Email: mark@ameyzoo.co.uk

Aquatic Frogs

Biology

Frogs and toads are a group within the Amphibia. They live in most habitats with access to fresh water and occur all over the world, with the exception of Antarctica. Most live on land and occasional return to water to soak themselves or breed. Some species, however, can live entirely in an aquatic environment. These types are fully equipped for permanent life in water but still breathe air from the surface and can move about on land if forced to. Some of the species that fall into this group are those from the family, Pipidae. Commonly available examples include the Clawed Frogs, Xenopus spp. and the Dwarf Clawed Frogs, Hymenochirus spp.

Housing

The most suitable containers for these animals are aquaria. Set up in a manner similar to those used for tropical fish, these tanks make admirable quarters. As some of the animals housed will tend to become quite large, it is best not to construct too elaborate a set up, for fear of it being wrecked by a boisterous inmate. A 24" x 12" x 12" aquarium would be large enough for a pair of animals at 4" each or about a dozen smaller animals at about 1" each. The water in the aquarium is best filtered in some way and the movement necessary to do this, used as aeration at the same time. Alternatively, a simpler system could be employed. Either the water is changed more frequently or a lush growth of plants is used to mop up pollutants. These filter-less systems are usually only recommended for tanks containing a few small frogs. An external canister type water pump, an under-gravel filter with an air lift or some similar device should otherwise be used. Whatever method is chosen, the object should be to remove gross contamination from the water by trapping the waste particles somewhere they can be periodically removed from or allowed to degrade to harmless bye products. Another function of filtration is to change harmful dissolved substances into less harmful or neutral products. Some of these may well be taken up by the plants growing in the aquarium, thus facilitating the overall effectiveness of the filter. To set up the tank, add the substrate to form a base and into this anchor the plants. Any other items of decor can then be positioned. Finally, fill the aquarium with water. Ordinary tap water is suitable but may be improved by adding a propriety conditioner. The filter should be installed and run for about a day to settle the environment. (If an under-gravel filter is used, it must of course, be installed before the substrate.) The substrate has a dual purpose. One is purely decorative and the other, functional. Where decor is concerned, much is dictated by personal taste but a few points are worth considering. Choose the colours to blend into a pleasing background that contrasts well with the animals. Either a very dark or very light colour will probably make the best contrast. A terraced effect built behind retaining walls gives the impression of depth and allows both the animals and plants access to different levels. The functional role of the substrate will centre around its ability to trap and hold particulate material and how much microbial life it can support. Chemically, it is better if it is inert. The best substances to choose are the fairly coarse, lime free sands and gravels used for aquariums. Alternatively, the artificial medium, Hortag is recommended. All substrates must be thoroughly rinsed before use. Plants again, serve in both decorative and functional roles. They are better planted towards the rear of the tank and choose a species like Elodea that is tough and will provide good oxygenation. The water will need heating to about 24ºC and this can best be done with a tropical fish tank heater and thermostat. Bring any fresh water up to this temperature before adding it to the tank.

Husbandry

Aquatic frogs cannot really be handled. If it is necessary to move them from one aquarium to another, a suitably sized net should be used. The net should be made from a soft material, as the skin is quite delicate. Return the frog to water as quickly as possible and avoid escape by capping the net with a free hand. Once each week replace about one third of the water with fresh in filtered systems or replace two thirds in unfiltered systems. Judge the quality of the water on its clarity and smell. Gross pollution will necessitate a complete water change immediately. The only other piece of maintenance that needs to be done is the periodic pruning of the plants.

Food & Feeding

Aquatic frogs recognise food by smell and movement. Like many amphibians they will snap at moving objects in the hope that they might be a meal. If the morsel tastes OK and is of a size that can be swallowed, it is eaten. Unlike most, however whole animals are probably the best foods as they contain a good balance of nutrients. Food should be offered two or three times per week with enough to be totally consumed in about half an hour. Do not leave uneaten food in the water. Most frogs are probably lost through overfeeding and the subsequent pollution it causes, than any other cause.

Reproduction

Aquatic frogs are some of the easiest frogs to breed and some of the excellent publications available will provide further information. Adult pairs will, of course, be required. To tell the sex of a frog it is usually necessary to wait until the individual is mature and then often, in breeding condition. This conditioning may be seasonal, so the right time of year is important.

Health & Disease

Pet frogs do not suffer from many problems. Occasional skin infections may show and can usually be dealt with preparations suitable for fish. The treatments and advice are available from aquarists and pet stores. Good practice, hygiene and first aid will probably deal with rest. If real disease is discovered, a vet must of course, be consulted. Pet frogs do not pose any real threat to human health. All the normal hygiene precautions regarding humans and animals should, however, be observed.