Subterranean Fishes of the World

Country

Types

Holotype and only known specimen: BNHS FWF 611, 179 mm TL.

Distribution

Known only from the type locailty: dug from soil at Nongriat Village, Sohra (= Cherrapunji), Khasi Hills, Meghalaya, India (25°14'49.2" N 91°40'1.2" E) 440 m asl.

Habitat

The original description gives the following details: "The holotype of Monopterus rongsaw was collected during daytime soil-digging searches with bladed hoes for fossorial caecilian amphibians. The specimen was found at a depth of ~ 40 cm in moist, rocky soil in a secondary forest ~ 4 km trekking distance from Double Decker living roots bridge in Nongriat. The specimen was unearthed ~ 50 m from an unnamed stream." (Britz et al. 2018).

Traditionally subterranean biologists have not considered the soil fauna as part of the subterranean realm and they have not studied it. However there are a number of similarities of habitat, especially darkness but also confined space analagous to interstitial habitats, and of evolutionary trajectories such as reduction in eyes and pigment and in body size (Culver and Pipan 2014:128-141). This species and Monopterus luicolus are the only known soil dwelling fishes but there are 35 known species which inhabit the interstitial subterranean environment which is in many ways analagous. Both are shallow, dark and space limited (Culver and Pipan 2014:106-127) and if the two Monopterus species are compared morphologicall to the most exteme interstitial species many similarities can be noted. [See also Culver and Pipan (2008) and Pipan and Culver (2012) for discussions of shallow (or superficial) subterranean habiitats, SSHs].

Systematics

A member of the 'Amphipnous group' of Monopterus.

Museum Holdings

As above only.