Fish Identification Guide - 20 Species of Puget Sound & the Northwestern USA

01
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Puget Sound, Washington

View of Seattle scuba diving.
A view of Seattle, Washington from Alki Cove 2, a popular shore diving and training site. © Lynne Flaherty

Divers huddle together, clutching coffee cups. Steam rises from between their hands, disappearing against a backdrop of gray skies and grayer water. It's 45° F in February, and the water temperature is only a few degrees warmer. Surprisingly, the divers do not appear deterred; they enthusiastically chatter while squeezing into their drysuits. What could be worth braving these conditions? The waters around Puget Sound, Washington boast some of the most colorful, bizarre sea life that a diver can encounter. In fact, Jaques Cousteau once named it his second favorite place to dive in the world. This isn't warm water Caribbean diving, but in many ways, it's better.

02
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Giant Pacific Octopus

photo of a large red cotopus underwater with a scuba diver
A giant pacific octopus, Enteroctopus dofleini. © istockphoto.com

The giant pacific octopus, Enteroctopus dofleini, is perhaps the most beloved denizen of Puget Sound. These reddish-brown giants average about 60 - 80 lbs, and the largest reported specimen was an astonishing 600 lbs and 30 feet across. Like all octopuses, the giant pacific octopus is venomous, but its venom is not dangerous to divers. The giant pacific octopus uses its poison to stun its prey before dragging it back to its den for a leisurely meal. Divers can often locate a giant pacific octopus den by looking for discarded piles of shells, known as a midden pile, that the octopus tosses out after finishing a snack.

More aquatic life:
Yellowhead Jawfish
•  Seahorses & Pipefish
Jellyfish

Octopuses are highly intelligent creatures, and the giant pacific octopus is no exception. This creature is curious, and occasionally emerges from its lair to investigate and interact with divers, especially when treats are offered. The internet is awash with images of these playful animals suctioning onto diver's heads, arms, and even regulators. While this may seem like great fun, having a mask or regulator pulled off could be dangerous, so divers would do well to exercise caution when interacting with a giant pacific octopus.

03
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East Pacific Red Octopus

photo of a small red ocotpus changing colors.
The east pacific red ocotpus, Octopus rubescens, can change its color to camouflage with its environment. © Lynne Flaherty

The east pacific red octopus, Octopus rubescens, looks like a miniature version of the giant pacific octopus. This small, solitary octopus can be found along the west coast of North America from California to Alaska, and is most commonly spotted in temperate waters of bays and estuaries. East pacific red octopuses average about 3 - 5 ounces in weight and slightly over 1 foot in length. Like the giant pacific octopus, east pacific red octopuses can sometimes be spotted by looking for a midden pile marking a den.

Octopuses can change color by means of special skin cells known as chromophores. The eastern pacific octopus can be difficult to spot because it can darken and lighten its skin to camouflage with its environment. The octopus can lighten to a whitish yellow and darken to a deep brown. It can even mimic the spots and patterns of its surroundings! The easiest way to spot an octopus is to look for movement, so keep an eye out for moving rocks or coral on dives. Doing so may draw your eyes to an octopus!

04
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Wolf Eel

photo of wolf eels
Mated wolf eels share a den. © Lynne Flaherty (main photo), © istockphoto.com (inset)

With a face like a wrinkled grandmother, an 8-foot long body, and razor-sharp teeth, wolf eels (Anarrhichthys ocellatus) appear anything but friendly. However, experienced divers know that the appearance of these fish is deceiving. Wolf eels are known to play with divers, and will even accept treats of sea urchins and shell fish directly from a brave diver's hand (not that this is particularly recommended).

During the day, wolf eels hide in their dens in rocky ledges or coral. Inside a den, divers may often spot a mated pair of wolf eels; they mate for life and work together to defend their eggs from predators. Divers can differentiate male and female wolf eels by their colors. Males are grey and females are brown.

