Mudpuppy or Tiger Salamander?
Mudpuppy photo (above) by Suzanne L. Collins, The Center for North American Herpetology
Tiger Salamander photos (above) by Greg Wolbrink, South Dakota Game, Fish and Parks.
Tiger Salamanders have five toes on the hind feet, mudpuppies have four.
What is it: A Mudpuppy or Tiger Salamander?
By Alyssa Kiesow
Winter is gone, spring is here, and summer is near. Mixtures of colors- green, blue, yellow, and purple- appear in the landscape as plants revive themselves. Camouflaged in the newly refreshed landscape are many animals, such as amphibians. Amphibians, like frogs, toads, and salamanders, rely on the environment and their behavior to regulate their body temperature- called ectothermy, thus they are found during the warm spring and summer months. As the climate warms up, the chorus of frogs and toads initiate the spring mating season, but unlike frogs and toads, salamanders do not create choruses in the night.
Salamanders, in particular Mudpuppies, have recently been a "hot" topic among many biologists, anglers, and naturalists. A short time ago, my husband and I discussed our encounters with Mudpuppies and Tiger Salamanders in the "field" and in bait shops. During our conversation, my husband mentioned that when he was in high school he handled Mudpuppies while working at a local bait shop. He recalled selling Mudpuppies to South Dakota anglers for use as bait, probably for bass or catfish. Because Mudpuppies are very rare in South Dakota, he thought it was unlikely that this local bait shop was selling so-called "Mudpuppies." Most likely, these "Mudpuppies" were actually larval (or sometimes adult) Tiger Salamanders unknowingly named as Mudpuppies, which happens quite commonly in bait shops, among anglers, and even among biologists.
Mudpuppies (Necturus maculosus) and (larval) Tiger Salamanders (Ambystoma tigrinum) are the two types of salamanders found in South Dakota that can be easily confused and misidentified (Figs. 1 and 2). Mudpuppies are permanently aquatic salamanders therefore they have gills, and they reside in permanent bodies of water. Tiger Salamanders, on the other hand, are usually found in water or on land (in moist areas), depending on their life stage. More specifically, larval (or sometimes adult) Tiger Salamanders live in permanent bodies of water, and adult Tiger Salamanders reside in moist areas on land such as cellars or basements. At times, land-dwelling adult Tiger Salamanders can be quite noisy, sounding like an unusual cricket, due their teeth gritting abilities even though they are harmless. Both of South Dakota's salamanders are active at night, resting in/under protective cover (e.g., logs, vegetation, etc.) during the day.
Tiger Salamanders have two life stages: 1) larvae and 2) adult. In the larval stage (and on a rare occasion in the adult stage), Tiger Salamanders can be mistaken as Mudpuppies (Figs. 1 and 2). Sometimes Tiger Salamanders remain in the gilled, larval stage as a mature adult - called a waterdog or neotene. The way to determine the difference between larval (and/or neotene) Tiger Salamanders and Mudpuppies is by counting the number of toes on the hind feet. Larval Tiger Salamanders have five toes on the hind feet (Fig. 3), while Mudpuppies have four. Oftentimes, the fifth toe (on the larval [and/or neotene] Tiger Salamander) is difficult to see, so flattening the toes on a sturdy surface allows the number toes to be revealed, providing for the correct identification of the species.
With rare species, correct identification is important. Because Mudpuppies are only found in extreme northeastern South Dakota, the South Dakota Natural Heritage Program monitors them. Currently, our database lists only three records from 1924 to 1972, which are restricted to Day and Marshall counties. On the other hand, Tiger Salamanders (of which there are three subspecies in South Dakota) are commonly found throughout the state.
If you come across a permanent pool of water with salamanders and try to identify whether the pool is occupied with Mudpuppies or Tiger Salamanders, please remember to count the toes on the hind feet. Those with four toes are probably Mudpuppies, while those with five toes are potentially Tiger Salamanders. If a Mudpuppy is encountered in the "field", please contact one of the biologists with the South Dakota Natural Heritage Program to help us with our monitoring efforts. Your help and cooperation will further our understanding of the Mudpuppy population in northeastern South Dakota.