Watersnakes | Herps of Texas

Nerodia clarkii

Mon, 01 Jan 0001 00:00:00 +0000

Scientific name. Nerodia clarkii

Common Name. Saltmarsh Snake

General information. Being able to live in a harsh salty environment makes Nerodia clarkii atypical among the snakes of Texas. Drinking no salt water during its existence in the marshes, it aquires all of its water from its prey. These prey species include frogs and a wide variety of invertebrates, including shrimp, crabs, and crayfish. This non-venomous snake, also found on many of the grass-lined coastal barrier islands, is not considered aggressive, though it will definitely bite without hesitation if handled.

Protected status. The Saltmarsh Snake is not a protected species in Texas and can be legally collected with a hunting license.

Diagnostic features. Divided anal plate 21-23 keeled dorsal scale rows near midbody.

Coloration. One of the most distinctly patterned snakes in all of Texas, with its four dark longitudinal stripes contrasting greatly with its light gray colored background. The upper two stripes are generally black with the two stripes found lower on the body either tan or light brown. The belly is red or brown, with a median row of light spots found on the ventrals. Some individuals may have three rows of these light spots on the belly.

General distribution. Only found in the U.S., Nerodia clarkii is found along much of the Texas coastal wetland, as well as along the entire coastline of Louisiana, Mississippi, Alabama, and the majority of the Florida coast.

Texas distribution. In Texas, Nerodia clarkii is found along the coastline, from Corpus Christi eastward to the Texas-Louisiana border.

Habitat. The Saltmarsh Snake is aptly named as this snake is rarely found in fresh water environments, spending its entire life among the salt-grass marshes of the tidal wetlands.

Reproduction. As many as 44 juvenile snakes may be born in a single litter. Nerodia clarkii is viviparous, giving birth to live young, which may be as long as 24.5 cm (9.5 in) when born.

Size. Not a large snake, Nerodia clarkii typically measures between 38-76 cm (15-30 in).

Map. Orange counties indicate new county records since previous Herps of Texas update in 1998; all other colored counties reflect known distribution prior to 1998 for species and/or subspecies. Map is based on museum voucher specimens.

Nerodia cyclopion

Mon, 01 Jan 0001 00:00:00 +0000

Scientific name. Nerodia cyclopion

Common Name. Mississippi Green Watersnake

General information. Eating a variety of fish, frogs, toads and salamanders, the non-venomous Nerodia cyclopion is primarily nocturnal, searching for its prey along the mud- and sand-lined banks of ponds or slow moving bodies of water at night. When cornered this non-aggressive snake will zealously defend itself with an arsenal of quick, repeated bites and a foul smelling musk released from its vent.

Protected status. The Mississippi Green Watersnake is not a protected species in Texas and can be legally collected with a hunting license.

Diagnostic features. The row of subocular scales found in Nerodia cyclopion is a unique character that separates it from all other species of Nerodia. Unfortunately, to accurately see this character it requires a close examination of the snake’s head, which may result in a painful bite from the non-venomous water snake Keeled dorsal scales, in rows of 27 to 29 near midbody Divided anal plate

Coloration. The dorsal surface is a deep olive or brown, with a gray or brown belly, and yellow throat Generally only a hint of dark dorsal pattern evident on dark dorsal surface The belly is marked with a random assortment of light colored spots or crescents.

General distribution. The range of Nerodia cyclopion is restricted to the United States. This species is found in much of the lower Mississippi River valley and parts of the coastline adjacent to the Mississippi River delta. It can be found as far north as Illinois, and is found along the Gulf of Mexico coastline from Texas to the Florida Panhandle.

Texas distribution. In Texas, Nerodia cyclopion is present along the upper Gulf Coast, from Port Aransas eastward to the Louisiana border. Additionally, N. cyclopion is found in the lower portions of the Sabine River, as it flows along the border between Texas and Louisiana.

Habitat. Nerodia cyclopion is one of the few water snakes in Texas which can occassionally be found in brackish water, though it is generally found in the fresh-water confines of lakes, marshes and swamps.

Reproduction. Nerodia cyclopion is a live-bearing snake and incredibly prolific, with as many as 101 offspring recorded in a single litter. The neonates measure 23-28 cm (9-11 in) at birth, which may take place between June and September.

