Chromis abadhah is a New Species of Damselfish from the Mesophotic Maldives

A new fish species has been described from the Maldives in the Indian Ocean. Chromis abadhah is described from four specimens collected between 95 and 110 m depth and can be distinguished from similar mesophotic species Chromis woodsi by having 13 dorsal spines versus 14, the absence of a black band on the base of the tail (present in C. woodsi), and by the genetic difference. It was described by Luiz A. Rocha, Hudson T. Pinheiro, Ahmed Najeeb, Claudia R. Rocha, Bart Shepherd and published in the journal Zookeys. 

Chromis abadhah was discovered via ichthyological surveys to depths of 150 meters at 21 locations across five atolls in the Maldives, Indian Ocean, between January 2022 and October 2023. The surveys were carried out by the California Academy of Sciences, the Maldives Marine Research Institute, and Rolex. Several new species of fish were discovered, and Chromis abadhah is the first of those discoveries to be described. 

78 valid Chromis species 

According to the research article, Chromis is still the most species-rich genus within Pomacentridae, comprising 78 valid species, they are all zooplanktivorous, and at least 10 of which, including several recently described, are found only below 60 m. Chromis is also the only genus of Pomacentridae that occurs below 80 m and down to at least 180 m depth. 

Habitat and Distribution 

The research article says that “Chromis abadhah is only known from the Maldives. It has been recorded at eight locations spanning 180 km (from Faadhippolhu to Dhaalu Atoll) so we presume it should be widely distributed across the Maldivian Archipelago. The type specimens were collected on a steep slope between 101 and 118 m depth off Maafilaafushi Island, and other individuals were observed elsewhere between 80 and 120 m depth. Habitat complexity was medium to high (small crevices and caves) but of low relief, with an apparently high diversity of encrusting sponges.” 

Common name 

The authors suggest the Common names of Abadhah Chromis, or Perpetual Chromis. The Rolex Perpetual Planet initiative funded the work that led to the discovery of this species. To honor the initiative, it is named “abadhah” (pronounced aa-BAH-duh), which means “perpetual” in Dhivehi, the local language of the Maldives. 

Citation 

Rocha LA, Pinheiro HT, Najeeb A, Rocha CR, Shepherd B (2024) Chromis abadhah (Teleostei, Pomacentridae), a new species of damselfish from mesophotic coral ecosystems of the Maldives. ZooKeys 1219: 165-174. https://doi.org/10.3897/zookeys.1219.126777

Picture Credit: Chromis abadhah in its natural habitat in Faadhippolhu Atoll, Maldives, at approximately 110 m depth. Photo by Luiz Rocha.