Beryx decadactylus Cuvier, 1829
Colour, Shape and Size
The Alfonsino has a deep compressed body. It has a single short-based dorsal fin. The anal fin has a much longer base and originates below the middle of the dorsal fin. The caudal fin is forked. This species has very large eyes, a large oblique mouth and small ctenoid scales. The Alfonsino is red to pink
sometimes shading to a silvery pink below.
External Anatomy
Dorsal spines (total): 4-4; Dorsal soft rays (total): 13-16; Anal spines: 4-4; Anal soft rays: 26-30. First infraorbital bone with a spine projecting laterally on anterior end.
Lateral line extends to caudal fin. A fleshy disk on inner face of exposed area of scale. In young fishes, the 2nd dorsal ray is elongated an it has pectoral fins with one spine and 17 soft rays. The Alfonsino has also been called Imperador, Longfin Beryx and Red Bream
Natural History
Inhabits deep, cold waters over steep continental slopes, ocean ridges and sea-mounts. Appears to be dispersed over both rough bottoms and steep, rough grounds where it feeds on crustaceans and fish.Orange Roughy have known to be found as deep as 180 – 1809m. In New Zealand, the main prey include mesopelagic and benthopelagic prawns, fish, and squid, with other organisms such as mysids, amphipods and euphausiids occasionally being important. Juveniles feed mainly on crustaceans. Grows very slowly and is one of the longest lived fish species known. Based on parasite and trace-element analyses, orange roughy is a sedentary species with little movement between fish-management zone. Little is known of the larvae and juveniles which are probably confined to deep water. The fishery targets sporadically formed dense spawning and non-spawning aggregations.
Capture
Sophisticated techniques are required to fish at these depths and scientific knowledge about the species of fish remains inadequate. The orange roughy season lasts from May to the following April. Alfonsino is processed on board fishing vessels while Orange roughy is processed on shore.
Specific Catch Restrictions
Commercial catches are subject to quota.
