Animal
Humpback anglerfish
The humpback anglerfish lives deep in the dark ocean. It has a little glowing light on its head, like a fishing rod. Small animals swim to the light, and the anglerfish gulps them up.
The humpback anglerfish is a small, round, black fish of the deep, dark ocean. A long spine on the female's head ends in a glowing lure, lit by tiny bacteria, which draws prey close enough to catch in her big, toothy mouth. The males are tiny, only about 3 centimeters long, and their job is to find a female.
Melanocetus johnsonii is a deep-sea ceratioid anglerfish (family Melanocetidae) found worldwide between 66° N and 53° S, mostly in the meso- and bathypelagic zones. Females (to about 18 centimeters) carry a bacterial bioluminescent lure on a modified dorsal spine; males are dwarfs that attach only temporarily. The IUCN lists it as Least Concern (2015).
Photo: Personnel of NOAA Ship DELAWARE II, public domain, via Wikimedia Commons
Meet the humpback anglerfish
The humpback anglerfish is a small, round, black fish.
It has a big mouth with lots of thin, pointy teeth. It has a little light on its head that glows in the dark.
The humpback anglerfish is a small fish with a big name. A grown-up female is up to about 15 to 18 centimeters long, smaller than a grown-up's hand, with a round, dark body and a huge mouth full of thin, sharp teeth.
It is called an anglerfish because it 'fishes' for its food. The first spine of the fin on its back has grown into a long rod with a glowing tip, like a fishing rod with bait. Its skin is covered in tiny spines.
Melanocetus johnsonii is a ray-finned fish (class Actinopterygii) in the family Melanocetidae, one of the deep-sea (ceratioid) anglerfishes of the order Lophiiformes. The IUCN gives females a maximum of 15.4 centimeters standard length and males up to 2.8 centimeters; FishBase gives 18 centimeters total length for females.
The species shows extreme sexual dimorphism. In females, the first dorsal spine is modified into an illicium (the 'rod') tipped by an esca (the lure). FishBase describes females with 48 to 134 teeth in the upper jaw and minute spinules over most of the skin. It was first described in 1864 from a specimen from Madeira (Fishes of Australia).
Quick facts
- Group
- Fish
- Length
- up to 18 cm
The deep, dark ocean
Humpback anglerfish live deep in the ocean.
It is very dark and cold down there. There is no sunlight at all.
Humpback anglerfish live in the Atlantic, Pacific and Indian Oceans, from far in the north to far in the south. They live in the deep, open ocean, mostly between a few hundred and 1,500 meters down, where little or no sunlight reaches.
Nobody sees them on reefs or near the shore. Scientists find them in deep research nets.
The IUCN gives a circumglobal range in the Atlantic, Pacific and Indian Oceans between 66° N and 53° S, in nets fished from 0 to 2,100 meters but mostly shallower than 1,500 meters; western Atlantic records span 175 to 2,700 meters, and near Hawaii it is known from 600 to 1,000 meters. It is described as rare and deep-dwelling.
Fishes of Australia notes records from off Newcastle, New South Wales, to the Great Australian Bight and calls the species circumglobal at temperate latitudes. Larvae live mainly in the upper 100 meters (FishBase).
Its habitat
Where can you find this animal?
- Lives here naturally · Countries and seas named by a scientific source
- Sightings recorded · Records of wild sightings (GBIF)
Lives here naturally · Countries and seas named by a scientific source
Deep open ocean worldwide between about 66° N and 53° S, mostly from a few hundred to 1,500 meters deep, sometimes deeper. Shading is by whole ocean; the species is rarely caught anywhere.
Places: Atlantic Ocean, Indian Ocean and Pacific Ocean.
Source: iucn-red-list · checked October 2026
Sightings recorded · Records of wild sightings (GBIF)
Counts of GBIF records of wild observations (human and machine) and preserved specimens. Records include introduced populations, vagrants, escaped or released animals and misidentifications, so a country with records is not necessarily part of the native range.
Wild sightings have been recorded in United States, Australia, New Zealand, Western Sahara, Mexico, Portugal, Spain, Canada and 46 more places.
Source: gbif · checked October 2026
Range maps show where scientists say an animal lives, often country by country. An animal may live in only part of a country shown, and sightings records can include animals that wandered far from home.
Fishing with a light
The anglerfish waits in the dark.
Its light glows. A small fish swims close to look. Then gulp! The anglerfish catches it.
The female humpback anglerfish lets her food come to her. She uses the glowing lure on her head to attract prey, then snaps it up with her big mouth.
Her mouth and stomach can stretch a lot. Scientists once found a fish inside a humpback anglerfish that was much longer than the anglerfish itself!
