Mud Puppies
The typical mudpuppies, scientifically called Necturus maculosus, are any of the five species of salamander in the genus Necturus. Mudpuppies are commonly referred to as water dogs, a name derived from the mistaken belief that they can bark like dogs. Notably, the other four related species include; the dwarf mud puppy(Necturus punctatus), the Neuse River mud puppy (Necturus lewisi), the Alabama mud puppy (Necturus alabamensis) and Gulf coast mud puppy (Necturus beyeri). Mudpuppies commonly inhabit rivers, lakes, and swamps, especially in Eastern North America (Britannica, par.1). They can also be kept as pets in aquariums and ponds. However, little information is known about mudpuppies, and this has often led to their death, especially by people who keep them as pets. This study seeks to provide information about their characteristics, habitat association, and diet in an ecosystem, hence reducing the risk of death due to poor handling, habitat pollution, or negligence.
Mudpuppies are increasingly rare animals to capture in the wild. These giant salamanders sharing the family Proteidae with four other species range from approximately eight to thirteen inches. The most massive mudpuppies can, however, grow as big as sixteen inches in length. However, the average length of mudpuppies is 11 inches. Mudpuppies make squeaky vocalizations that often sounds like a dog’s bark. This noise makes them referred to as water dogs. Unlike other amphibia in the same species, mudpuppies can easily be distinguished from their red, bushy external gills, which they grow as larva and maintain throughout the rest of their life. (National Geographic, par 3)
Externally, mudpuppies appear in gray or brownish-gray color and their trunks are usually covered in blue and black spots. Mudpuppies have a uniquely broad tail while their head is often flat. Mudpuppies have stubby legs, and each of their feet contains four toes. Their legs are also short and moderately robust. Also, the size of their eyes is relatively small when compared to the size of the head. Their underside is light gray. Just like other salamanders, female mudpuppies lay eggs in large clutches, which they guard till hatching. Young mudpuppies can be found in a range of colors. Some are black, while others are orange. Juvenile mudpuppies have longitudinal yellow stripes. They generally grow to between 20cm and 40cm.
In the United States, mudpuppies are found primarily in the Eastern parts of the country. Their range extends from South Eastern Manitoba and Southern Quebec to Eastern Kansas and the Eastern Mississippi, Alabama, and Georgia. In Minnesota, the ‘water dogs’ inhabit a wide range across several rivers. These rivers include; St Croix, the Mississippi River, the Minnesota River, and the Red River. Mudpuppies are also found in the Hudson River, although some studies posit that they may have been introduced. They are primarily aquatic animals, spending all stages of their life in the waters. They occupy bottoms of rivers, lakes, and streams. Often, they prefer rivers and streams with rocks and gravel-like substances. Such rocky and gravelly habitats serve as suitable ‘homes’ where mudpuppies reside. When they lay eggs, mudpuppies often hide them under these rocky surfaces and crevices away from predators. Mudpuppies mate during fall, where the males’ deposit sperm-filled capsules called spermatophores on the substrate. The female mudpuppies take these spermatophores into their cloaca using the cloacal lips. The eggs are usually up to a hundred eggs and are deposited during Spring. They are subsequently attached to the underside of logs, rocks, and other underwater structures. The female mudpuppies protect them from the prey until they hatch. The population density of mudpuppies is, therefore, entirely dependent on the suitability of breeding sites and hiding places such as rocks, logs, undercut banks, and slabs.
Mudpuppies can also be kept as pets. However, care must be observed to ensure adherence to particular environmental conditions. For instance, mudpuppies prefer the bottom of rivers and lakes when in their natural habitat. Also, they are most active during the night, away from sunlight (Dodd 26). Therefore, those who keep them as pets in aquariums should ensure enough floating leaves to protect them from direct sun rays. Mudpuppies are sensitive to light and can, therefore, be easily stressed when tamed in brightly lit aquariums. Aquariums should also be equipped with artificial plants and floating leaves to substitute for the log crevices and rocky hide-outs in the natural environment.
Also, mudpuppies being primarily aquatic, are best kept in large aquariums with plenty of natural space and good water filters. Water quality is of utmost significance to the healthy survival of mudpuppies. Just like other aquatic animals, their wastes are toxic. Thus, regular water changes are necessary to maintain a fresh and highly oxygenated environment. The bushy gills of mudpuppies are often bright red and conspicuous when in highly oxygenated waters. They, however, turn darker and shrunken when in lowly oxygenated water (DNR, par 3)
While under captive nurturing, mudpuppies can still reproduce. They become sexually active between four and six years and experience internal fertilization. The female mud puppy lays eggs in a cavity or under a rock, which mature in six to ten weeks. During this incubation period, the female mud puppy protects the eggs from predators until they hatch. When hatched, the larvae of mudpuppies are approximately 1 inch long. They can feed on blackworms and earthworms. Given the large size of mudpuppies, they cannot be confused with other salamanders. This original large size is also seen in larval mudpuppies, which are often at least twice the size of other salamander larvae. Most notable also is the larvae of mudpuppies are highly cannibalistic and should, therefore, be kept in large aquariums with a constant supply of food.
