''Typhlonectes compressicauda'', the Cayenne caecilian, is a species of

amphibian Amphibians are ectothermic, anamniote, anamniotic, tetrapod, four-limbed vertebrate animals that constitute the class (biology), class Amphibia. In its broadest sense, it is a paraphyletic group encompassing all Tetrapod, tetrapods, but excl ...

in the family

Typhlonectidae Typhlonectidae, also known as aquatic caecilians or rubber eels, are a family of caecilians found east of the Andes in South America. They are viviparous animals, giving birth to young that possess external gills. Of the five extant genera in th ...

that lives in water. It is found in Amazonian

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

Peru Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...

, and

Colombia Colombia, officially the Republic of Colombia, is a country primarily located in South America with Insular region of Colombia, insular regions in North America. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuel ...

as well as in

Guyana Guyana, officially the Co-operative Republic of Guyana, is a country on the northern coast of South America, part of the historic British West Indies. entry "Guyana" Georgetown, Guyana, Georgetown is the capital of Guyana and is also the co ...

and

French Guiana French Guiana, or Guyane in French, is an Overseas departments and regions of France, overseas department and region of France located on the northern coast of South America in the Guianas and the West Indies. Bordered by Suriname to the west ...

, and likely

Suriname Suriname, officially the Republic of Suriname, is a country in northern South America, also considered as part of the Caribbean and the West Indies. It is a developing country with a Human Development Index, high level of human development; i ...

, and according to some sources,

Venezuela Venezuela, officially the Bolivarian Republic of Venezuela, is a country on the northern coast of South America, consisting of a continental landmass and many Federal Dependencies of Venezuela, islands and islets in the Caribbean Sea. It com ...

. It is an aquatic caecilian that inhabits permanent rivers and marshes mainly in the lowland forest zone.

Description

The Cayenne caecilian is an elongated, dark grey, black or steely blue amphibian with no limbs. The body is flattened laterally and has a number of transverse folds, giving it a segmented appearance. A long fin runs along its back, and it grows to a length of . It has a more highly derived morphology than some more primitive species, showing differences in lung structure, the reproductive organs, and the kidneys.

Distribution

The Cayenne caecilian occurs in South America, including the

Amazon basin The Amazon basin is the part of South America drained by the Amazon River and its tributary, tributaries. The Amazon drainage basin covers an area of about , or about 35.5 percent of the South American continent. It is located in the countries ...

and river systems in

the Guianas The Guianas, also spelled Guyanas or Guayanas, are a geographical region in north-eastern South America. Strictly, the term refers to the three Guianas: Guyana, Suriname, and French Guiana, formerly British, Dutch, and French Guiana respectiv ...

. It is found at altitudes of up to above sea level. Because it is common and has a wide range, it is listed as of "

Least Concern A least-concern species is a species that has been evaluated and categorized by the International Union for Conservation of Nature (IUCN) as not being a focus of wildlife conservation because the specific species is still plentiful in the wil ...

" in the

IUCN Red List of Threatened Species The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is an inventory of the global conservation status and extinction risk of biological spe ...

Biology

The Cayenne caecilian lives in shallow streams and rivers. It spends the day in a communal burrow, emerging at night to hunt through the sediment for small invertebrates, such as insect larvae and shrimps. It also eats small fish. It has no functional eyes and probably detects its

prey Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not ki ...

by touch or by the vibrations made when the prey moves. It has slime glands all over its body and secretes copious amounts of noxious mucus if attacked. Nevertheless, it is eaten by birds, snakes, and large fish. At breeding time, a male and female Cayenne caecilian twine around each other and the male places a

spermatophore A spermatophore, from Ancient Greek σπέρμα (''spérma''), meaning "seed", and -φόρος (''-phóros''), meaning "bearing", or sperm ampulla is a capsule or mass containing spermatozoa created by males of various animal species, especiall ...

in the female's cloaca. Fertilisation is internal and the Cayenne caecilian is

ovoviviparous Ovoviviparity, ovovivipary, ovivipary, or aplacental viviparity is a "bridging" form of reproduction between egg-laying oviparity, oviparous and live-bearing viviparity, viviparous reproduction. Ovoviviparous animals possess embryos that develo ...

. Six to fourteen young hatch inside the female's oviduct with gills. At first, they feed on the yolks of their eggs, but they develop rasping teeth and later consume glandular secretions produced by the lining of the oviduct. Birth takes place after about eight months and the juvenile caecilians shed their temporary teeth and develop their

adult dentition Permanent teeth or adult teeth are the second set of teeth formed in diphyodont mammals. In humans and old world simians, there are thirty-two permanent teeth, consisting of six maxillary and six mandibular molars, four maxillary and four mandibu ...

. The Cayenne caecilian is considered to have several characteristics that are more highly derived than other more primitive species. Its

karyotype A karyotype is the general appearance of the complete set of chromosomes in the cells of a species or in an individual organism, mainly including their sizes, numbers, and shapes. Karyotyping is the process by which a karyotype is discerned by de ...

has been compared with that of other caecilians, and its

diploid Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Here ''sets of chromosomes'' refers to the number of maternal and paternal chromosome copies, ...

number has been found to be 28, a fact that does not support the hypothesis that, during the period of amphibian evolution, the number of chromosomes became reduced. However, many caecilians have not yet been karyotyped and the exact evolutionary relationships between the species have not yet been determined, so the hypothesis is not necessarily incorrect. ''Typhlonectes compressicauda'' was included in a study of the evolutionary origin of acoustic communication.

References

{{Taxonbar, from=Q1759945 compressicauda Caecilians of Brazil Amphibians of Colombia Amphibians of French Guiana Amphibians of Guyana Amphibians of Peru Amphibians described in 1841 Taxa named by André Marie Constant Duméril Taxa named by Gabriel Bibron Taxonomy articles created by Polbot