Females attract prey with the elongate first dorsal spine modified as a lure (IUCN). Fishes of Australia notes that the light is produced by luminous bacteria living in the esca, a form of symbiotic bioluminescence.
FishBase records that the species can catch and swallow prey larger than itself: a 6.6-centimeter individual held a roughly 24-centimeter viperfish (Chauliodus) in its stomach. Specific diet studies for this species are limited in the sources used.
Did you know?
Tiny bacteria make the anglerfish's light.
The glow in the anglerfish's lure comes from bacteria living inside it.
Female humpback anglerfish have bacterial bioluminescence: luminous bacteria in the esca produce the light (Fishes of Australia).
A glowing lure and a huge mouth
The anglerfish has a rod on its head with a light at the end.
The light is made by tiny living things called bacteria. Its body is dark and round.
The anglerfish's 'fishing rod' is really the first spine of its back fin, grown long. At the tip is a bulb called the esca. Inside it live tiny bacteria that make light, so the lure glows in the dark.
The female's mouth is very large, with many long, thin teeth. Only females have the lure. Males are much smaller and look very different.
The illicium is the modified first dorsal spine, and the esca at its tip has compressed anterior and posterior crests (FishBase). Fishes of Australia states that females have bacterial bioluminescence, with luminous bacteria in the esca producing the light.
FishBase describes metamorphosed females with 48 to 134 teeth in the upper jaw and 32 to 78 in the lower, the longest lower tooth reaching 8.4 to 25 percent of standard length, and an illicium 32.4 to 60.8 percent of standard length. Scales are cone-shaped, hollow and translucent.
Tiny males and floating eggs
Anglerfish dads are tiny, much smaller than moms.
A dad finds a mom in the dark. Their eggs float in the sea, and the babies grow up near the top.
Male humpback anglerfish are tiny, at most about 3 centimeters long. They have very good senses for finding females in the dark. When a male finds a female, he holds on to her body for a while. In this species, he does not stay attached for good.
The eggs are thought to float in jelly-like rafts. The babies, called larvae, live near the surface, in the top 100 meters of the ocean.
Males reach about 2.8 centimeters (IUCN) and have highly developed sensory organs for locating females, to which they attach temporarily (IUCN). FishBase describes the males as dwarfed and non-parasitic, unlike the permanently attached males of some other ceratioid families.
The species is oviparous with planktonic larvae; eggs are presumably carried in floating gelatinous rafts, and larvae occur mainly in the upper 100 meters (FishBase). Growth, age at maturity and lifespan are not given in the sources used.
A patient waiter
The mom anglerfish lets her light do the work.
It glows in the dark. When food comes close, she gulps it up.
The female humpback anglerfish lets her glowing lure do the work of bringing food close. When an animal comes near, she snaps it up, even one bigger than she is.
The tiny males behave very differently. They have no lure. Instead, they use their very good senses to search the dark water for a female. Because the species lives so deep, very little is known about how it behaves. Most of what scientists know comes from fish caught in deep nets.
Females attract prey with the luminous lure, drawing it within reach of the jaws (IUCN; Fishes of Australia). The lure is also produced only by females, consistent with the extreme sexual dimorphism of ceratioids.
Observations of living animals are scarce; most data come from trawls and plankton nets (FishBase notes capture in plankton nets), and the IUCN describes it as a rare species.
Did you know?
Baby anglerfish grow up near the top of the sea.
Even though adults live deep down, baby anglerfish live in the top 100 meters of the ocean.
Larvae are found primarily in the upper 100 meters (FishBase).
Hidden in the deep
Humpback anglerfish are not in danger.
They live very deep in the sea, far away from people.
The IUCN lists the humpback anglerfish as Least Concern. It lives across all the big oceans, and no major threats are known.
Sometimes one is caught by accident in deep fishing nets, but people do not fish for it. Because the deep sea is so hard to explore, there is still a lot to learn about it.
The IUCN assessed Melanocetus johnsonii as Least Concern (assessed May 2013, published 2015; annotated as needing an update). It is not used commercially and may occur as bycatch in trawl fisheries, such as off Namibia; there are no known major threats or species-specific conservation measures. A regional assessment exists for Europe.
As with many deep-sea species, its population size and trend are unknown, and the assessment relies on its very wide distribution.
IUCN Red List
How is the humpback anglerfish doing in the wild?
- Least Concern (this animal)
- Near Threatened
- Vulnerable
- Endangered
- Critically Endangered
- Extinct in the Wild
- Extinct
Least Concern
Not at risk of disappearing from the wild right now.
See the IUCN Red List assessment · The IUCN Red List of Threatened Species 2022.2
Amazing facts
-
Tiny bacteria make the anglerfish's light.
The glow in the anglerfish's lure comes from bacteria living inside it.
