Razor clams are highly prized for their delicious taste and nutritional benefits. Species of razor clams, such as Solen grandis and Cultellus attenuatus, are particularly important in the edible shellfish market and are major contributors to the economy in China. There has been a growing interest among researchers in the artificial breeding, aquaculture, development and utilization of these species. However, the taxonomy and phylogeny of these bivalves have not received much attention.
Species are the fundamental units of taxonomy. The formation of new species is the basis for the emergence and development of a new gene pool, which directly contributes to an increase in biodiversity.
Recently, the research team led by Prof. ZHANG Junlong from the Institute of Oceanology of the Chinese Academy of Sciences (IOCAS) discovered and reported a new species called Cultellus exilis. The team used an integrative taxonomic approach that included morphological comparisons, geometric morphometrics, and genetic analyses, which helps to accurately identify and classify this new species.
The study was published in Zoosystematics and Evolution on Apr. 9.
The holotype of new species was collected from the South China Sea using the Agassiz trawl in May 2021. This species can be morphologically distinguished from other congeners by its slender valve. The geometric morphometric analyses based on outline data of valves showed that samples of new species were obviously separated from other cultellusids. The results of three species delimitation (ABGD, bPTP, GMYC) based on mitochondrial COI genes demonstrated that this species belongs to the genus Cultellus but is genetically distinct from other known species.
In addition, phylogenetic analysis of the superfamily Solenoidea was performed based on the concatenation of three genes (COI+16S+28S) in this study. "The division of the subfamily Pharellinae previously established based on morphology is problematic and needs to be revised by combining more information and taxa," said YU Yanan, first author of the study.
The type specimens of this new species are preserved in the Marine Biological Museum, Chinese Academy of Sciences (MBMCAS). Moreover, researchers discovered some historical specimens collected over a century ago in the same museum that belong to this new species.
"MBMCAS contains a vast number of historical marine specimens, which can provide valuable materials for studying the taxonomy and phylogeny of marine organisms," said Prof. ZHANG, corresponding author of the study and also the lead curator of the museum.
Fig. 1 The holotype of Cultellus exilis
Fig. 2 The type materials of other species of the genus Culetellus
Yanan Yu, Yingyi Jiao, Junlong Zhang. (2024). Description of a new species of the genus Cultellus Schumacher, 1817 (Bivalvia, Pharidae) from the South China Sea, based on integrative taxonomy. Zoosystematics and Evolution.
(Text by ZHANG Junlong & YU Yanan)
Media Contact:
ZHANG Yiyi
Institute of Oceanology
E-mail: zhangyiyi@qdio.ac.cn
(Editor: ZHANG Yiyi)