Pacific and California Halibut Facts - Large and Unusual Fish

A California halibut from San Francisco Bay
A California halibut from San Francisco Bay | Source

Halibut - More Than Just a Food Source

To many people, halibut are simply a good food source. They are actually very interesting animals. Halibut are flatfish. Flatfish have flattened bodies and swim on their sides. At the start of their lives they look like other fish. As they grow, they gradually change their orientation in the water so that they are moving with their right or left side facing the water surface and their other side facing the ocean floor. In addition, the eye on their lower side slowly shifts in position until it lies next to the eye on their upper side.

Pacific halibut are the largest flatfish and can grow to be huge creatures. The biggest flatfish on record is a Pacific halibut that measured just over eight feet in length and had an estimated weight of around five hundred pounds. California halibut are also known as California flounders. They too can be big fish but generally don't grow as large as Pacific halibut. They reach a maximum length of five feet. The maximum recorded weight of a California halibut is seventy-two pounds.

Both fish hide by resting on the ocean bottom and covering themselves with sand or other sediments to camouflage their body. They are ambush predators and feed on fish and marine invertebrates.

A large Pacific halibut
A large Pacific halibut | Source

Types of Halibut

There are two kinds of true halibut - the Atlantic halibut (Hippoglossus hippoglossus) and the Pacific halibut (Hippoglossus stenolepis). The Pacific halibut is found along the Pacific coast of North America from California to Alaska. It's also found along the coasts of Russia, Japan and Korea and in the Bering Sea. The California halibut has the scientific name Paralichthys californicus and is found from Washington to Baja California.

The first part of the word "halibut" comes from the middle English word hali or haly, which means holy. The second part of the name is derived from the middle Dutch or German word butte, meaning flatfish. The earliest appearance of the word "halibut" is found in fourteenth century documents. Halibut were once considered to be a special fish and were eaten on holy days.

Halibut Classification

The Pacific and California halibut both belong to the order of fish known as the Pleuronectiformes. The Pacific halibut belongs to the family Pleuronectidae within the order Pleuronectiformes. The California halibut is currently classified in the family Paralichthyidae. Until quite recently, it was classified in the family Bothidae.

Pacific Halibut Catch and Release

Pacific and California Halibut Appearance

Like other flatfish, Pacific and California halibut have a flattened body and swim on their side. Both of their eyes are located on their upper surface. This surface has a mottled olive green, grey, brown or black pattern, which helps the fish blend in with the sandy or muddy ocean floor. The lower surface is generally white. The white colour helps to camouflage the fish against the bright sky when they are swimming away from the ocean bottom and are viewed from below. Halibut do have scales, but they are small and smooth and are buried in the skin.

Pacific Halibut

The body of a Pacific halibut has a triangular shape due to its pointed dorsal and ventral fins. Most Pacific halibut swim with their right side uppermost, but a very small percentage of Pacific halibut - reportedly only 1 in 20,000 fish - have their eyes on their left side and swim with their left side uppermost. Pacific halibut are known for their large mouths.

California Halibut

A California halibut has an oval body. Unlike the case in the Pacific halibut, the long dorsal and ventral fins of the fish aren't triangular. California halibut have either their right or their left side uppermost. They have the ability to modify the colouration on their upper surface to blend in with the ocean bottom. They also have large mouths that contain many teeth. The teeth are sharp and can potentially give a human a nasty bite.

A California Halibut in La Jolla Cove

Diet and Predators

Even though they often spend time hiding in sediment on the ocean bottom, Pacific halibut are strong swimmers. They are carnivores that feed on other fish such as cod, pollock, turbot, rockfish, sculpins and herring as well as on invertebrates such as shrimp, crabs and octopuses. Most of their hunting occurs on the ocean floor, but sometimes they move into open ocean to catch their prey.

California halibut are generally found in shallower water than Pacific halibut. Their main food is small fish, especially anchovies and sardines. They also eat squid. Like other halibut, they generally lunge at their prey from their hiding place but may chase their prey through open water if it escapes.

Halibut have several predators, including humans, killer whales, sea lions and sharks. Both Pacific and California halibut are popular food fish for people. Their flesh is white in colour and has a flaky texture and a pleasant taste. Some meals of fish and chips use halibut as the fish.

A camouflaged California halibut
A camouflaged California halibut | Source

Reproduction

The Pacific halibut spawns in the winter, especially from December to February. The fish migrate from the shallower water of their feeding grounds to deeper water, where they release their eggs and sperm. A female produces from five hundred thousand to over four million eggs, depending on her body size. Many of these eggs are eaten by predators, but some survive. Females don't begin laying eggs until they are between eight and twelve years of age, while males become mature when they are around seven to eight years old.

