A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle.
In biology, a nymph is the immature form of some invertebrates, particularly insects, which undergoes gradual metamorphosis (hemimetabolism) before reaching its adult stage. Unlike a typical larva, a nymph's overall form already resembles that of the adult, except for a lack of wings. In addition, while a nymph moults, it never enters a pupal stage. Instead, the final moult results in an adult insect. Nymphs undergo multiple stages of development called instars.
Mayflies are aquatic insects belonging to the order Ephemeroptera. This order is part of an ancient group of insects termed the Palaeoptera, which also contains dragonflies and damselflies. Over 3,000 species of mayfly are known worldwide, grouped into over 400 genera in 42 families.
Aquatic insects or water insects live some portion of their life cycle in the water. They feed in the same ways as other insects. Some diving insects, such as predatory diving beetles, can hunt for food underwater where land-living insects cannot compete.
Hemimetabolism or hemimetaboly, also called incomplete metamorphosis and paurometabolism, is the mode of development of certain insects that includes three distinct stages: the egg, nymph, and the adult stage, or imago. These groups go through gradual changes; there is no pupal stage. The nymph often has a thin exoskeleton and resembles the adult stage but lacks wings and functional reproductive organs. The hemimetabolous insects differ from ametabolous taxa in that the one and only adult instar undergoes no further moulting.
Sea lice are copepods of the family Caligidae within the order Siphonostomatoida. They are marine ectoparasites that feed on the mucus, epidermal tissue, and blood of host fish. The roughly 559 species in 37 genera include around 162 Lepeophtheirus and 268 Caligus species.
The common river galaxias or Canterbury galaxias is a galaxiid fish of the genus Galaxias, found only in Canterbury, New Zealand.
Dry fly fishing is an angling technique in which the lure is an artificial fly which floats on the surface of the water and does not sink below it. Developed originally for trout fly fishing, it is sometimes regarded as the supreme fishing sport, owing to its difficulty in both manual dexterity and understanding of the fish in its environment.
Ephemerellidae are known as the spiny crawler mayflies. They are a family of the order Ephemeroptera. There are 8 genera consisting of a total 90 species. They are distributed throughout North America as well as the UK. Their habitat is lotic-erosional, they are found in all sizes of flowing streams on different types of substrates where there is reduced flow. They are even found on the shores of lakes and beaches where there is wave action present. They move by swimming and clinging, they are very well camouflaged. Most species have one generation per year. They are mostly collector-gatherers.
Ephemera danica, the green drake or green drake mayfly, is a species of mayfly in the genus Ephemera.
Palingenia longicauda is an aquatic insect in the order Ephemeroptera. It is known as the Tisa or Tisza mayfly after the European Tisza river where it is found and also as the long-tailed mayfly and giant mayfly since it is the largest mayfly species in Europe, measuring 12 cm (4.7 in) from head to tail.
Chloroperlidae are a family of stoneflies, commonly known as green stoneflies, with more than 200 species and 22 genera. They appear green to yellow in colour, and are popularly used among fisherman as bait for trout fishing. Green stoneflies live in the benthic zone of the cold streams and rivers of five continents and four zoogeographical regions, emerging from the water to live in the riparian zone as adults. They are sensitive to pollutants, making them an indicator species for determining the quality of water bodies. Chloroperlidae are hemimetabolous, having no pupal stage, but instead hatch from eggs as nymphs and mature directly into adults. They are omnivorous, feeding on small organisms and plant particles, and become more carnivorous as they mature. The classification of Chloroperlidae is contested, with some believing that they should be considered as members of different orders, as opposed to the order Plecoptera that they currently belong to.
Siphlonurus lacustris is a species of mayfly belonging to the family Siphlonuridae. This species is present in most of Europe.
Coxoplectoptera or "chimera wings" is an extinct order of winged insects containing one family, Mickoleitiidae. Coxoplectopterans are closely related to the mayflies.
Dolania is a monotypic genus of mayfly in the family Behningiidae containing the single species Dolania americana. It is found in the southeastern United States, as far south as Florida, and is generally uncommon. The adult insects emerge before dawn in early summer, mate and die within the space of about thirty minutes. The female deposits her eggs in the water and dies within five minutes of emergence, believed to be the shortest adult lifespan of any insect.
Ephemera vulgata is a species of mayfly in the genus Ephemera. This mayfly breeds in stationary water in slow rivers and in ponds, the nymphs developing in the mud.
Hexagenia limbata, the giant mayfly, is a species of mayfly in the family Ephemeridae. It is native to North America where it is distributed widely near lakes and slow-moving rivers. The larvae, known as nymphs, are aquatic and burrow in mud and the adult insects have brief lives. They are often referred to as fish flies around the Great Lakes as they tend to cause the areas around water to smell like rotten fish.
Hexagenia bilineata is a species of mayfly in the family Ephemeridae. It is native to North America where it is found in the Upper Mississippi Valley. Sometimes adults of this mayfly are so abundant as to cause a nuisance because of their enormous numbers. The larvae are aquatic and burrow in mud and the adult insects have brief lives.
Cystidicoloides tenuissima is a species of nematodes in the order Spirurida and family Cystidicolidae. It is a parasite of salmonid fish in the northern hemisphere and has mayflies as the alternate host.
Invertebrate drift is the downstream transport of invertebrate organisms in lotic freshwater systems such as rivers and streams. The term lotic comes from the Latin word lotus, meaning washing, and is used to describe moving freshwater systems. This is in contrast with lentic coming from the Latin word lentus, meaning slow or motionless that typically describe still or standing waters such as lakes, ponds, and swamps.
