Sunday, December 1, 2024

[Ichthyology • 2024] Chromis abadhah • A New Species of Damselfish (Teleostei, Pomacentridae) from mesophotic coral ecosystems of the Maldives

 

Chromis abadhah
L.A. Rocha, Pinheiro, Najeeb, C.R. Rocha & Shepherd, 2024  
  
 
Abstract
A new species of Chromis (Teleostei, Pomacentridae) is described from four specimens collected between 95 and 110 m depth in mesophotic coral ecosystems in the Maldives, Indian Ocean. Chromis abadhah sp. nov. can be distinguished from all of its congeners by the following combination of characters: dorsal-fin rays XIII, 12–13; anal-fin rays II,11–12; pectoral-fin rays 17–18; tubed lateral-line scales 17; gill rakers 7+17–18 = 24–25; pearly white body with a large black marking covering the anterior two-thirds of the anal fin. The closest DNA barcode sequence (5.1% average uncorrected genetic distance on the mitochondrial COI gene), among those available, is Chromis woodsi, a similar mesophotic species known from the coastal western Indian Ocean (Somalia to South Africa). The new species is easily distinguished from C. woodsi by having 13 dorsal spines (versus 14 in C. woodsi), the absence of a black band on the base of the tail (present in C. woodsi), and by the genetic difference.

Key words: COI, deep reefs, ichthyology, Indian Ocean, rebreather diving, taxonomy

Holotype of Chromis abadhah, CAS 248401, 68.7 mm SL, shortly after collection.
Photo by Luiz Rocha.

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

 Chromis abadhah sp. nov.
 Suggested Maldivian name: Abadhah Chromis 
Suggested English name: Perpetual Chromis

Diagnosis: The following combination of characters distinguishes Chromis abadhah sp. nov. from all of its congeners: dorsal-fin rays XIII, 12–13; anal-fin rays II,11–12; pectoral-fin rays 17–18; tubed lateral-line scales 17; gill rakers 7+17–18 = 24–25; body pearly white; large black marking covering anterior two-thirds of anal fin; small black spot on upper edge of pectoral-fin base; no markings on caudal peduncle.

Etymology: The work that led to the discovery of this species was funded by the Rolex Perpetual Planet initiative through a Rolex Award for Enterprises to LAR. To honor this initiative, we name this species “abadhah” (pronounced aa-BAH-duh), which means “perpetual” in Dhivehi, the local language of the Maldives. We also hope that this species and its habitat remain perpetual. To be treated as a noun in apposition.


Luiz A. Rocha, Hudson T. Pinheiro, Ahmed Najeeb, Claudia R. Rocha and Bart Shepherd. 2024. Chromis abadhah (Teleostei, Pomacentridae), A New Species of Damselfish from mesophotic coral ecosystems of the Maldives. ZooKeys. 1219: 165-174. DOI: doi.org/10.3897/zookeys.1219.126777