Broad-snouted caiman

Last updated

Broad-snouted caiman
Temporal range: Late Miocene - Present,
9–0  Ma [1]
Jacare de papo amarelo zoo.jpg
CITES Appendix I (CITES) [3] [note 1]
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Archosauromorpha
Clade: Archosauriformes
Order: Crocodilia
Family: Alligatoridae
Subfamily: Caimaninae
Clade: Jacarea
Genus: Caiman
Species:
C. latirostris
Binomial name
Caiman latirostris
Daudin, 1801
The range of the broad-snouted caiman.png
Broad-snouted caiman range
Synonyms
Species synonymy
  • cynocephalusDumeril & Bibron, 1836
  • fissipes Spix, 1825
  • lutescensRovereto, 1912
  • scleropsWied, 1825

The broad-snouted caiman (Caiman latirostris) is a crocodilian in the family Alligatoridae found in eastern and central South America, including the Pantanal habitat of Bolivia, Southeast Brazil, and Paraguay, as well as northern Argentina and Uruguay. [4] Behind the black caiman ( Melanosuchus niger ), it is the second-largest caiman species; it is the third-largest alligatorid behind the American alligator ( Alligator mississippiensis ) and the aforementioned black caiman. Primarily, the species inhabits freshwater wetlands, including floodplains, marshes, swamps, and some mangrove forests, as well as various streams, rivers, lakes or ponds, preferring bodies of rather still or slower-moving water. [5] They will often utilize man-made cow ponds, disused stock tanks, and canals and ditches, as well. [6]

Contents

Classification

The broad-snouted caiman is one of three extant (living) species of the genus Caiman , the other two being the Spectacled caiman (Caiman crocodilus) and the Yacare caiman (Caiman yacare). There are also several extinct fossil species in the genus Caiman , possibly up to eight species. The broad-snouted caiman is a member of the caiman subfamily Caimaninae, and is one of six living species of caiman. Its relationship to the other caimans can be shown in the cladogram below, based on molecular DNA-based phylogenetic studies: [7]

Alligatoridae
Caimaninae

Paleosuchus palpebrosus Cuvier's dwarf caiman

Paleosuchus trigonatus Schneider's dwarf caiman

Jacarea

Caiman crocodilus Spectacled caiman

Caiman yacare Yacare caiman

Caiman latirostrisBroad-snouted caiman

Melanosuchus niger Black caiman

Alligatorinae

Alligator sinensis Chinese alligator

Alligator mississippiensis American alligator

Characteristics

In the wild, adults normally grow to 2 to 2.5 m (6 ft 7 in to 8 ft 2 in) in length, but a few old males have been recorded to reach up to 3.5 m (11 ft). [5] [8] Captive adults have weighed 23 to 65 kg (51 to 143 lb). [9] [10] A large adult male of 2.6 m (8 ft 6 in) would weigh around 80 kg (180 lb). [11] Most tend to be of a light olive-green color. A few individuals have spots on their faces. [6] The most notable physical characteristic is the broad snout from which its name is derived. [6] The snout is well adapted to rip through the dense vegetation of the marshes. Due to this, they swallow some of the dense vegetation while foraging for food. [12]

Caiman latirostris skeleton Broad-Snouted Caiman MAV 01.jpg
Caiman latirostris skeleton

Biology and behavior

Broad-snouted caiman (Caiman latirostris) on the border of pond in Bonito, Mato Grosso do Sul, Brazil Jacare-de-papo-amarelo (Caiman latirostris).jpg
Broad-snouted caiman (Caiman latirostris) on the border of pond in Bonito, Mato Grosso do Sul, Brazil

The broad-snouted caiman is ectothermic, depending on its external environment to regulate its body temperature. Its heart rate increases as the temperature increases and decreases when the temperature is lowered. [13] The heat of the sun is absorbed through the skin into the blood, keeping its body temperature up. An increased heart rate helps the newly absorbed heat transfer throughout the body more quickly. When the air becomes cooler, the need for the heart rate to remain elevated is lost. [13]

Young caimans rely heavily on their ability to find shelter to avoid predation. [14] This behavior drops off as they age. [14]

