Discoveries of small crustaceans known as tanaids by two researchers from the National University of Singapore’s (NUS’s) Tropical Marine Science Institute.
Tanaids are small crustaceans can be found in virtually all marine benthic habitats, from mangroves, rocky shores and coral reefs along the coasts to mud volcanoes, cold seeps and trenches in the deepest oceans. Tanaids even inhabit the shell surfaces of sea turtles, live inside gastropod shells like hermit crabs, and reside under the skin of deep-sea sea cucumbers.
Due to their sheer number, tanaids are likely to play important ecological roles and are often one of the dominant animals in the community. However, information on their biology remains elusive.
The knowledge gaps include the number of species there are and also their specific names.
Experts have estimated that there could be up to 57,000 tanaidacean species worldwide.
Unfortunately, less than 1,500 species have been described, and the majority of these are in the temperate environments.
Research Associate Mr Chim Chee Kong and Research Assistant Ms Samantha Tong from the Tropical Marine Science Institute at NUS are on a quest to discover more of these nameless taxa, specifically in the relatively species-rich but poorly studied tropical Indo-Pacific.
In a paper that was published in the journal Zootaxa on 31 March 2020, both researchers described two new species found in the abyssal polymetallic nodule fields in the eastern Pacific Ocean during an expedition in 2015. One of them was named Unispinosus eopacificus after the locality of where it was discovered, and the other was named Portaratrum birdi in honour of a leading tanaidacean taxonomist.
Discovery of these two species provide significant understanding for environmental management in the understudied area of the Clarion-Clipperton Zone, which is in the middle of the Pacific Ocean characterized by polymetallic nodule fields. These fields contain commercially valuable metals such as nickel, copper, and rare earth elements that were formed over millions of years.
“Data on the biodiversity in this resource-rich region can allow the International Sea Authority to make well-informed decisions on whether to prioritise certain areas for conservation,” explained Ms Tong.
In another deep-sea expedition to South Java in 2018, Mr Chim and Ms Tong have uncovered many tanaids that are new to science, and are in the process of describing them.
With access to a large amount of local material, primarily collected during the Comprehensive Marine Biodiversity Survey conducted in 2013, the two NUS researchers have also been able to identify more tanaids in local waters. To date, Mr Chim has identified more than 20 species of tanaids from local waters and, as a result, raised the current knowledge of our natural heritage. Prior to this study, only one tanaid species had been formally recorded from Singapore waters, based on specimens that were collected in the 1900s.
Last year, the two researchers described an unusual tanaidacean species found in Singapore that were living inside dead barnacles, which is a novel microhabitat recorded for this group of crustaceans. The findings on the newly named Xenosinelobus balanocolus were reported in the journal Zootaxa on 8 July 2019. [APBN]