California halibut mate between February and September and move into shallower water to breed. Fertilization is external. Females start releasing eggs at around four or five years of age while males begin releasing sperm when they are two to three years old.

Flatfish Metamorphosis

Metamorphosis

The fertilized eggs of halibut rise to the surface layer of the ocean and hatch into larvae after about fifteen days. The larvae and young fish are free-floating for about six months and are carried long distances by ocean currents. They feed on animals in the plankton. Plankton is a collection of tiny and microscopic plants and animals in the ocean. The organisms in the plankton cannot move on their own or are very weak swimmers. Small fish larvae are considered to be part of the plankton. Plankton is carried around by ocean currents.

The body of a young halibut gradually flattens and one eye migrates to the other side of the fish. In addition, the mouth twists so that most of it is on the upper side. Pigment appears on the upper side of the fish's body. The animal finally settles on the ocean bottom, lying on its side with its pigmented surface upwards.

Halibut Lifespan

The longest known lifespan for a Pacific halibut is fifty-five years. California halibut have lived for as long as thirty years.

Pacific Halibut Migration

Tag and release programs have shown that some Pacific halibut - especially young ones - participate in long distance migrations as well as seasonal migrations. The initial sites where the young halibut settle are referred to as nursery grounds. After living there for two or three years, the youngsters migrate to a permanent home. This journey may take several years. Older halibut may migrate, too. The longest recorded migration of a Pacific halibut took the fish from the Aleutian Islands to Oregon, a journey of 2,500 miles.

A Sustainable Pacific Halibut Fishing Industry

Halibut - Food and Nutrition for Humans

Halibut are an important food resource for humans. They're caught in commercial, subsistence and recreational fisheries. The fish is rich in protein and is a great source of B vitamins and certain minerals. It's also low in saturated fat and contains omega-3 fatty acids, which are believed to have important health benefits.

Omega-3 fatty acids may improve the health of our cardiovascular system, improve brain function and reduce inflammation. They may also play a role in reducing the risk of some types of cancer. Although halibut contain these potentially beneficial fatty acids, they also contain a moderate amount of mercury, so their consumption should be limited. Salmon and sardines are a lower-mercury source of omega-3 fatty acids.

Scuba Diving in the Californian Channel Islands

The California Channel Islands

A California halibut can be seen at the 5:55 mark in this video about marine life around the Californian Channel Islands. The islands form a chain off the coast of Southern California.

Discovering More About the Pacific and California Halibut

In addition to being a nutritious food, living halibut are interesting creatures. Their development is very unusual. They are potentially long-lived animals and there's still a lot to be learned about their behaviour.

I think it's a great shame that the fish are often appreciated for their food value but not for their natural history. The vast majority of YouTube videos about the two fish describe how to catch them and how to prepare them for a meal instead of showing their life in the ocean.

Hopefully the populations of both the Pacific halibut and the California halibut will continue to be monitored and carefully managed throughout their range. It's important that some of these fish live their full lifespan and help us learn more about the fascinating world of underwater sea life.

© 2012 Linda Crampton

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Comments 30 comments

kashmir56 profile image

kashmir56 4 years ago from Massachusetts

Hi my friend, this is all interesting information and facts on the Halibut, an most of it i did not know before,thanks for helping me learn more about this fish.

Vote up and more !!!


GoodLady profile image

GoodLady 4 years ago from Rome, Italy

Superb material in your Hub and I enjoyed reading it very much, enjoyed learning so much (including its nutritional value and that it is such a carnivore! Will pin this. (I don't get on with Facebook yet, but might try Facebook too). Voting etc.


AliciaC profile image

AliciaC 4 years ago from British Columbia, Canada Author

Thank you for the comment and the votes, Tom. I appreciate your visits to my hubs and your kind comments very much!!


AliciaC profile image

AliciaC 4 years ago from British Columbia, Canada Author

Thank you very much, GoodLady. I appreciate the comment and the pin. I'm looking forward to meeting you on Facebook!


b. Malin profile image

b. Malin 4 years ago

So Educational Alicia. I like Halibut, can be cooked in many delicious ways. Don't have it too often because of Mercury...Actually like Salmon better. I found this Hub so Interesting and Informative, loved looking at the Videos as well. Voted it UP and Interesting and Useful!


alocsin profile image

alocsin 4 years ago from Orange County, CA

Talk about a big fish in a big pound. Thanks for introducing me to creature, though now I'll think twice about eating it. Voting this Up and Interesting.


AliciaC profile image

AliciaC 4 years ago from British Columbia, Canada Author

Thanks for the comment and the votes, b. Malin! Halibut is certainly a very versatile food, and it's good to know that it's nutritious and healthy, too - apart from its mercury content.


