Lepidosiren paradoxa live in a subtropical climate with temperatures ranging from 24 to 28°C (Planquette et al., 1996). This species lives in South America, primarily in the Amazon river basin. They prefer stagnant water where there is little current, such as a swamp or lake. These fish typically stay very close to the surface of the water. In times of drought, they can burrow in the mud up to 50 cm to avoid drying out (Berra, 2001). Lepidosiren paradoxa are primarily freshwater fish and are physiologically unable to cross large expanses of saltwater (Alves-Gomes et al., 2003).
Range depth: 0 to .50 m.
Habitat Regions: tropical ; freshwater
Aquatic Biomes: lakes and ponds; rivers and streams
Wetlands: swamp
Information on the predators of Lepidosiren paradoxa, as well as any predator/anti-predator adaptations are largely unknown due to lack of research on this species.
Known Predators:
Lepidosiren paradoxa juveniles have a pattern of bright yellow spots which fade away as the fish matures (Alves-Gomes et al., 2003). Adult South American lungfish have a black or grey coloration. Lungfish have solid toothplates instead of individual teeth. Bodies are long and slender, somewhat like salamanders, with a diphycercal tail. These fish can grow up to 125 cm in length (Baensch et al., 1985).
Lepidosiren paradoxa young look a bit like amphibian larvae, with four external gills that they use for breathing until about seven weeks in age. After this time, they become obligate air breathers and regression of the external gills begins (Berra, 2001). They have a reduced bronchial apparatus which allows them to survive during times when oxygen levels are low. During drought, they can burrow into mud to 50 cm below the surface and become dormant until the environment becomes more hospitable (2001).
Surfactant composition of South American lungfish resembles that of amphibians. In contrast, the more primitive Australian lungfish, Neoceratodus fosteri, possesses surfactant that is almost identical to primitive air-breathing actinopterygiian fish (Orgeig, 1995). This could be one reason why L. paradoxa must breathe air as an adult, while other lungfish can breathe air or water.
Range length: 125 (high) cm.
Range wingspan: N/A to N/A mm.
Average wingspan: N/A mm.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry
Sexual Dimorphism: sexes alike
Lepidosiren paradoxa has not been well studied in terms of life span, but the studies that have been conducted show that the average lifespan of this species is a little more that eight years, both in the wild and in captivity.
Average lifespan
Status: wild: 8.3 years.
Average lifespan
Status: captivity: 8.25 years.
Average lifespan
Status: wild: 8.3 years.
Average lifespan
Status: captivity: 8.25 years.
Lepidosiren paradoxa is found in the neotropics of South America, including Argentina, Bolivia, Brazil, Colombia, French Guiana, Paraguay, Peru, and Venezuela (Planquette et al., 1996).
Details of the range of L. paradoxa are difficult to establish (Alves-Gomes et al., 2003). There has not been a lot of research on this species and the specimens that have been identified lack information on their origin.
Biogeographic Regions: neotropical (Native )
Lepidosiren paradoxa eat a variety of food items including some bony fish, algae and weeds, terrestrial plants (stems), shrimp, insects, clams, and snails (Berra, 2001). They are primarily carnivorous. Juveniles, which are strictly aquatic, feed on larval insects and snails.
South American lungfish capture prey by suction feeding. They use tooth plates, an enlarged cranial rib (which serves as the site for the origin of the muscle that depresses the hyoid apparatus), and a depressor mandibulae to manipulate and chew food prior to swallowing. Hydraulic transport achieved by movements of the hyoid apparatus is used to position prey within the mouth. This is parallel to the function of a tongue (Bemis, 1986).
Animal Foods: fish; insects; mollusks; aquatic crustaceans
Plant Foods: wood, bark, or stems; algae; macroalgae
Primary Diet: carnivore (Insectivore , Eats non-insect arthropods)
This species influences the neotropical ecosystem of the Amazon Basin. Lepidosiren paradoxa prey on some small bony fish, shrimp, clams, snails, and insects (Berra, 2001). Any role that they play as a prey item is largely unknown.
This species does not provide direct economic benefits to humans. It does provide intellectual benefits; lungfish represent an important step in vertebrate evolution and their origin provide insights into the origin of tetrapods (Alves-Gomes et al., 2003).