Hunting and diet

Upon hatching, the diet of the broad-nosed caiman consists mainly of small invertebrates it can find, such as beetles or arachnids. As the caiman reaches adolescence, it learns to crush shells with its jaws more effectively, enabling it to feed on more substantial prey, such as turtles and snails (including ampullarid snails). [6] [15] As C. latirostris reaches maturity, the size of its prey tends to increase. Young adult caimans still maintain a diet consisting of mostly invertebrates; however, older animals greatly vary their diet, increasing their intake of small mammals, birds, larger fish, amphibians, and reptiles. [12] [14] [15]

Omnivory

Captive specimens have been documented (and photographed) devouring the cone-shaped, mildly sweet fruits of 'split-leaf philodendron' (reclassified as Thaumatophyllum bipinnatifidum ) without external stimulation, though it is unclear if this is because of them being housed with omnivorous reptiles, such as tegu, or a genuinely natural curiosity or feeding behaviour. [16] A later study also concluded that C. latirostris and its relatives are obligate omnivores, and indeed play an important role in the dispersal of plant seeds in their habitats. [17]

Reproduction

Broad-snouted caiman baby Caiman latirostris DT -AR Zoo BBAA- (2) (20716879376).jpg
Broad-snouted caiman baby

The female lays 18 to 50 eggs at a time. While rare, up to 129 eggs have been found within a single nest, presumably from several layings. [5] They lay their eggs in two layers, with a slight temperature difference between the two layers. This will result in a more even ratio of males and females. [6] The caiman does not have sex chromosomes, but instead depends on temperature to determine the ratio of male and female offspring. Eggs at warmer temperatures (32 °C (90 °F) or higher) develop into males and eggs at cooler temperatures (31 °C (88 °F) or lower) develop into females. [18] Estrogen levels and stress levels of the mother can have an effect. Nests reared at the same temperature can differ in sex ratio. This indicates there are other factor that contribute to a nest having male or female eggs. [19]

Conservation

Larger-scale hunting of C. latirostris began in the 1940s, as the species' skin was greatly valued for leather production, with its smoother texture compared to other crocodilians. Until South American countries made hunting them illegal, this was by far the largest threat to the species. An eventual ban on hunting helped them to regain their population. [5] The newest threat is habitat destruction. [5] Deforestation and pollution run-off are the two leading causes to this loss of habitat. [6]

Notes

  1. Except populations of Argentina and Brazil which are included in Appendix II.

Related Research Articles

<span class="mw-page-title-main">Alligatoridae</span> Family of crocodilians including alligators, caimans and kin

The family Alligatoridae of crocodylians includes alligators, caimans and their extinct relatives.

<span class="mw-page-title-main">Crocodilia</span> Order of mostly large, predatory, semiaquatic reptiles

Crocodylia ) is an order of semiaquatic, predatory reptiles known as crocodilians. They first appeared during the Late Cretaceous and are the closest living relatives of birds. Crocodilians are a type of crocodylomorph pseudosuchian, a subset of archosaurs that appeared about 235 million years ago and were the only survivors of the Triassic–Jurassic extinction event. The order includes the true crocodiles, the alligators and caimans, and the gharial and false gharial. Although the term "crocodiles" is sometimes used to refer to all of these, it is less ambiguous to use "crocodilians".

<span class="mw-page-title-main">Alligator</span> Crocodilian in the genus Alligator of the family Alligatoridae

An alligator, or colloquially gator, is a large reptile in the genus Alligator of the family Alligatoridae of the order Crocodilia. The two extant species are the American alligator and the Chinese alligator. Additionally, several extinct species of alligator are known from fossil remains. Alligators first appeared during the late Eocene epoch about 37 million years ago.

<i>Caiman</i> (genus) Genus of reptiles

Caiman is a genus of caimans within the alligatorid subfamily Caimaninae. They inhabit Central and South America. They are relatively small sized crocodilians, with all species reaching lengths of only a couple of meters and weighing 6 to 40 kg on average.

