Marine Toad, Rhinella marina (Family Bufonidae)

The marine toad, locally known as crapaud, can be found throughout Trinidad and Tobago as it occurs in a variety of terrestrial habitats from urban areas, agricultural lands to forests. It may be considered the largest toad in the world with a maximum size of 238 mm SVL, with females larger than males. This species is known to feed on anything it can swallow. It can be distinguished from the Beebe's toad also found on Trinidad & Tobago by the position of its nostrils and its heavily webbed hind feet. It has toxic chemicals in its skin that can result in fatality if consumed.

Marine Toad, Cane Toad

Rhinella marina (Linnaeus, 1758)

Rana marinaLinnaeus, 1758, Syst. Nat., Ed. 10, 1: 211. Type(s): By indication including specimen illustrated in Seba, 1734, Locuplet. Rer. Nat. Thesaur. Descript. Icon. Exp. Univ. Phys. Hist., Type locality: "America"; restricted by Müller and Hellmich, 1936, Wissenschaft. Ergebn. Deutschen Gran Chaco Exped., Amph. Rept.: 14, to Surinam.

Bufo marinus — Schneider, 1799, Hist. Amph. Nat.: 219.

Chaunus marinus — Frost, et al. 2006, Bull. Am. Mus. Nat. Hist., 297: 364.

Rhinella marina — Chaparro, Pramuk, and Gluesenkamp, 2007, Herpetologica, 63: 211.

Distribution. Marine toads (Rhinella marina) occur naturally from southern Texas and Sonora and Tamaulipas Mexico southward to the Orinoco and Amazon River Basins of South America. They have been introduced over much of the tropical world to control agriculture pests to most tropical regions as a control for agricultural pests. They occur naturally in Trinidad and Tobago.

Marine toads, or crapauds as they are known in the islands, use shallow bodies of clear water with a high pH and minimal vegetation to reproduce. The breeding sites may be in shallow brackish waters in coastal areas or they may use pools in streams running through agricultural areas or forests. Man-made bodies of water such as concrete ponds, old foundations that collect water, abandoned swimming pools, or natural ponds in forests or forest edge situations.

The marine toad is so prevalent in Trinidad and Tobago that it has taken on a cultural role, albeit a superficial one. While Amerindians may have lived on the islands for thousands of years, Trinidad and Tobago were not discovered by the European world until Christopher Columbus' third voyage in 1498. And, early European colonization was slow. Trinidad's human population probably numbered in the hundreds until 1785, and Tobago's population was similarly small. Thus these islands have only been inhabited with substantial populations of Africans and Europeans for less than 300 years.
The toad's local name, "crapaud," is French for "toad," and in Speyside, Tobago there is a street named after this largest native amphibian. The marine toad has also become part of local culture and colloquialisms. Tobagonians wishing to silence a hostile witness in court will attempt to intimidate the witness by sewing a crapaud's mouth shut and placing it in the witness' house the night before the trial. Also, in predicting misfortune or offering a warning the phrase, "Crapaud smoke your pipe!" may be used (Niddrie, 1980). As we will see the crapaud has taken on a more complex role in other cultures.

The marine toad was one of the first (actually the eighth) amphibians to be described by science. Carl Linneaus, the Swedish founder of the current binomial nomenclatural system used by biologists, named and described the giant toad, "Rana marina" on page 211 of his first volume of Systema naturae... in 1758. Sixteen years later John Julius Walbaum proposed that Linnaeus' name for this toad was inappropriate. Walbaum (1784) (in Smith et al. 1977) wrote,

I seriously doubt that it usually lives in the ocean, because the structure of the feet is not such that it would be able to swim with them through the rough waves of the ocean. therefore I assume it to be a land frog which lives at the banks of rivers or shores of lakes. If this assumption is confirmed in the future, the Latin specific name applied by Linnaeus would have to be changed because it does not correctly characterize the species.

Wallbaum's proposal is not acceptable today because Article 18(a) of the International Code of Zoological Nomenclature makes it clear that a genus, or a species-group name, cannot be changed once it is established, even if it is inappropriate. But, a species may be moved from one genus to another. Linnaeus recognized only 10 genera of amphibians and reptiles in his 1758 work. Joseph Nicolaus Laurenti was the next person to review amphibian and reptile classification, and he established the genus Bufo in 1768. Today, Article 34(b) of the International Code requires that changes in species names must made so that they agree with the gender of the genus. Thus, Rana marina is feminine, while Bufo is masculine. When marinus was moved to Bufo, it therefore became Bufo marinus. When the species was re-assigned to the genus Rhinella, it again became feminine and today it is known as Rhinella marina.

