Species of the Month – Mudpuppies – September 2023


MudpuppiesNecturus maculosus

Mudpuppies get their name from the ‘barking’ noise they are rumored to make. Their captivating appearance lends them an almost otherworldly allure. Sporting a color palette that ranges from gray to rusty brown, embellished with distinct dark blue markings along their dorsal side, these creatures stand out. Notably, they possess vivid red external gills, allowing them to respire directly from the water. Their flattened heads aid in their environmental navigation, facilitating their concealment under rocks during daylight hours. With short yet robust legs, each adorned with four toes, and a broad tail, they efficiently traverse the depths of river basins and lakes. These salamanders can achieve impressive lengths ranging from 20 to 48 cm and may live for more than two decades. 

They are unquestionably a remarkable amphibian species, boasting numerous distinctive traits setting them apart from other amphibians. The mudpuppy, often referred to as an ‘eternal juvenile,’ maintains its unique identity because, unlike other salamander species, it never sheds its gills and remains submerged throughout its entire life. Renowned as early environmental indicators, these creatures possess sensitivities to water quality, with their skin and gills demanding ideal conditions for survival. Regrettably, their populations face threats from PCBs and organochlorine pesticides, with high concentrations detected in their eggs, leading to deformities such as missing or extra limbs during growth.


Mudpuppy, Photo credit: iNaturalist user cullen

Mudpuppies are primarily nocturnal, adding to the challenge of locating them. By day, they seek refuge beneath flat silt rocks in submerged caverns, often in calm, muddy waters. Come nightfall, they emerge from these sanctuaries to hunt a variety of prey, including worms, fish eggs, aquatic insects, crayfish, and even the invasive Round Goby. Their role in regulating the populations of smaller aquatic organisms contributes to ecological balance and the promotion of biodiversity in their habitats.

Males engage in intricate dances to court females, and upon selecting a suitable mate, females deposit their eggs in submerged crevices, which are subsequently fertilized by the male. Females attain sexual maturity at around 10 years of age, laying clutches of 30 to 90 eggs at a time. They diligently guard their eggs throughout the 1-2 month incubation period.

Misconceptions about mudpuppies have led to human mistreatment and, ultimately, their demise. Historically, some believed that placing a live mudpuppy on ice would enable it to survive winter and revive in spring to return to the water. In reality, mudpuppies will suffocate if left out of water for too long. There were also rumours of their supposed toxicity, resulting in misguided efforts to exterminate them. While mudpuppies do possess a mildly poisonous protective secretion, it poses no threat to humans.

At present, mudpuppies do not fall under the category of species of concern in Ontario. They have demonstrated resilience even in adverse conditions, playing a crucial role within the Lake Erie watersheds. Despite this, numerous aspects of this species remain shrouded in mystery, underscoring the significance of conducting additional research, particularly given their pivotal role as bio-indicators for our ecosystems. 

Victoria Quilitz – Stewardship and Outreach Technician, LPBLT 


Bohling, M. (2015, December 28). The misunderstood mudpuppy – MSU Extension. MSU College of Agriculture and Natural Resources. Retrieved September 25, 2023, from https://www.canr.msu.edu/news/the_misunderstood_mudpuppy_bohling15

McDaniel, T. V., Martin, P. A., Barrett, G. C., Hughes, K., Gendron, A. D., Shirose, L., & Bishop, C. A. (2009, June 9). Relative abundance, age structure, and body size in mudpuppy populations in southwestern Ontario. Journal of Great Lakes Research: Science Direct. 

Retrieved September 25, 2023, from https://www.sciencedirect.com/science/article/abs/pii/S0380133009000665

Ontario Nature. (n.d.). Mudpuppy. Ontario Nature. Retrieved September, 2023, from https://ontarionature.org/programs/community-science/reptile-amphibian-atlas/mudpuppy/

Sea Grant Michigan. (n.d.). Mudpuppy. Sea Grant Michigan. Retrieved September, 2023, from https://www.michiganseagrant.org/topics/ecosystems-and-habitats/native-species-and-biodiversity/mudpuppy/

Victoria Quilitz – Stewardship and Outreach Technician, LPBLT 

Jackie Ellefsen

Senior Development Manager