Pseudosphromenus dayi or Indian spiketail betta is a species of freshwater ray finned fish from the subfamilyMacropodusinae, part of the gouramifamilyOsphronemidae. It occurs in Kerala on both the coastal regions and the Western Ghats.[1] It is a species of still or slow flowing waters, especially lakes, ditches and swamps[2] in both fresh and brackish waters. Pseudosphromenus dayi is a bubble nester, the male creates a nest made of bubbles under an overhang or a leaf. The females lays eggs which drop to the substrate and are picked up by both fishes in the pair and placed in the bubble nest.[1] The name Polyacanthus cupanus dayi was first published in 1908 by Köhler in 1908 but Catalog of Fishes refers to this as a nomen nudum and attributes the valid use of the name, with a formal description, to P. Engmann in 1909. The type locality is given as Malacca which is probably an error and should be Kerala.[3] The specific name honors the Britishichthyologist and author of the Fishes of India, Francis Day (1830–1889).[4]