There are competing species for the honor of the largest toad. However, the largest toad species appears to be South American, and the contest for the largest species is between Blomberg's toad, Rhaebo blombergi, and the marine toad. Blair (1972) and Duellman and Trueb (1986) considered Blomberg's toad of Colombia the largest toad species, the latter authors give its length as 250 mm. Reed and Borowsky (1970) reported five female marinus ranging from 208-230 mm, all are museum specimens, and all are from Suriname and Guyana. A newspaper article (Anon., 1988) reported the death of a marine toad at the Blank Park Zoo, in Des Moines, Iowa. This animal, named "Totally Awesome," or Toad A, weighed 5 pounds 1.5 ounces (2.3 kg), and was 9.5 inches (241.3 mm) in total length. It was accepted into the Guinness Book of World Records (McFarland, 1991) as the largest toad. The zoo obtained the toad from a Miami animal dealer in 1983, thus the toad's exact age was unknown. A similarly sized specimen was reported by Tyler (1994), the specimen is currently in the Queensland Museum, and it measured 24.1 cm, and weighed (presumably when it was alive) 1.36 kg. Other toad species in the marinus Group also attain respectable sizes, Cei (1980) reported the maximum size of the kurúrú guazú (also spelled cururú), Bufo paracnemis as 210 mm in length. North American's largest toad is the Colorado River toad, Incilius alvarius, Stebbins (1985) described I. alvarius reaching 190 mm in body length. Asia also has toads that reach impressive lengths. As Boring and Lui (1934) pointed out, most continents have at least one toad species that reaches a large size.

The habitat used by Rhinella marina may have an impact on the size they reach. The largest specimens of Rhinella marina on Trinidad appear to come from the Northern Range. While the breeding population in Nariva is much smaller. This may be the result of completion for breeding sites. Shallow bodies of water are few in the Northern Range while breeding sites in Nariva Swamp are exceptionally common.

Breeding activity in Trinidad and Tobago coincides with the wet season which may start in May and continue until December or January. However, much of the activity occurs in the early and middle wet season in June and July. Males will call well after breeding has ceased.

Eggs are deposited in both permanent and ephemeral situations, the crapaud tends to prefer bodies of water with abundant aquatic plants and a neutral pH. One a female has selected a mate, they may remain in amplexus for a long period (up to two weeks). Clutch sizes of 4,000 to 36,000 have been reported, with larger females laying more eggs. Experiments with desiccating eggs fond the larvae could survive 10 hours without water as long as the surface was moist. Tadpoles emerge 48–72 hours after deposition. Tadpoles usually metamorphose 27–46 (however a range of 10–180 days has been reported). This may result from temperature differences of the water.

Marine Toad tadpoles feed on algae and other aquatic detritus (Hinckley, 1962) and its availability affects the time to metamorphosis (Tyler, 1975).

Tadpoles prefer warmer water and are adapted to high water temperatures, and are often exposed with little or no vegetative cover beside or in the water body. Tadpoles remain active throughout their development and swim in large aggregations mid water column (Straughan 1966; Krakauer 1970). Tadpoles may be cannibalistic and feed on individuals that are younger and smaller than they are, and they apparently tend to feed just on other Marine Toad tads, and not other species of anurans (Crossland, 1998a).

New metamorphosed and post-metamorphic toads remain near water because they can easily desiccate (Straughan, 1966; Alford et al., 1995a). As toads get older and larger they move farther from water and they shift their daily activity from diurnal to nocturnal behavior. Juveniles in the 30–70 mm emerge at dusk and are active at night—they are frequently found under lights, feeding on the insects attracted to the light (Krakauer, 1968).

Adults are tolerant and even thrive in human modified environments. They occur in gardens, around houses, and in water tanks (Wright and Wright, 1949). Krakauer (1968, 1970) notes that marine toads are frequently found in disturbed areas and rarely encountered in undisturbed habitats. Marine toads are nocturnal and attracted to house and patio lights that also attract the insects on which toads feed (Wright and Wright, 1949). Toads are only active 1 out of every three to five nights (Brattstrom, 1962a; Zug and Zug, 1979; Floyd and Benbow, 1984), and their activity tends to be correlated with rain (Floyd and Benbow, 1984). During the day they hide under debris on the ground and in burrows (Wright and Wright, 1949), and under long grass clumps out of direct sunlight (Cohen and Williams, 1992).

As their name suggests, marine toads are generally found along rivers and coasts in association with fresh and/or brackish water, including mangrove swamps. In a study by Krakauer (1970), adult toads were found to survive in 10‰ sea water, but quickly died in 15‰ sea water. We have observed this toad emerging from the surf along turtle nesting beaches in Trinidad, probably individuals that got washed down stream during heavy rains and followed the coast for a short distance until they could return to land.

Home range size is variable, dependent to an extent on the size of their water bodies and feeding sites (Brattstrom, 1962a; Carpenter and Gillingham, 1987). Displaced animals will return to their capture site using local landscape and visual cues providing the key inputs for orientation (Brattstrom, 1962a). Mark and recapture studies In Queensland, Australia, and the average minimum home range was calculated at 340 m2 (Pearse, 1979). A similar study by Zug and Zug (1979) found that at least some toads were familiar with an area of 2,812 m2.

Marine toads do not defend territories during the reproductive season at the breeding site or in their foraging area (Sabath, 1980). Adult toads do display some fidelity to shelter sites and prefer shelters with high soil moisture, and often increase soil moisture by urinating on the soil (Alford et al., 1995a).

Toads are able to reproduce at body lengths of 66–220 mm, with males averaging about 13 mm shorter than females (Wright and Wright, 1949; Easteal, 1986).

Marine toads feed on a wide variety of terrestrial arthropods. However, they will consume native frogs and toads, dog food, and feces (Alexander, 1964; Tyler, 1975; Rossi, 1983; Bartlett and Bartlett, 1999a). Other prey include snakes (Rabor, 1952), birds (Krakauer, 1968), and mammals (Oliver, 1949).

