Paleosuchus palpebrosus, Cuvier's dwarf caiman, is most commonly found in the wetlands of Brazil, French Guiana, Surinam, Guyana, and Venezuela. Widespread throughout the Orinoco and Amazon basins, P. palpebrosus inhabit areas extending from Colombia, Venezuela, and the Guianas south to Sao Paulo and the upper Rio Paraguay in southern Brazil and west to the Rio Pastaza in Ecuador.
Biogeographic Regions: neotropical (Native )
Distribution: Bolivia, Brazil (Goias etc.), Colombia, Ecuador, French Guiana, Guyana, NE Paraguay, Peru, Surinam, Venezuela.
Type locality: "Cayenne," French Guiana.
This species is the smallest of the alligator family. Males grow to about 1.3-1.5 meters, while the females grow to 1.2 meters. They can reach a mass of about 6-7 kg.
Paleosuchus palpebrosus retain a reddish-brown body color. The dorsal surface is mostly plain and nearly black, while the upper and bottom jaws are covered with several dark and light spots. The tail is marked with encircling bands to the tip. Most of these caimans have brown eyes, but some have also been known to have gold-yellow eyes. P. palpebrosus do not have the same dental formula as other caimans. Most caimans have 5 premaxillary teeth in the upper jaw, but this species only has 4. Scale characteristics allow the differentiations between all other species. P. palpebrosus has 17-20 longitudinal rows on their dorsal and its tail (double crest) has bands of 7-9 rows. Paleosuchus palpebrosus has more osteoderms (bony plates) covering its skin than any other species.
Range mass: 6 to 7 kg.
Range length: 1.2 to 1.5 m.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry
Sexual Dimorphism: male larger
This species can be found near rivers and inundated savanna areas including the Orinoco and Amazon rivers, as well as those in eastern Paraguay. This species prefers clean, clear, fast-moving streams or rivers in forested areas containing waterfalls and rapids. Paleosuchus palpebrosus mostly inhabit fordable freshwater, avoiding salty, briny waters. It likes cooler waters compared to other caimans. Across inhabited areas, P. palpebrosus has been known to occupy streams of varying sizes, where they are spotted resting near the shorelines. This species is also terrestrial, and has been seen relaxing on piles of small rocks and residing near decaying trees. Likewise, P. palpebrosus is known to dwell in burrows, which are up to 1.5-3.5 meters long. Populations in southern Brazil and Venezuela are limited to waters with very low nutrients. P. palpebrosus can be found resting on rocks, or in shallow water with its back exposed on the surface and its head facing the sun. Preferring colder temperatures, they can survive in cool conditions (as low as 6 degrees Celsius).
Habitat Regions: tropical ; terrestrial ; freshwater
Terrestrial Biomes: savanna or grassland ; forest ; rainforest
Aquatic Biomes: lakes and ponds; rivers and streams
Wetlands: marsh ; swamp
Other Habitat Features: riparian
Habitat and Ecology
P. palpebrosus is a nocturnal hunter, preferring to spend the daylight hours basking. The young feed on aquatic and shoreline insects of many species. Their food includes tadpoles, frogs, snails, crabs, shrimp, and small fish. Adults mainly consume tadpoles, frogs, snails, fish, small mammals, and a wide variety of insects. Diet changes with the size and age of this species. As an adult, there is an increase in the fish intake as well as a greater intake of small crabs, birds, reptiles, and small mammals. Like other crocodilians, P. palpebrosus experiment with their food, so they will capture whatever prey is available. Prey is usually swallowed whole or in large pieces. The stomach enzymes in crocodiles and alligators are so strong that pH levels are among the lowest ever recorded in any vertebrate. Another characteristic of P. palpebrosus is the amount of gastroliths (small stones) inside the stomach. The stones are found only in one chamber of the stomach, the gizzard, and this one chamber has walls with folds to permit expansion and contraction. It is said these gastroliths help in the process of digestion, the stones churn inside the stomach, breaking apart the food.
Animal Foods: birds; mammals; amphibians; reptiles; fish; insects; terrestrial non-insect arthropods; mollusks; terrestrial worms; aquatic crustaceans
Primary Diet: carnivore (Eats terrestrial vertebrates, Piscivore , Insectivore )
Cuvier's dwarf caiman is considered a "keystone species" that maintains ecosystem structure and function by selective predation on fish species (such as piranhas) that if left unchecked, would transform the ecosystem. Although P. palpebrosus is small in size, it is known to have fewer predators than related species because of its uniquely armored and jagged skin.