Wolf eels delight divers all along the pacific northwest, and may be found as far north as the Aleutian Islands. Interestingly, these cartilaginous fish are not true eels, but members of the wolffish family. As such, they have some unusual abilities including their ability to tolerate temperatures as cold as 30° F (below freezing!).

05
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Metridium Anemone

giant white anemones from seattle
Metrdium anomenes are gigantic -- check out the size of the anemones in comparison to the diver!. © Lynne Flaherty

Giant metridium anemones, Metridium farcimen, sprout all along the west coast of North America. These large, pale anemones can reach up to one meter in height and are often found growing in colonies. Like all anemones, metriduim anemones have stinging cells but do not pose a danger to divers who keep their distance. A giant anemone does not move quickly enough to reach out and attack a diver!

However, metridium anemones do move, albeit very slowly. As they move along the seafloor, these anemones sometimes leave small pieces of their foot behind, which grows into a genetically identical anemone. In this manner, whole colonies of cloned anemones may form. Colonies of metridium anemone clones have an interesting adaptation to repel invasion by others of their species. A special tentacle, known as a catch tentacle, will stick to any genetically different anemone the metriduim anemone touches, stinging and sometimes damaging the tissue of the invading anemone. Apart from cloning, metriduim anemones reproduce sexually by broadcast spawning, with males releasing sperm packets and females releasing eggs into the water column.

06
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Sunflower Sea Star

Sunflower starfish in puget sound.
Sunflower sea stars, Pycnopodia helianthoides, can be see in a variety of brilliant colors. © Lynne Flaherty (left) and NOAA (all others)

The sunflower sea star, Pycnopodia helianthoides, is the largest sea star in the ocean, with an arm span reaching up to 3 feet. Divers along the west coast of North America can spot these sea stars in a variety of brilliant colors, including orange, yellow, red and purple. Although sea stars are not known for their great speed, the sunflower sea star can move a relatively quick 3 feet/minute to capture clams, sea urchins, and other prey. Creatures that are normally stationary have been known to flee from an approaching sunflower sea star.

The sunflower sea star reproduces sexually, by spawning eggs and sperm into the water. However, this is not its only form of reproduction. The sea star is fissiparous, meaning that when one of its 16-24 arms is broken off, it can regenerate the severed limb. The severed limb can regenerate an entire sea star.

07
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Painted Greenling

Painted greenlings in puget sound scuba diving
Painted greenlings, Oxylebius pictus, are masters of camouflage. Can you see the painted greenling in the left-hand photo?. © Lynne Flaherty

Sometimes called the "convict fish" for its reddish-brown prison-shirt stripes, the painted greenling (Oxylebius pictus) is a small, bottom-dwelling fish inhabiting a range from Northern Alaska to Baja California. Like many bottom-dwelling fish, the painted greenling is a master of camouflage, darkening and lightening its skin to match its surroundings and hide from predators. On a night dive, a diver may be able to locate a spotted greenling despite its camouflage by looking around the bases of large anemones. The painted greenling often sleeps near large anemones for protection.

Divers may observe painted greenlings displaying some interesting breeding behaviors. During mating season, male painted greenlings change colors; they become nearly black with sparkly, iridescent spots. Once a female painted greenling lays her eggs, the male aggressively guards the bright orange brood until they hatch. He will attack any creature, including a diver, that ventures close to his unhatched young.

08
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Kelp Greenling

kelp greenlings, seattle scuba diving
Male kelp greenlings (main photo) and female kelp greenlings (right) are different colors. © Steve Lonhart, SIMoN

The kelp greenling, Hexagrammos decagrammus, is a strikingly beautiful fish found in coastal waters from Alaska to Southern California. As its name suggests, the kelp greenling is often found in kelp forests, though it is occasionally observed on sandy ocean floors and in other environments.