Noxious and toxic chemicals in the skin and tissues at all points in the toad’s life cycle keep the possible predators few in number. At the tadpole stage, dragonfly naiads will readily consume marine toad tadpoles and eggs, as will dytiscid beetles, water scorpions (Lethocerus sp.), notonectids (Anisops sp.), leeches, tortoises, Macrobrachium spp., and crayfish (Cherax quadricarinatus; Crossland, 1992, 1993; Alford et al., 1995a). Native fishes have been found to ignore or taste and reject toad tadpoles (Alford et al., 1995a; Lawler and Hero, 1997). The most frequent predators of toad eggs and tadpoles, however, are older cohorts of marine toad tadpoles (Alford et al., 1995b).

Toads are most vulnerable to predation immediately following metamorphosis, while the development of terrestrial skin glands is occurring (Cohen and Alford, 1993). Although there are no studies on predators of newly metamorphosed toads, several animals have been observed to eat them, including adult marine toads, ants, centipedes, wolf spiders, small mammals, and some birds (Cohen and Alford, 1993).

Marine toads are highly poisonous and secrete a whitish, viscous compound from their parotoid glands (in Wright and Wright, 1949; Allen and Neill, 1956; Licht, 1967b; Easteal, 1986). The parotoid glands produce and store a mixture of bufotenine and epinephrine—steroid-like substances that are toxic to most animals (Chen and Osuch, 1969; Freeland, 1986). When confronted by a predator the toad goes into a head-down defensive position marine toads assume to present their parotoid glands to potential predators. These toads are known to approach potential predators and attempt to force contact with their parotoid glands.

The oldest fossil of marinus is known from a floodplain deposit in the late Miocene (5.3-11.2 MYA) of Colombia (Estes and Wasserzug, 1963). Estes and Wasserzug considered marinus the most primitive member of the species group, and suggested it gave rise to populations adapted for life in wet and dry environments on mainland South America. Bertini and Cei (1962) suggested Rhinella marina had an Amazonian origin, later Cei (1972) hypothesized the Guiana shield was marinus' point of origin.


References

Abel, J. J. and D. I. Macht. 1911. The poisons of the tropical toad, Bufo agua. Journal of the American Medical Association 56:1531-1536.

Abel, J. J. and D. I. Macht. 1912. Two crystalline pharmacological agents obtained from the tropical toad Bufo agua. J. Pharmacol. and Exp. Ther. 3:319-377.

Alcala, A. C. 1957. Philippine notes on the ecology of the giant marine toad. Silliman Journal 4:90-96.

Alcala, A. C. 1986. Guide to Philippine Flora and Fauna. Vol. 10. Amphibians and Reptiles. National Resources Management Center and The University of the Philippines.

Alexander, T. R. 1965. Observations on the feeding behavior of Bufo marinus (Linne.). Herpetologica 20(4):255-259.

Allen, E. R. and W. T. Neill. 1956. Effect of marine toad toxins on man. Herpetolgical 17(2):150-151.

Barbour, T. 1914. A contribution to the zoögeography of the West Indies, with especial reference to amphibians and reptiles. Mem. Mus. Comp. Zool. 44:209-359.

Barbour, T. 1930. Some faunistic changes in the Lesser Antilles. Proc. New England Zool. Club 11:73-85.

Bartlett, K. A. 1949. US Dept. Agricul. R.A.S., 118:1.

Bartlett, K. A. 1949. A toad serves the sugar industry in Puerto Rico. Sugar J. (12):30.

Beebe, W. 1925. Studies of a tropical jungle: One quarter of a square mile of jungle at Kartabo, British Guiana. Zoologica 6(1):1-193.

Beebe, W. 1927. Edge of the Jungle. Garden City: Garden City Publishing Co.

Bekker, R. 1985. Predation on cane toads (Bufo marinus). Herpetofauna 16(2):52-53.

Benson, E. P. (ed.) 1981. The Olmec and Their Neighbors: Essays in Memory of Matthew W. Stirling. Washington, DC: Dumbarton Oaks.

Blair, A. P. 1947. Defensive use of parotoid secretion by Bufo marinus. Copeia 1947(2):137.

Blair, W. F. 1972. Introduction. Pages 3-5. In: Evolution in the Genus Bufo. W. F. Blair (ed.). Austin: University of Texas Press.

Bogert, C. M. and J. A. Oliver. 1945. Bull. American Mus. Nat. Hist. 83, art 6, 301-425.

Boring, A. M. and C. C. Liu. 1934. Giant toads in China. Copeia 1934(1):14-16.

Boulenger, G. A. 1896. The Tailess Batrachians of Europe. Vol. 1. London: The Ray Society.

Brattstrom, B. H. 1960. Thermoregulation in tropical amphibians. Yearbook Am. Phil. Soc. 1960:284-287.

Brattstrom, B. H. 1961. Homing in the giant toad, Bufo marinus. Herpetologica 18(3):176-180.

Brattstrom, B. H. 1962. Thermal control of aggregation behavior in tadpoles. Herpetologica 18:38-46.

Brattstrom, B. H. 1963. A preliminary review of the thermal requirements of amphibians. Ecology 44:238-255.

Brattstrom, B. H. 1968. Thermal acclimation in anuran amphibians as a function of latitude and altitude. Comp. Biochem. Physiol. 23:93-111.

Brattstrom, B. H. and N. B. Adis. 1952. Notes on a collection of reptiles and amphibians from Oaxaca, Mexico. Herpeptologica 8:59-60.

