The New Zealand triplefin Grahamina signata (Teleostei; Tripterygiidae): A junior synonym of G.gymnota from Tasmania

The triptcrygiid fish Grahamina signata Fricke & Roberts, 1993 was described from 174 specimens collected from several exposed locations around the coast of New Zealand. It was distinguished from the Tasmanian G. gymnota (Scott 1977) by the number of pored scales in the lower lateral line, the number of branches of the supraorbital tentacle, and the colouration of the pectoral-fin base.Examination of new material of G. signata from the Auckland region, and re-examination of type material of G. gymnota, show that the supraorbital tentacle and lower lateral line are not differences of taxonomic significance. Pectoral fin colouration in a published underwater photo of G. gymnota suggests that the colour difference was due to the effects of preservation. We therefore refer G. signata to the synonymy of G. gymnota. This synonymy, in combination with the restricted Tasmanian distribution and dispersal capabilities of the species, suggests that G. gymnota was introduced to Tasmania from New Zealand.

1993年由Fricke与Roberts发表的三鳍鳚科（Tripterygiidae）鱼类格雷氏细纹三鳍鳚（Grahamina signata Fricke & Roberts, 1993），其命名依据为采自新西兰沿岸多处开阔暴露生境的174号标本。该种曾以眼下侧线具孔鳞片的数量、眶上触手的分枝数以及胸鳍基部的体色，与塔斯马尼亚产的裸身格雷三鳍鳚（G. gymnota (Scott 1977)）相区分。对采集自奥克兰地区的G. signata新标本进行检视，并重新核查G. gymnota的模式标本后发现，眶上触手与眼下侧线的特征并不具备分类学意义。一篇已发表的G. gymnota水下照片显示，二者此前报道的胸鳍体色差异实则为标本保存效应所致。因此将G. signata归入G. gymnota的同物异名。结合该种有限的塔斯马尼亚分布范围与扩散能力，推测G. gymnota是由新西兰传入塔斯马尼亚的外来物种。