Male and female kelp greenlings look very different, which is unusual in fish. Both genders grow to about 16 inches in length and are gray or red-brown. Males have squiggly, iridescent blue patterns and red spots, while female kelp greenlings are marked with gold or red spots and have yellow or orange fins. Both males and females are favorites of underwater photographers!

09
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Black Rockfish

a black rockfish, seattle scuba diving
Black rockfish, Sebastes melanops, turn a mottled silver with age. © istockphoto.com

Divers who spot a black rockfish, Sebastes melanops, underwater should note its color. Black rockfish have an unusually long lifespan (up to 50 years!) and turn gray or white with age. Scuba divers may spot black rockfish along the coast from Alaska's Aleutian Islands to Southern California. These rockfish are pelagic, unlike some other species rockfish which are bottom dwellers. Divers may observe them hovering singly or in schools over rock piles and other topography.

Black rockfish have been called a variety of names, including black bass, black rock cod, sea bass, black snapper, pacific ocean perch, red snapper, and pacific snapper. However, according to the Monterrey Bay Aquarium, there are no snapper on the west coast of North America. Fish listed on a menu as pacific snapper are likely to be black rockfish! Unlike many other fish, black rockfish are listed as a stable species, so divers may enjoy them both in the water and on their dinner plates without guilt.

10
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Copper Rockfish

a copper rockfish
Copper rockfish, Sebastes caurinus, have a wide, pale line down the last 2/3s of their bodies. © Timothy J Nesseth, NOAA

Most west coast divers have probably already seen the common copper rockfish, Sebastes caurinus, resting over rocks or on the sea floor. Like its relative, the black rockfish, copper rockfish have long life spans of up to 40 years. Copper rockfish are notoriously hard to kill, earning them the nickname "never die" for their ability to survive in the air for a surprisingly long time. This hasn't deterred fisherman, and copper rockfish are a popular sport and food fish.

Copper rockfish are medium-sized, about 22 inches and 11 lbs. They may be difficult to identify because they are found in a variety of colors. Copper rockfish are most commonly pinkish to dark reddish-brown with copper or iridescent white mottling. However, in some regions they are red (California) or black (Alaska). In all cases, copper rockfish may be identified by their pale bellies, spiny dorsal fins, and the wide, pale stripe beginning below their dorsal fins and running to the base of their tails. Copper rockfish are also a known as chuckleheads and whitebellies.

11
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Quillback Rockfish

quillback rockfish, seattle scuba diving
Quillback rockfish, Sebastes maliger, do not have a pale line on their sides, distinguishing them from the copper rockfish. © Lynne Flaherty

Quillback rockfish, Sebastes maliger, are named for the quills or spines on their dorsal fins. While all rockfish have spines, the quills of the quillback rockfish are more obvious due to their coloration. The fish's body is mottled orange and brown, while its first few quills are light yellow. The quills will inject a painful poison if touched, but the fish is not deadly to divers. Quillback rockfish are the smallest of the rockfish listed in this guide, reaching a length of about 2 feet and a weight of between 2-7 lbs. They live to be about 32 years old.

More aquatic life:
•  Sea Urchins
•  Sharks
Fire Coral

Scuba divers can find quillback rockfish resting near or on the seafloor. They habitually hide among rock piles, in kelp, or in shelter holes, relying on their coloration and spines to protect them from predators. In Puget Sound, quillback rockfish usually stay within a home territory of about 30 square meters, making them easy to locate after an initial spotting. Quillback rockfish inhabit waters along the coast from Alaska to the Channel Islands in California.

12
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Grunt Sculpin

grunt sculpin, seattle scuba diving
A grunt sculpin's unique body shape allows it to fit comfortably in its favorite hiding place - the shell of a giant acorn barnacle. © Lynne Flaherty

Grunt sculpin, Rhamphocottus richardsonii spend most of their time hiding. Their favorite hiding place is inside giant acorn barnacle shells. If the fish backs into the barnacle shell, it's snout resembles the covering that the barnacle would use to seal off its shell. If the fish enters its hiding place head-first, its tail looks like the feeding tentacles of the barnacle. The grunt sculpin's ability to hide and camouflage is essential to its survival. This 2-3 inch fish has few other defenses and cannot swim quickly away from predators. It walks or hops over the floor on its orange pectoral fins -- it's endearing, but slightly pathetic.

