Opah | NOAA Fisheries

Skip to main content Species Directory Opah Overview Seafood Science Resources U.S. wild-caught opah is a smart seafood choice because it is sustainably managed and responsibly harvested under U.S. regulations.

Opah

Lampris guttatus, Lampris spp.

Also Known As Moonfish

Quick Facts

Region New England/Mid-Atlantic, Pacific Islands, Southeast, West Coast Opah moonfish. Credit: NOAA Fisheries

Opah moonfish. Credit: NOAA Fisheries

About the Species

Opah moonfish. Credit: NOAA Fisheries

Opah moonfish. Credit: NOAA Fisheries

U.S. wild-caught opah is a smart seafood choice because it is sustainably managed and responsibly harvested under U.S. regulations.

Population

The stock has not been assessed. Although the population level is unknown, management measures are in place.

Fishing Rate

Overfishing status is unknown, but management measures are in place.

Habitat Impact

Fishing gear used to catch opah rarely contacts the ocean floor so habitat impacts are minimal.

Bycatch

There is no directed fishery. Regulations are in place to minimize bycatch in the tuna and swordfish fisheries, which incidentally catch opah.

Population Status

• Opah has never been assessed so the population and overfishing status are unknown, but there is no evidence that populations are in decline or that fishing rates are too high.
• Despite the opah's value to commercial and recreational fishermen, little research on the basic biology and ecology of opah has been conducted.
• To begin to fill some of the data gaps, NOAA's Southwest Fisheries Science Center began collecting biological samples from opah in 2009 and initiated an electronic tagging program in 2011.
• Scientists hope to continue tagging opah to learn about their movements and range. This research will provide the basic life history information necessary for future population assessments and management.

Appearance

• Opah are an unusual looking fish—they have a round, flat body that’s silvery gray in color.
• Toward the belly, the silver shades to a rose red, dotted with white spots.
• Their fins and mouth are red, and their large eyes are encircled with gold.

Biology

• Because opah are not a major commercial seafood species and they live in the deep ocean, scientists know very little about their biology and ecology.
• Scientists assume opah share general characteristics with other Pacific Ocean pelagic fish.
• Scientists estimate that opah grow quickly.
• Although they’re not sure of opah’s exact life span, scientists age opah by their fin rays, assuming fin ray marks are formed annually.
• Most opah caught in longline fisheries are estimated to be between 1 and 6 years old.
• They average about 100 pounds with a diameter of 3 feet.
• Opah spawn in warm surface waters throughout the year in the tropics and more seasonally in cooler waters.
• Opah seem to be very productive, potentially spawning many times throughout the spawning season.
• Opah are capable of traveling long distances, often in response to changing oceanic conditions such as temperature.

Where They Live

Range

• Opah are found in tropical and temperate waters around the world.

Habitat

• Opah live in deep open ocean waters.

Fishery Management

• NOAA Fisheries and the Western Pacific Fishery Management Council manage this fishery in the Pacific Islands.
• Managed under the Fishery Ecosystem Plan for the Pelagic Fisheries of the Western Pacific:
  • No management measures specifically apply to opah. However, general management measures apply to the fisheries that harvest opah.
  • Fishermen are required to have permits and record their catch.
  • Gear restrictions and operational requirements to minimize bycatch and potential gear conflicts among different fisheries.
  • A limit on the number of permits for Hawaii and American Samoa longline fisheries controls participation in the fishery.
  • Longline fishing is prohibited in some areas to protect endangered Hawaiian monk seals, reduce conflicts between fishermen, and prevent localized stock depletion (when a large quantity of fish are removed from an area).
  • These zones are enforced through the NOAA Fisheries vessel monitoring system program (longline boats must be equipped with a satellite transponder that provides real-time position updates and tracks vessel movements).
  • Hawaii- and American Samoa–based longline vessels must carry onboard observers when requested by NOAA Fisheries, in part to record interactions with sea turtles, seabirds, and marine mammals.
  • Annual training in safe handling and release techniques for protected species is required, and all vessels must carry and use specific equipment for handling and releasing these animals.

Harvest

• Commercial fishery:
  • In 2021, commercial landings of opah in Hawaii totaled 460,000 pounds and were valued at $1.8 million, according to the NOAA Fisheries commercial fishing landings database.
  • While there is no directed fishery for opah, they are harvested in small but significant quantities. U.S. fishermen catch them incidentally in tuna and swordfish fisheries around the U.S. Pacific Islands and off southern California.
• Gear types, habitat impacts, and bycatch:
  • In Hawaii, opah are caught using longlines set deep below the surface to target bigeye tuna.
  • Off California, they're taken incidentally in the California drift gillnet fishery targeting swordfish.
• Recreational fishery:
  • Although not commonly caught, opah are prized by deepwater recreational anglers for their unique colors and light flavor.

