In 2022, rising prices driven by inflation forced Hakone‑en Aquarium in Kanagawa, Japan to change its penguins’ diet — and the result was… rejection. The penguins simply refused to eat the cheaper fish. Fortune+2english.alarabiya.net+2

Previously, the aquarium fed its penguins (and some other marine mammals) with “aji” — the Japanese horse mackerel — a fish the animals openly loved. However, due to a 20–30% rise in the price of aji (linked to low catches and inflation), the aquarium decided that in May 2022 they would substitute some of the aji with a cheaper alternative: “saba,” the more common mackerel. english.alarabiya.net+2KTVZ+2

But the animals were unimpressed. Keepers reported that although the penguins sometimes picked up the mackerel and pecked at it, they immediately dropped it — or turned their beaks away entirely. In some cases, they seemed to smell the fish, only to spit it out. According to the aquarium’s head keeper, Hiroki Shimamoto, the birds showed a strong aversion, as if they sensed “something is off.” english.alarabiya.net+2KTVZ+2

The refusal wasn’t limited to penguins. Otters at the aquarium reacted the same way, rejecting the cheaper mackerel uniformly. english.alarabiya.net+2NewsBytes+2

Faced with this dietary rebellion, Hakone-en Aquarium had to reverse course — at least partially — by returning to the original horse mackerel for animals that refused the new diet. Shimamoto emphasized that the facility would never force any animal to eat food they rejected. Nature World News+2Báo điện tử Dân Trí+2

This episode highlights how inflation and rising supply costs can affect even animal-care facilities. The aquarium, home to some 32,000 animals including sharks, seals, penguins, and otters, found itself having to economize in multiple ways — not just food. For example, in addition to changing the diet, they also reduced electricity usage by cutting back on circulation pumps in an effort to save costs. Nature World News+2KTVZ+2

Despite these pressures, Hakone-en said that their priority remained the well-being of the animals and the experience of visitors. They stated they had no plans to raise admission fees, preferring to absorb the increased costs as long as possible. UPI+2english.alarabiya.net+2

From a biological perspective, the incident also underscores how selective some animals can be when it comes to diet. Penguins are piscivorous: their natural diet in the wild includes a variety of fish, squid, and crustaceans — and they may be attuned not only to taste, but also to texture, smell, or nutritional content. Nature World News+2polarjournal.net+2

In short: what seemed a sensible cost-saving measure on paper — substituting with a cheaper fish — turned into a fiasco once the penguins had the final say. The episode offers a quirky but telling glimpse into how global economic pressures, like inflation, can ripple out to unexpected corners — even influencing what a captive penguin will or will not eat.