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1 (not at all) - 10 (very likely)

Key to freshwater fish families in New Zealand

This is a guide for identifying what family a fish is in, but to go futher and identify the species, you need to use our ID guides and keys.

Start at the top and work your way through the choices in the table below. In this key, we have relied on obvious external features and have tried to avoid using technical terms. There are a few features you might not be familiar with - look in the glossary for a definition. Use the Fish Finder if you have a common name for the fish you want to see.

Key to the Families

Item Characteristic Next
1 Scales absent or embedded go to item 2
Scales present go to item 5
2 Seven gill openings on each side of head Lamprey (Geotriidae)
One gill opening on each side of head go to item 3
3 Fish long and thin (snake-shaped) Eels (Anguillidae)
Fish not long and thin go to item 4
4 Barbels present around mouth Catfish (Ictaluridae)*
No barbels Whitebait and mudfish (Galaxiidae)
5 Fish flat and plate-shaped Flounder (Pleuronectidae)
Fish not flattened go to item 6
6 Tail rounded go to item 7
Tail not rounded go to item 9
7 One dorsal fin Live bearers (Poeciliidae)*
Two dorsal fins go to item 8
Three dorsal fins Estuarine triplefin (Tripterygiidae)
8 Gap present between dorsal fins Bullies (Eleotridae)
No gap present between dorsal fins Dart Goby
(Microdesmidae)
9 Adipose fin present go to item 10
Adipose fin absent go to item 11
10 Lateral line present Trout and salmon (Salmonidae)*
Lateral line absent Smelt (Retropinnidae)
11 One dorsal fin go to item 12
More than one dorsal fin go to item 13
12 Head slightly flattened with a dark band between the eyes Torrentfish (Pinguipedidae)
Head not flattened Carps (Cyprinidae)*
13 First dorsal fin with 4 spines Mullet (Mugilidae)
First dorsal fin with more than 4 spines Perch (Percidae)*

* indicates the the families of introduced species.