Size. Adult Nerodia cyclopion are 76-114 cm (30-45 in) in length

Nerodia erythrogaster

Mon, 01 Jan 0001 00:00:00 +0000

Scientific name. Nerodia erythrogaster

Common Name. Plain-bellied Watersnake

General information. Adults of both subspecies feed primarily on fish and amphibians, whereas juveniles often feed on tadpoles, small fish, and invertebrates. Nerodia erythrogaster has been found foraging both at night and during the day, though it is much more nocturnal in the western part of its range. Though non-venomous, N. erythrogaster will not hesitate to strike and bite an attacker, and will often release a terrible smelling musk to complement its defense. During the day, N. erythrogaster can be found basking on branches and vegetation overhanging the water. This allows for a quick escape into the water and a startled snake will frequently drop into the water and swim across to the opposite bank to seek refuge.

Protected status. The Plain-bellied Watersnake is not a protected species in Texas and can be legally collected with a hunting license.

Diagnostic features. 23-27 keeled dorsal scale rows near midbody. Divided anal plate.

Coloration. Superficially looks like many other species of water snakes, with a dark olive or gray dorsal coloration. There are two subspecies of N. erythrogaster found in Texas, distinguished by their dorsal and ventral color patterns.

General distribution. The range of Nerodia erythrogaster, including the four subspecies found in the U.S., stretches across much of the southeastern U.S., found from the east coast of the Atlantic to the southeast corner of New Mexico. Isolated populations are also present as far north as Ohio and Michigan. The range of N. e. transversa extends into northern Mexico and additional subspecies are found through the eastern portions of that country.

Texas distribution. In Texas, the two subspecies of Nerodia erythrogaster, are found throughout much of Texas, save the western half of the Panhandle and the most arid regions of the western Trans-Pecos. The two subspecies intergrade regularly along the borders of their ranges, especially in the southeastern corner of the state, east of Houston.

Habitat. The two Texas subspecies of Nerodia erythrogaster are commonly found near slow moving portions of rivers and streams, though N. e. transversa is more arid adapted, found in tanks and ponds in parts of the arid Trans-Pecos. Nerodia e. flavigaster is often seen in marshes, swamps and flooded woodlands.

Reproduction. As it is a viviparous snake, Nerodia erythrogaster will give birth to an average of 16 live snakes in August and September. The juveniles of both subspecies, measuring 19-33 cm (7.5-13 in) at birth, look different than their parents, having a series of brown saddles middorsally on a tan or pink dorsal background.

Size. Adult sizes of Nerodia erythrogaster are also typical of many species of Nerodia (adults 76-122 cm [30-48 in]).

Nerodia fasciata

Mon, 01 Jan 0001 00:00:00 +0000

Scientific name. Nerodia fasciata

Common Name. Southern Watersnake

General information. Non-venomous, Nerodia fasciata hunts fish and a wide variety of amphibians, particularly frogs. A nocturnal hunter, N. fasciata spends the day resting in the vegetation along the water’s edge or hides deep in rodent burrows along the bank. Many species of Nerodia are suspected of being venomous cottonmouths (Agisktrodon piscivorus) but the behavior of the two snakes is tremendously different. Cottonmouths move much more slowly in the water, often keeping their entire body afloat. When threatened, cottonmouths show off their namesake white lined mouth in a defensive posture. All species of Nerodia are quick, agile swimmers which move rapidly through the water and water snakes never gape open their mouths if threatened. They may instead flatten their bodies in an attempt to look larger.

Protected status. The Southern Watersnake is not a protected species in Texas and can be legally collected with a hunting license.

Diagnostic features. Keeled scales, usually in rows of 21 to 27 near midbody Divided anal scales.

Coloration. Dark crossbands on dorsal surface and dark ocular stripe Two subspecies of Nerodia fasciata are distinguished by dorsal background color Yellow or cream colored ventral surface.

General distribution. The three subspecies of Nerodia fasciata cover many of the southern U.S. states. Found in the western half of the lower Mississippi River valley, N. fasciata is also found along the coast of the Gulf of Mexico, from Texas to Florida, and along the Atlantic Coast, from Florida to North Carolina.