<span class="mw-page-title-main">Yacare caiman</span> Species of reptile

The yacare caiman, also known commonly as the jacare caiman, Paraguayan caiman, piranha caiman, red caiman, and southern spectacled caiman, is a species of caiman, a crocodilian in the family Alligatoridae. The species is endemic to Argentina, Bolivia, Brazil, and Paraguay. Brown in color and covered with dark blotches, males grow to a total length of 2–3 m and weigh around 40–50 kg (88–110 lb); while females grow to 1.4 m long and about 15–20 kg (33–44 lb). Typical habitats of this caiman include lakes, rivers, and wetlands. Its diet primarily consists of aquatic animals, such as snails, and occasionally land vertebrates. Mating occurs in the rainy season and eggs hatch in March, with young fending for themselves as soon as they hatch. The yacare caiman was hunted heavily for its skin to use for leather in the 1980s, which caused its population to decrease significantly. However, trading restrictions placed since have caused its population to increase. Its population in the Pantanal is about 10 million, and it is listed as least concern on the IUCN Red List.

<span class="mw-page-title-main">Black caiman</span> Largest extant species of caiman

The black caiman is a crocodilian reptile endemic to South America. With a maximum length of around 5 to 6 m and a mass of over 450 kg (1,000 lb), it is the largest living species of the family Alligatoridae, and the third-largest crocodilian in the Neotropical realm. True to its common and scientific names, the black caiman has a dark greenish-black coloration as an adult. In some individuals, the pigmentation can appear almost jet-black. It has grey to brown banding on the lower jaw; juveniles have a more vibrant coloration compared to adults, with prominent white-pale yellow banding on the flanks that remains present well into adulthood. The banding on young animals helps with camouflage by breaking up their body outline, on land or in water, in an effort to avoid predation. The morphology is quite different from other caimans but the bony ridge that occurs in other caimans is present. The head is large and heavy, an advantage in catching larger prey. Like all crocodilians, caimans are long, squat creatures, with big jaws, long tails and short legs. They have thick, scaled skin, and their eyes and noses are located on the tops of their heads. This enables them to see and breathe while the rest of their bodies are underwater.

<i>Purussaurus</i> Extinct genus of reptiles

Purussaurus is an extinct genus of giant caiman that lived in South America during the Miocene epoch, from the Friasian to the Huayquerian in the SALMA classification. It is known from skull material found in the Brazilian and Peruvian Amazon, Colombian Villavieja Formation, Panamanian Culebra Formation, Urumaco and Socorro Formations of northern Venezuela.

<span class="mw-page-title-main">Orinoco crocodile</span> Species of reptile

The Orinoco crocodile is a critically endangered crocodile. Its population is very small, and they can only be found in the Orinoco river basin in Venezuela and Colombia. Extensively hunted for their skins in the 19th and 20th centuries, it is one of the most endangered species of crocodiles. It is a very large species of crocodilian; males have been reported up to 6.8 m in the past, weighing over 900 kg (2,000 lb), but such sizes do not exist today, 5.2 m being a more widely accepted maximum size. A large male today may attain 4.2 m in length and can weigh up to 450 kg (1,000 lb), while females are substantially smaller with the largest likely to weigh around 225 kg (496 lb). Sexual dimorphism is not as profound as in other crocodilian species. The coloration is light even in adults.

<span class="mw-page-title-main">Cuvier's dwarf caiman</span> Species of reptile

Cuvier's dwarf caiman is a small crocodilian in the alligator family from northern and central South America. It is found in Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Paraguay, Peru, Suriname, Trinidad and Venezuela. It lives in riverine forests, 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 caimans. 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 community.

<span class="mw-page-title-main">Smooth-fronted caiman</span> Species of reptile

The smooth-fronted caiman, also known as Schneider's dwarf caiman or Schneider's smooth-fronted caiman, is a crocodilian from South America, where it is native to the Amazon and Orinoco Basins. It is the second-smallest species of the family Alligatoridae, the smallest being Cuvier's dwarf caiman, also from tropical South America and in the same genus. An adult typically grows to around 1.2 to 1.6 m in length and weighs between 9 and 20 kg. Exceptionally large males can reach as much as 2.3 m (7.5 ft) in length and 36 kg (79 lb) in weight.

<span class="mw-page-title-main">Dwarf crocodile</span> Species of reptile

The dwarf crocodile, also known as the African dwarf crocodile, broad-snouted crocodile or bony crocodile, is an African crocodile that is also the smallest extant (living) species of crocodile.

