Sharks have form and different
dimensions: there is for instance the great white shark (Carcharodon
carcharias), that reaches the 7 m, or the whale shark (Rhincodon
typus) that can reach even 18 m of length, but also very small
sharks exist, animals that would comfortably be in the palm of one
Only some aspects of their
behavior and their vital cycle are currently known and really for this
motive there will be interest about close examinations and specific
studies, bringing to scientific searches on the field, trying to resolve
all the mysterious aspect that don't allow to know well these strange
inhabitants of the sea depths.
Despite all some information, due above all to the study of samples accidentally captured, are known by the biologists and profits in this case to introduce a small card of each of these three small shark, with their principal characteristics:
Etmopterus carteri (max: 21 cm)
This shark has black body,
uniform, the face is short and rounded off and the head, as it suggests
the name, has a cylindrical form.
The two dorsal fins are of
averages dimensions and before each of them is present a strong grooved
thorn, precious defense tool against the attacks of the raiders. The
pectoral fins are lobate while the anal fin is absent.
It doesn't have commercial
value, probably for its redoubts dimensions and currently the develop
of the population is not known. (if the number of Etmopterus carteri
is in decrease, stable or in growth)
Etmopterus perryi (max: 21 cm)
Also this shark belongs to the family Etmopteridae, the most numerous of the order Squaliformes. The name of this shark is due to the presence of the photoforis, characteristic bright elements present above all around the mouth and along the sides, with the function to attract small preys creatures, attracted by these weak bright in an almost complete obscurity.
In fact also this lanternshark
normally swims in deep waters, among 280-430 m of depth, always in
proximity of the Caribbean coasts of Colombia.
Eridacnis radcliffei (max: 24 cm)
Very small shark of dark brown
color with characteristics dark banding in the two dorsal fins and in
the caudal fin, to form of ribbon and with the superior lobe very
The face is lengthened and the
eyes are middly developed, with the presence of a rudimentary nictitant
membrane. The Eridacnis radcliffei can swim to elevated depth,
from 70 up to 750 m and it is mainly diffused in the waters of India,
Philippines, Vietman and in the Indo-Pacific.
Bibliography: "Sharks & Rays, Elasmobranch
Guide Of The World". Ralf M. Hennemann,
Marco Angelozzi -