Caecilians Fossil range: Jurassic - Recent
"Caecilian"
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Amphibia Order: Gymnophiona Müller, 1832
Families
Rhinatrematidae Ichthyophiidae Uraeotyphlidae Scolecomorphidae Typhlonectidae Caeciliidae The Jurassic Period is a major unit of the geologic timescale that extends from about 199. ... Download high resolution version (907x550, 81 KB) Wikipedia does not have an article with this exact name. ... For other uses, see Scientific classification (disambiguation). ... For other uses, see Animal (disambiguation). ... Typical Classes See below Chordates (phylum Chordata) are a group of animals that includes the vertebrates, together with several closely related invertebrates. ... For other uses, see Amphibian (disambiguation). ... Johannes Peter Müller (July 14, 1801, Koblenz – April 28, 1858, Berlin), was a German physiologist, comparative anatomist, and ichthyologist not only known for his discoveries but also for his ability to synthesize knowledge. ... Genera  Epicrionops  Rhinatrema Rhinatrematidae is the family of neotropical tailed caecilians or beaked caecilians. ... Genera  Caudacaecilia  Ichthyophis The vent is an important taxonomic feature for Ichthyophis identification Ichthyophiidae is the family of asiatic tailed caecilians or fish caecilians. ... Species Uraeotyphlus interruptus Uraeotyphlus malabaricus Uraeotyphlus menoni Uraeotyphlus narayani Uraeotyphlus oxyurus Uraeotyphlidae is the family of Indian caecilians. ... Genera  Crotaphatrema  Scolecomorphus Scolecomorphidae is the family of tropical caecilians (Frost) or African caecilians (ITIS). ... Genera See text. ... Genera  Boulengerula  Brasilotyphlus  Caecilia  Dermophis  Gegeneophis  Geotrypetes  Grandisonia  Gymnopis  Herpele  Hypogeophis  Idiocranium  Indotyphlus  Luetkenotyphlus  Microcaecilia  Mimosiphonops  Oscaecilia  Parvicaecilia  Praslinia  Schistometopum  Siphonops Caeciliidae is the family of common caecilians. ...

The Caecilians are an order (Gymnophiona or Apoda) of amphibians that superficially resemble earthworms or snakes. They mostly live hidden in the ground, which makes them the least explored order of amphibians, and widely unknown. For other uses, see Amphibian (disambiguation). ... For the LPG album, see The Earthworm (album). ... For other uses, see Snake (disambiguation). ...

Anatomy

Caecilians completely lack limbs, making the smaller species resemble worms, while the larger species with lengths up to 1.5 m resemble snakes. The tail is short and the cloaca is near the end of the body. Their skin is smooth and usually dark-matte, but some species have colorful skins. Inside the skin are calcite scales, which suggests that they may be related to the fossil Stegocephalia. However the scales are now believed to be a secondary development, and not directly inherited from Stegocephalia. Owing to their underground life the eyes are small and covered by skin for protection, which has led to the misconception that they are blind. This is not strictly true, although their sight is limited to simple dark-light perception. All Caecilians share two tentacles at their head, which are probably used for a second olfactory capability in addition to the normal sense of smell based in the nose. Groups See text. ... A scorpion tail The tail is the section at the rear end of an animals body; in general, the term refers to a distinct, flexible appendage to the torso. ... In zoological anatomy, a cloaca is the posterior opening that serves as the only such opening for the intestinal, urinary, and genital tracts of certain animal species. ... For other uses, see Skin (disambiguation). ... Doubly refracting Calcite from Iceberg claim, Dixon, New Mexico. ... In this SEM image of a butterfly wing the scales are clearly visible, and the tiny platelets on each individual scale are just barely visible in the striping. ... For other uses, see Eye (disambiguation). ... Olfaction (also known as olfactics) refers to the sense of smell. ...

