- Nerodia
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diamondback water snake 
diamondback water snake, Nerodia rhombifer Scientific classification Kingdom: Animalia Phylum: Chordata Subphylum: Vertebrata Class: Reptilia Order: Squamata Suborder: Serpentes Family: Colubridae Subfamily: Natricinae Genus: Nerodia
Baird & Girard, 1853Synonyms Natrix Laurenti, 1768
Nerodia is a genus of nonvenomous colubrid snakes commonly referred to as water snakes.
Contents
Description
Nerodia species vary greatly, but all are relatively heavy-bodied snakes, sometimes growing to 1.2 m (4 feet) or larger. They have flattened heads, with small eyes that have round pupils, and keeled scales. Species like N. fasciata display distinct banding, where other species, like N. erythrogaster have blotching, and N. rhombifer have diamond-shaped patterning. Most species are brown or olive green, or some combination thereof with markings being brown, or black. Yellow or cream-colored accenting is common.
Behavior
Water snakes, as their name implies are largely aquatic. They spend the vast majority of their time in, or very near permanent sources of water. Often they can be found basking on tree branches which overhang slow moving streams or ponds. Their primary diet is fish and amphibians, and they are quite adept at catching both in their aquatic environment. They will also consume rodents.
While their initial instinct is to flee when disturbed, they do typically have a nasty disposition. They do not often hesitate to strike or bite if handled, and will often expel a foul-smelling musk from their cloacae.
Reproduction
diamondback water snake, Nerodia rhombifer giving birth
Nerodia species are ovoviviparous, breeding in the spring and giving birth in the late summer or early fall. They are capable of having 90 or more young, but broods generally are much smaller. Neonates are around 20-26 cm (8-10 in.) in length.
Species & subspecies
- salt marsh snake - Nerodia clarkii (Baird & Girard, 1853)
- green water snake - Nerodia cyclopion (Duméril, Bibron & Duméril, 1854)
- N. c. floridana (Goff, 1936)
- plainbelly water snake - Nerodia erythrogaster (Forster, 1771)
blotched water snake, Nerodia erythrogaster transversa- banded water snake - Nerodia fasciata (Linnaeus, 1766)
- Brazos water snake - Nerodia harteri (Trapido, 1941)
- Concho water snake - Nerodia paucimaculata (Tinkle & Conant, 1961)
- diamondback water snake - Nerodia rhombifer (Hallowell, 1852)
- Northern water snake - Nerodia sipedon (Linnaeus, 1758)
- brown water snake - Nerodia taxispilota (Holbrook, 1842)
Distribution
Nerodia species are widely spread around the southern and eastern half of the United States, north into Canada and south into Mexico, as well as to the island of Cuba. Many ranges overlap, and intergrading of subspecies is not unknown, but is rare.
- N. clarkii - around the Gulf of Mexico (Florida, Louisiana, Mississippi, Texas) and Cuba.
- N. cyclopion - Texas, Louisiana, Arkansas, Missouri, Illinois, Mississippi, Alabama, Georgia, Florida, South Carolina, Tennessee, and Kentucky.
- N. erythrogaster - Texas, Oklahoma, Kansas, Louisiana, Arkansas, Missouri, Mississippi, Alabama, Georgia, Florida, South Carolina, North Carolina, Illinois, Indiana, Ohio, Michigan, Iowa, Delaware and into Mexico ( (Durango, Zacatecas, Coahuila, Nuevo Leon).
- N. fasciata - Texas, Louisiana, Oklahoma, Arkansas, Mississippi, Alabama, Florida, Georgia, South Carolina, North Carolina, Missouri, and Illinois.
- N. harteri - Central Texas.
- N. paucimaculata - Central Texas.
- N. rhombifer - Texas, Oklahoma, Kansas, Louisiana, Arkansas, Missouri, Illinois, Indiana, Tennessee, Mississippi, and Alabama, as well as south into Mexico (Coahuila, Nuevo Leon, Tamaulipas, Veracruz)
- N. sipedon - Colorado, Nebraska, Kansas, Oklahoma, Iowa, Missouri, Arkansas, Minnesota, Wisconsin, Illinois, Tennessee, Louisiana, Mississippi, Alabama, Georgia, Florida, South Carolina, North Carolina, Kentucky, West Virginia, Virginia, Indiana, Ohio, Pennsylvania, New York, Vermont, New Hampshire, Maine, Massachusetts, Rhode Island, Connecticut, New Jersey, Delaware, Maryland, Michigan, and north into Canada.
- N. taxispilota - Florida, Alabama, Georgia, South Carolina, North Carolina, and Virginia.
In captivity
Due to how widespread and extremely common they are in the wild, water snakes are often found in the exotic pet trade, throughout the United States, though they are rarely captive bred. Their relative physical unattractiveness compared to other available pet snake species, and their poor disposition makes them less than attractive pets. They are easy to care for though, and do quite well in captivity.
Conservation concerns
Some species, such as N. harteri and N. paucimaculata are only found in very isolated localities and are protected by state laws, but the majority of Nerodia species hold no specific conservation status. Due to their habitat choice, poor disposition, and vague similarity to the venomous cottonmouth (Agkistrodon piscivorus), they are frequently mistaken for them. This results in many more water snakes being killed every year than cottonmouths. Often, water snakes found in areas where the cottonmouth does not range are still killed by humans out of ignorance and fear.
References
- "Nerodia". Integrated Taxonomic Information System. http://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=174241. Retrieved 12 May 2006.
- Northern Water Snake Species account from the Iowa Reptile and Amphibian Field Guide
- Diamondback Watersnake - Nerodia rhombifer Species account from the Iowa Reptile and Amphibian Field Guide
External links
Categories:- Colubrids
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