Caecilians are limbless burrowing Amphibians found in tropical regions of Asia, Africa and South America. They resemble Earthworms, with circular folds on their skin which make them look segmented and skin covering their eyes (though they can see), though they are true Vertebrates with visible jawbones, which all Worms lack.. Unlike snakes they have greatly reduced or even absent tails with their anus close to or at the tips of their bodies. Caecilians are predatory with a well developed sense of smell.
Members of the Family Ichthyophiidae are found in Asia from India east to the Philippines, and south through Myanmar to southern China, Thailand, and the Malayan Archipelago, ultimately reaching the Wallace Line. the Ichthyophiidae was formerly divided into three genera, Caudacaecilia, Ichthyophis, and Uraeotyphlus, but molecular phylogenies have suggested that Caudacaecilia and Ichthyophis are not genetically distinct, and thus all species from both genera have been placed in the single genus Ichthyophis (this having been named first). Thus, Ichthyophis currently contains 49 species of Caecillians, in two distinct colour types, one having a pair of lateral stripes in a yellow or cream colour, and one lacking any such. All members of a species appear to always belong to a single colour type, but this is no guide to relationships between species.
In a paper published in the journal Asian Herpetological Research on 9 December 2024, Dingqi Rao and Hongxin Zhou of the Kunming Institute of Zoology, Mingzhong Mo of the Forestry and Grassland Administration of Honghe Prefecture, Zhiyong Yu of the Fenshuiling National Nature Reserve, and Xiuyan Li and Shou Liu, also of the Kunming Institute of Zoology, describe a new species of Ichthyophis from Yunnan Province, China.
In 1922 German zoologist Rudolph Mell reported observing a unmarked species of Ichthyophis on Luofu Mountain in Guangdong Province, but aside from this, all other records of the genus in China are of striped species. Then, in June 2023, a group of local residents in Jinping County of Yunnan Province found a dead and partially dried Caecilian beside a road near the village of Maandi, which they took to Mingzhong Mo. He in turn took it to the Kunming Institute of Zoology, where it was recognised as a stripeless Ichthyophis.
A subsequent search of the area by zoologists from the Kunming Institute of Zoology recovered another five specimens, including two sub-adults, all od which were lacking in stripes. A subsequent genetic analysis confirmed that these were a new species of Ichthyophis, forming a sister species to Ichthyophis chaloensisi, a stripeless species from Vietnam. The new species is named in honour of Datong Yang, the first herpetologist to describe a new species of Ichthyophis from China.
The largest specimen of Ichthyophis yangi is 324 mm in length and 16 mm wide at its mid-body. All are grey in colour, without any markings. The head is flattened and widest behind the mouth, tapering towards the tip of the snout. The eyes are covered by skin. Teeth are small and hook-shaped. The species is only known from the area around Maandi Village, with most specimens found under stones on farmland close to a stream.
