We have 8 species of watersnake (Nerodia) in the state.
Yellowbellied watersnakes and blotched watersnakes are the same species. In the east they look like this:
Central and western part of the state they look more like this:
Broad-banded watersnakes almost always have orange/yellow broadly spaced bands and bright faces
Diamondback watersnakes have a distinctive greenish/tan color and chainlink pattern ("diamonds" on top)
And a few that never get posted but are present in Texas:
Mississippi green watersnakes are fairly non-descript. Pattern similar to diamondbacks. Pretty much only turn up in marshy areas in the far eastern part of the state
Gulf saltmarsh snakes are striped and live in brackish coastal habitats
There's an interesting population (and only one in the state) of northern watersnakes in central/north Dallas. Debated whether they are native or introduced.
One of the few endemic herps to Texas, the Brazos River watersnake. Only found in the Brazos and a few tribs north of Glenrose or so.
I don't have any photos of the last species, the Concho watersnake. They look a lot like the Brazos though.