Ecosystem Impact: keystone species
The most dangerous time in a caiman's life is while it is still in the egg. Without protection, predators such as rats, procyonids, and other carnivores can hastily clean a nest of eggs. If the eggs hatch, the young are still at a high risk of predation. The young are taken primarily by wading birds, snakes, and a host of other carnivorous animals. Due to the large number of bony osteoderms underneath the scales, many predators are not able to swallow this species. The only predators of adult P. palpebrosus are large boas, green anacondas, and jaguars.
- large rats (Muridae)
- procyonids (Procyonidae)
- opossums (Didelphidae)
- birds of prey (Falconiformes)
- other caimans (Caiman)
- snakes (Serpentes)
- herons (Ardeidae)
- green anacondas (Eunectes murinus)
- large boa constrictors (Boa constrictor)
- jaguars (Panthera onca)
Life History and Behavior
Communication begins in the egg and continues throughout their entire life. Sound, postures, motions, and touching are few of the many methods of communication in this species. Along with vocal signals, Paleosuchus palpebrosus communicate via nonverbal sounds, performing actions such as head-slapping or jaw-clapping at the water's surface. Like most caimans, P. palpebrosus males emit a grunt-like "chumph" sound by expelling air through the nostrils during courtship. When in water, exposure of the head, back, and tail above the surface conveys important information about an individual's social status and intent.
Communication Channels: visual ; tactile ; acoustic
Perception Channels: visual ; tactile ; acoustic ; chemical
When hatched, the young have almost the identical features as an adult. The sex of hatchlings is determined by the incubation temperature of the eggs. Differences in size can be used to differentiate the sexes. Growth continues throughout their lifespan. The fastest rate of growth occurs during the first 2 years, then declines with age thereafter. For the first 5 years, P. palpebrosus grow at a rate of 6-8 cm per year. It takes approximately 10 years to for one of these caimans to complete maturity and develop full adult characteristics.
Development - Life Cycle: temperature sex determination
The crocodilians are known to have long lifespans. Although P. palpebrosus adults are long lived, the exact longevity is not known. Generally, the adults have been known to live for 20-40 or more years. In captivity this species has a better longevity than of wild individuals.
Status: wild: 20 to 40 years.
Status: captivity: 20 to 60 years.
Lifespan, longevity, and ageing
Courtship and copulation take place at the end of the dry season. At this time, the males, are seen to lift their heads high and hold their tails almost vertically out of the water. The males release what is described to be a "roar"-like sound. The description of the "roaring" varies, and it commonly heard as simply a grunt-like call. The varying sounds and noises indicate the actual complexity of mating rituals within this species. The male, which mates with multiple females, performs distinctive mating displays, then approaches any receptive female. Rather than during the day, P. palpebrosus prefer to mate during the night. Normally in shallow waters, copulation takes place with the female mounting the male and twisting her tail under his. The actual mating process can last anywhere between 5-10 minutes or even up to a whole day. It can also occur repeatedly over several days, after which both male and female settle in the water for a period. Most females are only able to breed once a year, but on the other hand, if bred in captivity and fed efficiently, the females are able to breed 2 or 3 times a year.
Mating System: polygynous
This species is reported to nest during the dry season, during the wet season, or all year round, depending on the locality. More specifically, studies show P. palpebrosus prefer to nest at the end of the dry season and the beginning of the rainy season in areas with warm climates. When ready to start nesting, the females stop feeding and begin the mating process. The females can lay around 10-25 eggs. Both female and male P. palpebrosus build nests for their eggs. These nests are made of soil, usually mud, blended with fresh and rotten leaves, small branches, and other vegetation. Like other caimans, this species is a mound-nester where the females lay their eggs and bury them underneath the mound. These nests are generally small in diameter and height. These eggs are white, long, and weigh anywhere from 61-70 grams. The eggs hatch after 90 days. The female opens the nest in response to vocalizations of the young from within the nests. After the young hatch from their eggs, they continue to stay beneath the debris of the nest for several days, staying away from the water. It is said that the adults open the nest and direct their young toward the water, but studies do show the lack of parental care. The general behavior of adult males are to leave once after the female lays her eggs. Males do not regularly stay near the females during the hatching or post-hatching period. Sexual maturity is dependent on size, and relates to age as it correlates with growth. When a male reaches a size of 1.1 meters, it has become sexually mature and the females are ready to breed when they are about 1 meter in length. For P. palpebrosus to become completely sexually mature, it could take more than 10 years.
Breeding interval: Paleosuchus palpebrosus usually breed once a year. In captivity, however, when a female is well-fed, she can breed 2 or 3 times a year.