Brattstrom, B. H. and T. A. Howell. 1954. Notes on some collections of reptiles and amphibians from Nicaragua. Herpetologica 10:114-123.

Carpenter, C. C. and J. C. Gillingham. 1987. Water hole fidelity in the marine toad, Bufo marinus. Journal of Herpetology 21:158-161.

Cei, J. M. 1972. Bufo of South America. Pages 82-101. In W. F. Blair (ed.) Evolution of the genus Bufo. Austin: University of Texas Press.

Cei, J. M. 1980. Amphibians of Argentina. Monitore Zoologico Italiano, Monograph No. 2.

Chan, J. G. and L. L. Young. 1985. Bufo marinus (Marine Toad). (Anomaly). Herp. Rev. 16:23-24.

Clark, A. H. 1916. The present status and breeding season of the giant toad (Bufo agua) in Barbados, St. Vincent, Trinidad, and Demerara. Copeia 1916(27):13-14.

Clarke, R. D. 1974. Food habits of toads, genus Bufo (Amphibia: Bufonidae). Am. Midl. Nat. 91:140-147.

Clerke, R. B. and I. Williamson. 1992. A note on the predation of Bufo marinus juveniles by the ant Iridomyrmex purpureus. Australian Zoologist 28(1-4):64-67.

Cochran, D. M. 1955. Frogs of southeastern Brazil. United States National Museum Bulletin (206):1-423.

Cochran, D. M. and C. J. Goin 1970. Frogs of Colombia. United States National Museum Bulletin (288):1-655.

Cohen, M. 1996. Growth rates of Bufo marinus. Australian Soc. Herpetologists. Abstract.

Cohen, M. P. and R. A. Alford. 1996. Factors affecting diurnal shelter use by the cane toad, Bufo marinus. Herpetol. 52:172-181.

Conant, R. and J. T. Collins. 1991. A Field Guide to Reptiles and Amphibians of Eastern/Central North America. Boston:Houghton Mifflin.

Covacevich, J. and M. Archer. 1975. The distribution of the cane toad, Bufo marinus, in Australia and its effects on indigenous vertebrates. Memoirs Queensland Museum 17(2):305-310.

Crossland, M. R. 1996. Impact of cane toads on native anuran larvae. Australian Soc. Herpetologists. Abstract.

Crossland, M. R. 1998. Ontogenetic variation in toxicity of tadpoles of the introduced toad Bufo marinus to native Australian aquatic invertebrate predators. Herpetol. 54:364-369.

Dean, J. 1980. Effect of thermal and chemical components of bombardier beetle chemical defense: glosopharyngeal response in two species of toads (Bufo americanus, Bufo marinus). J. Comp. Physiol. 135:51-59.

Delvinquier, B. L. J . and W. J. Freeland. 1988b. Observations on Zelleriella antilliensis (Protozoa: Opalinata) from the cane toad Bufo marinus in Australia. Australian J. Zoology 36:317-333.

Dexter, R. R. 1932. The food habits of the imported toad, Bufo marinus, in the sugar cane setions of Porto Rico. Bulletin of the Fourth Congress of the International Society of Sugar Cane Technologists (74):1-6.

Dodds, C. T. 1923. A note on Bufo marinus. Copeia 1923(114):5-6.

Downs, T. 1948. Amphibians and reptiles of Tinian Island. Trans Kansas Acad. Sci. 51:112-116.

Duellman, W. E. 1961. The amphibians and reptiles of Michoacán, México. University of Kansas Publ. Mus. Nat. Hist. 15:1-148.

Duellman, W. E. 1965 A biogeographic account of the herpetofauna of Michoacán, México. Univ. Kans. Publ. Mus. Nat. Hist. 15:627-709.

Duellman, W. E. and A. Schwartz. 1958. Amphibians and reptiles of southern Florida. Bull. Florida St. Mus. 3:181-324.

Duellman, W. E. and L. Trueb. 1986. Biology of Amphibians. New York: McGraw-Hill Book Company.

Dunn, E. R. 1926. The frogs of Jamaica. Proc. Boston Soc. Nat. Hist. 38:111-130.

Easteal, S. 1981. The history of introductions of Bufo marinus (Amphibia: Anura); a natural experiment in evolution. Biol. J. Linn. Soc. 16:93-113.

Easteal, E., E. K. van Beurden, R. B. Floyd, and M. D. Sabath. 1985. Continuing geographical spread of Bufo marinus in Australia: range expansion between 1974 and 1980. J. Herpetology 19:185-188.

Edstrom, A. 1992. Venomous and Poisonous Animals. Malabar, FL: Krieger Publishing Co.

Estes R. and R. Wassersug. 1963. A Miocene toad from Colombia, South America. Breviora 193:1-13.

Evans, M., C. Yáber, and J.-M. Hero. 1996. Factors infulencing choice of breeding site by Bufo marinus in its natural habitat. Copeia 1996:904-912.

Fabing, H. S. and J. R. Hawkins. 1956. Intravenous bufotenin injection in the human being. Science 123:886-887.

Fellows, A. G. 1969. Toads and termites. Victorian Nat. 86:136.

Fellows, A. G. 1969. Cane beetles and toads. Victorian Nat. 86:165.

Fisher, H. I. 1948. Locality records of Pacific island reptiles and amphibians. Copeia 1948(1):69.

