Second revision of the New Zealand triplefin genus Forsterygion Whitley and Phillips, 1939 (Pisces: Tripterygiidae)

Abstract

The fish genus Forsterygion Whitley and Phillips, 1939 (Family: Tripterygiidae), previously including six nominal species but lacking synapomorphies, was redefined to include eight species: F. varium Schneider; F. malcolmi Hardy, 1987; F. lapillum Hardy, 1989; F. flavonigrum Fricke and Roberts, 1994; F. capito (Jenyns, 1841); F. gymnota Scott, 1977; F. nigripenne Valenciennes and F. maryannae (Hardy, 1987). The genera Grahamina and Obliquichthys are now included in Forsterygion.

Forsterygion may be distinguished from other tripterygiid genera in having otoliths with elliptic shape, the fifth hypural absent, pterygiophore opposite the neural spine of first vertebra absent, a urohyal with asymmetrical sides, and the first circulus straight. All Forsterygion species are endemic to New Zealand, although F. varium, F. gymnota and F. lapillum have been introduced to Australian waters. A possible hybrid of F. capito and F. varium is discussed.

Keywords:

• Tripterygiidae
• Forsterygion
• triplefin
• New Zealand

Acknowledgements

My sincere thank goes to Kendall Clements (Auckland University) and Graham Hardy (Ngunguru) for reading the manuscript and for their valuable advice and suggestions; Kendall Clements (Auckland University), Andrew Stewart (Te Papa Tongarewa), Brady Doak, Tony Hickey (University of Auckland), and B. Smith (Queen Victoria Museum, Launceston, Tasmania, Australia) for help in providing specimens.