|Lesser water boatman
Micronecta scholtzi, also known as the lesser water boatman, is a species of water boatman in the family Corixidae in the order Hemiptera. They are some 2 mm long and are common in freshwater ponds and lakes across Europe, preferring stagnant to moving water. It is one of some 45 species of Hemiptera used to assess and monitor the health of freshwater bodies.  The genus Micronecta is represented by five species, of which four are to be found only in permanent fresh water lakes. 
- Micronecta scholtzi (Fieber, 1860)
- M. minutissima (Linnaeus, 1758)
- M. griseola Géza Horváth 1899
- M. poweri (Douglas & Scott 1869)
M. scholtzi is easily differentiated from other species in this genus by the twisted left paramere of the male genitalia, (see traumatic insemination) the short pronotum and a distinctive dark pattern on the head. Little is known of its habits and habitat, but it is thought to flourish in the shallows of ponds or lake shores. 
A team of biologists and sound engineers from France and Scotland have recorded M. scholtzi producing sound up to 99.2 decibels, a volume comparable to a passing freight train. The noise was so unexpectedly loud that the engineers checked the calibration of their instruments. The male of this species produces its underwater courtship song by stridulating a ridge on its penis across corrugations on its abdomen, the area involved measuring only 50 micrometres across, or about the thickness of a human hair. Almost all volume is lost when sound moves from water to air, but even so remains audible to humans walking along the pond shore. For its size this species is considered the loudest of all animals. Despite knowing the mechanism of its sound production, researchers are still mystified by the volume produced and feel that once the process is understood, it could open up a useful avenue in ultrasonics.
- WiredUK (2 July 2011). "Bug’s Penis Makes Loudest Animal Sound". Wired Science. Wired.com, Condé Nast Digital. Retrieved 2 July 2011.
- Tree of Life Web Project. 2005
- Hufnagel, L.; Bakonyi, G.; Vásárhelyi, T. (1999). Environmental Monitoring and Assessment 58 (3): 305–316. doi:10.1023/A:1006047130545.
- Alicja Kurzatkowska. "Preference of Micronectidae (Heteroptera: Corixidae) for Low Trophism Lakes: Data from Mazurian Lake District (Northeastern Poland)". J. Ent. Res. Soc. 5 (1): 1–12. ISSN 1302-0250.
- Raoul GEREND (2006). "Micronecta scholtzi (Fieber, 1860) new to Luxembourg. With new records of three other rare aquatic heteropteran species (Insecta, Heteroptera)". Bull. Soc. Nat. Luxemb. 106: 63–65.
- Sueur, Jérôme; Mackie, David and Windmill, James F. C. (2011). "So Small, So Loud: Extremely High Sound Pressure Level from a Pygmy Aquatic Insect (Corixidae, Micronectinae)". PloS one 6 (6): e21089. doi:10.1371/journal.pone.0021089. PMC 3115974. PMID 21698252.
- Weise, Elizabeth (30 June 2011). "Loud bugs example of "runaway sexual selection"". USA Today. Archived from the original on 23 January 2014.
- Davies, Ella. (2011-06-30) 'Singing penis' sets noise record for water insect. BBC. Retrieved on 2011-07-08.