Behavior diversity in Odonata larvae is increased by water turbidity

Abstract

Aquatic insects’ behavior changes due to physiological constraints, trophic interactions, habitat selection, and biotic interactions. Addressing these topics can help to potentiate our understanding of ecosystem services and community structure. Here, the larval behavior of seven Odonata species was studied in the laboratory to evaluate variations in frequency associated with sex and three types of water: drinking water, dechlorinated tap water, and water from the collection habitat. Larvae were maintained into containers at ambient temperature, 12h light, and food ad libitum. Larval behavior included motionless, swimming, feeding, body movements, walking, grooming, changes in the body orientation, perching, molting, suspending, and sitting and waiting to capture prey. Larvae showed the highest number of behaviors in higher turbidity water (Habitat Water treatment). Males and females showed similar frequency in behaviors. The more active were of the Sympetrum gilvumand Rhionaeschna cornigera species. Species showed higher frequencies in behaviors such as resting, eating, prey capture (Anisoptera), perching and walking (Zygoptera). The frequency of larval behaviors in higher turbidity is modulated by the capability to obtain food and simultaneously, avoid predators. Larvae show higher diversity of behaviors in increased turbidity because darker habitats could be more secure. Our study calls attention to the importance of addressing the effect of abiotic conditions on behaviors of aquatic insects, and how it can influence their ecological fitness. Finally, although we have achieved crucial advancements on molecular tools and sophisticated statistical routines, the basic information about behaviors facets it is still a need in ecological studies.