Heptageniidae
Encyclopedia
Heptageniidae is a family of mayflies
with over 500 described species mainly distributed in the Holarctic
, Oriental, and Afrotropical regions, and also present in the Central American Tropics and extreme northern South America. These are generally rather small mayflies with two long tails. The wings are usually clear with prominent venation although species with variegated wings are known. As in most mayflies, the males have large compound eyes but not divided into upper and lower parts (the group is sometimes referred to as flat-headed mayflies).
Heptageniids breed mainly in fast-flowing stream
s (an alternative common name is stream mayflies) but some species will use still waters. The nymphs
have a flattened shape and are usually dark in colour. They use a wide range of food sources with herbivorous
, scavenging
and predatory
species known.
Mayfly
Mayflies are insects which belong to the Order Ephemeroptera . They have been placed into an ancient group of insects termed the Palaeoptera, which also contains dragonflies and damselflies...
with over 500 described species mainly distributed in the Holarctic
Holarctic
The Holarctic ecozone refers to the habitats found throughout the northern continents of the world as a whole. This region is divided into the Palearctic, consisting of Northern Africa and all of Eurasia, with the exception of Southeast Asia and the Indian subcontinent, and the Nearctic,...
, Oriental, and Afrotropical regions, and also present in the Central American Tropics and extreme northern South America. These are generally rather small mayflies with two long tails. The wings are usually clear with prominent venation although species with variegated wings are known. As in most mayflies, the males have large compound eyes but not divided into upper and lower parts (the group is sometimes referred to as flat-headed mayflies).
Heptageniids breed mainly in fast-flowing stream
Stream
A stream is a body of water with a current, confined within a bed and stream banks. Depending on its locale or certain characteristics, a stream may be referred to as a branch, brook, beck, burn, creek, "crick", gill , kill, lick, rill, river, syke, bayou, rivulet, streamage, wash, run or...
s (an alternative common name is stream mayflies) but some species will use still waters. The nymphs
Nymph (biology)
In biology, a nymph is the immature form of some invertebrates, particularly insects, which undergoes gradual metamorphosis before reaching its adult stage. Unlike a typical larva, a nymph's overall form already resembles that of the adult. In addition, while a nymph moults it never enters a...
have a flattened shape and are usually dark in colour. They use a wide range of food sources with herbivorous
Herbivore
Herbivores are organisms that are anatomically and physiologically adapted to eat plant-based foods. Herbivory is a form of consumption in which an organism principally eats autotrophs such as plants, algae and photosynthesizing bacteria. More generally, organisms that feed on autotrophs in...
, scavenging
Scavenger
Scavenging is both a carnivorous and herbivorous feeding behavior in which individual scavengers search out dead animal and dead plant biomass on which to feed. The eating of carrion from the same species is referred to as cannibalism. Scavengers play an important role in the ecosystem by...
and predatory
Predation
In ecology, predation describes a biological interaction where a predator feeds on its prey . Predators may or may not kill their prey prior to feeding on them, but the act of predation always results in the death of its prey and the eventual absorption of the prey's tissue through consumption...
species known.