Snout–vent length

Snout–vent length (SVL) is a morphometric measurement taken in herpetology from the tip of the snout to the most posterior opening of the cloacal slit (vent).

The SVL differs depending on whether the animal is struggling or relaxed (if alive), or various other factors if it is a preserved specimen.

When combined with weight and body condition, SVL can help deduce age and sex.

[3] Because tails are often missing or absent, especially in juveniles, SVL is seen as more invariant than total length.

Various devices are used to position the animal while the measurement is being taken, such as a snake tube, "Mander Masher",[5] or a "Salamander Stick".