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Species Profile

Marine Toad

Rhinella marina

Big toad. Bigger toxins.
Marku1988 - Public Domain

Marine Toad Distribution

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Invasive Species
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Found in 26 locations

Marine Toad in a tree

At a Glance

Wild Species
Also Known As Giant toad, Giant neotropical toad, Sapo de caña, Sapo-cururu
Diet Carnivore
Activity Nocturnal+
Lifespan 10 years
Weight 1.8 lbs
Status Least Concern
Did You Know?

Former name Bufo marinus; now placed in Rhinella based on modern taxonomy.

Scientific Classification

A very large true toad native to Central and South America and widely introduced elsewhere; notable for its prominent parotoid glands and potent skin toxins. Often associated with human-modified habitats and is a major invasive species in several regions.

Kingdom
Animalia
Phylum
Chordata
Class
Amphibia
Order
Anura
Family
Bufonidae
Genus
Rhinella
Species
Rhinella marina

Distinguishing Features

  • Very large toad with stout body and warty skin
  • Large triangular parotoid (toxin) glands behind the eyes
  • Broad head with pronounced bony ridges; horizontal pupils
  • Toxic secretions (bufotoxins) that can poison predators and pets

Physical Measurements

Males and females differ in size

Weight
♂ 1 lbs (0 lbs – 2 lbs)
♀ 1 lbs (0 lbs – 6 lbs)
Top Speed
0 mph
walking
Poisonous

Appearance

Primary Colors
Brown Tan
Secondary Colors
Cream Black Spotted
Skin Type Dry, thick, heavily warted (verrucose) skin with prominent toxin-secreting granular glands; large parotoid glands behind eyes exude milky bufotoxins when threatened.
Distinctive Features
  • Very large true toad (Bufonidae); formerly Bufo marinus, now Rhinella marina.
  • Adult snout-vent length (SVL) commonly ~10-15 cm; documented maximum SVL about 24 cm.
  • Robust body; broad head with pronounced bony cranial crests/ridges above eyes and snout.
  • Huge, triangular-to-elongate parotoid glands positioned behind the eyes; key identification trait.
  • Large, obvious tympanum (external eardrum) often visible behind the eye.
  • Short, sturdy limbs; terrestrial gait; strong hind limbs but typically not a long-distance jumper.
  • Nocturnal and highly synanthropic: frequently forages around lights, roads, gardens, and disturbed habitats.
  • Defense: potent bufotoxins from parotoid/skin glands; can poison predators that mouth or ingest it.
  • Breeds in fresh water (ponds, ditches, slow streams); not a sea-dwelling species despite "marine toad" name.
  • High fecundity: long egg strings; typical clutch sizes commonly reported in the thousands (often ~8,000-30,000 eggs).
  • Major invasive species in several regions; broad diet (invertebrates and small vertebrates) and rapid spread in human-modified landscapes.
  • Longevity: typically up to about 10-15 years.

Sexual Dimorphism

Females are typically larger and heavier-bodied than males. Males develop dark nuptial pads on the first fingers and have a more developed vocal apparatus, often showing a darker throat during breeding.

♂
  • Smaller average SVL and mass than females; more slender body profile.
  • Nuptial pads on inner/first fingers during breeding season (dark, roughened).
  • Vocal sac/vocal apparatus present; males call (advertisement trill) from breeding sites.
  • Throat often darker/grayish during breeding compared with females.
♀
  • Larger average SVL and mass; broader abdomen, especially when gravid.
  • Lack nuptial pads; less developed vocal structures and do not produce advertisement calls.
  • Often comparatively paler throat/underside outside of individual variation.

Did You Know?

Former name Bufo marinus; now placed in Rhinella based on modern taxonomy.

Large adults are commonly 10-15 cm snout-vent length (SVL); very large individuals can exceed 20 cm SVL (field reports commonly cite ~23-24 cm max).

Females can lay ~8,000-35,000 eggs per clutch in long gelatinous strings (e.g., Lever 2001; Shine reviews).

Eggs can hatch in as little as ~2-3 days in warm water; metamorphosis often occurs within ~3-12+ weeks depending on temperature and food.

The parotoid glands behind the eyes can exude potent bufotoxins; many predators die after biting or mouthing a cane toad (well documented in invaded Australia).

