The Natricinae are a

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end botanical subfamily names with "-oideae", and zo ...

of colubroid

snakes Snakes are elongated Limbless vertebrate, limbless reptiles of the suborder Serpentes (). Cladistically Squamata, squamates, snakes are ectothermic, amniote vertebrates covered in overlapping Scale (zoology), scales much like other members of ...

, sometimes referred to as a

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

(Natricidae). The subfamily comprises 36

genera Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial s ...

. Members include many very common snake

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

, such as the European grass snakes, and the North American water snakes and garter snakes. Some Old World members of the subfamily are known as keelbacks, because their dorsal scales exhibit strong keeling. Natricine snakes are found in

Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

, and

Central America Central America is a subregion of North America. Its political boundaries are defined as bordering Mexico to the north, Colombia to the southeast, the Caribbean to the east, and the Pacific Ocean to the southwest. Central America is usually ...

as far south as

Costa Rica Costa Rica, officially the Republic of Costa Rica, is a country in Central America. It borders Nicaragua to the north, the Caribbean Sea to the northeast, Panama to the southeast, and the Pacific Ocean to the southwest, as well as Maritime bo ...

. A single species, '' Tropidonophis mairii'', reaches

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

. Although the highest diversity is in North America, the oldest members are in Asia and Africa, suggesting an Old World origin for the group. Most species are semiaquatic and feed on fish and

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 ...

s, although a few are semi

fossorial A fossorial animal () is one that is adapted to digging and which lives primarily (but not solely) underground. Examples of fossorial vertebrates are Mole (animal), moles, badgers, naked mole-rats, meerkats, armadillos, wombats, and mole salamand ...

or leaf-litter snakes that feed on

invertebrate Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordata, chordate s ...

s. Most species are harmless to humans, but a few (e.g., '' Thamnophis sirtalis'', '' Thamnophis elegans'') are capable of inflicting bites that can result in local, non-life-threatening symptoms, and at least two members of the genus '' Rhabdophis'' ('' R. tigrinus'' and '' R. subminiatus'') are capable of inflicting life-threatening bites to humans, though they have only enlarged, ungrooved fangs in the back of the mouth. 364 pp. .

Classification

The Natricinae are recognised as a sister group of the

Dipsadinae Dipsadinae is a large subfamily of colubroid snakes, sometimes referred to as a family (Dipsadidae). Species of the subfamily Dipsadinae are found in most of the Americas, including the West Indies, and are most diverse in South America. There a ...

plus the Pseudoxenodontinae.

Genera

*'' Afronatrix'' *'' Amphiesma'' *'' Amphiesmoides'' *'' Anoplohydrus'' *'' Aspidura'' *'' Atretium'' *'' Blythia'' www.reptile-database.org. *'' Clonophis'' *'' Fowlea'' *'' Haldea'' *'' Hebius'' *'' Helophis'' *'' Herpetoreas'' *'' Hydrablabes'' *'' Hydraethiops'' *'' Iguanognathus'' *'' Isanophis'' *''

Limnophis ''Limnophis'' is a genus of snakes in the subfamily Natricinae of the Family (biology), family Colubridae. The genus contains three species. Geographic range Species of the genus ''Limnophis'' are Endemism, endemic to southern Africa. Species T ...

'' *'' Liodytes'' *'' Lycognathophis'' *'' Natriciteres'' *'' Natrix'' *'' Nerodia'' *'' Opisthotropis'' *'' Paratapinophis'' *'' Pseudagkistrodon'' *'' Regina'' *'' Rhabdophis'' *'' Rhabdops'' *'' Sahyadriophis'' *'' Smithophis'' *''

Storeria ''Storeria'' is a genus of snakes in the subfamily Natricinae of the Family (biology), family Colubridae. The genus is Endemism, endemic to North America and Central America. The genus consists of five species, four of which are known as brown ...

'' *'' Thamnophis'' *'' Trachischium'' *'' Trimerodytes'' *''

Tropidoclonion ''Tropidoclonion'' is a genus of snake in the subfamily Natricinae of the Family (biology), family Colubridae. The genus is Monotypic taxon, monotypic, containing the sole species ''Tropidoclonion lineatum'', Common name, commonly known as the li ...

'' *'' Tropidonophis'' *''

Virginia Virginia, officially the Commonwealth of Virginia, is a U.S. state, state in the Southeastern United States, Southeastern and Mid-Atlantic (United States), Mid-Atlantic regions of the United States between the East Coast of the United States ...

'' *'' Xenochrophis''

Classification

Genera

References

Further reading