HYPEROLIUS HIEROGLYPHICUS - Notes on care and breeding in captivity
by Martyn Pinto
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PHOTO 1: An adult female Hyperolius hieroglyphicus differs completely in coloration from the male (see PHOTO 2 below) and a juvenile (PHOTO 3) |
Distribution and classification:
The family Hyperoliidae are to be found only in Madagascar, Africa and the Seychelles. There are some 300 species, made up mainly of three large genera - Hyperolius, Afrixalus and Leptopelis. Hyperolius are often called Sedge or Reed frogs due to occupying reeds and other typical fauna near ponds, lakes and drainage ditches. They number just over a 100 species in total and range from rather small to medium size frogs with long hind legs.
Location and Habitat:
H. hieroglyphicus is a highland species from the eastern part of Nigeria and the adjacent Bamenda highlands of the Cameroon's. Most specimen seem to have been collected from the Obudu Plateau some 5000 ft. above sea level. Living in farm-bush fauna, males call from grasses and low bushes. There is no distinct wet or dry season as mist and light rain are frequent throughout the year in this region.
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PHOTO 2: An adult male Hyperolius hieroglyphicus |
Description:
Males: Dorsum coloration is bright translucent green, with a narrow greenish-yellow canthal stripe, which continues up over and behind the eye as a dorsolateral stripe. The ventrum is of a pale yellow to off white. Males have a clearly seen subgular vocal sac which appears white. The hands and feet are webbed and are of the same green coloration as the upper body but end in expanded and flattened red fingers and toe discs.
Females: Generally described as having a black dorsum, with vermenticular yellow markings; however I have noted that this coloration changes to light shades of green at varying times. The females also have the ability to vary the density of the pattern. The ventrum is of a wonderfully bright orange. The undersides of the hands along with the webbing and toes are of a blazing red. H. hieroglyphicus havs a horizontal pupil set in a glistering gold iris. All Hyperolids have horizontal pupils - this is one of the easiest ways of identifying and separating them from Afrixalus and Leptopelis species.
Call:
The male's call is not unlike the sound of a chirping cricket. No sound has been noted from the females.
Size:
Males obtain a SV-length of between 25 - 30 mm, females are generally somewhat bigger at 35 mm.
Housing:
Ten males and two females were first kept in a "Eco House"*~ measuring 20"x9"x14". Although there is no need for extra ventilation, these tanks come with plenty of pre-drilled holes in them. I also like to cut a section out of the top and back walls and then cover them with a fine mesh. The main reason for using these types of tanks is that they are lightweight, easy to move and clean unlike heavier glass tanks. The housing was re-arranged later and the frogs were moved to a larger all glass vivariums with ventilation across the back of the tank. A large body of water, which is approx. 5 inches deep, was introduced.
A twelve inch fluorescent tube is suspended from the roof to provide lighting and warmth throughout the day. In addition to this there is a small heat mat positioned on one wall, providing extra heat (it is the sole source of heat during the night). Temperature should be maintained between 22 and 28 degrees centigrade.
Inside the tank there are a number of small house plants such as Chlorophytums, Spathiphyllum's and Aracenes, to give the frogs a lot of cover: Even though most of them like to sit high up on the sides of the tank, they do also use these plants to call from at night or occasionally during the day.
I prefer not to use a substrate and therefore all the plants are left in their pots - this way they can also be changed easily. An old plastic tub serves as a water area - it is filled to about three inches with fresh water. Some fake ivy leaves hang into the water to allow for an easier exit. Also included are a few vertical reeds which are really there to allow any crickets which have fallen off the foliage onto the floor to climb back up.
Food:
Small crickets, which have been gut loaded, and occasionally pre-dusted, are excepted as readily as are fruitflies, houseflies, small moths and their larva. Reed frogs provide their keeper with a great display as they try to catch these food animals and although these frogs are most active during the night they will accept food given at any time.
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PHOTO 2: A juvenile Hyperolius hieroglyphicus |
Breeding:
In August 1997 I acquired ten males and two females. As the males were already calling, the decision was to keep a high humidity and spray the enclosure with water at least twice a day. The males were almost constantly calling in chorus with each other from the leaves near the water area or from high up on the sides of the tank. They would often be seen trying to grasp a female if one came to close but their attempts were always unsuccessful ending in the female leaping away to safety. No amplexus was ever witnessed, and as checking was done on all tanks early each morning and late in the evening, it was concluded that: A) Amplexus was short and B) probably took place a few hours after the lights had been turned off.
In the early morning of the 26th of November, eggs were noticed on and around the ivy leaves in the water area. These were about 2mm in size and black in coloration. Following a closer count it was observed that they numbered just over one hundred. All eggs were placed in a small container, no bigger than a youghurt pot, and an air pump was added to aerate the water.
