Featured Creature - Mudpuppy Necturus maculosus

Featured Creature - Mudpuppy Necturus maculosus.

These are our largest Canadian salamanders, and entirely aquatic. The Canadian range extends through southern Quebec, Ontario and Manitoba. Mudpuppies retain the gills and smooth skin of larvae as an adults, and can easily go undetected because of their secretive habits and nocturnal activity. They are found in rivers, lakes and other permanent bodies of water throughout east-central North America. In deep muddy waters they are mysterious and seen only occasionally at the end of a fisherman's line.

The rocky clear-water creek from the dam at Oxford Mills to the Prescott Street Bridge in Kemptville is the best place to find Mudpuppies in eastern Ontario. Unionid mussels, many fish, and Mudpuppies are abundant here, and in the summer the golden-brown water skimmed over the top of the dam can reach 32 C. In May each female Mudpuppy deposits a mat of 50-150 soft globes of jelly, each holding a pale egg like a small yellow pea, on the underside of a flat rock. In July the largest stones in midstream shelter the jelly remnants of egg envelopes on the ceilings of nest sites, helpless newly hatched larvae with pale yellow-green yolk sacs on the floors, and the foot-long lurking mothers, still attending their broods. In the shallows there are striped, black & yellow, yearling larvae, and males and smaller adults under other stones. The Mudpuppies are slow and cautious, though they can leave as fast as a fish when they want to.

Herpetologists have recently realized that Mudpuppies and other, southern, species of Necturus are active, and feed actively, all winter, because they can be caught in minnowtraps baited with fish in the winter but not in the summer. This winter the EOBM and Maries Treats & Treasures sponsored weekly night-time counts of Mudpuppies in the flat limestone area below the old Oxford Mills dam. We saw 10-30 Mudpuppies on nights with low water levels, walking up through the current, prowling the bottom, or feeding on fish and Crayfish (Orconectes virilis). The current is about 2.5 m/sec, so we estimated their sprint swimming speed in freezing water at 2 m/sec, since they can just barely stay in place in this current. When the level of the creek is raised by melting snow, the Mudpuppies cannot maintain their place in the main current, and we only find a few in a deep eddy.

Mudpuppies -- "fish with legs and ears" -- have long been persecuted and destroyed. Because they looked strange and ate some fish, they were wrongly accused of being poisonous and harming sport fisheries. Ice-fishers often leave incidentally captured Mudpuppies to die on the ice. Many are also killed by the larval lampricide, TFM, with which tributaries to the Great Lakes are doused to control the Sea Lamprey (Petromyzon marinus).

Leg and digit deformities that are likely due to persistent pollutants are frequent in lower St Lawrence populations of Mudpuppies that are being studied by Andreé Gendron. More than 55% of Mudpuppies from Akwesasne had limb deformites, and young individuals were infrequent there: 50% of females were older than 21 years. In the only big sample examined from Kemptville Creek, in July 1987, 3 of 54 (6%) had limb deformities, 2 with missing digits and one missing a leg. The Canadian Wildlife Service is sampling Mudpuppies to assess the health of the St Lawrence River and the Great Lakes System, so it is one of the few amphibian species in the surveillance programmes that monitor the impact of contamination in this large ecosystem.

We know Mudpuppies are in the Ottawa, St Lawrence, South Nation, Raisin, and Mississippi rivers, and in several lakes on the Shield, and there are few or old records for the Rideau and Castor rivers, but we haven't observed winter activity anyplace except Oxford Mills. Next winter we hope to expand our survey to many other dams and weirs, in order to get a better idea of where Mudpuppies are abundant. It's your only chance to see an active Amphibian when the air temperature is -26 C!