Evaluating the phylogenetic position of the goby genus Kelloggella (Teleostei: Gobiidae), with notes on osteology of the genus and description of a new species from Niue in the South Central Pacific Ocean

摘要

Kelloggella is a widely distributed but poorly studied genus of goby (family Gobiidae) that occurs in tide pool and reef flat habitats across the tropical Indo-Pacific region. The phylogenetic position of this genus has never been formally investigated, and its osteology has not been described in detail. The discovery of a new species of Kelloggella from the island of Nuie, coupled with the recent availability of fresh specimens, tissues and photographs of Kelloggella spp. from Hawaii and Easter Island, has led to the current study. Here, we describe the new species as Kelloggella avaiki sp. nov. and investigate the phylogenetic position of Kelloggella within Gobiidae. Molecular phylogenetic data from nuclear and mitochondrial genes suggest a close relationship between Kelloggella and Gobiodon, Eviota and Bryaninops, and possibly Kraemeria. A comparative osteological investigation identified few potentially informative characters, including a reduced ventral branch of the posttemporal, epioccipitals meeting along the dorsal midline posterior to the supraoccipital, hypurals 1-2 fused to hypurals 3-4 and the urostyle and the presence of tricuspid teeth. However, these characters occur elsewhere across gobies, and at best only offer weak support for the relationships hypothesized by the molecular tree. Lastly, we provide colour photographs of five species of Kelloggella and discuss some of the challenges in delimiting species.