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Macroinvertebrate Sensitivity

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Macroinvertebrate Sensitivity Macroinvertebrate sensitivity index Macroinvertebrates are used to monitor the health of rivers and wetlands because of their differing sensitivity to changes in water quality. They are good indicators of river and wetland health because they are abundant, widely distributed and complete part, if not all of their life cycle within aquatic habitats. The macroinvertebrate species presence or absence in a Caddis flies sample will give an indication of the health of the Order: Trichoptera river or wetland, generally, a greater diversity with numerous representatives of Description: May be free swimming or sensitive species indicates case dwelling retreat dwellers. Larvae better health. Stoneflies spin silk and attach debris to form cocoon like structures for protection. Order: Plecoptera The larvae dominate the life cycle. The Description: Two thin tails and adults are nocturnal and are short lived. gills extending from the abdomen. Habitat: The larvae live in all types of Very SensitiveMayflies bugs Habitat: Stoneflies prefer inland water environments. freshwater habitats. Adults can be Order: Ephemeroptera Maximum size: Up to 20mm found resting during the day on tree Description: Three long tails and trunks alongside streams. Larvae gills along the sides of their bodies. are found on stones and plants in Habitat: Commonly found under fast moving waters. rocks or among plants and leaf litter Maximum size: 7–40mm in standing water and fast flowing streams. Adult mayflies are found near freshwater environments. Maximum size: Up to 15mm Water mite Order: Acarina Description: Adults have a wide range of body shapes, typically Riffle beetle and larva round bodies with eight legs. Parasitic as larvae. Order: Coleoptera Habitat: Prefers standing or slow Family: Elmidae moving waters. Description: Both adults and larvae are Maximum size: Up to 5mm Sensitive bugsAlderfly larva aquatic. Adult beetles are small and Order: Megaloptera usually black. Larvae are brown. Description: Fleshy bodies with Habitat: Prefers fast-flowing water. a hard shelled head. Only the Maximum size: Up to 6mm larvae are aquatic. Habitat: Commonly found under rocks in a variety of flow conditions. Maximum size: Up to 50mm Water strider Order: Hemiptera Family: Gerridae Description: 15 of the Hemipteran Dragonfly families have aquatic life stages. Occur Order: Odonata in winged and wingless forms with long Suborder: Anisoptera pairs of middle and hind legs. Tolerant bugs Description: Extendible hinged mouth Habitat: Surface dwellers of still or parts and internal gills. slow-flowing waters. Habitat: Found amongst the leaf litter Maximum size: 8–12mm Freshwater mussel and on rocks of most aquatic habitats.. Phylum: Mollusca Maximum size: 12–50mm Class: Bivalvia Damselfly Description: Range in size from the Order: Odonata large mussel to the small pea shell Suborder: Zygoptera mussel. Two separate shells hinged Description: Larvae have three gill together enclosing a soft bodied animal. structures extending from the tail.. Habitat: Lives burrowed into sediment. Habitat: Found on rocks, vegetation and Maximum size: Up to 150mm leaf litter of most aquatic habitats. Maximum size: 16–33mm Freshwater shrimp Order: Decapoda Family: Atyidae Freshwater yabby/crayfish Description: Stalked eyes with prominent carapace and tail fan. Tolerant bugs (continued) Order: Decapoda Habitat: Large and small permanent Family: Parastacidae streams, slow flowing or still waters. Description: Prominent carapace and fan Maximum size: Up to 35mm Whirlygig beetle and larva tail with well developed claws. Lateral Order: Coleoptera rows of spines (Crayfish), no spines (yabby) Family: Gyrinidae Habitat: Large and small streams, slow flowing or still waters. Resides in burrows. Description: Both adults and larvae are Water scorpion/needle bug aquatic. Adults are a streamlined oval Maximum size: Up to 400mm Order: Hemiptera beetle that commonly swims in circles, due to their short hind legs. Have eyes Family: Nepidae for above and below water. Description: First pair of legs modified Scuds/side swimmers Habitat: Surface dwellers of for grasping. A short breathing tube still or slow flowing waters. Order: Amphipoda at the end of their abdomen. Several undescribed species have been recorded. Maximum size: 5–25mm Class: Crustacea Description: Carapace absent. Seven Habitat: Found among aquatic vegetation pairs of legs for swimming or walking. in still or slow flowing waters. Roundworms Habitat: Slow moving edge waters,. Maximum size: Up to 50mm burrows into sediment. Phylum: Nematode Maximum size: 6–20mm Description: Thin, elongated, cylindrical worms that can appear translucent. Commonly abundant. Habitat: Often free living or parasitic, burrows into sediment. Maximum size: Up to 12mm Water treader Order: Hemiptera Family: Mesoveliidae Description: 15 of the Hemipteran Mosquito larva families have aquatic life stages Order: Diptera Occur in winged and wingless forms. Very tolerant bugs Family: Culicidae Elongated oval shaped body. Description: 3 sub families. Habitat: Surface dwellers of still or slow flowing waters. Flatworm Breathes through respiratory siphon at the end of the abdomen. Maximum size: Up to 5mm Class: Turbellaria Habitat: Commonly found in still Family: Dugesiidae waters or stagnant waters. Description: Flat slow moving worms, Maximum size: Up to 25mm lacking tentacles. A distinct head usually with 2 (sometimes more) Freshwater slater eyespots. Dark brown or grey body. Order: Isopoda Habitat: Glides over substrate in a Description: No carapace, seven variety of flow conditions. pairs of walking legs. Maximum size: Up to 20mm Segmented Worm Habitat: Found in the leaf litter along Order: Oligochaeta the margins of still or slow flowing Description: Elongated streams. Diving Beetle segmented bodies. Often eyes Maximum size: Up to 20mm Order: Coleoptera absent and no larval form. A few species have aquatic gills Family: Dytiscidae posteriorly. Description: Both adults and Habitat: Found in the soft larvae are aquatic. sediments of still or flowing Habitat: Very common and found in waters. flowing to standing waters. Maximum size: Up to 30mm Maximum size: Up to 40mm Backswimmer Order: Hemiptera Family: Notonectidae Waterboatman Description: Adults and larvae are Order: Hemiptera aquatic. Large eyes, good swimmers who swim upside down. Adults can fly large Very tolerant bugs (continued) Family: Corixidae distances between habitats. Description: Piercing mouth parts. Habitat: Prefers still or slow flowing Elongated oval shape. waters. Bloodworm Habitat: Still or slow flowing waters. Maximum size: Up to 11mm Order: Diptera Maximum size: Up to 10mm Subfamily: Chironominae Description: Contains haemoglobin which gives this sub family it’s Jellyfish distinctive red color. Family: Olindiiae Habitat: Found in the soft sediments Description: Body is simple sack with of still or flowing waters Freshwater snail an opening for the mouth encircled by tentacles some with nematocysts. Maximum size: Up to 20mm Class: Gastropoda Habitat: Found in flowing and or still Description: Protective shell enclosing a waters including ponds, streams and soft-bodied animal. lakes. Found on stones and submerged Habitat: Generally found feeding on algae Leech vegetation and detritus. Free floating and on rocks and vegetation in still or slow commonly found in schools. Order: Hirudinea flowing waters. Maximum size: Up to 30mm Description: Limbless segmented body, Maximum size: Up to 25mm with a sucker on one or both ends. Habitat: Prefers still or slow flowing waters. Maximum size: 7-80 mm This index chart was produced using source material and permission from NSW Department of Environment, Climate Change and Water and Waterwatch NSW. Illustrations courtesy Christine Rockley Special thanks to the MDFRC team for their valuable input..
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