Diving insects

Diving Insects live some portion of their life cycle in the water. They feed in the same ways as other Insects. But diving insects, such as predaceous diving beetles, can hunt for food where land-living insects cannot compete. One problem that aquatic insects must overcome is how to get oxygen while they are under water.

All animals require a source of oxygen to live. Insects draw air into their bodies through spiracles, holes found along the sides of the abdomen. These spiracles are connected to tracheal tubes where oxygen can be absorbed. Some insects have densely packed hairs (setae) around the spiracles that allow air to remain near, while keeping water away from, the body. Aquatic insects have become adapted to their environment with the specialization of these structures.

• Aquatic adaptations
  1. Breath from bubble
  2. Breath using plastron
  3. extract oxygen using a “gill”
  4. storage of oxygen in hemoglobin molecules

References

• Drees, B.M. and Jackman, John, (1999), “Diving Beetle” in Field Guide to Texas Insects. Gulf Publishing Company, Houston, Texas. (see http://insects.tamu.edu/fieldguide/bimg133.html)

• Stanley, D. and Bedick, J. (1997). Respiration in aquatic insects. Retrieved Dec 27, 2003 from http://entomology.unl.edu/ent801/aqresp.html

• Hutchinson, Robert (1998). Adaptations seen in insects for living in or on water. Retrieved Dec 27, 2003 from http://www.roberth.u-net.com/waterinsect.htm

External Links

Insect stages - "Some larvae, nymphs and adult insects that live in freshwater." A UK-based web site with microscopic photos of various insects and other microorganisms as well as biological information.

---

(Text below contained in original page prior to rewriting)

Using bubble respiration:

• Insects pick bubble of air when going down.
• As they move down they use oxygen, therefore reducing partial pressure of oxygen
• Since water have more partial pressure of oxygen, oxygen from the water ill diffuse into the bubble.
• As partial pressure of nitrogen diffuses out of the bubble, it will pop

Using Plastron respiration

• Specialise insects have hydrofuse hair (10^6/mm^2)
• The hairs form bubble
• The bubbles are permanent, very small.
• The hairs are so close that water will not penetrate in the hair space
• The bubble is fixed in size
• As insects dive, partial pressure of oxygen outside will diffuse into the bubble.
• No nitrogen diffuse out so the bubble stay forever
• Theoretically, the insects can stay under water forever.