In Australia, cane toads were released in 1935 for sugarcane pest control; the population expanded dramatically beyond farms and towns.

At the invasion front in northern Australia, spread rates have been measured at roughly ~40-60 km/year, much faster than early expansion (e.g., Phillips et al. 2006; subsequent syntheses).

Unique Adaptations

  • Parotoid (poison) glands and skin toxins: bufotoxins (including bufagenins) provide strong chemical defense; milky secretions can deter or kill predators and irritate mucous membranes.
  • Bony cranial ridges and robust skull: characteristic "armored" head with ridges above the eyes and snout helps identification and offers protection.
  • High fecundity: very large clutches (thousands to tens of thousands of eggs) and frequent breeding in warm climates accelerate population growth.
  • Broad environmental tolerance: persists in human-modified habitats and can reproduce in a wide variety of freshwater bodies, aiding establishment after introduction.
  • Rapid evolution on invasion fronts: Australian cane toads have shown measurable shifts in dispersal-related traits (e.g., longer legs, higher movement rates in some studies), improving spread in new landscapes.

Interesting Behaviors

  • Nocturnal, human-associated foraging: often sits under streetlights or porch lights to ambush insects drawn to illumination.
  • Sit-and-wait predation plus scavenging: eats insects, snails, pet food, carrion, and occasionally small vertebrates; will exploit almost any edible resource in disturbed habitats.
  • Explosive breeding after rains: adults congregate at still or slow waters (ponds, ditches, dams), with males calling and clasping females (amplexus) for mass spawning.
  • Tadpole social chemistry: larvae form schools and respond strongly to chemical cues from conspecifics; studies in Australia show tadpoles can be attracted to and consume freshly laid eggs (cannibalism) under some conditions (Shine lab work).
  • Water-conserving behavior: in dry periods, adults shelter in cool, moist refuges (burrows, leaf litter, drains) and emerge to feed when humidity rises.
  • Invasive-edge movement: individuals at the invasion front tend to travel farther per night than long-established populations-behavioral and morphological shifts linked to rapid range expansion (documented in Australian populations).

Cultural Significance

Native to Central and South America, Rhinella marina is part of rural life and stories. Introduced for pest control—most famously to Australia in 1935—it is a symbol of invasive harm: poisoning predators, changing food webs, and sparking education and community toad-muster events. Older name Bufo marinus still appears.

Myths & Legends

In parts of Mesoamerica, toads are traditional symbols of rain, earth, and fertility; their calls and sudden appearance with storms link them to coming rains, and large native toads like Rhinella marina fit this image.

In Amazonian and Latin American folk tales, big toads like the Cane Toad (Rhinella marina) are seen as rainy-season omens, gate guardians, and animals that change into enchanted forms at night.

In Brazil, a well-known children's song and rhyme tells of a big, warty toad that sings at night by the water; the character is a folk toad, not a specific species like Rhinella marina.

In Caribbean and African diaspora folklore, cane toads (Rhinella marina) appear as witches' helpers, cursed animals, or protective house and yard spirits, with their night habits and poisons seen as dangerous and powerful.

Since the mid-1900s in Australia, cane toads (marine toads, Rhinella marina) became local legends: “monster toads,” tales of dogs poisoned after biting them, and community hunts to remove them, warning about meddling with nature.

Conservation Status

LC Least Concern

Widespread and abundant in the wild.

Population Increasing

Life Cycle

Birth 20000 tadpoles
Lifespan 10 years

Lifespan

In the Wild
5–15 years
In Captivity
10–35 years

Reproduction

Mating System Promiscuity
Social Structure Aggregation Group
Breeding Pattern Transient
Fertilization Substrate Spawning
Birth Type Substrate_spawning

Breeding is explosive after rains at ponds; males form dense calling aggregations and attempt amplexus with many females (scramble competition). In axillary amplexus, females deposit ~8,000-35,000 eggs in gelatinous strings; males externally fertilize. No parental care.

Behavior & Ecology

Social Congregation Group: 12
Activity Nocturnal, Crepuscular
Diet Carnivore Large-bodied beetles (Coleoptera)
Seasonal Hibernates

Temperament

HUBS: Mostly solitary and tolerant of conspecifics; strongest social clustering occurs around water/food and breeding sites.
Generally bold in human-modified habitats; readily uses shelters (debris, drains) and returns to moist refuges.
Low overt aggression during foraging; males may physically jostle during amplexus competition in breeding congregations.
Larvae can be strongly cannibalistic; tadpoles aggregate and may consume conspecific eggs (documented in invasive populations; e.g., Crossland & Shine 2011).

