The black angler fish is a creature shrouded in mystery. This deep-sea dweller lurks in the ocean’s dark depths, luring prey with its bioluminescent fishing rod-like dorsal spine. While angler fish as a group exhibit fascinating adaptations, the black angler fish possesses unique features that set it apart. This article aims to shed light on this elusive fish – from its anatomy and habitat to its feeding and reproductive behaviors. Read on to unravel the mysteries surrounding this denizen of the deep.
What is an Angler Fish?
Angler fish belong to the teleost order Lophiiformes. There are over 200 species across 16 families, all living in deep, dark ocean waters. These ambush predators share some common features:
- Bioluminescent lure: The most distinctive feature of angler fish is the modified dorsal spine that protrudes above their mouths. The tip houses bioluminescent bacteria that the angler fish can flash on and off to attract prey in the darkness of the deep sea.
- Large mouths and sharp teeth: Angler fish have enormous mouths filled with long, pointed teeth to seize prey attracted to their lure. Their stomachs can distend to accommodate prey even larger than themselves.
- Small eyes: Since they live at depths with little to no sunlight, angler fish have no use for well-developed eyes. Their eyes are generally small and vestigial.
- Tiny scales: Most species have soft, scaleless skin with wart-like growths. Some have thin, transparent scales that are too small to overlap.
- Short lifespans: Few anglerfish live beyond 10 years due to the toll of living in extreme deep-sea environments. Exceptions are the black seadevil and a few related genera that may live over 20 years.
While angler fish display diverse shapes and sizes, most grow to around 1-3 feet in length. Certain species can reach up to 3.3 feet long. In terms of weight, most weigh between 2 and 40 lbs, although some giant species can weigh over 100 lbs.
The Black Angler Fish: A Unique Species
The black angler fish refers to a specific type of angler fish in the Melanocetus genus. There are five described species of Melanocetus, all commonly called the black angler fish or black seadevil. They are:
- Melanocetus johnsonii (Smooth black seadevil)
- Melanocetus murrayi (Murray’s abyssal anglerfish)
- Melanocetus eustales (Eustales black angler)
- Melanocetus kreffti (Krefft’s black seadevil)
- Melanocetus pattersoni (Patterson’s black anglerfish)
These species possess several traits that distinguish them from other angler fish:
- Uniformly black skin: As their name suggests, black angler fish have jet black skin unlike the mottled brown shades of many angler species. This is due to a high concentration of melanin pigments.
- Pointed teeth: Their needle-like teeth point inward, allowing them to swallow prey whole rather than biting off chunks.
- Lack of scales: Their skin is scaleless with a velvety texture. Some species have dermal spinules (tiny spines) scattered across their skin.
- Long lures: The proportionately long illicium (fishing rod-like lure) of black angler fish allows them to face upward to attract prey swimming above them.
- Exclusively deep-sea habitat: No black angler fish inhabit shallow waters at abyssal depths below 3,300 feet.
- Long lifespans: Some species like the black seadevil can live over 20 years, significantly longer than most angler fish that live for under 10 years.
While most angler fish live in both freshwater and marine habitats, black angler fish are found exclusively in deep ocean waters. They have never been discovered in freshwater environments. If interested in purchasing a black angler fish, expect to pay around $50 to $200 from ethical specialty aquarium stores that capture and sell specimens sustainably.
The black angler fish exhibits several specialized physical features that aid its survival in the deep sea:
Black angler fish are typically small, growing to around 16 inches on average. However, some larger species like the black seadevil can reach up to 24 inches long. In terms of weight, most black angler fish weigh between 2 to 5 lbs. The largest confirmed specimen was a 24 inch long black seadevil weighing around 15 lbs.
As their name denotes, black angler fish have uniformly black skin. Their black coloration serves as camouflage in the dimly lit depths of the ocean. Some species may exhibit a dark gray hue. The black skin contains dense concentrations of melanin pigment granules that give it the dark coloration.
