image: Map of the North-western Pacific Ocean, showing the geographical distribution of Squalus shiraii view more
Credit: Sarah Viana
Newly discovered creatures can often be as impressive and exciting as the ones from the Japanese movies and shows. Many of those fictional characters, including inhabitants of the famous Pokémon universe, might have their analogues among the real animals native to Japan. Maybe, a new species of the dogfish shark published in the open-access journal Zoosystematics and Evolution is also "a real Pokémon" to be?
A new deep-water dogfish shark: Squalus shiraii, was discovered in the tropical waters of Southern Japan by an international team of scientists, led by Dr. Sarah Viana from South African Institute for Aquatic Biodiversity.
The new shark has the body length of 59-77 cm and some unique characteristics such as tall first dorsal fin and caudal fin with broad white margins. Currently, the species is known exclusively as a Japanese endemic, occurring in the tropical shallow waters of Southern Japan in the North-western Pacific.
Spurdogs represent commercially important for the world fish trade taxa. They are caught for a range of purposes: consumption of meat, fins and liver oil. Despite their high occurrence, the accurate identification data of species is scarce, population threats and trends remain unknown.
Japan currently represents one of the world's leading shark fish trade countries, though, during the last decades the amount of shark catches is decreasing and over 78 elasmobranch species traded in Japanese shark fin markets are now evaluated as threatened.
The new species Squalus shiraii previously used to be massively misidentified with shortspine spurdog, due to the resembling shape of body, fins and snout length. However, there are some differences, defining the specificity of the new species.
"Squalus shiraii has body brown in colour, postventral and preventral caudal margins whitish, dorsal and ventral caudal tips broadly white and black upper caudal blotch evident in adults. S. mitsukurii has body conspicuously black to dark grey and caudal fins black throughout with post-ventral caudal margin fairly whitish and black upper caudal blotch not evident in adults", shares lead author Dr. Viana.
Scientists propose the name for the newly described species as Shirai's spurdog in honor to Dr. Shigeru Shirai, the former Japanese expert of the group.
###
Original source:
Viana STFL, Carvalho MR (2020) Squalus shiraii sp. nov. (Squaliformes, Squalidae), a new species of dogfish shark from Japan with regional nominal species revisited. Zoosystematics and Evolution 96(2): 275-311. https://doi.org/10.3897/zse.96.51962
Journal
Zoosystematics and Evolution