Eel
Eels (Anguilliformes) are an order
of fish, which consists of four suborders, 20 families,
111 genera and approximately 800 species. Most eels
are predators. The term "eel" is also
used for some other similarly shaped fish, such
as electric eels and spiny eels, but these are not
members of the Anguilliformes order.
Eels are elongated fish, ranging in length from
5 centimetres (2.0 in) in the one-jawed eel
(Monognathus ahlstromi) to 4 metres (13 ft)
in the slender giant moray. Adults range in weight
from 30 grams to well over 25 kilograms. They possess
no pelvic fins, and many species also lack pectoral
fins. The dorsal and anal fins are fused with the
caudal or tail fin, forming a single ribbon running
along much of the length of the animal. Most eels
live in the shallow waters of the ocean and burrow
into sand, mud, among rocks, or in cracks found
in coral reefs. A majority of eel species are nocturnal,
and thus are rarely seen. Sometimes, they are seen
living together in holes, or "eel pits".
Some species of eels also live in deeper water on
the continental shelves and over the slopes deep
as 4,000 metres (13,000 ft). Only members of
the Anguillidae family regularly inhabit fresh water,
but they too return to the sea to breed.
Eels begin life as flat and transparent larvae,
or leptocephali. Eel larvae drift in the surface
waters of the sea feeding on marine snow, small
particles that float in the water. Eel larvae then
metamorphose into glass eels and then become elvers
before finally seeking out their juvenile and adult
habitats.
(Source: Wikipedia.org)
|
