Captive Care
In March 1995 I acquired 10 specimens of the aquatic caecilian Typhlonectes natans (identified by cloacae denticulation after Wilkinson, 1996) which had been imported from Guyana. I immediately lost two as a result of an ill-fitting aquarium lid. Another died after only six days as a result of a severe bacterial infection which did not respond to antibiotic treatment. The remaining 7, however, thrived. They ranged from 25cm to 35cm in length and were on average 1-2cm in diameter.
I established them in a 180cm x 61cm x 46cm (6ft x 2ft x 1.5ft) tank with a substrate of river sand (from a local unpolluted stream) 10cm deep, and a water depth of 30cm (later raised to 40cm) of soft acid water (pH 5-6 & dH 3)#, at 74¦C with external filtration. The tank was furnished with plenty of bogwood and extensive non rooting plants (java fern, java moss and rigid hornwort) as I anticipated extensive burrowing.
The caecilians do burrow but not as much as I expected. They are active equally by day and night and appear oblivious to bright light even when shone directly on them. Their tastes are catholic and they seem to do well on frozen bloodworm, chopped mussels, prawns and chopped sprats (later I stopped using sprats because of the mess and potential for fouling of the water; as a codicil, if feeding with non-live food remember to feed freshwater animals with marine fish/prawns - this reduces the risk of disease transmission). They grew well and by 1997 the largest individual measured 3cm in diameter and approximately 55cm in length.
Initially, I was loath to introduce fish to the aquarium, fearing that they would be eaten or even attack the caecilians. I experimented with small tetras and, when these remained unscathed, gradually introduced a full community of Amazonian fish. To this date no living fish has ever been harmed - even small loaches resting amongst the inactive caecilians under the bogwood. Similarly, the large cichlids ignore the caecilians even when their breeding territories are violated. When a fish dies, however, it is consumed immediately leading me to speculate that carrion forms a significant part of wild caecilians' diets. This is backed up by the relative abundance of Typhlonectes sp. near riverside fishing villages in Northern South America, where they have been observed eating the entrails of gutted fish (Hofer, 2000).