Breeding season: Nesting takes place at the end of the dry season and the beginning of the rainy season in warmer climates.
Range number of offspring: 10 to 25.
Range gestation period: 4 to 5 months.
Range age at sexual or reproductive maturity (female): 8 to 15 years.
Range age at sexual or reproductive maturity (male): 8 to 15 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization ; oviparous
The degree of parental care after hatching varies with local conditions. The nest is made by both parents. Studies show that the females remain with the hatchling group for only a few weeks before the hatchlings disperse. Then, the young are left alone and the mother leaves. The female rarely returns to her nesting site to search for her young, but can recognize them by smell. The nesting period is very dangerous for the young. Many predators lurk around nests to snatch eggs for food. In response, the female and male parents become defensive and take whatever action is necessary to guard their eggs. The female is always alert and remains near the nest during this period and will react to the slightest movement. Males do not regularly stay near the female during the hatching or post-hatching period. Furthermore, captive caimans are much more aggressive during their nesting period. The female can become very hostile and charge from the water at any sudden movement near the nest. She remains by the eggs for long periods, even without an apparent threat. Other defensive behaviors are tail slapping and splashing water by snapping their jaws. Sometimes, P. palpebrosus hatchlings are found alone or in pairs without any parental protection at all.
Parental Investment: pre-fertilization (Provisioning); pre-hatching/birth (Provisioning: Female, Protecting: Male, Female); pre-weaning/fledging (Protecting: Female); pre-independence (Protecting: Female)
Molecular Biology and Genetics
Barcode data: Paleosuchus palpebrosus
Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.
See the BOLD taxonomy browser for more complete information about this specimen and other sequences.
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Download FASTA File
Statistics of barcoding coverage: Paleosuchus palpebrosus
Public Records: 4
Specimens with Barcodes: 5
Species With Barcodes: 1
Right now, P. palpebrosus is not considered in need of active conservation. The IUCN rates at as Lower Risk, and of Least Concern. However the species is listed in Appendix II of CITES, which regulates international trade in the animals or their parts. The recent removal of larger, dominant crocodilian species (e.g. Caiman crocodilus) may have allowed smaller species like P. palpebrosus to expand into habitats from which it formerly was excluded.
US Federal List: no special status
CITES: appendix ii
IUCN Red List of Threatened Species: lower risk - least concern
IUCN Red List Assessment
Red List Category
Red List Criteria
- Needs updating
Relevance to Humans and Ecosystems
This species has no negative economic affect on humans.
As pets, P. palpebrosus are notoriously hostile and cannot be handled comfortably. Bites from adults are exceedingly painful.
Negative Impacts: injures humans (bites or stings)
Although the meat of P. palpebrosus is indeed very palatable, these small animals do not produce enough to be considered beneficial. The skin is also traded to a degree. However, alternatives are usually favored over the small and extremely tough hide of this dwarf caiman. Also hunting Cuvier's dwarf caiman is difficult due to their reclusive, solitary nature and their preference for densely forested habitat.
Small crocodilians such as Paleosuchus palpebrosus and Paleosuchus trigonatus are currently popular in the pet trade due to their relatively small and theoretically manageable size.
Positive Impacts: pet trade ; food ; body parts are source of valuable material
Cuvier's dwarf caiman
Cuvier's dwarf caiman (Paleosuchus palpebrosus) is a small crocodilian from northern and central South America in the alligator family. It is found in Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Paraguay, Peru, Surinam and Venezuela. It lives in riverine forests, in flooded forests near lakes, and near fast-flowing rivers and streams. It can traverse dry land to reach temporary pools and tolerates colder water than other species of alligator. Other common names for this species include the musky caiman, the dwarf caiman, Cuvier's caiman and the smooth-fronted caiman. It is sometimes kept in captivity as a pet and may be referred to as the wedge head caiman by the pet trade.
Cuvier's dwarf caiman was first described by the French zoologist Georges Cuvier in 1807 and is one of only two species in the genus Paleosuchus, the other species being P. trigonatus. Their closest relatives are the other caimans in the subfamily Caimaninae. With a total length averaging 1.4 m (4.6 ft) for males and typically up to 1.2 m (3.9 ft) for females, Cuvier's dwarf caiman is not only the smallest extant species in the alligator and caiman family, but also the smallest of all crocodilians. An adult will typically weigh around 6 to 7 kg (13 to 15 lb). Its lack of size is partly made up for by its strong body armour, provided by the bony bases to its dermal scales, which provides protection against predators. Juvenile dwarf caimans mainly feed on invertebrates, but also small fish and frogs, while adults eat larger fish, amphibians and invertebrates, such as large molluscs. This caiman sometimes uses a burrow as shelter during the day and in the Pantanal may aestivate in the burrow in order to stay cool in the dry season. The female buries her eggs on a mounded nest and these take about three months to hatch. She helps the hatchlings to escape from the nest and provides some parental care for the first few weeks of their life. This caiman has a wide range and large total population and the IUCN lists its conservation status as being of least concern".