In the natural habitat, mudpuppies which can grow up to over twenty years, prefer clear water with little or no silt. They usually hide under stone debris, rocks or logs during the day. They are nocturnal and carnivorous, foraging all year-round. Mudpuppies feed on small aquatic animals such as crayfish, minnows, mollusks, goldfish, dragonfly larvae, hellgrammites, and eggs of other marine animals. The National Geographic also cites worms and snails as an alternative food for mudpuppies (NatGeo, 4).
According to a study by Michigan State University, there are commonly held beliefs about mudpuppies that are not true. The common misbeliefs are; mudpuppies are a type of fish, they are blind and poor hunters, they eat so many fish eggs that they decrease sport fish population, mudpuppies are overly in large numbers. They do not need protection like other species, and mudpuppies abandon their eggs once laid, anglers who hook mudpuppies should decapitate the line because they are poisonous. When thrown on the ice by anglers, mudpuppies revive in the springs when the ice melts. These misconceptions are one of the main reasons why mudpuppies and other aquatic amphibia are at risk of death and extinction. (MSU, par 1- 10)
To demystify these common misbeliefs, Bohling of Michigan State University Extension notes that; mudpuppies are amphibians, and although they have lungs, they primarily rely on their bushy red external gills for oxygen. Also, mudpuppies are not blind though their sight is limited, and they depended profoundly on scent to detect their prey. Furthermore, Bohling argues that mudpuppies’ leading food is crayfish, insect larvae, small fish, and snails. As such, there is no evidence postulating that mudpuppies negatively impact the population of fish. On the contrary, mudpuppies benefit the fish population by feeding on non-native aquatic species. Additionally, mudpuppies protect their eggs and guard their nests until the juvenile mudpuppies emerge and disperse. Also, the Michigan Department of Natural Resources regulates mud puppy harvesting between November and May, usually a high harvesting season. When anglers throw mudpuppies on ice, they suffocate and may freeze to death. And finally, although mudpuppies’ skins are moist and slimy, they are not poisonous.
According to National Geographic, mudpuppies are common throughout their range and have no special conservation status. However, factors of climate change, pollution, and loss of habitat are negatively impacting their existence and putting pressure on their natural population. For instance, the department of natural resources in Minnesota observes that damage to the community resulting from damming, siltation, dredging, and the introduction of TFM chemicals into waterways is a significant threat to mudpuppies and other aquatic species. Further, the Ontario Nature program notes that poor water quality in St. Lawrence River due to organochlorine pesticides is mostly to blame for limb deformities such as missing or extra toes and over 60% decline in mud puppy population along the river. (Ontarionature.org par 8, DNR, par 4).
Thus, mudpuppies, which can be found in five species of the genus Necturus, are primarily aquatic salamanders. They inhabit rivers, lakes, and streams but can also be kept as pets in aquariums. They can live up to twenty years or more in their natural habitat and can grow up to 16 inches. Mudpuppies mainly feed on crayfish, snails, insect larvae ad other miniature aquatic organisms. When kept as pets, they can be fed on earthworms, blackworms, shrimps, snails, and insect larvae. Their characteristic large size, flat head with red, bright gills, and steady feet with four toes make them distinct among other amphibia. Whether existing naturally in the wild or kept as pets in aquariums, water quality is paramount for their survival. Though not poisonous, mudpuppies just like other aquatic animals’ secret wastes that are toxic. Hence, water should be changed regularly while keeping the light levels low, sing floating leaves or artificial plants.
Work Cited
Dodd, C. Kenneth, and Kenneth C. Dodd. The amphibians of Great Smoky Mountains National Park. Univ. of Tennessee Press, 2004.
https://www.nationalgeographic.com/animals/amphibians/m/mudpuppy/. Accessed 15 May 2020.
https://www.dnr.state.mn.us/eco/mcbs/mudpuppy.html. Accessed 15 May 2020.
“Mudpuppy | Reptiles & Amphibians In Ontario | Ontario Nature.” Ontario Nature, 2020, https://ontarionature.org/programs/citizen-science/reptile-amphibian-atlas/mudpuppy/.
“Mud Puppy | Salamander.” Encyclopedia Britannica, 2020, https://www.britannica.com/animal/mud-puppy.
“The Misunderstood Mudpuppy.” MSU Extension, 2020, https://www.canr.msu.edu/news/the_misunderstood_mudpuppy_bohling15.