Freshwater Biodiversity and Aquatic Insect Diversification

Abstract

Inland waters cover less than one percent of Earth's surface, but harbor more than six percent of all insect species: nearly 100,000 species from 12 orders spend one or more life stages in freshwater. Little is known about how this remarkable diversity arose, although allopatric speciation and ecological adaptation are thought to be primary mechanisms. Freshwater habitats are exceptionally susceptible to environmental change, and exhibit marked ecological gradients. The amphibiotic lifestyles of aquatic insects result in complex contributions of extinction and allopatric and non-allopatric speciation in species diversification. In contrast to the lack of evolutionary studies, the ecology and habitat preferences of aquatic insects have been intensively studied, in part because of their widespread use as bio-indicators. The combination of phylogenetics with the extensive ecological data provides a promising avenue for future research, making aquatic insects highly suitable models for the study of ecological diversification.

Physiological responses to short-term thermal stress in mayfly (Neocloeon triangulifer) larvae in relation to upper thermal limits

“…Freshwater ecosystems support a disproportionate percentage of the earth's biodiversity (Dijkstra et al, 2014) and are among the most threatened by human activities and global climate change (Carpenter et al, 1992). Aquatic insects often dominate freshwater ecosystems in terms of biodiversity and ecological processes such as organic material processing and energy flow (Merritt et al, 2008;Wallace and Webster, 1996).…”

It's Not a Bug, It's a Feature: Functional Materials in Insects

“…Despite covering only 1% of the surface of the Earth, they are home to more than 10% of taxonomically identified species, 80% of which (up to 200 000) are estimated to be aquatic insects. [126] At least fourteen orders of insects contain aquatic species, and five of those orders consist mostly or entirely of aquatic insects. [127] Insects have developed a variety of physiological systems to survive and thrive in water, including systems optimized for feeding, for respiration (discussed in Section 4.2), osmoregulation, and locomotion.…”

“…[132] Many of the best-known aquatic insects come from the true bugs (order Hemiptera), which includes water striders, water boatmen, backswimmers, and shore bugs. [126] Legs of insects in this order are well adapted to movement through water or on its surface. Gerromorphan bugs (water striders, shore bugs) have hairs on their legs and bodies that increase surface area and create trough-shaped depressions on the surface of water.…”

Natural history: Restore our sense of species

“…Species make each place special and thus worth fighting for. Life is like water, a branching river system literally a genealogy: with a unique history in every separate stream, one human action can erase an irreplaceable ecosystem 4 . Although a hydroelectric dam might seem a sapient energy solution, it can mean ecocide to a 'specient' mind -one with species sense.…”