Introduction

The purpose of this atlas is to help non-experts identify New Zealand’s freshwater fish and learn about their life cycles and distribution patterns. Each species of fish belongs to a family of fishes that have similar characteristics. This guide describes the distinguishing characteristics of each fish family in New Zealand fresh waters and the species in that family that occur here.

New Zealand has a sparse but unique freshwater fish fauna. There are 35 or so native (or indigenous) species, many of which are only found in this country (endemic). Some of these species have such a restricted distribution that they are only found in a few streams or lakes. During the daytime, many native fish species hide under banks or beneath rocks on the streambed. Most people are not even aware that they are there and express surprise when they learn that there is more to the native fauna than just eels and whitebait.

In addition to our native fauna, several other species of fish have been introduced to New Zealand, including all the species of trout and salmon, as well as fish like perch and carps. Some of the introduced species are considered to be nuisance species because they may have a detrimental impact on the environment or the native fauna. There are also several species that periodically wander into fresh water but that are really marine fish, like the grey and yelloweyed mullet.

This atlas contains a brief summary for each species, including the marine wanderers. Each summary includes:

• a picture of the fish
• how to distinguish that fish from others
• some interesting facts about the species and
• a distribution map.

The distribution maps were produced using data from the New Zealand Freshwater Fish Database (NZFFD), a computer-based system that records the occurrence of fish throughout the country. NIWA manages the NZFFD, but data are regularly contributed to it by a wide variety of organisations including the Department of Conservation, universities, regional councils, consultants, and fish and game councils. As of August 2006, the NZFFD has over 25,000 records.

Fish are identified by both their common name and scientific (or Latin) names. Although they can be a mouthful, the use of scientific names is encouraged because each one is unique to a single species. Common names can be shared by several species, e.g. whitebait can be one of five species, or change from place to place, e.g. in Australia, our inanga is known as the common jollytail.

Scientific names always consist of two words, the genus and species. The generic name (or genus) helps us to know how that fish is related to others. In New Zealand, there are many species of Galaxias, but as soon as we see that name, we already know many things about that fish, like it does not have any scales. The second (or specific) name in the scientific name often tells us something about the unique features of that species. For example, the scientific name of the upland longjaw galaxias, Galaxias prognathus, describes the distinguishing characteristic of this fish, the forward (pro) jaw (gnathos). The correct way to write a scientific name is to place it in italics. The generic name must begin with a capital letter, but the specific name is all in lower case, as in the longjaw galaxias example given above.

Although I have tried to avoid using technical terms, it was impossible not to use some. The labelled pictures in the key to families and the glossary will help users to understand where and what some of the features used to identify fish are. A reading list of references suitable for youngsters and novice biologists is also included.

NIWA welcomes feedback on this website, including suggestions for improvements. You can email fwdba@niwa.co.nz. We propose to update the pages periodically, adding in any new native species that have been described in the meantime and providing new distribution maps for the others. I hope this atlas gives users an insight into the unique, varied, and attractive fish that reside in New Zealand’s waterways.

Acknowledgements

Many individuals voluntarily contributed the photographs used in this atlas. I would like to thank Bob McDowall and Steve Moore in particular for their superb and generous contributions. Ian Jowett developed the software used to produce the distribution maps and his programming skills and willingness to accommodate my idiosyncratic requirements are greatly appreciated. Ian and Richard Allibone both made useful comments on the text and Janice Meadows put it all together. This project was funded by contract C01820 from the Foundation for Research, Science and Technology.