Texas distribution. In Texas, Nerodia fasciata confluens is found in the eastern third of the state. Nerodia f. pictiventris is restricted, at present, to Cameron County, having been introduced there in the first half of the century from Florida.

Habitat. Both subspecies of Nerodia fasciata prefer heavily vegetated lakes and ponds, though both are occassionally seen along canals and streams.

Reproduction. Like all Nerodia, N. fasciata is viviparous and may have give birth to as many as 50 live offspring per litter. These neonates measure 19-26.5 cm (7.5-10.5 in) when born during the early summer months and are more brightly colored than their parents.

Size. Adult Nerodia fasciata commonly average between 56-106.5 cm (22-42 in) in length.

Nerodia harteri

Mon, 01 Jan 0001 00:00:00 +0000

Scientific name. Nerodia harteri

Common Name. Brazos River Watersnake

General information. A diurnal hunter, Nerodia harteri depends on the rocks in its habitat for security and without rocks, there are no Brazos watersnakes. Nerodia harteri is not considered a food generalist, prefering a diet of small fish, though individuals have been recorded as eating a variety of salamander and frog species, as well as an occassional crayfish. Much of the habitat for this species is disappearing due to human influences. Dams have been built, flooding the prefered rocky shoreline habitat of N. harteri. Additional introductions of non-native plants, including salt cedar have further changed shoreline habitats, making them unsuitable for this snake species.

Protected status. The Brazos River Watersnake is recognized as threatened by the Texas Parks and Wildlife Department and is fully protected by the law.

Diagnostic features. Anal plate divided Keeled dorsal scales in rows of 21 to 25 near midbody. Two small scales present in between the posterior set of large chin scales

Coloration. Brown-gray or green-brown dorsum Four rows of dark dorsal spots running the length of body giving a checkerboard appearance Belly pink or orange and pigmented with spots along margins of ventral scales. Throat and neck are yellow or cream in color.

General distribution. The Brazos River Watersnake has one of the most restricted ranges of any Texas snake, found only along portions of the Brazos River.

Texas distribution. Nerodia harteri is restricted to the upper portions of the Brazos river drainage in north-central Texas.

Habitat. The exclusive habitat of Nerodia harteri are the rocky stream beds and banks of the Brazos River; this species is not found along the sandy stretches of this river system.

Reproduction. The Brazos watersnake is viviparous, meaning it gives birth to live young. This occurs generally occurs in September and October as litters of as many as 23 young are born, with neonates measuring between 18-25.5 cm (7-10 in) in length.

Size. Adult Nerodia harteri average 51-76 cm (20-30 in) in length.

Nerodia paucimaculata

Mon, 01 Jan 0001 00:00:00 +0000

Scientific name. Nerodia paucimaculata

Common Name. Concho Watersnake

General information. A non-venomous snake, Nerodia paucimaculata is primarily diurnal, actively foraging for food (mainly fish) during the morning and early afternoon. Rarely found more than 2 meters (6.5 ft) from the water, Concho watersnakes bask over the water, allowing for a quick escape when threatened by would-be attackers.

Protected status. The Concho Watersnake is considered an endangered species by the Texas Parks and Wildlife Department and is fully protected by the state. Additional protection has been afforded to this species as the U.S. Fish and Wildlife Service considers the Concho watersnake to be a federally threatened species.

Diagnostic features. Divided anal scale Keeled dorsal scales in 21-23 rows near midbody. A single row of scales separate the posterior chinshields

Coloration. Dorsal ground color is light tan with reddish tint Four faint rows of dorsal blotches Orangish or pink belly is either lightly marked with dark pigment or immaculate. If faint belly markings are present, they are found on the margins of the ventral scales.

General distribution. The entire range of Nerodia paucimaculata is found in Texas.

Texas distribution. Nerodia paucimaculata is only found along the Concho and Colorado Rivers in west-central Texas.

Habitat. Unfortunately, damming of the Concho and Colorado Rivers has flooded much of the essential habitat of this snake: rocky shorelines. Additional habitat of the Concho Watersnake has been altered due to increased vegetation and sedimentation. Much of the increased vegetation is caused by introduction of non-native species, with the primary culprit being salt cedar. Further construction of dams threaten over 20% of the remaining habitat for these snakes.