Flier, J., M. Edwards, J. W. Daly, and C. Myers. 1980. Widespread occurrence in frogs and toads of skin compounds interacting with the oubain site of Na+, K+, ATPase. Science 208:503-504.

Floyd, R. B. 1983. Ontogenetic change in the temperature tolerance of larval Bufo marinus (Anura: Bufonidae). Comp. Biochem Physiol. 75A:267-272.

Floyd, R. B. 1984. Variation in temperature preference with stage of development of Bufo marinus larvae. J. Herp. 18:153-158.

Floyd, R. B. and K. F. Benbow. 1984. Nocturnal activity of a population of cane toads. Koolewong 12-14.

Frauca, H. 1974. Crows, channel-bill cuckoos and cane toads. Aust. Birdl. 1:112-114.

Freeland, W. J. 1984. Cane toads: a review of their biology and impact on Australia. (Conservation Commission of the Northern Territory: Winnellie, NT)

Freeland, W. J. 1985. The need to control cane toads. Search 16:211-215.

Freeland, W. J. 1986. Invasion north successful conquest by the cane toad. Australian Natural History 22(2):69-72.

Freeland, W. J. 1986. Populations of cane toad, Bufo marinus, in relation to time since colinisation. Australian Wildlife Research 13:321-339.

Freeland, W. J. 1987. Cane toads and the balance of nature. Wildl. Aust. 1987:12-15.

Freeland, W. J. and S. H. Kerin. 1988. Within-habitat relationships between invading Bufo marinus and Australian species of freg during the Tropical Dry Season. Australian Wildlife Research 15:293-305.

Freeland, W. J. and S. H. Kerin. 1991. Ontogentic alteration of activity and habitat selection by Bufo marinus. Australian Wildlife Research 18:431-443.

Freeland , W. J. and K. C. Martin. 1985. The rate of range expansion by Bufo marinus in Northern Australia, 1980-84. Australian Wildlife Research 12:555-559.

Freeland, W. J., B. L. J. Delvinqueir, and B. Bonnin. 1986. Food and parasitism of the cane toad, B. marinus, in relation to time since colonisation. Australian Wildlife Research 13, 489-499.

Frost, S. W. 1932. The amphibian in art and literature. The Scientific Monthly 34:369-375.

Gans, C. and G. C. Gorniak. 1982. Functional morphology of lingual protrusion in marine toads. The Amer. J. Anat. 163:195-222.

Garman, S. 1887. West Indian batrachia in the Museum of Comparative Zoology. Bull. Essex Inst. 19:13-16.

Gebhart, L. 1967. Plague of toads. Science News 92:38-39.


Gimlette, J. D. 1971. Malay Poisons and Charm Cures. London: Oxford University Press.

Gimlette, J. D. and H. W. Thomson. 1939. A Dictionary of Malay Medicine. London: Oxford University Press.

Grant, C. 1931. Notes on Bufo marinus (Linnaeus). Copeia 1931(2):62.

Grant, C. 1937. Herpetological notes with new species from the American and British Virgin Islands. J. Agriculture University of Puerto Rico 21(4):503-522.

Grant, C. 1948. Selection between armed and unarmed arthropods as food by various animals. J. Ent. Zool. Clarmont Cal. 40:66.

Grant, G. S. 1996. Prey of the introduced Bufo marinus on American Samoa. Herp. Rev. 27:67-69.

Hamley, T. and A. Georges. 1985. The Australian snapping tortoise, Elysa latisternum: a successful predator on the introduced cane toad. Australian Zoologist 21:607-610.

Hammond, N. 1991. Cuello considered: summary and conclusion. Pp. 235-248. In: N. Hammond (ed), Cuello, an Early Maya Community in Belize. Cambridge: Cambridge University Press.

Hearnden, M. N. 1991. The reproductive and larval ecology of Bufo marinus (Anura:Bufonidae).


Heatwole, H. 1966. The effect of man on the distribution of some reptiles and amphibians in eastern Panama. Herpetologica 22(1):55-59.

Heatwole, H., S. B. de Austin, and R. Herrero. 1968. Heat tolerances of two species of tropical anurans. Comp. Biochem. Physiol. 27:807-815.

Heatwole, H. and R. C. Newby. 1972. Interaction of internal rhythm and loss of body water in influencing activity levels of amphibians. Herpetologica 28:156-162.





Heatwole, H. and A. Heatwole. 1968. Motivational aspects of feeding behavior in toads. Copeia 1968:692-698.

Heatwole, H. D. S. Sade, and R. Hildreth. 1963. Herpetogeography of Puerto. 1. Herpetofauna of Cayo Santiago and Cayo Batata. Carib. J. Sci. 3:1-5.

Heatwole, H. and R. Shine. 1976. Mosquitoes feeding on ectothermic vertebrates: a review and new data. Australian Zool. 19:69-75.

Heatwole, H. and P. J. Suárez-Lazú. 1965. Supernumerary legs in Bufo marinus and abnormal regeneration of the tail in Ameiva exsul. J. Ohio Herp. Soc. 5:30-31.

Helmunth, N. M. 1974. Comments. Current Anthropology 15:155-156.

Henderson, F. G., J. S. Wells, and K. K. Chen. 1962. Parotoid secretions of Indonesian toads. Science 136:775-776.