Etymology and taxonomy
Cuvier's dwarf caiman was first described by the French zoologist Georges Cuvier in 1807 as Crocodylus palpebrosus from a type locality described as "Cayenne". Since then it has been given a number of names by different authorities; Crocodilus (Alligator) palpebrosus (Merrem, 1820), Jacaretinga moschifer (Spix, 1825), Champsa palpebrosa (Wagler, 1830), Alligator palpebrosus (Dumeril and Bibron, 1836), Champsa gibbiceps (Natterer, 1841), Caiman palpebrosus (Gray, 1844), Caiman (Aromosuchus) palpebrosus (Gray, 1862) and Jacaretinga palpebrosus (Vaillant, 1898). Muller, in 1924, and Schmidt, in 1928 were the first to use the currently accepted name of Paleosuchus palpebrosus. No subspecies are recognised.
The genus Paleosuchus contains only two members, Paleosuchus trigonatus, commonly known as the smooth-fronted or Schneider's dwarf caiman, and Paleosuchus palpebrosus, both from South America. Paleosuchus is distinguished from other caimans in the alligator subfamily Caimaninae by the absence of an inter-orbital ridge and the presence of four teeth in the premaxilla region of the jaw where other species of caiman have five. The genus name Paleosuchus is derived from the Greek palaios meaning "ancient" and soukhos meaning "crocodile". This refers to the belief that this crocodile comes from an ancient lineage that diverged from other species of caiman some thirty million years ago. The specific name palpebrosus is derived from the Latin palpebra meaning "eyelid" and osus meaning "full of". This refers to the bony plates (palpebrals) present on the upper eyelids.
Common names include the musky caiman, the dwarf caiman, Cuvier's caiman and the smooth-fronted caiman, although the last of these is also used to refer to the closely related Paleosuchus trigonatus. In the pet trade it is sometimes referred to as the wedge head caiman.
|Phylogenetic relations of Paleosuchus palpebrosus within Caimaninae.|
Cuvier's dwarf caiman is the smallest living New World crocodilian. Males grow to a maximum length of about 1.6 metres (5 ft 3 in) while females do not usually exceed 1.2 metres (3 ft 11 in) in length. The largest specimen on record measured 1.72 m (5.6 ft) in length. This may be an underestimate of the animal's maximum size as nearly all large adults have lost the tips of their tails and the largest specimen measured in the Pantanal region had a snout-to-vent length of 1.125 m (4 ft) (equivalent to a total length of 2.1 m (6.9 ft) with an intact tail). An adult will typically weigh around 6 to 7 kg (13 to 15 lb), around the same weight as a 6–12-month-old specimen of several larger species of crocodilians. The Cuvier's dwarf caiman has strong body armour on both the dorsal (upper) and ventral (lower) sides which may compensate for its small body size in reducing predation. The dermal scales that provide this protection have a bony base and are known as osteoderms.
The head has an unusual shape for a crocodilian with a dome-shaped skull and a short smooth, concave snout with an upturned tip, the shape rather resembling the head of a dog. The upper jaw extends markedly further forward than the lower jaw. There are four pre-maxillary and fourteen to fifteen maxillary teeth on either side of the upper jaw and twenty-one or twenty-two teeth on each side of the lower jaw giving a total of about eighty teeth. The neck is relatively slender and the dorsal scutes are less prominent than in the smooth-fronted caiman (Paleosuchus trigonatus). The double row of scutes on the tail are small and project vertically. Adults are dark brownish-black with a dark brown head while juveniles are brown with black bands. The iris of the eye is chestnut brown at all ages and the pupil is a vertical slit.