<i>Mecistops</i> Genus of reptiles

Mecistops is a genus of crocodiles, the slender-snouted crocodiles, native to sub-Saharan Africa.

<i>Paleosuchus</i> Genus of reptiles

Paleosuchus is a South American genus of reptiles in the subfamily Caimaninae of the family Alligatoridae. They are the smallest members of the order Crocodilia in the Americas.

<span class="mw-page-title-main">Spectacled caiman</span> Species of crocodilian native to the Neotropics

The spectacled caiman, also known as the white caiman, common caiman, and speckled caiman, is a crocodilian in the family Alligatoridae. It is brownish-, greenish-, or yellowish-gray colored and has a spectacle-like ridge between its eyes, which is where its common name come from. It grows to a length of 1.4–2.5 m and a weight of 7–40 kg (15–88 lb), with males being both longer and heavier than females. Its diet varies seasonally, commonly consisting of crabs, fish, small mammals, amphibians and snails. Breeding occurs from May to August and 14–40 eggs are laid in July and August. This crocodilian has a large range and population; it is native to much of Latin America, and has been introduced to the United States, Cuba, and Puerto Rico.

<i>Mourasuchus</i> Extinct genus of reptiles

Mourasuchus is an extinct genus of giant, aberrant caiman from the Miocene of South America. Its skull has been described as duck-like, being broad, flat, and very elongate, superficially resembling Stomatosuchus from the Late Cretaceous.

<span class="mw-page-title-main">Caiman</span> Subfamily of reptiles

A caiman is an alligatorid belonging to the subfamily Caimaninae, one of two primary lineages within the Alligatoridae family, the other being alligators. Caimans are native to Central and South America and inhabit marshes, swamps, lakes, and mangrove rivers. They have scaly skin and live a fairly nocturnal existence. They are relatively small-sized crocodilians with an average maximum weight of 6 to 40 kg depending on species, with the exception of the black caiman, which can grow more than 4 m (13 ft) in length and weigh in excess of 450 kg. The black caiman is the largest caiman species in the world and is found in the slow-moving rivers and lakes that surround the Amazon basin. The smallest species is the Cuvier's dwarf caiman, which grows to 1.2 to 1.5 m long. There are six different species of caiman found throughout the watery jungle habitats of Central and Southern America. The average length for most of the other caiman species is about 2 to 2.5 m long.

<span class="mw-page-title-main">Jacarea</span> Clade of reptiles

Jacarea is a clade of caimans within the subfamily Caimaninae. Jacarea was first named by Norell in 1988 to include the extant species within the genera Caiman and Melanosuchus, while excluding the dwarf caiman genus Paleosuchus. In 1999, Brochu formally cladistically defined Jacarea as the last common ancestor of Caiman latirosris, Caiman crocodilus, Caiman yacare, Melanosuchus niger, and all its descendants. Molecular DNA phylogenetic studies recover Paleosuchus as outside of Jacarea, although morphological studies are inconsistent.

Globidentosuchus is an extinct genus of basal caimanine crocodylian known from the late Middle to Late Miocene of the Middle and the Upper Members of the Urumaco Formation at Urumaco, Venezuela. Its skull was very short and robust, with large units of spherical teeth used to break the shells of molluscs as part of its durophagus diet. It is thought to be one of the most basal Caimanines, even sharing some traits with alligatorids.

Caiman brevirostris is an extinct species of caiman that lived during the Late Miocene, around 11.6 million years ago, to the end of the Miocene 5.3 million years ago in Acre and Amazonas, Brazil as well as Urumaco, Venezuela. Several specimens have been referred to the species, but only 3 of them are confidently placed in the species. C. brevirostris was originally named in 1987 on the basis of a single, incomplete rostrum with an associated mandibular ramus that had been found in Acre, Brazil. C. brevirostris is very distinct among Caiman species and caimaninae overall in that it preserves a characteristically short and robust skull that bears blunt posterior teeth that were built to break down harder foods. This was an adaption for durophagy, likely to crush shells of mollusks and clams which were common in the wetlands that C. brevirostris resided in.

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