There appeared to be no visible change to the eggs until day four, when it was visible that they had become elongated. By day seven all eggs had hatched. The young tadpoles were kept in the same container, with regular changes to water, for a period of one week. After this they were placed into a small glass aquarium, filled with several inches of water. Some pond weed and an air pump was added to the tank. No ground medium or filters were used as water was changed almost every other day. Water temperature was approx. 22-24 degrees centigrade.
Rearing tadpoles:
Feeding took place regularly, the food being either ordinary tropical fish flakes ground to a powder (sometimes with a little bit of calcium powder mixed in), or with gnat larvae - these can be bought in little jars from most aquarium supply shops in UK. It was noticeable that when the tadpoles were fed on flakes, the water became polluted much quicker than when they were fed on gnat larvae. Lighting was provided during the day mainly due to being in a dark corner of the room, The tadpoles grew rapidly, obtaining a head to tail length of up to 35 mm quickly. Cannibalism was not noticed among them, but if a tadpole died and was left in the water, the other would eat it. Thus all casualties noticed were removed from the water.
On the 23rd of January clearly visible hind legs were observed on nearly all tadpoles. It took a week more for these to become fulIy developed. At the same time the tadpole's coloration change began to take place, with a greenish tinge appearing on many to the legs and the dorsum. The first signs of dorsoluteral stripes could be seen, resembling the patterns of an adult male. [Could this indicate males at such an early age?] At this point the water level was lowered and some rocks and floating platforms of polystyrene were added in anticipation of nearing metamorphosis. A screened top was also placed over the tank to stop escapees as they would emerge from the water. And only 8 days later almost all had their front legs through and the first froglets were coming out of the water.
Out of the twenty tadpoles kept (the remainder being distributed among local hobbyists), 17 finally left the water and other 3 died for no apparent reason. The tails took a few days to become fully absorbed. All froglets turned out looking like miniature males, none had the adult female coloration. After consulting with several others who had received tadpoles, it was apparent that they too had had a high rate of success in numbers metamorphosed and that all individuals resembled adult male coloration. Either the female coloration would develop later on, or factors such as water temperature had affected the determination of which sex the tadpole would develop.
The set up for froglets is exactly the same as for the adults. They are subject to dehydration at this early age so missing is essential A water area pauses no problems. as they are good swimmers and although they will climb up the sides of the container. it is a good idea to make sure there are some leaves hanging into the water to assist climbing out if need be.
Further developments:
A pump with spray bar was added to the adult tank to create frequent rain showers, usually for a few hours early morning and again in the evening. Still there were no signs of further interest from the females to mate. At the beginning of March '98, with the males still calling, the pump was turned completely off.
Two weeks after the pump had been turned off amplexus was observed on several mornings. Eggs were laid early morning (7-8am) in the main body of water and attached to water plants. Approx. 100 eggs were laid. One week later, second female laid 150 eggs and then again a week later, the first female laid eggs again, only 2 weeks after it's previous spawning. Shortly after the last clutch of eggs were laid, one female was lost - perhaps the continuous egg-laying had strained and weakened her physically?
3 - 4 months went by with no other efforts to breed from the remaining female, but the males would call continuously despite of no rain in the tank. Sadly the last female was then also lost.
The frogs from the first breeding have grown well, being approximately nine months from the time of their metamorphosis now. Several younger frogs from latter spawnings have been kept and are also doing well. In total about 90 survived metarmorphoses and those first few troublesome weeks.
Female to Male ratio:
The first changes to any of the young frogs was noticed in the last batch which were six months old at the time when female coloration started to appear on one of the froglets. The male stripes could still be seen, but the back was now covered in a camouflage pattern. As far as I am aware, all the frogs from the first breeding have still got male coloration (these being the ones given to other hobbyists). Interestingly, not all have vocal sacs present! Perhaps climate changes may trigger off a change in females?
Anyone wishing to contact me can do so at joy@ashvalepark.demon.co.uk . Please mark your messages clearly as to: Martyn - Re: Frogs.
References:
- Schiotz, A. 1967. The Treefrogs (Rhacophoridae) of West Africa. Spolia Zoologica Musi Hauniesrisis. #25.
- Mattison. C. 1998. Frogs and Toads of the World Blandford Press.
- Passmore and Carruthers, 1995. South African Frogs - a complete guide. Southern books/witwatersrand University Press.
- *ECO House: One of many - 'Annihouses' made by Living Designs.Victoria Road, Wood Green. London N22 4XB. 0180 374 2511
- **Gnat Larvae: Interpet. Dorking England. Rll4 3YX.
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