The grunt sculpin's appearance is almost stranger than its method of locomotion. It has a long snout and a large, thick head which makes up about 60% of its total body length. The patterns of the grunt sculpin are an array of wild animal prints over a cream, yellow or tan body. The fish has stripes like a zebra, a leopard's spots, and giraffe-like blotches, all outlined in black. Grunt sculpins are named for the grumpy, grunting sound they make when removed from the water.

13
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Scalyhead Sculpin

a sculpin fish on a seattle scuba dive.
Scalyhead sculpin, Artedius harringtoni, have bright orange gills. © Lynne Flaherty

Scalyhead sculpin, Artedius harringtoni, are masters of disguise, blending in flawlessly with algae, sand, rocks, sponges and coral. These fish lay flat on the bottom and change their colors to match the environment. Scalyhead sculpin can pale or darken, and may even adjust their patterns for camouflage. At times, iridescent blue squiggles, shiny red dots or dark, thick bars are visible on the the fish's body.

Regardless of the colors that a scalyhead sculpin chooses to wear, the fish may be identified by its bright orange gills. Several orange lines run through the scalyhead sculpins' eyes, and cirri (small branching appendages) are visible on its forehead. Observant divers may also spot tiny, fleshy protrusions beginning at the fish's head and continuing in a row down its body. The bellies of the scalyhead sculpin have round, pale spots.

14
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Longfin Sculpin

Longfin sculpin, seattle scuba diving
Longfin sculpin, Jordania zonope, can be bright red. © Lynne Flaherty

Longfin sculpin,

Jordania zonope

, are a favorite of underwater photographers. They are brilliantly colored, often displaying bright crimson hues. Longfin sculpin, like other members of the sculpin family, are bottom dwellers. Divers can spot them perching atop rocks, sponges and coral. They are more active other types of sculpin, and their darting movements help divers locate them despite their camouflage and small size (max 6 inches). Longfin sculpin can be differentiated from similar fish by the orange and green lines radiating from their eyes in a sunburst pattern.

15
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Showy Snailfish

a showy snailfish, seattle scuba diving
Showy snailfish, Liparis puchellus, have thin lines running from snout to tail. © Lynne Flaherty

Showy snailfish, Liparis puchellus, are perfectly named. With soft, scaleless bodies and tapering tails, the showy snailfish resembles nothing so much as a snail without a shell. The showy snailfish has smooth lines running from its blunted snout to the tip of its tail, interrupted by the occasional cluster of spots. The snailfish moves and looks a bit like an eel, but unlike eels it has small pectoral fins. A continuous dorsal (top) and ventral (bottom) fin runs the length of its body.

Dive travel:
• Wreck Diving in Tobermory, Canada
• Mozambique, Africa
•  Ambergris Caye, Belize

Showy snailfish are most commonly sighted resting on soft, sandy bottoms, often curled up around their tails like sleeping dogs. They range in color from pale, golden yellow to chocolate brown. Showy snailfish can be found along the coast from the Aleutian Islands in Alaska to central California.

16
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Pacific Spiny Lumpsucker

a spin lumpsucker fish, seattle scuba diving
Pacific spiny lumpsuckers, Eumicrotremus orbis, have fused pelvic fins that act as a suction cup. © Lynne Flaherty and NOAA (inset)

Pacific spiny lumpsuckers, Eumicrotremus orbis are so ugly that they are cute. These adorable fish are difficult to spot. They have spherical bodies that are only 1-3 inches long, come in a variety on unexpected colors such as pink and yellow, and usually sit motionless on rocks or other perches. Finding a pacific lumpsucker is worth the effort. They have comical, almost confused expressions, often appear slightly flustered, and tend to roll their eyes around dramatically. When disturbed, the pacific spiny lumpsucker will flutter its nearly useless fins to move itself aimlessly around in the water column before settling on a new perch.

