[1][2] The species occurs in East Asia, in the shallow coastal waters of the north-western Pacific Ocean.

[4] E. ijimae is found off the coasts of China, Japan (including the Ryukyu Islands), and Taiwan.

Adult males typically see an increase in BW from early spring to late summer and females occasionally undergo a rapid BW decrease from late autumn to early spring followed by a steady weight regain.

[2] Neonates begin reproductive activity in the second or third summer and third spring after birth.

Studies have suggested that E. ijimae is an income breeder that relies on temporal energy intake to produce offspring.