Scientific Classification

Kingdom	Animalia
Phylum	Chordata
Class	Actinopterygii
Order	Lampriformes
Family	Lampridae
Genus	Lampris
Species	guttatus

Last updated by NOAA Fisheries on 03/21/2025

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Seafood Facts

Is Opah Sustainable?

U.S. wild-caught opah is a smart seafood choice because it is sustainably managed and responsibly harvested under U.S. regulations.

Availability

Year-round, but landings seem to peak from April through August.

Source

U.S. wild-caught from Hawaii, California, and surrounding high seas.

Taste

Opah has a rich, creamy taste. The flavor is distinctive, a cross between tuna and swordfish.

Texture

Firm and fatty with large flakes.

Color

Raw flesh ranges from dark red to orange to pink, and turns white when cooked.

Health Benefits

Opah is a rich source of omega-3s, protein, niacin, vitamins B6 and B12, phosphorus, and selenium. It is also low in sodium.

Nutrition Facts

Servings: 1; Serving Weight: 4 oz. (raw); Calories: 170; Protein: 24 g; Total Fat: 8 g; Total Saturated Fatty Acids: 2.5 g; Carbohydrate: 0 g; Total Sugars: 0 g; Total Dietary Fiber: 0 g; Cholesterol: 60 mg; Selenium: 49 mcg; Sodium: 80 mg

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Opah Recipes

Opah makes a great substitute in your favorite tuna or swordfish recipe. If you need some cooking inspiration, browse these recipes for opah chili, grilled fish steak, and more!

Read More

Last updated by NOAA Fisheries on 03/21/2025

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Science Overview

NOAA Fisheries conducts various research activities on the biology, behavior, and population health of opah. The results of this research are used to inform management decisions for this species. Opah have not been assessed.

Opah Research in the Eastern Pacific Ocean

Opah are a mid-water pelagic fish that occur seasonally in the Southern California Bight. While they are not targeted, they are taken incidentally in both local recreational fisheries for tuna and the California drift gillnet fishery targeting swordfish.

Despite their value to commercial and recreational fishermen, little research on the basic biology and ecology of opah has been conducted, especially in the Southern California Bight. For example, there are limited data on foraging ecology, size composition in fisheries, essential habitat, and stock structure. Scientists at NOAA’s Southwest Fisheries Science Center have begun to fill some of the data gaps by collecting and analyzing biological samples since 2009 and initiating an electronic tagging program in 2011.

Genetic Analyses of Biological Samples

Genetic analysis has determined that there are multiple species of opah, those caught off California being a different species than those caught off Hawaii. Opah also appear to have a gill arch structure that has never been seen before. The unique structure might help scientists understand their ability to forage deep in the water column, from generally 50 meters at night down to 200 meters during the day. The vertical movements are likely due to opah following prey with similar migrations. Opah primarily forage on squid and deep water fish, such as barracudinas, a small elongated fish of up to 50 centimeters. Barracudinas are notable mid-water predators and they are an important food for large fish, such as tunas, swordfish, bigeye thresher shark and, evidently, opah.

NOAA scientists continue to conduct biological sampling and genetic analysis of opah to further explore intraspecific differences. This includes stomach processing to identify the important prey for opah and whether the diet changes with environmental conditions and dissections of the gills and whole fish to learn about the anatomy of opah and their swimming mechanics.

Tagging Opah

Scientists also hope to continue tagging opah to learn about their movements and range. This research will provide the basic life history information necessary for future population assessments and management. Historical catch data may also show correlations between opah catch and abundance with changes in sea surface conditions such as El Niño and La Niña.

Research & Data

American Samoa Longline Logbook Reports 2023

Logbook summary reports for the 2023 calendar year. March 07, 2025 - Data Set , Pacific Islands

American Samoa Longline Logbook Reports 2022

Logbook summary reports for the 2022 calendar year. February 06, 2024 - Data Set , Pacific Islands

Hawai'i and California Longline Logbook Reports 2022

Logbook summary reports for the 2022 calendar year. February 06, 2024 - Data Set , Pacific Islands

Hawai'i and California Longline Logbook Reports 2021

Logbook summary reports for the 2021 calendar year. November 03, 2022 - Data Set , Pacific Islands View More

More Information

• Southwest Fisheries Science Center
• Seafood Industry and Scientists Team Up to Make the Most of Opah
• Warm Blood Makes Opah an Agile Predator

Last updated by NOAA Fisheries on 03/21/2025

Data & Maps

Data

American Samoa Longline Logbook Reports 2023

Logbook summary reports for the 2023 calendar year.

Pacific Islands Data

American Samoa Longline Logbook Reports 2022

Logbook summary reports for the 2022 calendar year.

Pacific Islands Data

Hawai'i and California Longline Logbook Reports 2022

Logbook summary reports for the 2022 calendar year.

Pacific Islands Data

Hawai'i and California Longline Logbook Reports 2021

Logbook summary reports for the 2021 calendar year.

Pacific Islands More Data More Maps

Research

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Last updated by NOAA Fisheries on 03/21/2025