Yunnanilus macrogaster

{{Short description|Species of fish}}

{{Speciesbox

| status = DD

| status_system = IUCN3.1

| status_ref = {{cite iucn |author=Devi, R. |author2=Boguskaya, N. |date=2009 |title=Yunnanilus macrogaster |volume=2009 |page=e.T23176A9425350 |doi=10.2305/IUCN.UK.2009-2.RLTS.T23176A9425350.en |access-date=14 November 2021}}

| taxon = Yunnanilus macrogaster

| authority = Kottelat & X. L. Chu, 1988{{FishBase | genus = Yunnanilus | species = macrogaster | month = October | year = 2017}}

}}

Yunnanilus macrogaster is a hypogean species of stone loach endemic to China. This species is endemic to the endorheic drainage system which feeds the Datangzi Marsh in Luoping County, Yunnan,{{cite journal | author = Kottelat, M. | author-link = Maurice Kottelat | year = 2012 | title = Conspectus_cobitidum.pdf Conspectus cobitidum: an inventory of the loaches of the world (Teleostei: Cypriniformes: Cobitoidei) | url = https://lkcnhm.nus.edu.sg/app/uploads/2017/06/Conspectus_cobitidum.pdf| journal = The Raffles Bulletin of Zoology | volume = Supplement No. 26 | pages = 1–199}} the marsh has been formed by the outflow of a stream from its underground course. It is a demersal species and the waters where it was found were densely vegetated, it feeds on worms and insects. It is sympatric with Yunnanilus niger and Y, paludosus, forming a small species flock.{{cite journal | author1 = Maurice Kottelat | author2 = Chu Xin-Luo | year = 1988 | title = Revision of Yunnanilus with descriptions of a miniature species flock and six new species from China (Cypriniformes: Homalopteridae) | journal = Environmental Biology of Fishes | volume = 23 | issue = 1–2 | pages = 65–94| doi = 10.1007/BF00000739 }} Abstract It lays eggs which it does not guard.{{cite book | author1 = Aldemaro Romero | author2 = Yahui Zhao | author3 = Xiaoyong Chen | year = 2008 | chapter = The Hypogean fishes of China | doi = 10.1007/s10641-009-9441-3 | title = Chinese Fishes. Developments in Environmental Biology of Fishes, vol 28| editor1 = Noakes D.L.G. | editor2 = Romero A. | editor3 = Zhao Y. | editor4 = Zhou Y. | publisher = Springer, Dordrecht | isbn = 978-90-481-3458-8}}

Yunnanilus macrogaster has a moderately elongated and compressed body with a short lateral line which has 6–10 pores and a line of pores on the head. The caudal peduncle is around 1.4 times as long as it is deep and its eyes have a diameter of slightly less than one-fifth of the head length. It grows to a standard length of 63.2 mm. The body is yellowish with an irregular pattern of brown spots on its back and flanks with the dorsal surface of the head being darker and there is a dark patch on the operculum to the rear of the eye. The fins are hyaline and the caudal fin has a vertical black bar at its base but this does not extend to the upper and lower edges of the caudal peduncle. It shows no adaptations to living in caves.

The specific name macrogaster means "large stomach", referring to the swollen bellied appearance of this species.{{cite web | url = http://www.etyfish.org/loaches3/ | title = Order CYPRINIFORMES: Family NEMACHEILIDAE (Stone Loaches) | access-date = 27 January 2018 | publisher = Christopher Scharpf and Kenneth J. Lazara | work = The ETYFish Project Fish Name Etymology Database | year = 2017}}