This species is known from scattered localities in Thailand (Taylor, 1962), Lao People's Democratic Republic and Viet Nam (A. Ohler pers. comm.) and is wholly within the range of O. martensii. It probably occurs more widely than current records suggest, especially in areas between known sites.
Habitat and Ecology
Animals fitting the description of magnapustulosus occur in seepages, puddles and other shallow waters along streams and rivers, where they also breed. It has also been recorded from disturbed habitats such as gardens.
Any population data on magnapustulosus, if a recognisable species, is drowned in the population data of the sympatric and abundant O. martensii.
Water pollution might be a threat to this species.
Animals fitting the description and reputed range of magnapustulosus occur within adequately protected areas (Pha Taem National Park, Mae Yom National Park, Phu Luang Wildlife Sanctuary, Phu Kradung National Park). A thorough taxonomic re-evaluation of O. magnapustulosus is needed.
This species is frequently considered to be a synonym of Occidozyga martensii. It is possibly a sub-adult stage of O. martensii (Taylor (1962) was uncertain of its status). Its placement in Occidozyga is debatable.
Peter Paul van Dijk, Annemarie Ohler 2004. Occidozyga magnapustulosa. In: IUCN 2013