This figure is the Big-scaled Redfin, known in Japan as Ugui, Pseudaspius hakonensis (originally posted as Tribolodon hakoensis, but the genus was updated in 2011), number 07 from the first series. It’s the first non-salmonid since the first figure, the Ayu , a smelt. The Big-scaled redfin is one of many true minnows referred to as a ‘dace’, which is not specifically defined as anything other than a type of minnow (kind of a pointless word then…).