Reproduction. Little is known about the reproductive natural history of this species, other than it is viviparous.

Size. Adult Nerodia paucimaculata typically measure 51-76 cm (20-30 in) in length

Nerodia rhombifer

Mon, 01 Jan 0001 00:00:00 +0000

Scientific name. Nerodia rhombifer

Common Name. Diamond-backed Watersnake

General information. Along with being a habitat generalist, Nerodia rhombifer is also a food generalist, eating fish, frogs, toads, crayfish and an occasional young turtle. Again, although N. rhombifer is non-venomous, it is a zealous biter and will bite an attacker repeatedly. The attacker is also frequently covered with musky feces released by the agitated snake.

Protected status. The Diamond-backed Watersnake is not a protected species in Texas and can be legally collected with a hunting license.

Diagnostic features. Anal plate is divided Keeled dorsal scales are in 25 to 31 rows near midbody.

Coloration. The background color typically light olive-brown dorsally, with the olive becoming brown laterally. A series of rhomboid-shaped blotches runs the length of the vertebral column, with each of the blotches being connected to another series of vertical black bars found on each side by thin black lines. Belly is either yellow, olive, or buff and is marked with dark crescents found along the margins of the ventral scales. Top of the head is a deep olive color and the majority of the supralabial scales are yellow, outlined with black pigment.

General distribution. The range of Nerodia rhombifer covers many states of the lower Mississippi River Valley, found as far north as Iowa; Mexican subspecies of N. rhombifer are found in Mexico and occur along the Atlantic coast of that country.

Texas distribution. In Texas, Nerodia rhombifer is found in a majority of water holes in the eastern half of the state.

Habitat. Nerodia rhombifer is the habitat generalist of the watersnakes. They can be commonly found in a variety of water bodies: swamps, rivers, ditches and water tanks; three individuals have even been found floating in a car tire in a pond.

Reproduction. Nerodia rhombifer is viviparous, giving birth to an average of 47 live young, each of which measure between 20-33 cm (8-13 in). These young snakes are born in the late summer and early fall.

Size. Reaching lengths of 152.5 cm (60 in), Nerodia rhomibfer is usually encountered at lengths of 76-122 cm (30-48 in).

Nerodia sipedon

Mon, 01 Jan 0001 00:00:00 +0000

Scientific name. Nerodia sipedon

Common Name. Common Watersnake

General information. Like most watersnakes, the northern watersnake is extremely wary and will dive into water to escape potential predators. When cornered and threatened, this watersnake will flatten its entire body and will proceed to vigorously lunge and try to bite its aggressor. Watersnakes are notorious for producing copious amounts of foul smelling musk in an attempt to drive off predators. Fish and amphibians make up the majority of the northern watersnake's diet.

Protected status. The Common Watersnake is not a protected species in Texas and can be legally collected with a hunting license.

Diagnostic features. Dorsal scales keeled, in rows of 23 at midbody Divided anal plate

Coloration. Dorsal color dark brown to reddish brown Crossbands complete on neck and anterior quarter of body; crossbands broader dorsally, narrower laterally Crossbands broken in posterior portion of body, intermixed with lateral bars. Wide interspaces tan, reddish-brown, or gray-brown. Dorsal pattern may fade and become indistinct with age. Ventral surface marked with two rows of red or reddish-brown half moons. Head unmarked (brown) save pigment outlining labial scales.

General distribution. In North America, Nerodia sipedon is found across the U.S. Midwest and East Coast.

Texas distribution. The presence of Nerodia sipedon in Texas is based on two specimens collected in Grayson County along the Red River; the two specimens are assigned to the subspecies N. s. pleuralis and it is not known whether this taxon still persists in Texas.

Habitat. The Common Watersnake prefers slow-moving streams and rivers with gravel bottoms, but may be found in swamps, marshes, lakes and ponds.

Reproduction. Live young are born in late summer with litter sizes ranging from 8-46. Neonate snakes measure 19-30 cm (7.5-12 in) at birth.

Size. Adult Nerodia sipedon average 55-100 cm (22-40 in) total length.