Description
Neptune Grouper – Cephalopholis igarashiensis
Cephalopholis igarashiensis, known as the Neptune Grouper, is one of the most legendary and visually striking deepwater reef fish in existence. Its radiant rose-to-gold coloration, accented by glowing magenta bands and a luminescent sheen, makes it a living gem of the mesophotic zone. Endemic to deep outer reef slopes, this elusive species inhabits near-freezing depths where collection requires extreme technical diving. Revered as the pinnacle of rarity and beauty, the Neptune Grouper stands as the crown jewel of any serious marine collection.
Origin: Western Pacific – Japan, Taiwan, Palau, Indonesia, and occasionally the Philippines
Depth: 100–250 m (330–820 ft)
Lighting: Low (prefers very subdued, blue-spectrum lighting to mimic deepwater environment)
Flow: Moderate to strong with stable oxygenation
Tank Placement: Lower regions with shaded caves and vertical rock faces
Temperature: 68–74°F (20–23°C)
Salinity: 1.022–1.026 SG
pH: 8.1–8.4
Diet: Carnivorous – feeds on small marine fish, shrimp, squid, and other meaty foods; should be trained onto frozen or prepared diets
Temperament: Semi-aggressive predator; generally tolerant of larger, robust tankmates
Size: Up to 45 cm (18 inches)
Care Level: Expert – requires large, mature aquariums with deepwater acclimation, chilled temperature stability, and exceptional filtration
Compatibility: Best suited to dedicated species or large-display systems; incompatible with small ornamental fish or crustaceans
Collector’s Note: Cephalopholis igarashiensis is among the rarest and most coveted deepwater fish in the marine trade. Specimens are collected from extreme depths exceeding 200 m, where decompression and survival rates are extraordinarily low. Each successfully acclimated individual represents a true triumph of marine husbandry — a masterpiece specimen reserved for only the most advanced aquarists and elite Collector’s Corner displays.
