Eel of Fortune

My hovercraft is full of eels

– Monty Python

The weather has been cooler and drier compared to most years – fewer rainy days and not many actually hot days.  Some nights in June needed blankets, and there were a couple of days when long sleeves were the right choice.

But now July is here and we’ve had our first taste of real sweltering, sticky weather.  Thank goodness the summer holidays (13 years of teaching English in Japan, and I still refuse to use the word “vacation”) are almost upon us, because the kids turn into zombies when the temperatures and humidity rise but the tests have all finished.


One outcome of the hot, sticky weather is a natural decrease in appetite (plus a desire to be thin for the pool/beach look), causing iron deficiencies, which can lead to anaemia – or, so the popular belief goes.

The reality is many people don’t get enough protein and vitamin B1 during this period.  They tend to remain as motionless as possible in air-conditioned rooms, and their appetite decreases.  They avoid eating meat because they’re not hungry and end up feeling listless and too tired to eat.

The Japanese have a word for this – natsubate.

The Japanese also have a favourite booster for their iron, protein and vitamin B intake at this time of year, and that is grilled eel.

My first encounter with eel was during my 12 month stint in Nagoya (1992-3).  Nagoya is famous for its eel cookery, and combines methods from eastern and western Japan.  Every establishment – some of them in business for generations – has its own sauce, and I can understand the passion for the taste of freshly grilled eel, particularly unagikabayaki.

Mmmm… unagikabayaki. Good, but not cheap. And getting even more not cheap.  Photo taken from Wikipedia (Do you think I can afford to eat this?!)

Eels and their distant relatives (morays, congers and lampreys) must be cooked – their blood contains proteins which, in their raw state, are toxic to humans.


Two kinds of freshwater eel are native to Japan, the Japanese eel (Anguilla japonica) and the marbled eel or giant mottled eel (Anguilla marmorata).  The former, known locally as unagi (鰻) is found in freshwater all over the country.  Actually, the term unagi applies to any eel in general, so the japonica is occasionally called Nihon unagi to differentiate it from other commercial species.

Japanese freshwater eel. This is how eels spend much of their time – buried in substrate. Photo taken from Wikipedia.

The marmorata’s range is known to be as far north as the Tone River, but it is largely restricted to the sub-tropics, and is very rare north of southern Kyushu.  Known as o-unagi (大鰻) – literally “big eel” – it is a protected species in many areas north of the sub-tropics.  Again, the name is generic for all giant eel species.

Giant mottled eel. Younger specimens may lack the skin pattern and be difficult to distinguish from other eels. These eels can grow over 2 metres in length and live for more than 40 years.  Photo taken from Wikipedia.

Japanese eels grow up to 1 metre long, and giant mottled eels more than double that.  Both species are primarily nocturnal, feeding on worms, insects, fish, frogs and crustaceans.  They spend much of their time either burrowed or hidden under wood or rocks.


Freshwater eels have a life-cycle that is almost the opposite of salmon.  Whereas salmon hatch in rivers, live most of their lives at sea and return to the rivers to spawn, eels spawn at sea, live most of their lives in rivers and lakes, and eventually return to the sea to spawn.

Despite their importance as a commercial fish for centuries, it was not known until recent years exactly where they spawned, a point west of the Mariana Islands.

Newly hatched eel larvae (leptocephali) are thin and transparent, and lack red blood cells; it is hard to imagine them as eels.  Through a combination of swimming and ocean currents, they make their way toward land – in the case of the Japanese eel, this trip is up to 3000 km.  During this period, they develop red blood cells and take on a more eel-like appearance.  They are known as glass eels, as their skin is still transparent.  At the glass eel stage they make their way into fresh water, where they continue to grow and skin pigmentation develops and the young are known as elvers.


Glass eels. Note that the internal organs can still be seen. Photo taken from Wikipedia.

Eels have been in the news recently because catches are down and (naturally!) the prices have gone up.  Even though most eel consumed in Japan is artificially raised, it still must be caught at the glass eel stage, which depends on wild eels successfully breeding.

Experimental artificial breeding in the laboratory has proven successful (including feeding the larvae on yolks of shark eggs) but is still too expensive to be applied to commercial aquaculture.

Meanwhile, wild eel populations have decreased, possibly in part due to a shift in ocean currents, changes in water temperatures, and effects of the Great East Japan Earthquake, but mostly due to the usual reasons – overfishing and loss of habitat.


I have written quite a lot here about the eel’s status as a food source – it is almost a national cult – but there are a few surprising exceptions.

Several towns hold the eel to be a messenger of the gods.  Hino in Tokyo has a legend that eels plugged a hole in a dyke when the Tama river flooded, saving the town.  Yotsuya in Shinjuku Ward, Tokyo, has the same legend.  The Minamimura area of Gujo in Gifu Prefecture holds that a millennia ago eels drove away demons.  Older families in these areas often don’t eat eel, and some towns may not have any eel restaurants at all.  Eel fishing may even be prohibited by local ordinance.


I actually have a pet eel (by pet, I mean that it is NOT going to end up on the table), and I’m pleased to have found that other people also keep eels in the aquarium.  The more people who see aquatic wildlife as something other than a dish, the better.

Kabachan, my pet eel. “What’s that I can smell?”

“Aha! Lunch!” Kabachan about to munch on a worm.

This entry was posted in Suburban wildlife and tagged , , , , . Bookmark the permalink.

2 Responses to Eel of Fortune

  1. Chris hole says:

    I am soon to be one of the cast of the new tv show eel of fortune on animal planet

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