Positive Impacts: research and education
There are no known adverse effects of Lepidosiren paradoxa on humans.
Newly hatched Lepidosiren paradoxa resemble amphibian tadpoles. The have four external gills which they use to breathe for the first seven weeks of their lives (Berra, 2001). After this time, they become strictly air breathers and their gills begin to regress (2001). During the breeding season, the males develop gill-like structures that allow them to release oxygen into their burrows for their developing young (2001). These structures disappear after the breeding season is over.
Development - Life Cycle: metamorphosis
Lepidosiren paradoxa is not listed on the IUCN Red List, CITES appendices, or the U.S. Endangered Species List. The abundance of this fish is largely unknown (Alves-Gomes et al., 2003).
US Federal List: no special status
CITES: no special status
There is not a lot known about communication and perception in Lepidosiren paradoxa. They have small eyes which suggests that L. paradoxa relies on other senses to detect prey and potential predators.
Communication Channels: visual
Perception Channels: visual
Lepidosiren paradoxa was the first living species of lungfish to be formally named (Alves-Gomes et al., 2003). There are three living genera of lungfish, Neoceratodus, Lepidosiren, and Protopterus.
Fossil evidence has placed some Devonian lungfish in fully marine habitats as well as freshwater deposits (2003). Lepidosirenids show a clear vicariance pattern that is consistent with the separation of the African and South American continents during the Cretaceous (2003).
Because of their relationship with both fish and tetrapods, lungfish are a very important evolutionary step. More research should be done so that they can be more fully understood.
There is very little information on the mating systems of Lepidosiren paradoxa.
Lepidosiren paradoxa breed during the rainy months when adults are able to move into areas that have been flooded and build nests (Alves-Gomes et al., 2003). Other information, including egg development, the number of offspring per breeding season, and gestation periods is unknown.
Breeding interval: Unknown; minimum population doubling time is greater than 14 years.
Breeding season: Breeding occurs during the rainy months of the year.
Key Reproductive Features: iteroparous ; seasonal breeding ; sexual ; fertilization (External ); oviparous
Both parents gather debris to make a nest. The nest is then guarded by the male parent. The males can increase oxygen levels for their developing young by using gill-like structures formed during the breeding season. These gill-like structures are highly vascularized, feathery structures developed from the pelvic fin (Berra, 2001). These structures allow the male to release oxygen from his blood into the surrounding nest and remove carbon dioxide (2001).
Parental Investment: pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Protecting: Male)
The South American lungfish (Lepidosiren paradoxa), also known as the American mud-fish[6] and scaly salamanderfish.[7] is the single species of lungfish found in swamps and slow-moving waters of the Amazon, Paraguay, and lower Paraná River basins in South America.[8] Notable as an obligate air-breather, it is the sole member of its family Lepidosirenidae, although some authors also place Protopterus in the family.[9][10] In Brazil, it is known by the indigenous language Tupi name piramboia, which means "snake-fish" (Portuguese pronunciation: [piɾɐ̃ˈbɔjjɐ]), and synonyms pirarucu-bóia ([piɾɐɾuˈku ˈbɔjjɐ]), traíra-bóia ([tɾɐˈiɾɐ ˈbɔjjɐ]), and caramuru ([kɐɾɐmuˈɾu]).
