Boomsong's stream snake is a rare snake only known from three specimens. It was originally described as Parahelicops boonsongi in 1958 on the basis of a single specimen[4] and has since been argued by different authors to fall within either Parahelicops or Opisthotropis.[5][2] Most recently, a 2015 study described a new genus, Isanophis, to accommodate this species on the basis of morphological differences in the teeth size, eye size and placement, pupil shape, keel shape, gross body morphology, and presence of a single prefrontal scale.[6]
Higher taxonomy of Isanophis is variable, with some authors recognizing Natricidae as its own family[6] and others treating it as a subfamily (Natricinae) of the family Colubridae.[2]
Geographic range
I. boonsongi is known only from Loei Province in northeastern Thailand although it may occur in Laos, southern China, and Vietnam.[6]
^ abBeolens B, Watkins M, Grayson M (2011). The Eponym Dictionary of Reptiles. Baltimore: Johns Hopkins University Press. xiii + 296 pp. ISBN978-1-4214-0135-5. ("Boonsong's Stream Snake, Opisthotropis boonsongi ", p. 31).
^ abcdDavid, Patrick; Pauwels, Olivier S. G.; Nguyen, Truong Quang; Vogel, Gernot (2015). "On the taxonomic status of the Thai endemic freshwater snake Parahelicops boonsongi, with the erection of a new genus". Zootaxa3948 (2): 203-217. (Isanophis, new genus, pp. 205–206; Isanophis boonsongi, new combination, pp. 206–208, Figure 1).