Heyer, W. R., R. W. McDiarmid, and D. L. Weigmann. 1975. Tadpoles, predation and pond habitats in the tropics. Biotropica 7(2):100-111.

Hinckley, A. D. 1966. Diet of the giant toad, Bufo marinus. Herpetologica 18(4):253-259.

Honnegger, R.. 1970. Eine Kröte erobert die Wett. Natur und Museum 100:447-458.

Horgan, J. 1990. Bufo abuse. Scientific America (263):26-27.

Hutchings, R. W. 1979. A native predator of the cane toad (Bufo marinus). N. Qld. Nat. 45(124):4-5

Hutchison, V. H. and M. A. Kohl. 1971. The effect of photoperiod on daily rhythms of oxygen consumption in the tropical toad, Bufo marinus. Zeitschrift für vergleichende Physiologie 75:367-382.

Illingworth, J. F. 1942. Feeding habits of Bufo marinus. Proc. Hawaian Entomological Soc. 11(1):51.

Jakowska, S. 1972. Lesions produced by ticks, Amblyomma dissimile in Bufo marinus toads from the Dominican Republic. Am., Zool. 12:731.

Johnson, C. R. 1972. Thermal relations and daily variation in the thermal tolerance in Bufo marinus. J. Herpetology 6(1):35-38.

King, W. and T. Krakauer. 1966. The exotic herpetofauna of southeast Florida. Quart. J. Florida Acad. Sci. 29:144-154.

Knoefel, P. K. and M. C. Covi. 1991. A Hellenistic Treatise on Poisonous Animals. Lewiston: The Edwin Mellen Press.

Knowles, R. P. and J. Levin. 1964. The poison toad and the canine. Small Animal Clinician 59:39-42.

Krakauer, T. 1968. The ecology of the neotropical toad, Bufo marinus in South Florida. Herpetologica 24:214-221.

Krakauer, T. 1970a. Tolerance limits of the toad, Bufo marinus, in south Florida. Comparative Biochemistry and Physiology 33(1):15-26.

Krakauer, T. 1970b. The invasion of the toads. Florida Nature 43:12-14.

Lescure, J. 1975. Observations ecologiques sur les amphibiens dans l'amazonie du nord-ouest. Leur place dans l'environment humain. Pages 65-69. In P. Centlivers, J. Gasche, and A. Lourteig (eds.) Culture sur Brûlis et Evolution du Milieu Forestier en Amazonie du Nord-Ouest. Geneve: Claude Swary.

Lever, R. J. A. W. 1945. The giant toad in the Solomon Islands. Agri. J. Fiji. 16:1.

Lewis, S. 1989. Cane Toads: An Unnatural History. New York: Doubleday.

Licht, L. E. 1967. Death following possible ingestion of toad eggs. Toxicon 5:141-142.

Licht, L. E. 1968. Unpalatability and toxicity of toad eggs. Herpetological 24:93-98.

Licht, L. E. and B. Low. 1968. Cardiac responses of snakes after ingestion of toad parotoid venom. Copeia 1968(3):547-551.

Lillywhite, H. B. and P. Licht. 1974. Movement of water over toad skin: functional role of epidermal sculpturing. Copeia 1974:165-171.

Lutz, A. and B. Lutz. 1939. Mosquitos biting batrachians and pragmosis in casque headed frogs. Ann. Acad. Brasilsira Sci. 11:250-252.

Macht, D. I. 1935. Action du venin de cobra sur le seuil de la Douleur chez L'homme et chez le cobaye. Comples rendus des seances la Societe de biologie. 1935:286. (Macht, D. I. 1935. Pharmacological and therapeutic aspects of toad and cobra venoms. Abstract/Translation)

Matsui, M. 1975. On the record of the giant toad, Bufo marinus, from Minami-Daitojima, Ryukyu Archipelago. Japanese J. Herpetol. 6:43-47.

May, D. W. 1926. The Surinam toad (Bufo agua). P.R. Agric. Exp. Stn. Agric. Notes 26:2.

May, D. W. 1927. Puerto Rico Agriculture Experiment Station Report. 1926:1-31.

McFarland, D. 1991. Guiness Book of World Records. New York: Bantam Books.

McKeown, S. 1978. Hawaiian Reptiles and Amphibians. Honolulu: Oriental Publishing Co.

McManus, J. J. and D. W. Nellis. 1975. The critical thermal maximum of the marine toad, Bufo marinus. Carib. J. Sci. 15(1-2): 67-69.

Menzies, J. I. 1976. Handbook of Common New Guinea Frogs. Wau, PNG: Wau Ecology Institute Handbook No. 1.

Meshaka, W. E. 1993. Hurricane Andrew and the colonization of five invading species in South Florida. Florida Scientist 56(4):193-201.

Mullens, D. P. and V. H. Hutchison. 1992. Diel, sesonal, postprandial and food-deprived thermoregulatory behaviour in tropical toads (Bufo marinus). J. Therm. Biol. 17:63-67.

Mungomery, R. W. 1937. The present situation regarding the giant American toad in Queensland. Cane Growers Quarterly Bulletin 1937:12.

Murphy, J. C. 1997. Amphibians and Reptiles of Trinidad and Tobago. Malabar, FL: Krieger Publishing Co.

Niddrie, D. L. 1980. Tobago. Gainesville: Litho Press. 243 pp.

