Rio Grande de Santiago Nightsnake

About the Rio Grande de Santiago Nightsnake

Adapted from Wikipedia, available under CC BY-SA.

Frequently asked: Rio Grande de Santiago Nightsnake

Is the Rio Grande de Santiago Nightsnake venomous?

The Rio Grande de Santiago Nightsnake (Hypsiglena affinis) is rear-fanged and only mildly venomous. It is not considered dangerous to humans (its venom is weak and its fangs sit at the back of the mouth) but a bite can cause local swelling or irritation, so it should not be handled.

Is the Rio Grande de Santiago Nightsnake poisonous?

Snakes are venomous, not poisonous. "Poisonous" means harmful to eat or touch; "venomous" means injecting toxins through a bite. The Rio Grande de Santiago Nightsnake is neither poisonous nor venomous.

Is the Rio Grande de Santiago Nightsnake dangerous?

The Rio Grande de Santiago Nightsnake is not dangerous to humans. It has no medically significant venom and bites only defensively if cornered or handled.

Where does the Rio Grande de Santiago Nightsnake live?

The Rio Grande de Santiago Nightsnake has verified records in 1 country, including Mexico. See the distribution section below for its full range.

How do I identify the Rio Grande de Santiago Nightsnake?

Pale gray with dark blotches, vertical pupils, and dark neck blotches.

How big does the Rio Grande de Santiago Nightsnake get?

Small, 12–26 in.

Where it is found

More Colubridae snakes

• 
  Chihuahuan Nightsnake
  Hypsiglena jani
• 
  Desert Nightsnake
  Hypsiglena chlorophaea
• 
  Coast Night Snake
  Hypsiglena ochrorhynchus
• 
  Sinaloan Nightsnake
  Hypsiglena torquata
• 
  Baja California Night Snake
  Hypsiglena slevini
• 
  Tanzer’s Night Snake
  Hypsiglena tanzeri
• 
  Isla Santa Catalina Nightsnake
  Hypsiglena catalinae
• 
  Islas Revillagigedo Nightsnake
  Hypsiglena unaocularus

Classification

How scientists group this snake, from the broadest category down to the exact species. Each step narrows to its closest relatives.

OrderThe broad group of scaled reptiles: all snakes and lizards

Squamata

FamilyA group of related snakes that share key traits

Colubridae

GenusA close-knit group of very similar species

Hypsiglena

SpeciesThis exact snake, named in the two-part scientific name

Hypsiglena affinis

Keep learning

• What to Do If You Find a SnakeFound a snake at home or on a trail? Here is how to stay calm, give it space, identify it safely, and know when to call a professional.
• Venomous vs Nonvenomous: How to Tell the DifferenceThe folk rules for telling venomous snakes apart, where each one fails, and why location-based identification beats guessing by sight.
• What Is a Snake? Anatomy and the BasicsA clear overview of what makes a snake a snake: limbless body plan, anatomy, evolution from lizards, species diversity, and why they are ectothermic.
• How to Keep Snakes Out of Your Yard and HomeA practical guide to keeping snakes out of your yard and home using habitat changes that work, plus what to skip and what to do if one shows up.