Oblique Swimming Triplefin

Body elongated, laterally compressed posteriorly; mouth strongly angled upward; notched scales absent; short, distally complex gill rakers, body yellow with a broad, black stripe extending along upper side of body. Discontinuous lateral line with 16-22 tubular scales. Anterior 2 spines of first dorsal fin shorter than remainder, which are of equal length. No sensory papillae on frontal, temporal and upper part of otic areas. Post-temporal partially serrated. Dorsal fin formula V-0N-0-1-0-1. Ten procurrent rays in both upper and lower caudal lobes; in the upper lobe, 1 procurrent ray between upper lobe and posterior epural, 3 rays opposite posterior epural, 1 ray between posterior and anterior epurals. Two opposite anterior epural, 1 opposite neural spine of second preural vertebra; in lower lobe, 3 rays opposite haemal spine of second preural vertebra, 4 rays between haemal spines of second and third preural vertebra, 2 rays opposite haemal spine of third preural vertebra and 1 anterior haemal spine of third preural vertebra.

Dorsal spines (total): 24 - 29; Dorsal soft rays (total): 12 - 15; Anal spines: 0 - 1; Analsoft rays: 24 - 27; Vertebrae: 42 - 46

Adults are found over rocky reefs at depths of 1- 50 m (Ref. 13227) and usually seen schooling up to 5 m above substratum, although often seen resting in crevices (Ref. 84085).

fisheries: of no interest

The oblique-swimming triplefin, Forsterygion maryannae, is a triplefin, found along the north east coast of the North Island of New Zealand from depths of about 5 m to 50 m. They are the only triplefins not to spend most of their time resting on the bottom, instead swimming in loose schools of up to hundreds of individuals above rocky reefs. When swimming their head is higher than the tail, giving rise to their common name.

Its length is between 5 and 8 cm. The body is orange-brown with a red tinged head, a black eye, and a wide black lengthwise stripe on each flank. Oblique-swimming triplefins are plankton feeders taking their tiny copepod and euphausid crustacean food in mid-water.

Its specific name honours the underwater photographer Maryann W. Williams.