Like all angler fish, black angler fish have a prominent bioluminescent lure protruding above their jaws. Their lures are proportionally larger and longer than most angler fish, extending up to 5 inches in front of the head. The lure consists of a modified dorsal ray bone called the illicium attached to a fleshy bulb containing bioluminescent bacteria. The angler fish can flash or blink this “fishing rod” to attract prey towards its giant mouth.
Jaws and Teeth
Black angler fish have enormous jaws that can distend to over twice the diameter of their bodies, allowing them to swallow prey nearly their size. Their mouths contain long fang-like teeth that all angle inward. These needle-like teeth grab prey and prevent escape once sucked into their cavernous mouths.
Eyes and Vision
Since black angler fish occupy perpetually dark habitats, they have fairly reduced eyes. Their eyes are generally small and poorly developed, adapted for detecting bioluminescence rather than forming images. A layer of reflective material covers the eyeballs, allowing them to pick up what little light exists in the abyssal zone.
Black angler fish have soft dorsal and anal fins with 13-21 rays each. The broad-based pectoral fins aid with steering and maneuvering. A short, stout caudal (tail) fin provides forward propulsion. Since they are slow swimmers, their fin structures are designed more for maneuverability than speed.
The skin of black angler fish contains no scales or pigment. Instead, it has a thin, soft, velvety texture. In some species, the skin bears dermal spinules – small, bony spikes that may protect against predators trying to swallow them.
Habitat and Distribution
Black angler fish exclusively inhabit lightless ocean depths below 3,300 feet in a zone known as the abyssal plain. Some specifics on their habitat range:
- Depth range: 1,000 – 14,000 feet deep
- Temperature range: 2 – 4°C (36 – 39°F)
- Ocean basins: Found in all major oceans – Atlantic, Pacific, Indian, and Southern. They occupy bathypelagic and abyssopelagic zones.
- Seafloor terrain: Mostly soft, muddy or sandy substrates on flat, featureless plains.
- Proximity to land: Their range extends hundreds of miles offshore from continental shelves and coastlines.
Due to their habitat’s remoteness and extreme conditions, black angler fish remain mysterious and rarely observed in the wild. Specimens are sometimes captured in commercial trawl nets or wash ashore after storms. Tanks require very cold water and complete darkness to replicate abyssal conditions. A suitable captive habitat would be a 400+ gallon tank with dim blue lighting and temperatures below 10°C. Black angler fish appearing in shallow water or washing up on shores likely involve sick or dying individuals carried by currents.
Diet and Feeding Habits
Black angler fish employ several specialized adaptations to capture prey in near-total darkness:
- Sit-and-wait ambush predators: They remain stationary on the seafloor, waiting to attract prey with their lure.
- Bioluminescent fishing lure: The light emitted from the lure attracts zooplankton, smaller fish, and other prey towards the angler fish’s giant mouth. They can flash the lure on and off or wave it back and forth.
- Hinged jaw: Their mouths open extremely wide to create strong suction that pulls in struggling prey. The inward-facing needle teeth prevent escape.
- Expandable stomach: Their stomachs can distend to accommodate enormous meals. A 12 inch angler fish can swallow prey up to twice its length and mass.
- Opportunistic diet: They will consume any animal small enough to be sucked into their mouths and swallowed whole. Their prey includes fish, squids, shrimps, jellyfish, and zooplankton.
While most angler fish are generalist predators, the black seadevil has more specific feeding habits, mainly on lanternfish, bristlemouths, shrimps, and other midwater animals that migrate from surface waters at night. Its upward-aimed lure is an adaptation for attracting descending prey.
There is no evidence that angler fish can harvest black pearls. As deep-sea fish, they do not inhabit areas where pearl oysters grow in tropical coastal waters. While angler fish do consume mollusks, they are not known to forage for pearls inside them.
Reproduction and Lifespan
The reproductive behaviors of black angler fish are as strange and extreme as their appearance:
- Dwarf males: At around 1-2 inches long, male black angler fish are tiny compared to females and lack functional digestive systems. Their sole purpose is to find a female and mate.
