Page 54 - Present Day Wildlife_Float

Eels are snake-like fish. There are around 900 to 1000 species of eel that consist of eight
suborders, 20 families, and 164 genera, in the order Anguilliformes. Eels are a global species and
although many species are found in the shallow waters of the oceans, others also inhabit inland
freshwater rivers, marshlands and lakes. The size of eels varies from a length of around 5 cm to 4
metres and a weight of around 30 g to well over 25 kg. The largest known eel is believed to be the
European conger that weighs around
110 kg and is about 3 metres in
length. Other eels are known to be
longer - like the Giant moray, at 4
metres - but are not so heavy.

Eels are recognisable by their
long snake or worm-like bodies. Alt-
hough recognised as fish, they do not
have pelvic nor in most species pec-
toral fins. They have a continuous
dorsal fin, an anal and caudal fin.
Their bodies are scaleless, and their
colour is usually grey or black in
deep-sea eels, but bright and colour-
ful in tropical reef species. They
swim in an undulating motion creat-
ing waves to push themselves both
backwards and forwards.

An eel’s life cycle starts as a flat and transparent larva,
called leptocephali. This larva simply drifts near the water’s
surface feeding on any edible particles, like diatoms and mi-
nute crustaceans, floating in the water. The larva goes through
several stages of, metamorphosis before becoming a glass eel.
It’s only when it reaches this stage that the larva is recognisable
as a juvenile eel. It’s then that it will begin to search for its nat-
ural habitat. Depending on the species some will remain in the
shallow waters along the coastline while many will find fresh-
water inlets and swim further inland to marsh areas or lakes.
Eels are able to survive out of water for quite a long time, and
are known to move across grassy wetland, so any inland obsta-
cles can often be traversed. Depending on the species eels can
live for 20 to 80 years, before they finally leave their habitat
and return to the ocean and their birthplace to spawn.

Eels are carnivores, preying on small fish, invertebrates,
crustaceans, shrimp, crabs and sea urchins. Some species will
eat insect larvae, while others are known to be cannibals. All
eels are scavengers, and will feed on refuse and other decaying
organic matter, like dead animals. Eels also have their fair
share of predators who feed on them. These include larger fish
and seabirds, like the heron. Some mammals will also eat eels
including raccoons and humans. Its man’s involvement, how-
ever, that has had the biggest impact on the dwindling eel
numbers. For decades the eel was a cheap natural sea food that
most could afford. However, as numbers dwindled its status
has been elevated to luxury food and very expensive. Now, seen
as a very profitable product, this has resulted in some species
like the European, American and Japanese eels being over
fished and listed as endanger species. However, many coun-
tries refuse to restrict or ban the import of this exclusive and
very profitable product.