Necturus maculosus - Invasive Species

Distinguishing Characteristics

Photo: Trevor Persons

  • Very large, approximately 8 to 12 inches in length
  • Fully aquatic, with large, permanent, dark red bushy external gills
  • Brownish color overall with black spots or blotches
  • Flat head, small eyes, powerful flattened tail

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Status and Distribution in Maine

  • Uncommon
  • Exotic (non-native)
  • Central region

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  • Fully aquatic, uses lakes, marshes, drainage ditches, and streams
  • In Maine, only known from lakes and large ponds

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  • Eats insects and crayfish, sometimes also fish and fish eggs

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Seasonal Changes

  • Active year-round; sometimes caught by people ice-fishing

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Natural History Notes

  • Accidentally introduced into Great Pond (Belgrade Lakes) around 1940; may have spread to other sites from use as fishing bait
  • Mates and lays eggs in spring; eggs attached to underside of rocks or logs on lake bottom

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Share Your Sighting

There is much still to learn about the distribution and ecology of Maine’s herpetofauna, and we encourage members of the public to share their photo-documented observations as part of the Maine Amphibian & Reptile Atlas Project (MARAP).

To see if a township still needs documentation of a species, consult this distribution map (PDF). If a township lacks a photo or specimen record, we want your observation!

There are two ways to share your observations:

Submit your reptile or amphibian observation online

No service? No problem. Click here to download the survey to your device while connected, then take offline to collect observations from anywhere. Tip: The survey works best on Google Chrome and Safari.

Or upload sightings to the iNaturalist citizen science project through their website at or mobile app.

  1. When submitting an observation through iNaturalist add a description of the location (and other noteworthy information) to the “notes” field. This serves as a check on the locations automatically generated by smartphone cameras, which may be imprecise if cell service or GPS coverage is weak.

Thank you for doing your part to help conserve Maine’s reptiles and amphibians.