Except for one lungless species - Atretochoana eiselti, only known from a single specimen collected somewhere in South America - all Caecilians have lungs, but also use the skin or the mouth for oxygen absorption. Often the left lung is much smaller than the right one, an adaptation to body shape that is also found in snakes. Human respiratory system The lungs flank the heart and great vessels in the chest cavity. ... This article is about the chemical element and its most stable form, or dioxygen. ...

Distribution

Caecilians are found in most of the tropical regions of South-East Asia, Africa, the Seychelles islands and South America, except the dry areas and high mountains. In South America their distribution extends well into the temperate zone in the north of Argentina. They can be seen as far south as Buenos Aires, when they are carried by the flood waters of the Parana river coming from farther north. No studies have been made in central Africa, but it is likely that caecilians are found in the tropical rainforests there. The northernmost distribution is of the species Ichthyophis sikkimensis of Northern India. In Africa caecilians are found from Guinea Bissau (Geotrypetes) to Northern Zambia (Scolecomorphus). In South-East Asia the Wallace-Line is not crossed and they are not found in Australia or the islands in between. Ichthyophis is also found in South China and North-Vietnam. For other uses, see Buenos Aires (disambiguation). ... This article needs cleanup. ... Wallaces hypothetical line between Australasian and Southeast Asian fauna. ... Genera  Caudacaecilia  Ichthyophis Ichthyophiidae is the family of asiatic tailed caecilians or fish caecilians. ...

Reproduction

Maternal care in Ichthyophis

Caecilians are the only order of amphibians which only use internal insemination. The male Caecilians have a penis-like organ, the phallodeum, which is inserted into the cloaca of the female for 2 to 3 hours. About 25% of the species are oviparous (egg-laying); the eggs are guarded by the female. For some species the young caecilians are already metamorphosed when they hatch; others hatch as larvae. The larvae are not fully aquatic, but spend the daytime in the soil near the water. The penis (plural penises, penes) is an external male sexual organ. ... A Pieris rapae larva An older Pieris rapae larva A Pieris rapae pupa A Pieris rapae adult Metamorphosis is a process in biology by which an individual physically develops after birth or hatching, and involves significant change in form as well as growth and differentiation. ...

75% of the species are viviparous, meaning that they give birth to already developed offspring. The fetus is fed inside the female with special cells of the oviduct, which are eaten by the fetus with special scraping teeth. A viviparous animal is an animal employing vivipary, a method of reproduction in which the embryo develops inside the body of the mother from which it gains nourishment, and not from an egg. ... In oviparous animals (those that lay eggs), the passage from the ovaries to the outside of the body is known as the oviduct. ...

The egg laying species Boulengerula taitanus feeds its young by developing a special outer layer of skin, high in fat and other nutrients, which the young peel off with similar teeth. This allows them to grow by up to ten times their own weight in a week. The skin is consumed every three days, the time it takes for a new layer to grow, and the young have only been observed to eat it at night. It was previously thought that the juveniles subsisted on a liquid secretion from their mother, but the BBC documentary 'Life In Cold Blood' filmed the bizarre feeding ritual for the first time to reveal the surprising truth.^{[1] [2][3]} For other uses, see BBC (disambiguation). ...

Some larvae, such as those of Typhlonectes, are born with enormous external gills which are shed almost immediately. Ichthyophis is oviparous and is also known to show maternal care. In aquatic organisms, gills are a respiratory organ for the extraction of oxygen from water and for the excretion of carbon dioxide. ...

Diet

The diet of caecilians is not known well, though it seems it mostly consists of insects and invertebrates found in the habitat of the respective species. The stomach contents of 14 specimens of Afrocaecilia taitana consisted of mostly undefinable organic material and plantal remains. Where identifiable remains were most abundant, they were found to be termite heads. ^[4] While it was suggested that the undefinable organic material shows that the caecilians eat detritus, others believe these are in fact the remains of earthworms. Caecilians in captivity can be easily fed with earthworms, and worms are also common in the habitat of many caecilian species. Detritus may refer to: In geology, detritus is the name for loose fragments of rock that have been worn away by erosion. ... Earthworm is the common reference for the larger members of the Oligochaeta (which is either a class or subclass depending on the author) in the phylum Annelida. ...