The South American lungfish is most closely related to the African lungfishes (family Protopteridae), and both families are thought to have diverged during the Early Cretaceous. Some papers suggest classifying both Lepidosiren and Protopterus within Lepidosirenidae, though authorities continue to classify both as distinct families.[9][10][11]
The immature lungfish is spotted with gold on a black background; in the adult, this fades to a brown or gray color.[12] Its tooth-bearing premaxillary and maxillary bones are fused as in all Dipnoi. South American lungfish also share an autostylic jaw suspension (where the palatoquadrate is fused to the cranium) and powerful adductor jaw muscles with the other extant Dipnoi. Like the African lungfishes, this species has an elongated, almost eel-like body. It may reach a length of 125 cm (4.10 ft).[8] The pectoral fins are thin and thread-like, while the pelvic fins are somewhat larger, and set far back. The fins are connected to the shoulder by a single bone, which is a marked difference from most fish, whose fins usually have at least four bones at their base, and a marked similarity with nearly all land-dwelling vertebrates.[13] The gills are greatly reduced and essentially non-functional in the adults.[14]
Juvenile lungfish feed on insect larvae and snails, while adults are omnivorous, adding algae and shrimp to their diets, crushing them with their heavily mineralized tooth-plates. The fish's usual habitats disappear during the dry season, so they burrow into the mud and make a chamber about 30–50 cm (12–20 in) down, leaving a few holes to the surface for air.[14] During this aestivation, they produce a layer of mucus to seal in moisture, and slow their metabolism down greatly.[12]
Relatively little is known about the South American lungfish. They have adapted to cope with both droughts and floods due to evolving pulmonary mechanoreceptors.[15][16] When the rainy season begins, they come out and begin to mate. The parents build a nest for the young, which resemble tadpoles and have four external gills. To enrich the oxygen in the nest, the male develops highly vascularized structures on his pelvic fins that release additional oxygen into the water.[14] The young become air-breathing at about seven weeks. Juveniles have external threadlike gills very much like those of newts.[12] Fossils of the modern species have been found between 72 and 66 mya during the Maastrichtian stage of the late Cretaceous just before the KPG extinction that killed off the non-avian dinosaurs.[17]
The South American lungfish (Lepidosiren paradoxa), also known as the American mud-fish and scaly salamanderfish. is the single species of lungfish found in swamps and slow-moving waters of the Amazon, Paraguay, and lower Paraná River basins in South America. Notable as an obligate air-breather, it is the sole member of its family Lepidosirenidae, although some authors also place Protopterus in the family. In Brazil, it is known by the indigenous language Tupi name piramboia, which means "snake-fish" (Portuguese pronunciation: [piɾɐ̃ˈbɔjjɐ]), and synonyms pirarucu-bóia ([piɾɐɾuˈku ˈbɔjjɐ]), traíra-bóia ([tɾɐˈiɾɐ ˈbɔjjɐ]), and caramuru ([kɐɾɐmuˈɾu]).
The South American lungfish is most closely related to the African lungfishes (family Protopteridae), and both families are thought to have diverged during the Early Cretaceous. Some papers suggest classifying both Lepidosiren and Protopterus within Lepidosirenidae, though authorities continue to classify both as distinct families.
The immature lungfish is spotted with gold on a black background; in the adult, this fades to a brown or gray color. Its tooth-bearing premaxillary and maxillary bones are fused as in all Dipnoi. South American lungfish also share an autostylic jaw suspension (where the palatoquadrate is fused to the cranium) and powerful adductor jaw muscles with the other extant Dipnoi. Like the African lungfishes, this species has an elongated, almost eel-like body. It may reach a length of 125 cm (4.10 ft). The pectoral fins are thin and thread-like, while the pelvic fins are somewhat larger, and set far back. The fins are connected to the shoulder by a single bone, which is a marked difference from most fish, whose fins usually have at least four bones at their base, and a marked similarity with nearly all land-dwelling vertebrates. The gills are greatly reduced and essentially non-functional in the adults.
Female above, male below Juvenile lungfish feed on insect larvae and snails, while adults are omnivorous, adding algae and shrimp to their diets, crushing them with their heavily mineralized tooth-plates. The fish's usual habitats disappear during the dry season, so they burrow into the mud and make a chamber about 30–50 cm (12–20 in) down, leaving a few holes to the surface for air. During this aestivation, they produce a layer of mucus to seal in moisture, and slow their metabolism down greatly.
Relatively little is known about the South American lungfish. They have adapted to cope with both droughts and floods due to evolving pulmonary mechanoreceptors. When the rainy season begins, they come out and begin to mate. The parents build a nest for the young, which resemble tadpoles and have four external gills. To enrich the oxygen in the nest, the male develops highly vascularized structures on his pelvic fins that release additional oxygen into the water. The young become air-breathing at about seven weeks. Juveniles have external threadlike gills very much like those of newts. Fossils of the modern species have been found between 72 and 66 mya during the Maastrichtian stage of the late Cretaceous just before the KPG extinction that killed off the non-avian dinosaurs.
