Plants and Animals
Ophiogomphus anomalus Extra-striped snaketail
Adults average 1.7 in long. The species has a bright green thorax with side stripes which form a conspicuous N-shape just above the leg bases. Face and occiput are green. There are heavy, black crosslines on face with the upward-arching lower line interrupted. The female snaketail has a pair of small, upright, black "horns" in the center of the occiput. Abdomen is mostly black with long, yellow top spots; spots on 7 and 8 are shorter. Segments 9 and 10 each show a round spot. Sides of segments 7 to 10 with variously shaped yellow spots. Legs black.
Status and Rank
State Status: SC - Special Concern (rare or uncertain; not legally protected)
Global Rank: G4 - Apparently secure
State Rank: S2S3 - Rank is uncertain, ranging from imperiled to vulnerable
|County||Number of Occurrences||Year Last Observed|
Information is summarized from MNFI's database of rare species and community occurrences. Data may not reflect true distribution since much of the state has not been thoroughly surveyed.
Lotic - erosional depositional of small cold streams. Medium to large moderate-gradient rivers; free flowing with very high water quality, larvae burrow in bottom. Clear rapid rivers. Adults spend much of their time aloft and rarely perches low or on rocks. Adults appear in river/stream/riparian/floodplain corridor.
Specific Habitat Needs
Sand, gravel, cobble needed in: Headwater stream (1st-2nd order), run; Mainstem stream (3rd-4th order), run.
Natural Community Types
- Headwater stream (1st-2nd order), riffle
- Headwater stream (1st-2nd order), run
- Mainstem stream (3rd-4th order), run
For each species, lists of natural communities were derived from review of the nearly 6,500 element occurrences in the MNFI database, in addition to herbarium label data for some taxa. In most cases, at least one specimen record exists for each listed natural community. For certain taxa, especially poorly collected or extirpated species of prairie and savanna habitats, natural community lists were derived from inferences from collection sites and habitat preferences in immediately adjacent states (particularly Indiana and Illinois). Natural communities are not listed for those species documented only from altered or ruderal habitats in Michigan, especially for taxa that occur in a variety of habitats outside of the state.
Natural communities are not listed in order of frequency of occurrence, but are rather derived from the full set of natural communities, organized by Ecological Group. In many cases, the general habitat descriptions should provide greater clarity and direction to the surveyor. In future versions of the Rare Species Explorer, we hope to incorporate natural community fidelity ranks for each taxon.
Species threatened by habitat degradation, low water quality, siltation, non-point source pollution (agricultural). Threats also are altered sediment loads, dams, dredging, channelization, pesticides/herbicides, urban, municipal and industrial pollution.
An exuvia survey consists of searching the banks and protruding rocks of rapid streams for the cast skin of dragonfly larvae. Adults apparently spend most of their time in treetops far from water, but can be found perched on bushes near the tree line bordering riffles. It rarely perches on rocks, and is unwary.
Survey Period: From first week of January to fourth week of December
Time of Day: Daytime
Water Level: Low Water Levels
Water Turbidity: Low Turbidity
Survey Method Comment: Larvae
Survey Period: From fourth week of May to third week of June
Time of Day: Daytime
Survey Method Comment: Adults/Larva
Visual, aerial net
Survey Period: From fourth week of May to first week of August
Time of Day: Daytime
Survey Method Comment: Adults
- Foster, S.E. and D.A. Soluk. 2004. Evaluating exuvia collection as a management tool for the federally endangered Hine's emerald dragonfly, Somatochlora hineana Williamson (Odonata: Cordulidae). Biological Conservation 118: 15-20.
- Martin, J.E.H. 1977. The Insects and Arachnids of Canada (Part 1): Collecting, preparing, and preserving insects, mites, and spiders. Publication 1643. Biosystematics Research Institute, Ottawa.
- Dunkle, S.W. 2000. Dragonflies through Binoculars. Oxford University Press, Oxford. 266pp.
- Mead, K. 2003. Dragonflies of the North Woods. Kollath-Stensaas Publishing, Duluth. 203pp.
- Merritt, R.W. and K.W. Cummins. 1996. An introduction to the aquatic insects of North America, 3rd ed. Kendall/Hunt Publishing Company, Dubuque. 862pp.
- NatureServe. 2005. NatureServe Explorer: An online encyclopedia of life [web application]. Version 4.5. NatureServe, Arlington, Virginia. Available http://www.natureserve.org/explorer.
- Walker, E. M. 1958. The Odonata of Canada and Alaska, Vol. 2: The Anisoptera- Four Families. University of Toronto Press, Toronto. 318pp.