Fish

Toadfish

Batrachoididae · also called toadfishes, midshipman, oyster toad

Least Concern → carnivore Ocean Coasts & shorelines

A toadfish is an ugly, warty lump of a fish that lies half-buried in harbour mud and sings. In the breeding season, males hum against their swim bladders with the fastest muscles in any vertebrate, and a marina full of them produces a droning foghorn chorus loud enough to travel through boat hulls and keep people awake.

Overview

Toadfish are the family Batrachoididae, around 80 species in shallow coastal and estuarine waters worldwide, most in warm regions. They are squat, broad-headed ambush predators that lie still and lunge at crabs, shrimp, molluscs, and small fish, crushing shells with strong jaws. They are extraordinarily tough — tolerant of low oxygen, pollution, heat, and being stranded out of water for a day or more.

The singing fish

Males call females by drumming a pair of sonic muscles against the gas-filled swim bladder, producing a sustained foghorn hum. Those muscles contract up to 200 times a second — the fastest muscle known in any vertebrate, a standard lab model. A chorus of males around a marina has drawn noise complaints from houseboat residents, most famously in Sausalito, California.

Guarding fathers and glowing bellies

The male builds a nest under a rock or shell, calls in females to lay eggs on the roof, and guards the eggs and young for weeks. The midshipman toadfish are named for rows of light organs along the belly that resemble uniform buttons. Some toadfish have venomous dorsal spines, and oyster toadfish flew on the Space Shuttle for inner-ear research.

Status

Least Concern and stable. Toadfish are widespread, notably tolerant of degraded water, and of only minor interest to fisheries.

Toadfish: common questions

Why do toadfish make so much noise?

The sound is a courtship call made by males. During the breeding season a male toadfish settles into a nest site and produces a loud, droning hum, sometimes called a boat whistle, by rapidly vibrating a pair of muscles attached to its swim bladder, which acts as a resonating drum. The call advertises the male and his nest to females ready to spawn. Because many males call at once and the sound couples efficiently into the water and into anything touching the water, such as a boat hull or a dock, a breeding aggregation can produce a continuous background drone loud enough to be heard inside moored boats and to prompt noise complaints. The famous case is the plainfin midshipman in Sausalito, California, in the 1980s.

What is a midshipman fish, and why the name?

Midshipman fish are toadfish of the genus Porichthys. They are named for the rows of light-producing organs, called photophores, that run in lines along their undersides and were thought to resemble the buttons on a naval midshipman's uniform. The photophores glow with a soft light, used in social signalling and possibly in camouflaging the fish's silhouette from below. The plainfin midshipman of the Pacific coast of North America is the best-known species and is both the loudest singer in the family and a fish that migrates from deep water into the intertidal zone to breed, where its nests under rocks are a major food source for herons, otters, and raccoons at low tide.

Are toadfish dangerous to handle?

They can hurt you, though not seriously. All toadfish have sharp spines on the first dorsal fin and sharp edges on the gill covers, and a struggling fish can drive these into a hand, causing a painful puncture wound that is prone to infection like any fish injury. In the true venomous toadfishes, mostly found off Central and South America, those dorsal spines are hollow and linked to venom glands, and a sting produces intense local pain, swelling, and redness, treated by immersing the area in hot water. None are considered life-threatening. Anglers who catch oyster toadfish, which are common bait stealers, usually handle them with a cloth or pliers and keep clear of the fin and gill edges.

How do toadfish survive in such poor water?

Toadfish are among the toughest of coastal fish. They tolerate very low oxygen levels that would kill most species, can switch to gulping air at the surface, and withstand large swings in temperature, salinity, and pollution. They can also survive being stranded out of water for a day or more if they stay moist, breathing across their skin and the lining of the mouth. This hardiness lets them thrive in warm, muddy, low-oxygen harbours, estuaries, and tidal creeks, and it is part of why oyster toadfish are so easy to keep in aquariums and so useful as laboratory animals.

Sources & further reading

Written by HideShark Editorial Team · reviewed by HideShark Science Desk. Published September 10, 2026. Last updated September 10, 2026.

Quick facts

Scientific name: Batrachoididae
Diet: An ambush predator that lies still and half-buried, then lunges at crabs, shrimp, molluscs, worms, small fish, and almost anything else that passes within reach, crushing hard shells with strong jaws, and it will readily scavenge and take a baited hook
The singing fish: Male toadfish attract females by contracting a pair of muscles against the gas-filled swim bladder to produce a loud, sustained, foghorn-like hum or boat-whistle call, and a chorus of dozens of males around a marina can carry through boat hulls and has generated noise complaints from houseboat residents in San Francisco Bay and elsewhere
The fastest muscle in any vertebrate: The sonic muscles of the toadfish contract and relax up to around 200 times per second, faster than any other known vertebrate muscle, including a hummingbird's wing muscles or a rattlesnake's tail, and they are a standard laboratory model for studying superfast muscle
It can breathe air and survive out of water: Toadfish tolerate low oxygen, pollution, wide swings in temperature and salinity, and can gulp air and stay alive out of water for a day or more if kept damp, which lets them live in warm, stagnant, muddy harbours where few other fish persist
Guarding fathers: The male makes a nest under a rock, shell, can, or tyre, calls in one or more females to lay a single layer of large adhesive eggs on the roof, and then guards the eggs and the newly hatched young for weeks, the hatchlings staying attached to the nest by a yolk sac until they can swim
Some species are venomous: The dorsal-fin spines and gill covers of many toadfish are sharp, and in the venomous toadfishes of the family they are hollow and connected to venom glands, delivering a painful sting to a careless angler or wader, though not a dangerous one
A fish that went to space: Oyster toadfish were flown on Space Shuttle missions in the 1990s because their large, simple balance organs made them ideal for studying how the vertebrate inner ear adapts to weightlessness
Range: Shallow coastal and estuarine waters of the Atlantic, Pacific, and Indian Oceans, mainly in warm-temperate and tropical regions, on mud, sand, rubble, and rocky bottoms, around oyster reefs, pilings, seagrass, and harbour structures, from the intertidal zone to around 100 m, with a few species entering fresh water in Central and South America.
Conservation status: Least Concern → ≈ Toadfish are not of conservation concern, with the roughly 80 species widespread in their coastal habitats, notably tolerant of degraded and polluted water, and of only minor interest to fisheries, with the oyster toadfish taken as a minor food and bait species along the US Atlantic coast and the plainfin midshipman important mainly as prey for other animals, so populations are generally considered stable in the wild