Female humpback anglerfish have bacterial bioluminescence: luminous bacteria in the esca produce the light (Fishes of Australia).
-
Only the moms have the glowing light.
Only female humpback anglerfish have the lure. Males are tiny and look very different.
The lure is a female trait; males are dwarfed (to about 2.8 centimeters) with highly developed sense organs (IUCN).
-
An anglerfish can eat a fish bigger than itself.
One humpback anglerfish only 6.6 centimeters long had swallowed a fish about 24 centimeters long.
A 6.6-centimeter individual contained an approximately 24-centimeter viperfish, showing it can take prey larger than itself (FishBase).
-
Baby anglerfish grow up near the top of the sea.
Even though adults live deep down, baby anglerfish live in the top 100 meters of the ocean.
Larvae are found primarily in the upper 100 meters (FishBase).
Words to know
- lure
- something that attracts animals, like bait on a fishing line
- bioluminescence
- light made by a living thing
- bacteria
- tiny living things made of just one cell
- deep sea
- the dark, cold part of the ocean far below the surface
- larva
- a very young animal that looks different from the adult
- specimen
- an animal collected so scientists can study it
Discovery challenge
-
What does an anglerfish have on its head?
What does a female humpback anglerfish use to attract prey?
Which structure does the female use to attract prey?
- A glowing lure
- A big horn
- A crown of feathers
Show the answer
A glowing lure
It has a glowing light, like a fishing rod with bait.
A long spine on her head ends in a glowing lure that draws prey close.
The illicium, a modified first dorsal spine, tipped by a luminous esca.
-
What makes the anglerfish's light?
What produces the light in the anglerfish's lure?
What is the source of the esca's light?
- Tiny bacteria
- Sunlight
- Electricity from a battery
Show the answer
Tiny bacteria
Tiny living bacteria make the light.
Bacteria living inside the lure glow in the dark.
Symbiotic luminous bacteria housed in the esca.
-
Are anglerfish dads big or tiny?
How do male humpback anglerfish compare with females?
Which describes male Melanocetus johnsonii?
- Bigger than moms
- Tiny, much smaller than moms
- The same size as moms
Show the answer
Tiny, much smaller than moms
Dads are tiny, only about 3 centimeters long.
Males are only about 3 centimeters long and have no lure; females are much bigger.
Dwarfed, non-parasitic males to about 2.8 centimeters that attach to females only temporarily.
-
Where do humpback anglerfish live?
Where do humpback anglerfish live?
Which zones does Melanocetus johnsonii inhabit?
- Deep in the dark ocean
- In shallow coral reefs
- In rivers and lakes
Show the answer
Deep in the dark ocean
They live deep down in the dark ocean.
They live deep in the open ocean, mostly above 1,500 meters, in all the big oceans.
The meso- and bathypelagic zones, worldwide between 66° N and 53° S.
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For parents & teachers
What children will learn
- Explain how the female humpback anglerfish uses a bioluminescent lure to catch food.
- Describe the big difference between female and male anglerfish.
- Understand why deep-sea animals are hard to study and why many photos show collected specimens.
Recommended ages: 3 to 17 · About 10 minutes
Talk about it
- Why might waiting with a lure be a good way to find food in the dark?
- How do you think living light helps animals in the deep sea?
- Why do you think scientists still know so little about deep-sea fish?
Try at home or in class
- In a dark room, wave a small flashlight on a stick and see how eyes are drawn to the light, like prey to an anglerfish lure.
- Make an anglerfish from a paper plate, with a pipe-cleaner rod and a glow-in-the-dark sticker lure.
Key vocabulary: lure, bioluminescence, bacteria, deep sea, larva, specimen
Where these facts come from
- The IUCN Red List of Threatened Species , International Union for Conservation of Nature (IUCN terms of use (no redistribution of Red List data or range maps))
- GBIF Backbone Taxonomy and GBIF Occurrence Search , Global Biodiversity Information Facility (CC0 1.0 (backbone); occurrence counts are facts derived from records under CC0, CC BY and CC BY-NC)
- Melanocetus johnsonii (Humpback Anglerfish), 2015 global assessment , IUCN Red List of Threatened Species
- Melanocetus johnsonii, Humpback anglerfish: species summary , FishBase
- Humpback Blackdevil, Melanocetus johnsonii , Fishes of Australia (Museums Victoria)
- Wikidata , Wikimedia Foundation (CC0 1.0)
- Wikimedia Commons , Wikimedia Foundation (Per file: Public domain, CC0, CC BY or CC BY-SA only (credited on each page))
Checked, not yet human-reviewed. Last updated October 27, 2026. Spotted a mistake? Tell us.
Picture credits
- Photo: Personnel of NOAA Ship DELAWARE II, public domain, via Wikimedia Commons · source