Communication

Male advertisement call: long, low-pitched trill used to attract females and space rival males Chorusing at breeding sites
Release call: short vocalization by clasped individuals to terminate amplexus.
Distress vocalization: brief squeak when seized by predators/handled Reported for bufonids, including R. marina in field guides
Chemical defense signaling: bufotoxin/bufadienolide secretions from parotoid/skin glands deter predators; may condition predator avoidance.
Chemical cueing in larvae: tadpoles respond to conspecific chemical cues Including toxin-related cues) affecting aggregation and foraging/cannibalism (e.g., Crossland & Shine 2011
Tactile communication: prolonged axillary amplexus; females' contact and movement cues influence pair coordination and spawning.
Visual/postural cues: body inflation, head-raising, and immobility used in threat display and predator deterrence.

Habitat

Rainforest Forest Woodland Grassland Savanna Shrubland Wetland Swamp Marsh Pond Lake River/Stream Mangrove Estuary Coastal Agricultural/Farmland Plantation Urban Suburban +13
Biomes:
Tropical Rainforest Tropical Dry Forest Savanna Temperate Forest Freshwater Wetland
Terrain:
Plains Coastal Riverine Valley Hilly Plateau Island Sandy Muddy +3
Elevation: Up to 5249 ft 4 in

Ecological Role

Opportunistic mesopredator (often invasive) that strongly influences local food webs through heavy predation on invertebrates and occasional predation on small vertebrates; also functions as toxic prey that can poison susceptible predators via bufotoxins.

Regulation of nocturnal insect populations (including some agricultural pest taxa) Energy transfer from abundant invertebrates to higher trophic levels (where predators are toxin-tolerant) In invaded systems, alters community structure via predation and competition; indirectly affects predator populations through toxin-mediated mortality

Diet Details

Main Prey:
Beetles Ants Termites Cockroaches Crickets and katydids Moths and caterpillars Flies Earwigs Spiders Scorpion Centipedes Earthworms Snails and slugs Crabs and small crustaceans Frogs and toads Small lizards Small snakes Nestling birds and small ground birds Small mammals Carrion and animal-based human refuse and pet food +14

Human Interaction

Domestication Status

Wild

Rhinella marina (cane toad, marine toad) is not domesticated. People moved it widely for pest control (e.g., Australia 1935), creating large invasive populations in towns and farms. It is kept as pets and used in research, medicine, and education. Adults are large, make strong bufotoxins, breed many eggs, and may live 10–15+ years in care.

Danger Level

Moderate
  • Toxic skin/parotoid gland secretions: can cause intense irritation and inflammation if it contacts eyes or mucous membranes; accidental ingestion is dangerous.
  • Systemic poisoning is possible if toxin is ingested (e.g., contaminated hands/objects, intentional misuse): reported effects include nausea/vomiting, hypersalivation, neurologic symptoms, and potentially serious cardiac effects (arrhythmias) due to cardioactive bufadienolides.
  • Risk is highest for children and for pets (dogs commonly poisoned by mouthing/biting toads); humans are usually harmed through mishandling and subsequent eye/mouth contact rather than bites.
  • Secondary human risks in invaded areas: increased pet-vet costs, wildlife impacts, and nuisance encounters (yards, roads), especially near artificial lights and water bodies.

As a Pet

Not Suitable as Pet

Legality: Laws vary. Many places ban or strictly control keeping cane toads (Rhinella marina), especially where they are invasive (e.g., Australia). Some areas need permits. Always check local rules; releasing them is illegal and harmful.

Care Level: Experienced

Purchase Cost: Up to $75
Lifetime Cost: $500 - $2,500

Economic Value

Uses:
Historical pest-control introductions (biological control) with largely negative outcomes Invasive-species management costs (control/eradication, monitoring, public education) Biomedical/toxicology research (bufotoxins and cardioactive steroids) Education/outreach animals in zoos/nature centers (limited, regulated) Small, regionally variable pet/curiosity trade (where legal)
Products:
  • Research specimens and toxin-related biomedical knowledge (no standardized commercial product recommended/endorsed)
  • Invasive-control services and materials (traps, barriers, community removal programs)

Relationships

Predators 7

Keelback
Keelback Tropidonophis mairii
Meat ant Iridomyrmex purpureus
Rakali Hydromys chrysogaster
Torresian crow Corvus orru
White-faced heron Egretta novaehollandiae
Black kite
Black kite Milvus migrans
Monitor lizard
Monitor lizard Varanus spp.