The most outstanding feature of the pacific spiny lumpsucker is its pelvic fins, which are fused into a modified suction cup. The fish suctions onto a rock or other solid surface, then remains as still as possible to escape predators. The fish's skin is covered with scaly plates which have spiny protrusions, called tubercles, lending it a lumpy appearance. These silly, delightful fish can be found all along the western coast of North America.

17
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Ling Cod

a ling cod, seattle scuba diving
Ling Cod, Ophiodon ozymandias, are aggressive predators. © Magnus Kjaergaard, wikipedia

Ling cod, Ophiodon ozymandias, are endemic (only found) along the west coast of North America. Despite its name, the ling cod is not true cod, but a type of bottom-dwelling greenling. They are very large, reaching up to 5 feet and 100 lbs, but camouflage themselves well in mottled shades of green, yellow, gray and brown.

Ling cods have long, eel-like bodies and very large heads, earning them the nickname "bucketheads." The most prominent feature of the ling cod is its huge mouth filled with many sharp teeth. Ling cods are voracious predators that will eat almost anything they can fit in their mouths. These fish are not usually dangerous to divers, but males have been known to aggressively guard their nests when eggs are present. Divers should give nesting ling cods plenty of space to avoid being nipped!

18
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Cabezon

cabezon fish, seattle scuba diving
The male cabezon guards its eggs (pink). Cabezons may be observed guarding eggs in a variety of brilliant shades -- each color is from a different female! Stay far away from nesting males as they will become quite aggressive if their nests are threatened. © Peter Rothschild

Cabezon, Scorpaenichthys marmoratus, are the largest type of bottom-dwelling sculpin found along the pacific coast of North America, reaching 25 lbs and 30 inches. They resemble scorpionfish, displaying dappled shades of brown, green, red and yellow. Like many bottom-dwelling fish, the cabezon is an expert at camouflage. It hunts by hiding in plain sight and snapping up prey that venture close to its wide-lipped mouth.

Cabezon are identifiable by their large heads (cabezon means "big head" in Spanish), thick, tapered bodies, and the fleshy appendages above their eyes. They do not have scales, but a cabezon's dorsal fin is laced with sharp spines. With excellent camouflage, great size, and defensive spines, cabezon have few natural predators. However, males guarding nests will often remain stubbornly in place, and are easy prey for spear and sport fisherman.

19
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Alabaster Nudibranch

an alabaster nudibranch, seattle scuba diving
Alabster nudibranchs, Dirona albolineata, have fleshy appendages with frosty white tips. © Lynne Flaherty

Alabaster nudibranchs,

Dirona albolineata

, are relatively large (5 inches), marine gastropods that are quite common in Puget Sound. They have beautiful, white-tipped, fleshy appendages known as

cerata

. Nudibranchs use cerata to breathe underwater, absorbing oxygen from the ocean through the appendage's thin flesh. Alababaster nudibranchs can be found in hues ranging from white to salmon pink. This nudibranch is also called the white-lined dirona, chalk-lined dirona, and frosted nudibranch.

20
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Clown Nudibranch

a clown nudibranch, seattle scuba diving
The clown nudibranch, Triopha catalinae, is most likely named for its bright orange spots. © Lynne Flaherty

The clown nudibranch, Triopha catalinae, is found in waters all along the west coast of North America. It is easy to identify, with a white body covered orange or yellow cerata. The clown nudibranch has two, orange tipped rhinopores, organs which it uses as chemical sensors. The rhinopores look a bit like short tentacles and have tightly packed, thin layers of flesh that resemble gills, but are not used for breathing. More Fish Identification: Caribbean Reef Fish Guide >>

* Special thanks to Lynne Flaherty for her photos and consultation on this guide!