Pacific Fanfish, Pteraclis aesticola (Jordan & Snyder, 1901)

Introduction

Pacific Fanfish have greatly expanded dorsal and anal fins. The species occurs in marine waters throughout much of the Pacific region.

Identification

The Pacific Fanfish has a strongly compressed body that is covered with spiny scales. It has a narrow caudal peduncle and strongly forked caudal fin. The eyes are positioned well away from the arched head margin. The fan-like dorsal and anal fins of adults can be depressed into slots created by enlarged scales.

The species is silvery, blue-greenish to black with bright blue dorsal and anal fins.

The genus name comes from the Greek word "ptera" meaning wing and "clis" meaning shut. The name refers to the impressive dorsal and anal fins of this species and presumably how they retract into scaly sheaths along the upper and lower margins of the fish.

The Pacific Fanfish looks similar to the Fanfish Pteraclis velifera. The two species can be separated by the number of vertebrae (45-48 in the Pacific Fanfish vs 51-54 respectively), dorsal fin rays (49-52 vs 54-57) and anal fin rays (40-44 vs 47-50).

Distribution

The Pacific Fanfish occurs in marine waters throughout much of the Pacific region.

In Australia it is known from marine waters of northern to central New South Wales.

The map below shows the Australian distribution of the species based on public sightings and specimens in Australian Museums. Source: Atlas of Living Australia.