A Photographic Guide to Freshwater Invertebrates of Taranaki’s Rivers and Streams This book was first published in 1998 and adapted from a publication originally produced in 1997 by S C Moore, Otago Regional Council. This edition was updated and reprinted in 2009. For further information please contact the Taranaki Regional Council, 47 Cloten Road, Private Bag, 713, Stratford 4352. Phone: (06) 765-7127, Fax: (06) 765-5097 Email: [email protected], Web: www.trc.govt.nz Table of Contents Introduction 2 Beetles Nematode worms 17 Where to look and How to Elmidae 10 Proboscis worms 17 Sample 2 Scirtid 11 Paddle-worms 17 Identifying the Major Hydraenidae 11 Horse-hair worms 18 Invertebrate Groups 3 Hydrophilidae 11 Hirudinea (leeches) 18 Photographic Guide to the Berosus 11 True flies Freshwater Invertebrates 4 Dytiscidae 11 Orthoclad midges 18 Mayflies Bugs Maoridiamesa 18 Deleatidium 5 Microvelia 11 Tanytarsus 18 Coloburiscus 5 Sigara 12 Tanypodinae 18 Austroclima 5 Anisops 12 Polypedilum 19 Zephlebia 5 Dobsonfly Chironomus 19 Mauiulus 5 Archichauliodes 12 Harrisius 19 Nesameletus 5 Damselflies & Dragonflies Nothodixa 19 Ameletopsis 6 Xanthocnemis 12 Paradixa 19 Ichthybotus 6 Austrolestes 12 Aphrophila 19 Stoneflies Procordulia 12 Limonia 20 Stenoperla 6 Crustaceans Zelandotipula 20 Zelandoperla 6 Paranephrops 13 Paralimnophila 20 Megaleptoperla 6 Paratya 13 Eriopterini 20 Austroperla 6 Isopoda (estuarine) 13 Hexatomini 20 Zelandobius 7 Isopoda (freshwater) 13 Ceratopogonid 20 Acroperla 7 Paracalliope 13 Austrosimulium 21 Caddisflies Paraleptamphopus 13 Empididae 21 Olinga 7 Daphnia 14 Culex 21 Beraeoptera 7 Copepods 14 Syrphidae 21 Confluens 7 Ostracods 14 Muscidae 21 Pycnocentrodes 7 Simocephalus 14 Anthomyidae 21 Pycnocentria 8 Notostracans 14 Pyschodidae 22 Hudsonema amabilis 8 Helice 14 Mischoderus 22 Oecetis 8 Molluscs Tabanidae 22 Oeconesid caddisflies 8 Potamopyrgus 15 Ephydridae 22 Helicopsyche 8 Physa 15 Stratiomyidae 22 Triplectides 8 Lymnaea 15 Sciomyzidae 22 Hudsonema aliena 9 Gyraulus 15 Caterpillars Oxyethira 9 Melanopsis 16 Hygraula 23 Hydrobiosella 9 Amphibola 16 Mites Paroxyethira 9 Hyridella 16 Acarina 23 Aoteapsyche 9 Sphaeriidae 16 Coelenterata 23 Psilochorema 9 Latia 16 Paludicella (Bryozan) 23 Hydrobiosis 10 Ferrissia 16 Summary 23 Costachorema 10 Worms Further Information 24 Neurochorema 10 Oligochaete 17 References 24 Polyplectropus 10 Cura(flatworms) 17 Plectrocnemia 10 Temnocephalus 17 Note: Images courtesy of Mr SC Moore Landcare Research NZ Ltd. 1 This “Photographic Guide is designed to assist Introduction anyone interested in learning about stream life or the condition of their local waterbodies. Turn over a few rocks in a shallow, fast flowing The following pages introduce all of the major section of any stream and you will soon notice invertebrate groups using microscope images, movement. Small, dark insect-like shapes and a brief description of the habitat preferences scuttling for cover. You may well discover some of each group. This guide may be useful in of the surprisingly large members of the mayfly, any part of the region. Particular emphasis is stonefly, caddisfly or dobsonfly groups. These placed on those invertebrate groups which are insects are in their larval (juvenile) stages recognised as useful indicators of water quality. and are just a few of more than 150 aquatic All of the invertebrates shown in this guide are invertebrates widely distributed around the present in Taranaki. Region. In addition to insects you may find crustaceans, snails, worms, and leeches particularly in weedy Where to Look and stream habitats. Collectively these creatures How to Sample are known as “aquatic invertibrates” (animals without backbones). This guide is designed for those without a great deal of freshwater biological experience Invertebrates are a vital part of the freshwater or access to laboratory facilities. Even if you ecosystem. They include grazers, plant do not have equipment such as sampling shredders, filterers, and predators. Many of nets, containers or microscopes, you can use them feed on plant matter (algae, leaf litter and this guide to identify as many invertebrate aquatic “weeds”) and in turn they provide the groups as possible and make some conclusion most important food source to almost all of the regarding the “state of health” of your chosen freshwater fish found in New Zealand. Without waterbody. the invertebrates we would have none of the native eels, bullies or “whitebait” species, and A single site can be used for a spot check, no introduced trout, salmon or perch in our although most biological surveys involve a freshwater habitats. series of sites along a particular waterbody. Select sites with easy and safe access, and Invertebrates can tell us a