Niven, B. S. 1988. Logical synthesis of an animal's environment: sponges to non-human primates. V. The cane toad, Bufo marinus. Australian J. Zoology 36:169-94.

Oliver, J. A. 1949. The peripatetic toad. Natural History 58:29-33

Oliver, J. A. 1955. The Natural History of North American Amphibians and Reptiles. Princeton, NJ: D. Van Nostrand Co.

Oliver, J. A. and C. E. Shaw. 1953. The amphibians and reptiles of the Hawaiian Islands. Zoologica 38:65-95.

Pemberton, C. E. 1949. Longevity of the tropical American toad, Bufo marinus L. Science 110:512.

Perkins. C. B. 1947. A note on longevity of amphibians and reptiles in captivity. Copeia 1947(2):144.

Pickering, C. and R. Alford. 1991. Tasty toads. Australian Natural History 24(5):70. (Letter and response)

Pippet, J. R. 1975. The marine toad, Bufo marinus in Papua New Guinea. Papua New Guinea Agricultural Journal 26(1):23-30.

Pliny, 1840 (reprint) The Natural History of Pliny (translated by J. Bostock and H. T. Riley). London: Henry G. Bohn. Vol. 6. (see pages 22-23).

Pope, P. H. 1917. The introduction of West Indian Anura into Bermuda. Bull. Mus. Comp. Zool. 61:123-124.

Poynton, J. C. 1964. The Amphibia of Southern Africa: a faunal study. Ann. Natal. Mus. 17:1-334.

Quesnel, V. C. 1998. Bufo marinus decline and recovery in Trinidad. Froglog 27:1.

Rabor, D. S. 1952. Preliminary notes on the giant toad, Bufo marinus (Linn.), in the Philippine Islands. Copeia 1952:281-282.

Rabor, D. S. 1955. The rat problem on Mindanao Island. The Sillman Journal 2:13-26

Rand, A. S. and P. J. Rand. 1966. The relation of size and distance jumped in Bufo marinus. Herpetol. 22(3):206-208.

Rands, R. L. 1955. Some manifestations of water in Mesoamerican art. Bureau Amer. Ethology Bull. 157:265-393. [see p. 362]

Reed, C. A. and R. Borowsky. 1970. The "world's largest toad" and other herpetological specimens from southern Suriname. Studies on the Fauna of Suriname and other Guyanas: No. 50.159-171.

Reinhardt, J. T., and C. F. Lütken. 1863. Bidrag til det vestindiske Öriges og naunligen til de dansk-vestindiske Öers Herpetologie. Videnskabelige Meddelelser frå Dansk Naturhistorisk Forening i Kjobenhavn, (4):153-291.


Riemer, W. J. 1958. Giant toads of Florida. Quart. J. Fla. Acad. Sci. 21(3):207-211.

Rivero, J. A. 1978. Los Anfibos y Reptiles de Puerto Rico. Mayagüez: Universidad de Puerto Rico.

Robins, A., G. Lippolis, A. Bisazza, G. Vallortigara, and L. J. Rogers. 1998. Lateralized agonistic responses and hindlimb use in toads. Animal Behavior 56:875-881.

Roff, C. 1975. Honeybees, giant toads, and hivestands. Qld. Agric. J. 101:689-91.

Rose, W. 1962. The Reptiles and Amphibians of Southern Africa. Cape Town: Maskew Miller.

Rossi, J. V. 1983. The use of olfactory cues by Bufo marinus. J. Herp. 17:72-73.

Ruthven, A. G. 1916. The breeding season of Bufo marinus (L) in Demerara. Copeia 1916:43-44.


Sabath, M. D., W. C. Boughton, and S. Easteal. 1981. Expansion of the range of the introduced toad Bufo marinus in Australia from 1935 to 1974. Copeia 1981:676-680.

Savage, J. M. 1960. Geographic variation in the tadpoles of the toad Bufo marinus. Copeia 1960:233-236.

Schmidt, K. P. 1928. Amphibians and land reptiles of Porto Rico. New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands. 10:167-200.

Schwartz, A. and R. Thomas. 1975. A checklist of West Indian Amphibians and Reptiles. Carnegie Mus. Nat, Hist. Sp. Publ. No. 1.

Schwartz, A. and R. W. Henderson. Amphibians and Reptiles of the West Indies, Descriptions, Distributions, and Natural History. Gainesville: University of Florida Presses

Seabrook, W. 1991. Range expansion of the introduced cane toad Bufo marinus in New South Wales. Australian Zoologist 27(3-4):58-62.

Sein, F. 1937. The development of the giant Suriname toad Bufo marinus L. Journal of Agriculture, University of Puerto Rico 21(1):77-78.

Sexton O. J., H. Heatwole, and D. Knight. 1964. Correlation of microdistribution of some Panamanian reptiles and amphibians with structural organization of the habitat. Caribbean Journal of Science 4(1):261-295.

Shine, R. and J. Covacevich. 1983. Ecology of highly venomous snakes: the Australian genus Oxyuranus. J. Herp. 17:60-69.

Shoemaker, V. H. and H. Warring. 1968. Effect of hypothalamic lesions on the water balance response of a toad. (B. marinus). Comp. Biochem. and Physiology 24:47-54.

Smith, A. G. 1949. Notes on the herpetology of Guam, Débridment Marianas Islands. Nat. Hist. Misc. 37:1- 2.

