A survey of fishing villages along Madagascar’s coastal shores has revealed the first confirmed records of the endemic blue-spotted bamboo shark Chiloscyllium caeruleopunctatum in 20 years. The species is a member of the family Hemiscyllidae, a group commonly referred to as longtail carpet sharks or bamboo sharks; the common name walking sharks has gained traction because of the ability of members of this family to walk over coral and rocky reefs and between tide pools using their pectoral fins.

Chiloscyllium caeruleopunctatum was described in 1914 from a single specimen collected off Fort Dauphin (now Tôlanaro), on the south-east coast of Madagascar. The holotype is housed at the Paris Museum of Natural History (1914-0009). Its taxonomic history has been somewhat convoluted, with most authors until recently considering it a synonym of the white-spotted bamboo shark, Chiloscyllium plagiosum, an Indo–West Pacific species known from India to Southeast Asia, Indonesia, China, the Philippines and Japan. A second specimen—the only confirmed record we could find of this species since 1914—was caught and photographed in 2006 off Toliara on the west coast of Madagascar.

During a September 2025 survey of the elasmobranch fauna of Madagascar, four specimens of this mysterious shark were encountered, bringing the total number of known specimens to six. Three specimens were from the east coast, at the Ampilao fish landing site near the village of Andranodaro. These records extended the known range by 418 km north of Tôlanaro and are the first confirmed records from the east coast of Madagascar. The fourth specimen was found in the fish collection of the University of Tulear, in Toliara on the west coast.

Previously known only from Tôlanaro and Toliara, which are at a coastline distance of 621 km, the new records from Andranodaro extend the known range to c. 1,000 km of coastline. The Ampilao fish landing site is an artisanal fishery where fishers go out for the day. The three specimens were caught locally to the landing site, and, according to the fishers who caught them, at a depth of 11 m. Bamboo sharks are considered inhabitants of shallow coastal waters, making them potentially vulnerable to intense fishing exploitation.

The 2021 IUCN Red List assessment categorized C. caeruleopunctatum as Data Deficient. Rediscovery of the blue-spotted bamboo shark highlights the importance of enhanced collaboration between academic, governmental and non-governmental institutions in finding these lost sharks, and the need for a reassessment of the species’ Red List category.

DAE acknowledges the Save Our Seas Foundation (grant 594) for support of the Lost Sharks programme.