Animals in schools

Tadpole

There are two situations where frogs are permitted to be kept in schools.

1. Adult Green Tree Frog(s) are acquired from a licensed amphibian supplier and kept at the school for educational purposes. This keeping of Green Tree Frogs is covered by the school sector scientific licence as long as the frogs are housed and cared for in accordance with the advice provided in the Frog section.
2. Collection and housing of up to 20 tadpoles until they change into frogs. Approval for this activity has been granted by the National Parks and Wildlife Service and is exclusive to schools. Tadpoles must not be collected from a National Park and the frogs must be released back to the water source from where they were originally collected. This licence is provided on the Animal Research Authority. A condition of this licence is that hygiene procedures must be followed and handling of the tadpoles is not permitted. The tadpoles must only be observed. The minimum hygiene requirements are described below.

The reasons for the need of this licence are:

• Most tadpoles are native species and therefore their collection is illegal
• The collection and subsequent release of the tadpoles or frogs has been found to contribute to the transmission of disease, in particular the Amphibian Chytrid Fungus.

The Amphibian Chytrid Fungus has been found to be one of the key components in the decline in frog populations worldwide. The fungus is easily spread and is listed as a Key Threatening Process under the NSW Threatened Species Conservation Act 1995.

Minimum hygiene requirements for the collection, observation and temporary housing of tadpoles in schools

All contact equipment, including the housing tank, tank furniture, filtration equipment, water containers, food dishes, collection nets must be sterilised prior to use. It is recommended that this equipment is cleaned with a dilute bleach solution (5%), rinsed and sun dried for a period of 5 days, prior to use and between uses.

1. The collection of tadpoles is to be undertaken by the class teacher either with or without student participation. If multiple classes are interested in the activity it is strongly recommended that a single collection event be organized.
2. Students must not be encouraged or asked to collect tadpoles and bring them to school.
3. Collection is to be made from a single site only, e.g. one pond/creek/dam. Under no circumstances may tadpoles be collected from multiple locations or from National Parks.
4. On metamorphoses, frogs are to be returned to the exact point of collection. Frogs are not to be distributed to students, staff or other parties but are to be released at the point of capture.
5. At the completion of the activity all contact equipment, including the housing tank, tank furniture, filtration equipment, water containers, food dishes, collection nets must be sterilised. It is recommended that this equipment is cleaned with a dilute bleach solution (5%), rinsed and sun dried for a period of 5 days.

Remember that this licence is to enable school students to enjoy this educational activity while protecting our valuable frog species. It is important that teachers not only carry out this procedure carefully but explain to students its significance.

Collection and care of tadpoles

Tadpoles are poikilothermic, that is, the temperature of the environment determines their body temperature. This means that the ideal temperature range of their water is 18-22°C. The water used for tadpoles needs to be absent of chlorine. This means that rainwater can be used or if town water is used then it must be aged. Water can be aged by allowing it to stand in an open container for 24 hours prior to use so that the chlorine evaporates or by adding commercially prepared aging solutions.

Maintaining the environment

As with all aquatic animals, the best way to monitor their health is to monitor and maintain a healthy environment, i.e. the water in the tank.

A good way of ensuring a healthy environment for the tadpoles is to change 30-50% of their water daily or at least on school days. The easiest way to do this is to mark, on the side of their tank, a line showing 50-70% of the water remaining in the tank. Place a dip net across the mouth of the jug to ensure that tadpoles are not inadvertently removed with the water.

The removed water should have bleach added to it prior to disposal by pouring down the toilet. This reduces the chances of transmitting disease to your surrounding environment.

Feeding

Tadpoles should be fed once a day. Feed only enough to be eaten within one hour. If there is food left at the end of this time, remove it and feed less the next day. Uneaten food can reduce water quality and increase the chance of health problems.

Suitable foods include algae disks, fish flakes or boiled lettuce. Lettuce must be boiled so that the plant cells are broken down.

Handling

Once collected from the wild, the tadpoles must remain in their housing tank until they are returned to their original source. They may be moved from one tank to another to allow cleaning of their tank, but must not be removed and handled for examination. Observation must be passive and be carried out while the tadpoles are in their tank.

Health

Good health is maintained by maintaining good water quality and appropriate feeding. The volume of water that tadpoles have access to can affect their growth rate. They should not be overcrowded.

As the tadpoles develop legs, their gills recede and they are then unable to breathe under water. At this stage, the tadpoles need areas where they can sit above the water line.

Record keeping

A monitoring chart should be kept, documenting water changes, feeding and comments about the behaviour and development of the tadpoles.

Release of tadpoles and frogs

When approximately two tadpoles have metamorphosed into frogs, they should be returned, with the remaining tadpoles, to the exact place from where they were initially collected. Transport the animals in new or disinfected containers.