Related Species 7

Cururu toad Rhinella horribilis Shared Genus
Schneider's toad Rhinella schneideri Shared Genus
Giant toad
Giant toad Rhinella icterica Shared Genus
Argentine toad Rhinella arenarum Shared Genus
Sonoran Desert toad Incilius alvarius Shared Family
Asian common toad Duttaphrynus melanostictus Shared Family
Common toad
Common toad Bufo bufo Shared Family

Ecological Equivalents 5

Animals that fill a similar ecological role in their ecosystem

Asian common toad Duttaphrynus melanostictus The cane toad (Rhinella marina) is a large, toxic toad that lives near people, forages at night on ground-dwelling invertebrates, breeds in disturbed lowland waters, thrives in urban and farm areas, and often becomes invasive.
Colorado River toad Incilius alvarius Similar niche: a very large, glandular, toxin‑defended toad that is primarily nocturnal and opportunistically predatory on invertebrates and small vertebrates. Both possess prominent parotoid glands and can exploit irrigation canals and ponds for breeding in otherwise harsh landscapes.
American bullfrog
American bullfrog Lithobates catesbeianus Large amphibian that lays many eggs and is closely associated with human-made wetlands; invasive in many areas. Eats a wide range of prey from insects to small vertebrates, uses artificial water bodies, and spreads with human-altered habitats. Has relatively few skin toxins.
European green toad Bufotes viridis Comparable generalist toad that tolerates disturbed, open, and urban habitats; a nocturnal surface-forager and explosive breeder in ephemeral and constructed waters, mirroring cane toad use of roadside ditches, ponds, and canals.
Smooth newt Lissotriton vulgaris Functional parallel in breeding strategy—aquatic eggs and larvae in still waters—and in reliance on small freshwater bodies within fragmented landscapes. Although diet and toxicity differ, it is a useful comparator for amphibian use of anthropogenic ponds and ditches.

A large female marine toad can lay a clutch (group) of eggs numbering over 40,000.

A marine toad is a carnivore that eats insects, small birds, rodents, and other amphibians. This toad grows to be four to six inches in length and weighs around two pounds. Females are normally larger than males. The average lifespan of a marine toad is five years, but it can live up to 15 years in captivity. These toads can release poison from glands located on its shoulders.

5 Marine Toad Facts

• Marine toads were introduced into the wild by scientists to control the population of sugar cane beetles

• These toads are nocturnal

• Marine toads live in tropical and subtropical regions

• They sometimes eat dead animals (carrion) that they find

• These toads can detect moving and non-moving prey

Marine Toad Scientific Name

The marine toad is sometimes called a cane toad, giant toad, or Bufo toad. Its scientific name is Bufo marinus. This name is Latin, Bufo meaning toad and marinus meaning marine. This toad belongs to the Bufonidae family and is in the class Amphibia.

There are hundreds of species of toads in the Bufonidae family. Examples include the western leopard toad, Oak toad, eastern leopard toad, and American toad.

Marine Toad Appearance and Behavior

These toads has brown or grayish skin covered with bumps. It has large dark eyes and parotid glands located on its shoulders. These glands release poison when the toad feels threatened.

The average marine toad measures from four to six inches in length and weighs around two pounds. A marine toad that is six inches in length, is as long as three golf tees. The weight of these toads is equal to two and a half cans of soup that you may find in your pantry.

The record for the largest marine toad is held by a marine toad named Prinsen. This toad weighs five pounds, 13 ounces and is a little more than two feet long! Just imagine two rulers you use at school lined up end to end – that’s about the length of Prinsen.

The brown skin of these toads helps it to blend in with the trees, dry grass, and other plants in its environment. This can serve as protection from predators. If a predator does find this toad, it can release a poison from glands on its shoulders. A predator can become ill or even die from the poison.

