Fish
Barred mudskipper / Periophthalmus argentilineatus / Minami tobihaze / ミナミトビハゼ
As its name implies, this fish lives on the sandy mudflats of mangrove forests, where it preys on small animals like crabs and worms. In fact, it avoids deep water, moving away from the tide and even climbing mangrove shrubs or concrete seawalls. It has gills that hold water, and it can breathe through its skin. The female is the larger sex, growing up to 10 centimeters long, while the male averages 5 centimeters. The eyes of the barred mudskipper protrude frog-like from its head, but can be retracted when it is frightened. The fish moves in various ways, including crawling forward with a “rowing” motion using its pectoral fins. It also earns its name by propelling itself in leaps of up to 1 meter by rapidly folding and expanding its tail like a spring.
Ryukyu ayu fish / Plecoglossus altivelis ryukyuensis / Ryukyu ayu / リュウキュウアユ
The Ryukyu ayu is endemic to Amami-Oshima. It is a slightly smaller subspecies of the sweetfish found throughout mainland Japan. It was also found in Okinawan waters as recently as 1978, but has since become extinct on that island. Its habitat is now limited to a few rivers on Amami-Oshima. The fish reaches a maximum length of about 20 centimeters, and has a silvery body with hints of other colors. The eggs hatch in winter not far from the mouth of the river, and the young migrate to the sea, where they grow into juveniles. In April and May they swim upstream, where they stay until returning to the lower reaches of the river between December and February. There they lay eggs before their life ends. Although the species is a prized food fish in Japan, the Ryukyu subspecies, now designated a critically endangered species, needs protection to survive.
