Aquatic nymph stage of Damselfly insect.
Close view of head and thorax showing face mask, mouth parts and embryonic wing stubs.
England, UK
Family Coenagrionidae.
The aquatic stage of a damselfly’s life cycle is the larval phase, which occurs in freshwater habitats such as ponds, lakes, streams, and rivers. Damselflies undergo incomplete metamorphosis, meaning they have three life stages: egg, nymph (larva), and adult. The aquatic stage, or nymphal stage, is a crucial part of their development and plays a significant role in their ecology. Here are some key points about the aquatic stage of a damselfly:
Damselfly nymphs are aquatic organisms that inhabit a variety of freshwater habitats, ranging from still ponds and marshes to flowing streams and rivers. They are often found among submerged vegetation, debris, or sediment, where they can hide from predators and hunt for prey. They have elongated bodies with six jointed legs, large eyes, and powerful jaws adapted for hunting. They are typically dorsoventrally flattened, allowing them to move efficiently through the water. Their abdomen is equipped with gills or rectal tracheal gills, which they use to extract oxygen from the water.
These aniamals are carnivorous predators, feeding on a variety of small aquatic organisms such as mosquito larvae, mayfly nymphs, small crustaceans, and even tadpoles. They use their sharp mandibles to capture and consume prey, often ambushing them from hidden positions among vegetation or debris.
They undergo several instars, or stages of growth, during their aquatic phase. As they grow, they molt their exoskeletons, shedding their old skin and emerging with a larger one. The number of instars varies among species and can depend on factors such as temperature, food availability, and habitat quality.
Primarily nocturnal feeders, although they may also be active during the day. They use a combination of swimming and crawling movements to navigate their aquatic environment, often employing a sit-and-wait hunting strategy to ambush passing prey.
Damselfly nymphs are vulnerable to predation by a variety of aquatic predators, including fish, amphibians, larger invertebrates, and even other damselfly nymphs. To defend themselves, they may use camouflage, rapid movements, or chemical defenses to deter potential predators.
After completing their development as nymphs, damselflies undergo metamorphosis and emerge from the water as winged adults. This emergence typically occurs during the warmer months of the year and may be synchronized with environmental cues such as temperature, day length, or humidity.
Overall, the aquatic stage of a damselfly’s life cycle is a critical period of growth and development, during which nymphs play important roles in freshwater ecosystems as predators and prey. Their adaptations to aquatic habitats and behaviors contribute to the ecological diversity and functioning of freshwater environments.
