The Aralam Wildlife Sanctuary is enriched with several streams and rivers. A survey by Shaji, et.al. (1995) has reported a total of 39 fishes from the sanctuary.
The species such as Pristolepis margenata, Batasio travancoria and Pontius denisonii are endemic to Kerala.
Barilius canarensis and Osteochilus thomassi are new records to the rivers. Besides these, the endangered Tor khudree also abounds in the Cheenkannipuzha.