MACROINVERTEBRATES

MACROINVERTEBRATES Blake Newton UK Entomology

Midge Larvae -not always red, especially after preservation in alcohol -four small legs, two near the head, two near the back -distinct head, head usually dark in color -no legs or gills along the main part of the abdomen Easily confused with: aquatic worms: these will not have a distinct head or any legs Caddisfly larvae: it is sometimes hard to see all of the legs on these, but they have six legs on the front. The two hooks on the rear are not true legs

Aquatic Beetle Larvae -lots of species, lots of variety -some have lateral gills along the side, some don’t -typically, wide head with large mandibles (most of these are predators) -six legs and often two filaments on the end of the abdomen Easily confused with: Stoneflies: typically flatter, with longer legs Dobsonfly larvae: typically much larger than aquatic beetle larva

More Aquatic Beetle Larvae Riffle Beetle larvae (note tiny hooks on the end) Water Beetle larvae -but this one has it’s own slot on the assessment sheet More-typical riffle beetle larva

Caddisfly Larvae -not always encased in rocks or twigs -six legs, plus two leg-like “hooks” at the end Easily confused with: midges: these are usually smaller, and have 4 legs instead of 6 Beetle larvae: the filaments at the end of beetle larva USUALLY will not have hooks

Aquatic Worms -always legless, no distinct “head” -many colors and sizes -some look just like earthworms -on most assessment sheets, this category includes horsehair worms and “flatworms” but not leeches. Easily confused with: midges: midges have four legs, but the legs can be hard to see Leeches: leeches ARE technically worms, but they have suction cups on both ends of the body (hard to tell when the creature is dead, though!) Cranefly larvae: usually thicker

Non-point Source Pollution and Macroinvertebrates Impacts on Macros:

Non-point Source Pollution and Macroinvertebrates Impacts on Macros: -sediment -nutrients -temperature -oxygen

Low Impact Development and Macroinvertebrates -primary role of Macros in LID = sampling -how can LID impact macroinvertebrate populations?