They are solitary animals. Breeding season is the only time you’ll find them living close together. This is a shy animal that wants to avoid humans and larger animals, if at all possible. 

marine toad (Bufo marinus) marine toad in grass at night

Marine Toad Habitat

These toads live in southern parts of the United States as well as in Central and South America. In addition, they live in Australia and near some Caribbean islands.

These toads live in a tropical or subtropical climate. When the weather becomes a little cooler in these environments, these toads hide in crevices between rocks and in hollow logs to stay warm.

These toads have an annual migration in March where they go to a pond, lake, or other body of water to begin their breeding season.

Marine Toad Diet

What do these toads eat? The marine toad’s diet is one of the most interesting things about this amphibian. These carnivores eat a variety of things including beetles, spiders, small lizards, and salamanders. They’ll also eat dead animals left behind by other predators. Eating dead animals (carrion) is unusual for other toads.

Marine Toad Predators and Threats

As you’ve probably guessed, the poison released by this toad allows it to escape many predators. However, snakes, eagles, rats, and caimans are all animals that can sometimes manage to eat these toads.

As a matter of fact, some animals have developed ways to eat these toads while avoiding the poison. For example, the Australian crow kills a marine toad and quickly turns it onto its back to eat it, so it doesn’t get near its poisonous glands. The Australian tarantula as well as the common wolf spider are two other animals that have figured out how to eat these toads without taking in the poison.

The marine toad was released by scientists back in the 1930s to control the population of sugar cane beetles among other pests. Over the years, the population of these toads has actually grown to a point of causing it to become the pest! Because there are so many marine toads, they consume a lot of the smaller animals in their habitat. This leaves less food for other species of animals that share the habitat with marine toads. So, there’s now an overpopulation of marine toads in Australia, among other places.

The official conservation status of these toads is least concern.

Marine Toad Reproduction, Babies, and Lifespan

The breeding season for these toads goes from March to September. During this time, these toads move to a pond, lake, or stream. A male mates with different females each breeding season and uses a particular call that attracts the females. It is similar to a purring sound. Not surprisingly, it can get very noisy around ponds and lakes during the breeding season of these toads!

After pairing up, a female toad lays strings of eggs in a slow-moving pond or stream. The male fertilizes the eggs and when all of the eggs have been laid, both toads move away. Neither one stays to care for the eggs.

A female toad lays an average of 30,000 eggs in one clutch (group). Instead of floating on the surface, the strings of eggs sink to the bottom of the pond or stream clinging to underwater plants. These eggs are vulnerable to frogs, fish, and other predators that swim in the water. However, because a female lays so many, there is an excellent chance that many of the eggs will survive.

It takes just three days for the marine toad eggs to hatch and take the form of tadpoles. Initially, tadpoles eat the eggs they just came out of along with algae. As they grow into young toads, they start to eat small insects. Tadpoles grow into young marine toads, or toadlets, in about 30 to 50 days. It takes a toadlet one year to grow into an adult.

An adult toad lives an average of five years in the wild. In captivity, where there are few or no predators to threaten them, they can live to be about 15. The record for the oldest marine toad living in captivity is 35 years!

Marine Toad Population

The population of these toads throughout the world numbers in the millions. As an example, there are approximately 200 million marine toads in Australia alone.

The population of these toads is increasing, and its conservation status, according to the International Union for the Conservation of Nature (IUCN), is least concern.

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Sources

  1. David Burnie, Dorling Kindersley (2011) Animal, The Definitive Visual Guide To The World's Wildlife / Accessed May 17, 2010
  2. Tom Jackson, Lorenz Books (2007) The World Encyclopedia Of Animals / Accessed May 17, 2010
  3. David Burnie, Kingfisher (2011) The Kingfisher Animal Encyclopedia / Accessed May 17, 2010
  4. Richard Mackay, University of California Press (2009) The Atlas Of Endangered Species / Accessed May 17, 2010
  5. David Burnie, Dorling Kindersley (2008) Illustrated Encyclopedia Of Animals / Accessed May 17, 2010
  6. Dorling Kindersley (2006) Dorling Kindersley Encyclopedia Of Animals / Accessed May 17, 2010
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Marine Toad FAQs (Frequently Asked Questions)

The marine toad lives in Australia, the southern part of the United States, Central America, South America and near some of the Caribbean Islands.

They can survive in tropical, sub-tropical and semi-arid climates. They keep cool during the day hiding in rock crevices and inside hollow logs.

View Marine Toad Photos