An enormous 'isopod' has been discovered in the Gulf of Mexico

These giant isopods can grow up to 1.64 feet.
Nergis Firtina
Image of Bathynomus. yucatanensis
Image of newly identified Bathynomus. yucatanensis

Journal of Natural History/ Ming-Chih Huang

  • Scientists just discovered a new species of giant isopod in the Gulf of Mexico.
  • The new species was named 'Bathynomus yucatanensis.'
  • B. yucatanensis are thinner and shorter than other species. report says

Scientists recently discovered a giant isopod off the coast of Mexico. After analyzing the anatomy and DNA of the woodlouse relative, scientists revealed that it was a completely new species.

The recent study described Bathynomus yucatanensis, a giant isopod subspecies that could grow up to 1.64 feet (49.98 cm) from oblong head to rounded tail. The team’s work is published in the Journal of Natural History.

“It is increasingly evident that species of Bathynomus may be exceedingly similar in overall appearance, and also that there is a long history of misidentification of species in the genus,” the researchers said.

When seen with the naked eye, isopods look like a grain of rice and can dwell on the seafloor, scavenging on the marine snow that all dead things in the ocean become.

During the research, the team discovered that the newly found Bathynomus yucatanensis was thinner and shorter, and was yellower than its other relatives in the gulf. Upon comparing Bathynomus yucatanensis to other species found in the gulf, researchers found that the new giant isopod is similar to B. giganteus than to the species B. maxeyorum.

More about giant isopods

A giant isopod is any of the almost 20 species of large isopods in the genus Bathynomus. They are abundant in the cold, deep waters of the Atlantic, Pacific, and Indian Oceans. Giant isopods were first described by the French zoologist Alphonse Milne-Edwards in 1879, with contributions from his colleague Alexander Agassiz.

Study abstract

Bathynomus jamesi Kou, Chen, and Li, 2017 from Zhengbin fishing port in Keelung, Taiwan, was identified by the shape of the distolateral corner of the uropodal endopod, the shape of the clypeus, and the nucleotide sequences of the COI (cytochrome c oxidase subunit 1) and 16S rRNA genes. Only two species of Bathynomus have previously been recorded from Taiwan, B. doederleini Ortmann, 1894 and B. decemspinosus Shih, 1972. Bathynomus kensleyi, previously known from the South China Sea as well as the south-east Swain Reefs, Coral Sea, was primarily differentiated by the elongate and upturned pleotelson spines, but that character is now shown to also occur in mature Bathynomus jamesi. Two specimens from the Gulf of Mexico (obtained from the Enoshima Aquarium in Japan) were compared to species of Bathynomus from the western North Atlantic. Sequence data showed that one of two samples was not B. giganteus Milne-Edwards, 1879, as had been assumed, and it did not match any other species of Bathynomus. That specimen was collected off the Yucatán Peninsula and is morphologically distinct from both B. giganteus (in the relative length of the antennal flagellum and the length:width ratio of the pleotelson) and B. maxeyorum Shipley, Brooks, and Bruce in Shipley et al., 2016 (the number of pleotelson spines is seven and the distolateral corner is produced on the uropodal exopod). Therefore, it is here described as B. yucatanensis sp. nov. Bathynomus is currently a very minor fisheries resource in Taiwan and Japan, but this find demonstrates the continuing importance of the fishing industry to marine biological exploration.

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