Smith, H. M., T. Schneider, and R. B. Smith. 1977. An overlooked synonym of the giant toad Bufo marinus (Linnaeus) (Amphibia, Anura, Bufonidae). J. Herp. 11:423-425.

Stejneger, L. 1904 The herpetology of Puerto Rico. Report of National Museum, (1902):551-724.

Straughan, I. R. 1966. The natural history of the "cane toad" in Queensland. Australian Natural History 15(7):230-232.

Strüssmann, C., M. B. R. do Vale, M. H. Meneghini, and W. E. Magnusson. 1984. Diet and foraging mode of Bufo marinus and Leptodactylus ocellatus. J. Herp. 18:138-146.

Stuart. L. C. 1951. The distributional implications of temperature tolerances and hemoglobin values in the toads Bufo marinus (Linnaeus) and Bufo bocourti Brocchi. Copeia 1951:220-229.

Summey, M. R. and A. Mathis. 1998. Alarm response to chemical stimuli from damaged conspecifics by larval anurans: tests of three Neotropical species. Herpetol. 54:402-408.

Szent-Ivany, J. J. H. 1972. Insect pests of agriculture and forestry. P. 562. In: Encyclopedia of Papua New Guinea. Vol. 1., N.U.P.-University of Papua New Guinea.


Takano, S. and K. Iijima. 1937. Studies on the life history and habits of Bufo marinus L. in Formosa. Part I. The relation between the growth of the tadpole and the quality of the breeding water. Taiwan Govt. Sug. Expt. Stat. Report Jap. 9:212-213.

Takano, S. and K. Iijima. 1939. Studies on the life history and habits of Bufo marinus L. in Formosa. Part II. Ecology of the tadpole and toadlet. Taiwan Govt. Sug. Expt. Stat. Report Jap. 4:51.

Tucker, R. W. E. 1940. Bufo marinus in Barbados. Agric. J. Barbados 8:145-150.

Tyler, M. J. 1987. Frog and cane toad skin secretions. Pp. 329-339. In: Toxic Plants and Animals: A guide for Australia. J. Covacevich. P. Davie, and J. Pearn. (Eds.). Brisbane: Queensland Museum.

Tyler, M. J. 1994. Australian frogs. Ithaca: Cornell University Press.

Tyler, M. J. 1995. Frogs and drugs. Australian Natural History 24(12):46-51.

Tyler, M. J. n.d. (post 1989) The cane toad: a search for a biological control agent. Australian Biologist :6-7.

van Beurden, E. K. 1981. Bioclimatic limits to the spread of Bufo marinus in Australia. A baseline. proc. Ecol. Soc. Aust. 11:143-149.

van Beurden, E. K. and G. C. Grigg. 1980. An isolated and expanding population of the introduced toad Bufo marinus in New South Wales. Aust. Wildl. Res. 7:305-310.

Van Volkenberg, H. L. 1935. Biological control of an insect pest by a toad. Science 82:277-279.

Waite, F. C. 1901. Bufo agua in the Bermudas. Science 13:342-343.

Wasson, V. P. and R. G. Wasson. 1957. Mushrooms, Russia, and History. 2 vols. New York: Pantheon Press.

Weber, N. A. 1938. The food of the giant toad, Bufo marinus (L.), in Trinidad, and British Guiana with special reference to the ants. Annals Entomological Soc. America 31:499-503.

Weil, A. T. and W. Davis 1992. Ancient Mesoamerica June issue

Wilson, L. D. and L. Porras. 1983. The ecological impact of man on the south Florida herpetofauna. University of Kansas, Museum of Natural History, Special Publ. 9:1-89.

Wingate, D. B. 1965. Terrestrial herpetofauna of Bermuda. Herpetologica 21:202-218.

Wolcott, G. N. 1923. The food of Porto Rican lizards. J. Dept. Agri. Porto Rico 7:5-37.

Wolcott, G. N. 1937. What the giant Surinam toad Bufo marinus L. is eating in Puerto Rico. Journal of Agriculture of the University of Puerto Rico, 21(1):79-84.

Wolcott, G. N. 1948. What has happened to the giant Suriname toad, Bufo marinus in Puerto Rico? Rev. Agric. P. R. 38:25-29.

Wood, W. 1807. Zoography; or, the Beauties of Nature Displayed in Select Descriptions from the Animal, and Vegetable, with Additions from the Mineral Kingdom. Systematically Arranged. London: Cadell and Davies. Vol. II. (see pages 30-37).

Wright, A. H. and A. A. Wright. 1949. Handbook of Frogs and Toads of the United States and Canada. Ithaca: Comstock Publishing Associates.

Wright, J. W. 1992. A case of the missing marinus. Froglog 3:3.

Zhao, E.-M. and K. Adler. 1993. Herpetology of China. SSAR Contributions to Herpetology No. 10.

Zug, G. 1983. Bufo marinus (Sapo Grande, Sapo, Giant Toad, Marine Toad). Pp. 368-387 In: Costa Rican Natural History D. Janzen (ed.). Chicago: University of Chicago Press.

Zug, G. R., E. Lindgren, and J. R. Pippet. 1975. Distribution and ecology of the marine toad, Bufo marinus, in Papua New Guinea. Pacific Science 29(1):31-50.

Zug, G. R. and P. B. Zug. 1979. The marine toad, Bufo marinus, a natural history resume of native populations. Smithsonian Contri. Zool. (284):1- 57.