AliciaC profile image

AliciaC 4 years ago from British Columbia, Canada Author

Hi, alocsin. Yes, halibut can get very big! It's amazing how heavy they can get, too. Thanks for the votes.


Movie Master profile image

Movie Master 4 years ago from United Kingdom

Hi Alicia, I had no idea the Halibut could live up to 55 years and their eyes can be on the same side! fascinating information and educational hub.

Halibut is one of my favourite fish, it's delicious!

Many thanks and voted up


A.A. Zavala profile image

A.A. Zavala 4 years ago from Texas

Northwest coast indians used to make Halibut lures made out of carved wood shaped like little men. The leader was made of a weaker rope than the mainline, so if they hooked a giant fish it could break free. Completely interesting!


AliciaC profile image

AliciaC 4 years ago from British Columbia, Canada Author

Thanks, Lesley. Halibut and the other flatfish are very interesting fish. I enjoy learning about their lives!


AliciaC profile image

AliciaC 4 years ago from British Columbia, Canada Author

Thank you very much for the comment and for the interesting information as well, Augustine.


Peggy W profile image

Peggy W 4 years ago from Houston, Texas

We love eating halibut and knew that it was a flatfish. Had no idea that they can live to be so old or that they can be so large. I watched every video and found them fascinating. They truly blend into the ocean floor perfectly with their coloration on the one side. Voted this up, useful, interesting + tweeted and sharing with my followers. Thanks Alicia for another fascinating hub!


AliciaC profile image

AliciaC 4 years ago from British Columbia, Canada Author

Thank you for the comment, Peggy. Thank you for all the shares, too! I appreciate them very much. It is amazing that halibut can become so big.


drbj profile image

drbj 4 years ago from south Florida

Hi, Alicia, What a strange fish is the halibut.

It starts life as round then becomes flat just for the hellavit.

It's bigger than flounder. Flatter, not rounder,

With a migrating eye, near as I can tell of it.


AliciaC profile image

AliciaC 4 years ago from British Columbia, Canada Author

Thank you for the visit and for the witty and amusing poem that brightened up my day, drbj!


susiebrown48 profile image

susiebrown48 4 years ago from Clearwater, FL

Fascinating! We fish but I've never encountered a Halibut. Loved your well-written, insightful, well researched article. Voting up!


AliciaC profile image

AliciaC 4 years ago from British Columbia, Canada Author

Thank you very much for the comment and the vote, susiebrown48. It's nice to meet you!


prasetio30 profile image

prasetio30 4 years ago from malang-indonesia

Very informative hub, Alicia. I had never heard about this fish. Thanks to introduce Halibut with us. I wish I can see it in person. Voted up and press the buttons, except funny. Take care :-)

Prasetio


AliciaC profile image

AliciaC 4 years ago from British Columbia, Canada Author

Hi, Prasetio. Thank you very much for the comments and all the votes. I appreciate them!


teaches12345 profile image

teaches12345 4 years ago

I now know what this fish looks like and more about its life habits. Another interesting post and well done.


AliciaC profile image

AliciaC 4 years ago from British Columbia, Canada Author

Thank you for the comment, teaches. The life cycle of the Pacific halibut is interesting. I'm hoping that researchers learn more about the behavior of the fish soon.


aviannovice profile image

aviannovice 4 years ago from Stillwater, OK

An excellent piece! I enjoyed the video, as well as all the info that you provided. I was not aware that the eyes migrated during growth. Again, great job!


AliciaC profile image

AliciaC 4 years ago from British Columbia, Canada Author

Thank you very much, aviannovice! I appreciate your visit and the great comment.


ologsinquito profile image

ologsinquito 2 years ago from USA

This is a very interesting article about a very interesting fish. Voted up and shared.


AliciaC profile image

AliciaC 2 years ago from British Columbia, Canada Author

Thank you very much for the comment, the vote and the share, ologsinquito!


rebeccamealey profile image

rebeccamealey 2 years ago from Northeastern Georgia, USA

The ocean holds so many awesome creatures! Thanks so much for sharing this. Well researched!


PegCole17 profile image

PegCole17 2 years ago from Dallas, Texas

That fish in the first picture is huge. Wow. It's kinda creepy, too. I never knew that they started out with eyes on both sides and that one moved over. Eeek.


AliciaC profile image

AliciaC 2 years ago from British Columbia, Canada Author

Hi, Rebecca. I think that ocean creatures are awesome, too! Thank you very much for the visit and the comment.


AliciaC profile image

AliciaC 2 years ago from British Columbia, Canada Author

Hi, Peg. Yes, the fish is huge! The halibut is an interesting animal. Thanks for the visit!

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