---
title: "What the sources say about the Atlantic Halibut | AnimalTracks.wiki"
description: "52 claims from the Atlantic Halibut profile, each beside the words of the source that backs it."
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# What the sources say about the Atlantic Halibut (*Hippoglossus hippoglossus*)

> 52 claims from the Atlantic Halibut profile, each beside the words of the source that backs it. A "..." marks a cut in a quote and [brackets] an insertion.

Profile: [Atlantic Halibut](https://animaltracks.wiki/animals/atlantic-halibut/)

## Atlantic Halibut. NOAA Fisheries.

https://www.fisheries.noaa.gov/species/atlantic-halibut

| The page says | The source says |
| :--- | :--- |
| The world's largest flatfish | Atlantic halibut is the largest species of flatfish in the world. |
| Sand, gravel and clay seabed of the northern Atlantic, 160 to 6,560 feet down | Atlantic halibut are demersal fish that live on or near sand, gravel or clay bottoms at depths of between 160 and 6,560 feet. |
| Invertebrates when small; almost exclusively fish from about 31 inches long | smaller fish (up to 12 inches in length) feed almost exclusively on invertebrates. The proportion of fish in the diet increases as the fish grow in size until they feed almost exclusively on fishes when they reach approximately 31 inches. |
| The adult ends up as a right-eyed flounder. NOAA tells it from other right-eyed flounders by its size, a concave tail fin, a large gaping mouth and an arched lateral line. | Atlantic halibut can be distinguished from other right-eyed flounders by their large size, concave caudal fin, large, gaping mouth, and arched lateral line. |
| The largest Atlantic halibut on record was taken off Cape Ann, Massachusetts, and weighed 615 pounds gutted with the head still attached | The largest Atlantic halibut recorded was taken off Cape Ann, Massachusetts, and weighed 615 pounds (eviscerated with the head still attached). |
| NOAA estimates it weighed about 700 pounds alive | It likely weighed 700 pounds when it was alive. |
| says it can reach up to 15 feet in length | Atlantic halibut can reach up to 15 feet in length |
| Full-grown females average 100 to 150 pounds, and males tend to be smaller | Full grown females average 100 to 150 pounds, while males tend to be smaller. |
| NOAA calls it a long-lived, late-maturing species: it can live up to 50 years | It is a long-lived, late-maturing species that can live up to 50 years. |
| the average age at maturity is about 10 years | Average age at maturity is about 10 years. |
| Small halibut, up to about 12 inches long, feed almost exclusively on invertebrates | smaller fish (up to 12 inches in length) feed almost exclusively on invertebrates |
| The proportion of fish in the diet increases as they grow, and by roughly 31 inches they eat almost exclusively fish | The proportion of fish in the diet increases as the fish grow in size until they feed almost exclusively on fishes when they reach approximately 31 inches |
| They live on or near sand, gravel or clay at depths of 160 to 6,560 feet | live on or near sand, gravel or clay bottoms at depths of between 160 and 6,560 feet |
| The range runs from Labrador and Greenland to Iceland, and from the Barents Sea south to the Bay of Biscay and Virginia | Atlantic halibut are found from Labrador and Greenland to Iceland, and from the Barents Sea south to the Bay of Biscay and Virginia. |
| In U.S. waters, they are most common in the Gulf of Maine | In U.S. waters, halibut is most common in the Gulf of Maine. |
| NOAA's 2024 stock assessment found the stock overfished | According to the 2024 stock assessment, the Atlantic halibut stock is overfished. |
| A rebuilding plan has a target date of 2055 | A rebuilding plan to rebuild the stock to the target population level is in place with a target date of 2055. |
| In 2024, U.S. commercial landings totalled 76,000 pounds, valued at about $480,000 | In 2024, commercial landings of Atlantic halibut totaled 76,000 pounds and were valued at approximately $480,000 |
| federal waters have a limit of one fish per vessel per trip | Regulations include a minimum fish size and a limit of one fish per vessel per trip in federal waters. |
| NOAA calls it the largest species of flatfish in the world | Atlantic halibut is the largest species of flatfish in the world. |
| The Atlantic halibut is a flatfish | Atlantic halibut is the largest species of flatfish in the world. |
| Up to 15 feet long, says NOAA | Atlantic halibut can reach up to 15 feet in length |
| An average full-grown female weighs 100 to 150 pounds | Full grown females average 100 to 150 pounds |
| The record fish, landed off Cape Ann in Massachusetts, weighed 615 pounds with its guts removed and probably about 700 pounds alive | The largest Atlantic halibut recorded was taken off Cape Ann, Massachusetts, and weighed 615 pounds (eviscerated with the head still attached). It likely weighed 700 pounds when it was alive. |
| Up to 50 years, according to NOAA | can live up to 50 years |
| They are slow to breed as well: on average they mature at about 10 years old | It is a long-lived, late-maturing species that can live up to 50 years. Average age at maturity is about 10 years. |
| It depends on size | Halibut food preferences vary by fish size |
| Halibut up to 12 inches long eat almost exclusively invertebrates | smaller fish (up to 12 inches in length) feed almost exclusively on invertebrates |
| The share of fish in the diet climbs as they grow, until at approximately 31 inches they eat almost exclusively fish | The proportion of fish in the diet increases as the fish grow in size until they feed almost exclusively on fishes when they reach approximately 31 inches |
| The Atlantic halibut is the largest flatfish in the world | Atlantic halibut is the largest species of flatfish in the world. (note: vibe.reason) |
| takes about 10 years to mature | Average age at maturity is about 10 years. (note: vibe.reason) |
| weightKg: 57 | Full grown females average 100 to 150 pounds, while males tend to be smaller. (note: task #1267: 125 lb midpoint is 57 kg; 45 to 68 kg is Medium class throughout) |
| tags: giant-size | Atlantic halibut is the largest species of flatfish in the world. (note: task #1267) |

