Grammatonotus bianchi – Andaman splendid perch
Grammatonotus bianchi – Andaman splendid perch ©FAO/E. D’Antoni
Class: Osteichthyes.
Family: Callanthiidae.
Brief description: Caudal fin with extended upper and lower lobes, bright yellow coloration, reddish spots, and a violet or fuchsia edge.
Size: Up to 10 cm in length.
Described by: M.W. Lisher, H. Thein and P.N. Psomadakis (2021).
Etymology: Grammatonotus: Greek "gramma" = signal + "atos" = mark + "noton" = back; bianchi: named in honour of Dr Gabriella Bianchi, former research coordinator of the Nansen Programme.
The Andaman splendid perch is a small fish with a large head and eyes. It has a distinctive colouration, with a unique bright yellow caudal fin covered by reddish spots and a fuchsia or violet distal portion. It is only known from off Myanmar’s Tanintharyi coast in the Andaman Sea, at depths of 182 m to 184 m.
The discovery
Recent surveys conducted in 2013, 2015 and 2018 under FAO’s EAF-Nansen programme, in collaboration with the Myanmar government, utilized the research vessel Dr. Fridtjof Nansen to explore Myanmar’s coastal waters. These efforts culminated in the production of a FAO marine species identification guide to be used by scientists and fisheries data collectors in Myanmar. The guide documents 15 fish species new to science, and identifies 51 potentially undescribed species. Among the notable discoveries were two specimens of the genus Grammatonotus, which could not be identified as belonging to any known species based on morphological characteristics. These specimens were therefore sent to the South African Institute for Aquatic Biodiversity in Grahamstown for detailed examination by taxonomists, who described this new species in 2021.
Features and characteristics
The Andaman splendid perch is characterized by a combination of unique morphological features and vibrant colouration. It possesses a large head, with a proportionally short caudal peduncle that enhances its streamlined appearance. Its eyes are particularly large, a feature that likely aids in navigating its deep-sea habitat. The caudal fin is distinctive, with elongated upper and lower lobes that add elegance to its silhouette. The species’ fresh coloration sets it apart: the bright yellow caudal fin is adorned with reddish spots, transitioning to a vivid fuchsia or violet hue along the outermost edge.
The members of the family Callanthiidae are mostly small (< 25 cm) brightly coloured fishes usually found near the bottom over rocky areas and on reefs at depths of 4 to 660 m. They are popularly known as splendid perches (or groppos) for their magnificent colours and systematic position within the perciform order.
Most are part of deep-reef and mesophotic ecosystems, contributing to the biodiversity and trophic dynamics of these less-explored habitats.
Photo of Grammatonotus bianchi ©FAO/O. Alvheim
Callanthiidae species are not primary targets for commercial or artisanal fisheries. Their relatively small size, deep-water habitat, and often patchy distribution mean they are rarely caught in significant numbers. Their presence in fishing areas can serve as an indicator of habitat health and biodiversity. Maintaining healthy populations of such species helps ensure the overall sustainability of deep-sea fisheries and ecosystems.
Geographical distribution
This species is only known from the Andaman Sea.