great deal about always seek permission to cross property. The the “state of health” of our waterbodies. The widest range of stream invertebrates can be presence of many invertebrate species usually found in shallow (but permanently submerged), indicates clean water, cool temperatures and fast-flowing, stony-bedded reaches known as generally natural conditions. A stream which “riffles”. Larger, more stable rocks usually lacks any invertebrate life has a major habitat support the most invertebrate types, although problem, possibly because of recent pollution, the rocks need to be small enough to be lifted or low flow conditions. or turned over. Each year the Taranaki Regional Council Invertebrates can be picked or scraped off rocks (TRC) monitors the condition of the freshwater and placed into a tray or transparent container. invertebrate communities around Taranaki The more invertebrate types found, the more (1020 sites monitored in total to date). This useful information you will gain relating to the work compliments chemical (water quality) “state of health” of the site. Be sure to look for and hydrological (water quantity) monitoring the smaller species as well as the more obvious, programmes, and together these programmes larger species. are significantly improving our understanding of the state of our freshwater resources, and monitoring the performance of consent holders. 2 If you are interested in weedy streams, ponds, Having separated your invertebrates into these lakes or wetlands, you may find a wide range primary visual categories, you may choose to of invertebrates in permanently submerged refer to the corresponding photographic section vegetation. You will see the invertebrates of this guide. Further identification will be easy more easily of you place a sample of vegetation for many invertebrate groups however. Try the into a tray or suitable viewing container. The following secondary categories: invertebrate groups you find may differ to those found in stony habitats, but the general rule Six-legged insect larvae about rich communities reflecting “healthy” Those with three tail filaments and gills conditions can still apply. Many plant-associated along the sides of the body (mayflies) invertebrates are described in this booklet. - pp 5-6 Those with two tails (stoneflies) - pp 6-7 The TRC uses a “kick-sampling” method where Those inhabiting a portable case (cased the streambed is disturbed by foot, and fine, caddisflies) - pp 7-9 organic matter (including the invertebrates) Those with a soft grub-like body and two is swept into a hand-held net. A detailed tailhooks (free-living caddisflies) - pp 9-10 description of the TRC sample collection and Those with a hard outer cover and biting analysis methods can be obtained from the mouthparts (beetles) - pp 10-11 Technical Services Section Unit of the TRC. Those with pointed, sucking mouthparts Once you have obtained a collection of (bugs) - pp 11-12 invertebrates from a site, use the following Those with leg-like gills along the body sections of this guide to identify each group (as (dobsonflies which resemble the centipedes far as possible) and to establish stream health. at first glance) - p 12 Those with extendable hinged lower jaws (damselflies and dragonflies) - p 12 Identifying the Major Eight (or more) legged crustaceans Invertebrate Groups The crayfish with distinct “pincers” - p 13 The shrimps (similar to small crayfish, but Published scientific identification keys require lacking large pincers) - p 13 the use of a microscope to recognise the features of each group, and it is assumed that Those resembling sand hoppers the observer has a good understanding of (amphipods) - p 13 scientific terms. The following guide however Those resembling wood lice (isopods) - p 13 is designed for those without these advantages, The water fleas (small, open-water although a magnifying glass would make the swimmers) - p 14 task easier. The seed-shaped ostracods - p 14 Those resembling horseshoe crabs The first step is to sort your collected (notostracans) - p 14 invertebrates into the major groups which are Estuarine crabs - p 14 visually distinct. Try the following primary categories: Molluscs Dark, chunky pond snails - p 15 Six-legged insect larvae - pp 5-12 Bubble-shaped fragile pond snails - p 15 Eight (or more) legged crustaceans Large conical pond snails - p 15 (shrimps, water fleas etc) - pp 13-14 Flat-spiralled snails - p 15 Molluscs (snails and bivalves) - pp 15-16 Estuarine snails - p 16 Others (worms, legless insect larvae, Large freshwater mussels (bivalves) - p 16 leeches etc) - pp 17-22 Small pea shells (bivalves) - p 16 Freshwater limpets - p 16 3 Others Some invertebrates cannot tolerate any form of Worms similar to small earthworms