A new species of Trimma goby has been described from Tabuaeran and Kirimati Atolls, Kiribati. The Long-Spined Pygmygoby, Trimma longispinum, is a tiny goby just one inch long or smaller (24.8mm Holotype,) and was collected from a coral reef near the middle of a lagoon.
It joins 109 other valid species within the genus, most of which stay under 30mm in length, are often colorful, and are primarily associated with Indo-Pacific coral reefs. The type species is Trimma caesiura, and was described in 1906 by Jordan & Evermann.
Trimma longispinum differs from its congener T. barralli in having 6 (rather than 5) sensory papillae in cheek row c and in color pattern and distribution, but shares a very elongated second spine of the first dorsal fin. It differs from T. erdmanni and T. preclarum in a longer second spine in the first dorsal fin, and in lacking either a light longitudinal stripe on the cheek (T. erdmanni) or the three pale yellow lines on the body (T. preclarum), the latter of which also has 5 papillae in row c (vs. 6 in T. erdmanni).
Its specific name “longispinum” is derived from the Latin longus (meaning long or extended), in combination with the Latin spinum (meaning spine), in reference to the elongated second spine of the first dorsal fin. It was described by Richard Winterbottom of the Royal Ontario Museum, Canada.
The Tabuaeran and Kirimati Atolls in Kiribati was formerly known as Fanning Island and Christmas Island in the Line Islands. The species is also present off Sand Island, Palmyra Atoll about 370 km to the northwest of Kiribati, as well as possibly at the Marshall Islands (Eniwetok Atoll), and Guam (Mariana Islands).
The species description has been published in the Journal of the Ocean Science Foundation. For more information see Winterbottom, R. (2023) A new species of Trimma (Teleostei: Gobiidae) from the northwestern tropical Pacific Ocean. Journal of the Ocean Science Foundation, 40, 29–36. doi: https://doi.org/10.5281/zenodo.7933655