- Post occipitals - Usually 2 rows (usually 1 row)
- Nuchals - Usually 4 to 5 rows (usually 4 rows but sometimes 5)
- Dorsals - 18 longitudinal rows and 6 to 10 transverse rows, neatly arranged, with 4 rows between hind legs (18 longitudinal and 6 to 7 transverse rows, haphazardly arranged, with usually 2 rows between hind legs)
- Ventrals - 21 to 22 longitudinal rows and 16 transverse (19 to 21 longitudinal and 10 to 12 transverse rows)
- Tail - Single crest, usually 19 to 21 scales (17 to 19 scales)
- Tail - Double crest, usually 9 or 10 rows (usually 9 or 10 rows)
- Tail - Lateral, small scales disrupt 2 or 3 rows (5 to 8 rows)
Distribution and habitat
Cuvier's dwarf caiman is native to tropical northern and central South America. It is present in the drainages of the Orinoco River, the São Francisco River and the Amazon River, and the upper reaches of the Paraná River and the Paraguay River. The countries in which it is found include Peru, Ecuador, Colombia, Venezuela, Guyana, Surinam, French Guiana, Brazil, Bolivia and Paraguay. The range of this species is rather larger than that of the sympatric smooth-fronted caiman as it extends into Paraguay and includes a larger area of Brazil.
Cuvier's dwarf caiman is a freshwater species and is found in forested riverine habitats and areas of flooded forest around lakes. It seems to prefer rivers and streams with fast-flowing water but is also found in quiet, nutrient-poor waters in Venezuela and southeastern Brazil. It is able to travel quite large distances overland at night and sub-adult individuals have sometimes been found in isolated, temporary pools. In the northern and southern parts of its range it is also found in gallery forests in savannah country, but it is absent from such habitats in Los Llanos and the Pantanal. Cuvier's dwarf caiman seems relatively tolerant of cool water compared to other species of alligator. During the day, individuals sometimes lie up in burrows but at other times rest on piles of rocks or sun themselves while lying, facing the sun, in shallow water with their backs exposed.
Behaviour and ecology
Cuvier's dwarf caiman is mainly nocturnal, and adults feed on fish, amphibians, small mammals, birds, crabs, shrimps, molluscs and other invertebrates which they catch in the water or on land. Juveniles eat fewer fish but also consume crustaceans, tadpoles, frogs and snails as well as land invertebrates such as beetles. The prey is mostly swallowed whole and is ground up by stones in the gizzard. In the Pantanal, Cuvier's dwarf caiman aestivates in burrows during the dry season and is able to maintain its temperature at around 22 °C (72 °F) for days at a time.
Adult Cuvier's dwarf caiman are usually found singly or in pairs. The breeding of this species has been little studied but it does not appear to be seasonal in nature. The female builds a mound nest out of vegetation and mud somewhere in a concealed location and lays a clutch of from ten to twenty-five eggs, hiding them under further vegetation. The incubation period is around ninety days and the sex of the hatchlings depends on the temperature of the nest during that time. When the eggs begin to hatch, the female opens the nest in response to the calls made by the young. Newly emerged juveniles have a coating of mucus and may delay entering the water for a few days until this has dried. Its continuing presence on their skin is believed to reduce algal growth. The female stays with the young for a few weeks after which time the hatchlings disperse. The young grow at the rate of about 8 to 10 cm (3 to 4 in) per year and reach sexual maturity at around eight years.
Cuvier's dwarf caiman is considered to be a keystone species whose presence in the ecosystem maintains a healthy balance of organisms. In its absence, fish such as piranhas might dominate the environment. The eggs and newly hatched young of Cuvier's dwarf caiman are most at risk and are preyed on by birds, snakes, rats, raccoons and other mammals. Adult caimans are protected by the bony osteoderms under the scales and their main predators are jaguars, green anacondas (Eunectes murinus) and large boa constrictors (Boa constrictor).
Status and conservation
Many crocodilians are hunted for their skins but this is not the case with the Cuvier's dwarf caiman. This may be because the ventral skin in this species is too heavily armoured to make it easy to tan. Some individuals are killed by indigenous peoples for food and others, particularly in Guyana, are collected for the pet trade but there is no evidence that populations are dwindling as a result. There are some threats to this species from habitat destruction, including the mining of gold, but these are not thought to be of great significance. The estimated total population is over one million individuals.
In its Red List of Threatened Species, the IUCN lists Cuvier's dwarf caiman as being of "Least Concern". This is because its range is extensive, covering much of northern and central South America, and although its population trend is unknown, it appears to be abundant in many of the localities in which it is found. It is listed in Appendix II of CITES.
Cuvier's dwarf caiman can be kept as a pet but before obtaining one, careful consideration should be given as to whether appropriate conditions can be provided. Some of the factors that should be considered are their long life, their initial cost, their ongoing heating costs, the difficulty of maintaining their enclosure and the fact that they are dangerous to handle. The cute youngster will grow into a formidable reptile needing plenty of space. In many countries permits or licenses are necessary and most veterinarians have little experience of these exotic animals.
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