Tuesday, February 19, 2008


Part of the process for building a frog pond at school was deciding which fish to introduce. Extensive research was undertaken to identify a local, native fish species that would control mosquito larvae without eating frogs eggs or tadpoles.

A colourful Empire Gudgeon found in Wolli Creek.

The following fish occur locally in the freshwater sections of Wolli Creek:
Firetail Gudgeon
Empire Gudgeon
Striped Gudgeon
Flathead Gudgeon
Common Jollytail

Of these, only the Firetail Gudgeon is considered frog-friendly and not needing saltwater for part of its life-cycle so it would be the most suitable species for the school pond.

However, if fish of this species were sourced from aquariums they might have come from warmer climates and may not be acclimatised to Sydney outdoors! The species for our school pond will be sourced locally with the help of Canterbury Council and NSW Fisheries.

Firetail Gudgeon occur in streams, ponds, swamps and drains, usually among aquatic weeds. Juveniles feed on zooplankton while adults feed on insects, larvae and small crustaceans. They breed between October and January in response to rising water temperatures. Male colouration intensifies at this time. Eggs are laid underneath rock ledges, logs or leaves and are guarded and fanned by the male parent until hatching, 3-5 days later.


- contact Voren for activity sheets relating to local native fish species.


Activity - Divide the class (Yr 6) into small groups. Give every group the following set of criteria.

Ideally fish for our pond would be:
- a small species;
- suitable to still water;
- suitable to freshwater habitat;
- native to Australia;
- that would eat mosquito larvae;
- that would not eat frogs eggs;
- that would not need filtration; and
- that would be suitable to East Coast (Sydney) climate.

Give each group a different fact sheet for a particular species. Or get them to google the species for homework.

  • Crimson-spotted Rainbow Fish, Melanotaenia splendida fluviatilis
  • Blue-spot Goby, Pseudogobius olorum
  • Western Carp Gudgeon, Hypseleotris klunzingeri
  • Bony Bream, Nematalosa erebi
  • Southern Pygmy Perch, Nannoperca australis
  • Australian Smelt, Retropinna semoni
  • Agassiz's Glassfish (Ambassis agassizii)
  • Common Jollytail (Galaxias maculatus)

Ask groups to present the case for or against their species being introduced to the school's eco pond.


Some useful websites:

Fresh Water Fish of the Sydney Region (poster)

Australian Museum Fish Site