## Hippoglossus hippoglossus summary page. FishBase.

https://www.fishbase.se/summary/Hippoglossus-hippoglossus.html

| The page says | The source says |
| :--- | :--- |
| Near Threatened, in an assessment from 2021 | Near Threatened (NT) ; Date assessed: 12 February 2021 |
| It is uniformly dark brown or black, while young fish are marbled or spotted with paler marks | Uniformly dark brown or black; young marbled or spotted with paler marks |
| Its genus name comes from Greek for "horse tongue" | Hippoglossus: Greek, ippos = horse + Greek, glossa = tongue |
| FishBase gives 7 to 8 years for males and 10 to 11 for females | Males reach sexual maturity at 7-8 years and females at 10-11 years. |
| with slow growth and late maturity, halibut populations can be seriously affected by overfishing | Slow growth rate and late onset of sexual maturity, halibut populations can be seriously affected by overfishing |
| FishBase says they feed mainly on cod, haddock, pogge, sand-eels, herring and capelin, but also take cephalopods and large crustaceans | Feed mainly on other fishes (cod, haddock, pogge, sand-eels, herring, capelin), but also takes cephalopods, large crustaceans and other bottom-living animals. |
| Adults are benthic, meaning they live on the bottom, though they are occasionally pelagic | Adults are benthic but occasionally pelagic |
| lives mostly on the bottom as an adult | Adults are benthic but occasionally pelagic (note: vibe.reason) |

## Bolstad & Novales Flamarique (2022). Chromatic organization of retinal photoreceptors during eye migration of Atlantic halibut (Hippoglossus hippoglossus). Journal of Comparative Neurology.

https://doi.org/10.1002/cne.25423

| The page says | The source says |
| :--- | :--- |
| a fish that moves one of its eyes across its head | the metamorphic process whereby one eye migrates to the other side of the head |
| Moves an eye to the other side of its head during metamorphosis | the metamorphic process whereby one eye migrates to the other side of the head |
| in flatfishes eye migration is the metamorphic process (a change in body form) whereby one eye migrates to the other side of the head | In flatfishes experiencing eye migration (i.e., the metamorphic process whereby one eye migrates to the other side of the head) |
| the larva's hexagonal lattice of single cones gives way to a mostly square mosaic of four double cones around each single cone | the hexagonal lattice of single cones present in the larva undergoes major restructuring resulting in a dominant square mosaic postmetamorphosis consisting of four double cones surrounding each single cone |
| It happens during metamorphosis, a big change in body form. In flatfishes this is called eye migration: one eye travels across to the other side of the head | In flatfishes experiencing eye migration (i.e., the metamorphic process whereby one eye migrates to the other side of the head) |
| The retina is restructured along the way, with the larva's hexagonal pattern of single cone cells giving way to a mostly square one | the hexagonal lattice of single cones present in the larva undergoes major restructuring resulting in a dominant square mosaic postmetamorphosis |

## Sæle et al. (2004). Staging of Atlantic halibut (Hippoglossus hippoglossus L.) from first feeding through metamorphosis, including cranial ossification independent of eye migration. Aquaculture.

https://doi.org/10.1016/j.aquaculture.2004.05.025

| The page says | The source says |
| :--- | :--- |
| the frontal bone shows torsion (a twist) correlated with eye migration | The Frontale exhibited torsion correlated with eye migration |
| metamorphosis is protracted in halibut | Because metamorphosis is protracted in halibut |
| though its full hardening into bone is independent of the eye's move | calcification began earlier and full calcification was independent of ocular displacement |
| with a metamorphosis that is drawn out | Because metamorphosis is protracted in halibut (note: vibe.reason) |

## Cadrin et al. (2022). Hippoglossus hippoglossus. The IUCN Red List of Threatened Species 2022: e.T10097A148035632.

https://doi.org/10.2305/iucn.uk.2022-2.rlts.t10097a148035632.en

| The page says | The source says |
| :--- | :--- |
| Near Threatened | IUCN Red List category: Near Threatened (NT). |