''Typhlonectes compressicauda'', the Cayenne caecilian, is a species of amphibian 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 genera in the famil ...

that lives in water. It is found in Amazonian

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

Peru , image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = Seal (emblem), National seal , national_motto = "Fi ...

, and Colombia as well as in Guyana and

French Guiana French Guiana ( or ; french: link=no, Guyane ; gcr, label=French Guianese Creole, Lagwiyann ) is an overseas departments and regions of France, overseas department/region and single territorial collectivity of France on the northern Atlantic ...

, and likely

Suriname Suriname (; srn, Sranankondre or ), officially the Republic of Suriname ( nl, Republiek Suriname , srn, Ripolik fu Sranan), is a country on the northeastern Atlantic coast of South America. It is bordered by the Atlantic Ocean to the north ...

, and according to some sources,

Venezuela Venezuela (; ), officially the Bolivarian Republic of Venezuela ( es, link=no, República Bolivariana de Venezuela), is a country on the northern coast of South America, consisting of a continental landmass and many islands and islets in ...

. 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 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 of Boli ...

and river systems in

the Guianas The Guianas, sometimes called by the Spanish loan-word ''Guayanas'' (''Las Guayanas''), is a region in north-eastern South America which includes the following three territories: * French Guiana, an overseas department and region of France ...

. 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 categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. Th ...

" in the IUCN Red List of Threatened Species.

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 where 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 kill the ...

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 mucous 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 or sperm ampulla is a capsule or mass containing spermatozoa created by males of various animal species, especially salamanders and arthropods, and transferred in entirety to the female's ovipore during reproduction. Spermatophores ...

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

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

. Six to 14 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. 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 metaphase 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 disce ...

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. Sets of chromosomes refer to the number of maternal and paternal chromosome copies, respecti ...

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.

References

{{Taxonbar, from=Q1759945 compressicauda Amphibians 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