- Sexual parasitism: To reproduce, a male bites onto a female and latches on until the tissues fuse. Their skin and blood vessels intertwine until the male becomes a parasitic mate.
- Sperm transfer: The attached males provide a constant supply of sperm to the females for egg fertilization. A single female may host 6 or more parasitic males.
- Short male lifespan: Attached males survive solely off the nutrients supplied by the female host. They spend their entire 2-3 year lifespan fused to the female.
- Long female lifespan: Female black angler fish live considerably longer than males, averaging 15-25 years. The longest recorded lifespan was a female black seadevil that lived to 40 years old in an aquarium.
- Slow reproduction: The female must expend significant energy developing eggs. As a result, spawning may only occur every several years. The eggs are buoyant and float up after being released.
- No parental care: Black angler fish do not care for eggs or offspring after spawning. The eggs drift with currents and hatch into free-swimming larvae.
The bizarre mating habits of angler fish allow them to find mates and reproduce in the deep sea where individuals are few and far between. Their extreme sexual dimorphism maximizes chances of fertilization in this sparse environment.
Black Angler Fish in Popular Culture
The black angler fish’s ominous appearance and elusive nature has intrigued the popular imagination. Some examples of the black angler fish in media include:
- Movies: Angler fish inspired the huge gulper eel monster in Finding Nemo. A black angler fish appears in Moana during the song “Where You Are.”
- Television: In Spongebob Squarepants, an old angler fish is the wife of Mr. Krabs.
- Video Games: Angler fish are enemies in games like Subnautica and Far Cry.
- Literature: In 20,000 Leagues Under the Sea, Captain Nemo and the crew encounter a monstrous angler fish.
- Cartoons: The light of the angler fish’s lure is depicted as a hypnotic trap for prey in cartoons.
- Art: Salvador Dali painted melting black angler fish in surrealist artworks like Dream Caused by the Flight of a Bee Around a Pomegranate.
- Tattoos: Black angler fish make dramatic tattoo designs symbolizing danger, darkness, the unconscious, and the allure of the unknown depths.
Cliparts of angler fish can commonly be found on websites like Freepik and Flaticon. Black and white designs present a more stark, minimalist, artistic representation of their unusual form.
How big is the black seadevil?
The black seadevil is one of the larger black angler fish species, reaching lengths of 16-24 inches and weighing up to 15 lbs. Their growth is larger than many other angler fish that average around a foot long.
What eats the black sea devil?
As adults, black sea devils and other black angler fish have few natural predators, if any, thanks to their formidable size and camouflage. However, their eggs and larvae floating in the water column are vulnerable to predation by larger fish, sharks, marine mammals, seabirds, and other predators. Recently hatched larvae in particular, suffer extremely high mortality rates from predation. Their chances of surviving to adulthood are estimated to be less than 1 in 5,000.
How deep is the black seadevil found?
The black seadevil occupies some of the deepest points in the ocean, inhabiting depths from around 1,000 feet down to 14,000 feet beneath the surface. They are truly creatures of the abyss, adapted to the bathypelagic zone’s crushing pressures and perpetual darkness.
Are black angler fish suitable pets?
Due to the extreme difficulty of replicating their natural environment, most experts advise against angler fish as pets. They require highly specialized aquarium equipment, complete darkness, frigid water temperatures, and particular live foods. Their specific needs make them challenging for the average aquarist to care for properly. Those interested should strongly research their requirements.
The black angler fish remains one of the most mysterious creatures of the deep ocean. While sightings of these elusive fish are extraordinarily rare, their unique adaptations provide a fascinating glimpse into the extremes of life on our planet. From their light-producing lures to parasitic mating methods, angler fish demonstrate the wonders evolution has produced even in the most inhospitable habitats. As deep sea exploration continues, marine biologists will hopefully uncover further secrets of these denizens of the abyss. Until then, the black angler fish remains a reminder of how much is yet to be discovered far beneath the ocean’s surface.