- The Dytiscidae is the largest family of aquatic beetles.
- They have streamlined bodies, are slightly convex, and range in size from 1.0 to 40.0 mm.
- Color is variable, ranging from black, greenish in
a few species, to brown and reddish-brown. Some species have stripes or variegated markings on the elytra.
- The antennae are filiform.
- The hind
legs are oar-like, fringed with long setae, and stroke in unison when the beetle swims.
- Dytiscids are dependent on atmospheric oxygen but
may obtain oxygen from air bubbles in an “air space” under the elytra or from submerged vegetation.
- Adults are often seen popping to the surface
to renew their air supply and then diving quickly.
- When at rest they cling to vegetation or debris with the middle pair of legs and
may stay submerged for considerable periods of time.
Text by Charles Staines. |
Acilius fraternus (Harris)
Photo by Charles Staines. |
REFERENCES
Carlton, C. E. 2006. Louisiana State
Arthropod Museum.
Integrated Taxonomic Information System. 2007. On-line database, http://www.itis.gov.
Maddison, D. R. and K. S. Schulz (eds.) 1996-2006. The Tree of Life Web Project. Internet address: http://tolweb.org.
Myers, P., R. Espinosa, C. S. Parr, T. Jones, G. S. Hammond, and T. A. Dewey. 2006. The Animal
Diversity Web (online). Accessed 2007 at http://animaldiversity.org.
Staines, C. L. 2006. Edgewater, Maryland 21037.