Origin of the name

The name Caecilian derives from the Latin word caecus = blind, referring to the small or sometimes non-existing eyes. The name dates back to the taxonomic name of the first species described by Carolus Linnaeus, which he gave the name Caecilia tentaculata. The taxonomic name of the order derives from the Greek words γυμνος (gymnos, naked) and οφις (ophis, snake), as the caecilians were originally thought to be related to snakes. This article is about the visual condition. ... Carl Linnaeus, Latinized as Carolus Linnaeus, also known after his ennoblement as  , (May 13, 1707[1] – January 10, 1778), was a Swedish botanist, physician and zoologist[2] who laid the foundations for the modern scheme of nomenclature. ...

Taxonomy

Caecilian from the San Antonio Zoo

Taxonomically the caecilians are divided into 6 families. The species numbers are approximate and many of these species are identified on the basis of only one specimen. It is likely that not all species have been described yet, and that some of the species described below as different may be combined into one species in future reclassifications. Image File history File links Caecilian. ... Image File history File links Caecilian. ... The San Antonio Zoological Gardens and Aquarium is an Association of Zoos and Aquariums-accredited zoo in San Antonio, Texas, United States. ...

• Beaked Caecilians (Rhinatrematidae) - 2 genera, 9 species
• Fish Caecilians (Ichthyophiidae) - 2 genera, 39 species
• Indian Caecilians (Uraeotyphlidae) - 1 genus, 5 species
• Tropical Caecilians (Scolecomorphidae) - 2 genera, 6 species
• Aquatic Caecilians (Typhlonectidae) - 5 genera, 13 species
• Common Caecilians (Caeciliidae) - 26 genera, 99 species

Genera  Epicrionops  Rhinatrema Rhinatrematidae is the family of neoptropical tailed caecilians or beaked caecilians. ... Genera  Epicrionops  Rhinatrema Rhinatrematidae is the family of neotropical tailed caecilians or beaked caecilians. ... Genera  Caudacaecilia  Ichthyophis Ichthyophiidae is the family of asiatic tailed caecilians or fish caecilians. ... Genera  Caudacaecilia  Ichthyophis The vent is an important taxonomic feature for Ichthyophis identification Ichthyophiidae is the family of asiatic tailed caecilians or fish caecilians. ... Genera  Uraeotyphlus Uraeotyphlidae is the family of Indian caecilians. ... Species Uraeotyphlus interruptus Uraeotyphlus malabaricus Uraeotyphlus menoni Uraeotyphlus narayani Uraeotyphlus oxyurus Uraeotyphlidae is the family of Indian caecilians. ... Genera  Crotaphatrema  Scolecomorphus Scolecomorphidae is the family of tropical caecilians (Frost) or African caecilians (ITIS). ... Genera  Crotaphatrema  Scolecomorphus Scolecomorphidae is the family of tropical caecilians (Frost) or African caecilians (ITIS). ... Genera See text. ... Genera See text. ... Genera  Afrocaecilia  Boulengerula  Brasilotyphlus  Caecilia  Dermophis  Gegeneophis  Geotrypetes  Grandisonia  Gymnopis  Herpele  Hypogeophis  Idiocranium  Indotyphlus  Luetkenotyphlus  Microcaecilia  Mimosiphonops  Oscaecilia  Parvicaecilia  Praslinia  Schistometopum  Siphonops Caeciliidae is the family of common caecilians. ... Genera  Boulengerula  Brasilotyphlus  Caecilia  Dermophis  Gegeneophis  Geotrypetes  Grandisonia  Gymnopis  Herpele  Hypogeophis  Idiocranium  Indotyphlus  Luetkenotyphlus  Microcaecilia  Mimosiphonops  Oscaecilia  Parvicaecilia  Praslinia  Schistometopum  Siphonops Caeciliidae is the family of common caecilians. ...

