it swim by using its tail, its dorsal and anal fins, or its pectoral fins. Most fish swim by using their tail, including these families: jacks, groupers, snappers, grunts, tarpon, sharks, and barracuda. Some fish swim using primarily their dorsal fin, such as: triggerfish, boxfish, and pufferfish. Two families swim using their pectoral fins, parrotfish and wrasse, this is a key clue to identify these families. You can also note how much of the body is involved in swimming, eels have a wave-like swimming pattern that moves the entire length of the body.

a gray snapper swims using its tail

Caribbean reef sharks swim using their tail

Cero mackerel have a keel near their tail to make swimming more effecient

Stoplight parrotfish swim using their pectoral fins

Spotted trunkfish swim using their dorsal and anal fins

Spotted morays have a wave-like swimming pattern

Other unique behaviors – some fish are mouth brooders (cardinalfish and jawfish) meaning that they protect their eggs by keeping them safe within their mouths. Many of the highly camouflaged bottom dwelling fish are ambush predators and remain extremely still and wait for an unsuspecting smaller fish to swim by, then they attack! Frogfish and batfish wave an appendage to lure smaller fish to them. Bar jacks will follow Southern stingrays around hoping to grab a free snack when the stingray feeds, this is called shadow feeding.

From the camouflaged bottom dwellers to the sleek swimmers of the open water, fish have mastered the art of adapting to their environment in incredible ways. Whether they’re blending in with the seafloor, schooling for safety, or using unique methods to move and hunt, each species has its own fascinating behaviors and strategies for survival. Next time you’re underwater, take a moment to observe how these amazing creatures position themselves in the water column, and you’ll unlock a whole new level of appreciation for the diverse, dynamic world beneath the waves. Happy snorkeling!

A longlure frogfish waiting to ambush its next meal! 

I’d love to hear about your own fish identification experiences! Drop a comment below and share what fish you've spotted or any tips you've picked up along the way.

To help you along your fish ID journey, some great resource are the app Fishes: Greater Caribbean by D. Ross Robertson and James Van Tassell and the ID books Reef Fish Identification Florida, Caribbean, Bahamas by Paul Humann and Ned DeLoach and Caribbean Reef Life – A Field Guide for Divers by Mickey Charteris

All photos from Sara and Lee Richter