Hello, Frank Indiviglio here.
Please see Parts I and II of this article for general information and for details concerning the care of elephant nosed and butterfly fishes.
Dwarf Clawed or African Dwarf Underwater Frog, Hymenochirus boettgeri, H. curtipes
This tiny (males to 1 inch, females to 1.4 inches) aquatic frog is a real pleasure to keep. It is perpetually on the prowl, sticking its pointed little head into every nook and cranny in its ceaseless search for food. A group so engaged is really quite comical to behold…they look like nothing so much as squadron of tiny, flattened divers!
Habitat and Habits
Dwarf clawed frogs move slowly about the aquarium bottom and among the plants, and save “free swimming” for trips to the surface for air. In deep aquariums, they do best when provided with “ladders” to the surface in the form of (preferably live) plants. They are at their best in heavily planted aquariums, and will utilize every square inch available to them.
Small size and bold demeanors render these frogs ideal observation subjects. It is quite easy to provide them with a habitat in which they will reveal to you nearly all of their natural behaviors, and captive reproduction is not uncommon. Dwarf clawed frogs are not favored aquarium animals in the USA, due largely to the fact that they are usually kept improperly. Typically housed in bare tanks with active fishes that out-compete them for food, they usually expire in short order.
Feeding Dwarf Clawed Frogs
In addition to dense cover, dwarf clawed frogs need a varied diet of small, live invertebrates. Blackworms can account for up to 75% of their food intake, supplemented whenever possible with live brine shrimp (brine shrimp alone are not an appropriate diet), whiteworms, bloodworms, mosquito larvae and similarly-sized aquatic organisms. Newborn guppies may be taken by particularly large individuals. I’ve had my best breeding results when I provided my frogs with occasional meals of pond-seined fairy shrimp and other tiny invertebrates.
I have not had much success in inducing dwarf clawed frogs to accept non-living food items, but others have reported good results with some individuals. I suggest that you feed them as described above, but experiment with Reptomin Select-A-Food (freeze dried and pelleted components), freeze-dried fish foods (mysis shrimp, daphnia, bloodworms) and frozen mosquito larvae.
As dwarf clawed frogs feed largely by day and elephant nosed fishes by night, competition for live blackworms is rarely a problem.
A Unique Hunting Strategy
Dwarf clawed frogs use a suction-based feeding technique, unique among amphibians, to capture their prey. The tiny hunters lunge forward while extending the front limbs and opening the mouth, after which the body is recoiled. Like other members of the family Pipidae (African clawed frogs, Surinam toads), dwarf clawed frogs are tongue-less.
Hybrids and Feral Frogs
Only Hymenochirus boettgeri and, to lesser extend, H. curtipes, appear in the trade; there is some evidence of hybridization between the two. H. boettgeri has been introduced to Florida and is apparently well established.
An Important Distinction
It is important that you are able to distinguish this frog from young African clawed frogs (Xenopus laevis). The two are frequently housed together in pet stores….Xenopus grows quite large and will consume smaller frogs, fishes and shrimp.
In dwarf clawed frogs, the appendages of all 4 limbs (fingers and toes) are webbed; Xenopus possesses webbed feet only. Dwarf frogs are also more flattened in body form, and their heads are very narrow, nearly “pointed”.
Giant African Fan Shrimp, Atya gabonensis
This stoutly-built West African native is bound to become more popular as time goes on. Built more along the lines of a crayfish than a shrimp, yet completely benign toward tank-mates, it feeds by sweeping food into its mouth with feathery appendages. Fan shrimp are quite social in nature, with groups often sharing the same shelter even when others are available.
The Importance of Shelter
I have found African fan shrimp to be compatible with the other animals mentioned in this article, provided that they have access to secure shelters. They seem to be very much “home oriented”, and become quite stressed when their retreats are disturbed in any way.
Be sure to supply your shrimp with caves and other such hideaways that will not be disturbed by foraging elephant- nosed fishes (the other species pose no concerns), and do not move the shelters once they have been occupied. Small rock dens or Mopani wood shelters are ideal.
Please see my article on the Natural History and Care of African Fan Shrimp for husbandry details.
I was recently told of an unusually large (possibly 8 inch) fan shrimp that was residing in a local pet shop. I went to see the animal, only to find that it had expired and had been discarded. Please write in if you have observed fan shrimp larger than 5 inches or so – we have a great deal to learn about this animal…perhaps there is more than 1 species in the trade.
You can read more about the dwarf clawed frog and its relatives at http://research.amnh.org/herpetology/amphibia/names.php?taxon=&family=&subfamily=&genus=hymenochirus&commname=&authority=&year=&geo=0&dist=&comment=.
Please write in with your questions and comments. Thanks, until next time, Frank Indiviglio.