Recent discoveries

A Swiss researcher, Daniel Hofer, has recently found that certain caecilians produce potent skin poisons from specialized poison glands. The poison prevents predation and the poison of the bright yellow caecilian of São Tomé Island (Schistometopum thomense) in West Africa kills other animals kept in the same tank within a few days. The chemical contents of caecilian poison have not been well studied. Werner Himstedt has shown that the skin glands of Ichthyophis protect the eggs from germs and fungi. It has also been shown that these poisons are very different from those from other amphibians such as the Poison dart frog. For other uses, see Poison (disambiguation). ... Distribution of Dendrobatidae (in black) Genera Proposed subfamily Colostethinae proposed genus Ameerega Colostethus Epipedobates proposed genus Silverstoneia Proposed subfamily Hyloxalinae Proposed genus Hyloxalus Proposed subfamily Dendrobatinae Proposed genus Adelphobates Dendrobates Minyobates Proposed genus Oophaga Phyllobates Proposed genus Ranitomeya Proposed obsolete (invalid) Dendrobatidae genera: Cryptophyllobates Nephelobates Poison dart frog (also poison...

British nature expert David Attenborough found that the young can increase their weight up to ten times in one week, post birth. When on filming the nest the young had teeth. It was then discovered that the young did not just diet on secretion/ milk but that the mother was able to reproduce fatty skin every three days for the young to feast on. This was documented on his BBC programme Life in Cold Blood and is the only currently known instance of dermatotrophy, or deriving necessary nutrients from the consumption of skin. Sir David Frederick Attenborough, OM, CH, CVO, CBE, FRS,FZS (born on 8 May 1926 in London, England) is one of the worlds most acclaimed broadcasters and naturalists. ... For other uses, see BBC (disambiguation). ... Life in Cold Blood is a BBC nature documentary series presented by David Attenborough, which is currently in production. ...

See also

• Eocaecilia - a genus of extinct Jurassic caecilians that had legs and well-developed eyes.

The Jurassic Period is a major unit of the geologic timescale that extends from about 199. ...

References

Wikisource has the text of the 1911 Encyclopædia Britannica article Caecilia.

• Werner Himstedt, Die Blindwühlen, ISBN 3-89432-434-1 (German)
• San Mauro, Diego; David J. Gower, Oommen V. Oommen, Mark Wilkinson and Rafael Zardoya (November 2004). "Phylogeny of caecilian amphibians (Gymnophiona) based on complete mitochondrial genomes and nuclear RAG1". Molecular Phylogenetics and Evolution 33: 413-427.
• San Mauro, Diego; Miguel Vences, Marina Alcobendas, Rafael Zardoya and Axel Meyer (May 2005). "Initial diversification of living amphibians predated the breakup of Pangaea". American Naturalist 165: 590-599.

For other uses, see BBC (disambiguation). ... 2008 (MMVIII) is the current year, a leap year that started on Tuesday of the Anno Domini (or common era), in accordance to the Gregorian calendar. ... is the 40th day of the year in the Gregorian calendar. ... is the 42nd day of the year in the Gregorian calendar. ... 2008 (MMVIII) is the current year, a leap year that started on Tuesday of the Anno Domini (or common era), in accordance to the Gregorian calendar. ... Image File history File links Wikisource-logo. ... The original Wikisource logo. ... Encyclopædia Britannica, the eleventh edition The Encyclopædia Britannica Eleventh Edition (1910–1911) is perhaps the most famous edition of the Encyclopædia Britannica. ...

External links

• Image of Grandisonia alternans, a Seychelles caecilain
• New Scientist article on Boulengerula taitanus
  • Video of Boulengerula behaviour
  • BBC footage of young Caecilians feeding on their mother