The information on this page is written by Ms. Fahmida
Iffat, who is a Marine
Survey Department, Karachi.
All information on this page is the copyright property of
Ms. Fahmida Iffat. As such any information taken
from this section should be given proper credits to the
are around 55 species of sea snakes which are found in the
seas of the world but in the coastal waters of Pakistan,
only 14 species have so far been recorded. Sea snakes
include the group of poisonous snakes which have fangs
that are fixed in front of the upper jaw. This type of
fang is called Proteroglyphous.
On land, poisonous snakes. Cobra and Krait, have
such fangs. Another type of fang called Solenoglyphous
does not exist in sea snakes as it is characteristic of
snakes produce venom from a poison gland that acts on the
victim's nervous system. Its poison contains neurotoxin
operating on the nerve cells of the victim. Neurotoxin
paralyses the respiratory system, ultimately causing
death. The phenomenon is the same as in the case of Cobra
and Krait poisoning. However, the poison of a sea snake is
severer than that of a Cobra or a Krait.
following characteristics distinguish the sea snakes from
the land snakes:
Laterally compressed fin-like tail.
Body is flattened side to side, accompanied by loss of
nostrils are directed upwards and can be closed tightly to
exclude water. Sea snakes feed on fish, crabs and weeds.
Breeding takes place mostly during March - April. All sea
snakes are viviparous, and the number of their young
ranges from 2 - 17. Sea snakes come to surface for
respiration. They can live in the sea from 2 to 8
hours.Their left lung is larger and is almost equal to the
of their body (except the tail). The posterior part of the
lung is used for swimming and balancing the body. Thus its
function is similar to that of the swim bladder of a fish.
sea snakes, except Pelamisplaturus, are found in
the tropical parts of India and the Pacific Ocean. Pelamus
platurus is found beyond these limits.
of living sea snakes in the water is usually based on
their colour pattern, habitat, and behaviour. This
requires practice and experience. In the laboratory,
snakes are identified according to the number and
characteristics of the scales on their head, body, belly
The skin of sea snakes is very much valued in Hong Kong
because of its use in bags, shoes and purses etc.
They are sometimes used for human consumption. Sea snakes
are sold in
fish market at Hai-ho" (Haiman), where they are
chopped up to make
and are eaten by the natives of Tahiti in the South
The poison extracted from sea snakes is used to prepare
many countries. In Pakistan, however, sea snakes
caught during fishing are destroyed, killed, and
Tip of the upper jaw protruding in a hook over the lower
jaw. Mental shield elongated and concealed in cleft,
colour dirty white to pale greenish gray. There are 40 -
50 dark round blotches on the back, with age bands
remaining dorsally, their scales are granular and the
total length range is 470 - 1162mm.
Sindh and Balochistan coast.
is found in deep sea, where the bottom is sandv or rockv.
It is also seen in tidal creeks and other sheltered spots
Commonest of all sea snakes.
The only sea snake with parietal shield on head broken up
into small pieces. It is a small snake with stout
cylindrical body compressed posteriorly, with 45 to 55
series of dark greenish brown, crose
bare. Snout Vent length recorded 676 - 900 mm.
inhabits the rocky coast and visits the surface to take
Most common snake.
This species is common along the western Mekran Coast and
Manora but rare in Karachi.
Ground colour pale peach to greenish white, 25 to 35
rhomboid dorsal blotches fused along midline. Its head is
short, distinct from the neck. Its body is cylindrical
anteriorly and compressed posteriorly, ventral 181-2911,
anterior ones half of the width of body. white throat,
860 to 970 mm.
It inhabits the coastal water and creek.
Recorded in Sindh and Balochistan coasts.
small headed sea snake
Body is long, slender anteriorly, much compressed
posteriorly, its greatest diameter being 4-5 times that of
the neck. 40-60 bands posteriorly, with age the markings
disappear. Adult is usually grayish above, paler below,
ventrals at mid body divided numbering fewer than 350.
1265 mm to 1490 mm .
It inhabits sandy bottoms and muddy mangrove swamps.
small-headed sea snake
Anterior half of body is light olive to yellow, getting
paler below. Posterior half body dark olive above,
yellowish laterally, body with 49 -61 gray to blackbars,
ventrals 393 -404.
Shallow water with muddy and sandy bottom.
A small snake with elongated, depressed head. Snout long.
Ground colour yellow. Scale rows at mid body 47-63.
Ventrals at mid-body divided.
535 mm to 880 mm
It spends long hours on the surface and is active in water
when its temperature is above 25 degree centigrade. It
inhabits coastal waters.
Sindh and Balochistan coasts.
Head moderately broad, slightly depressed; body
cylindrical. There are 41-70 block bandswhich expand
vertebrally. Head is black withhorse-shoe shape marked on
crown. Bands wider than interspace between them. Scales
rows onbneck 29-35, on mid body 37-47; ventrals 290-390.
length of specimens ranged from 850-1185 mm.
It inhabits shallow, muddy and mangrove swamps during
Sindh coast (coastal areas of Karachi); Balochistan coast
(Makran coast, Shimal Bandar).
Head large and broad body olivaceous dorsally, merging in
yellow ventrally and is adorned with 34-70 black bands,
which are narrower than the spaces between them. Scale
rows on midbody 37-41, ventrals 266 to 368. Length of the
snake ranged 1145-1500 mm.
It inhabits off-shore water.
In Sindh it is abundant along the coast of Karachi.
banded sea snake
Head elongated and slightly depressed. Body anterior
cylindrical, posteriorly compressed and heavy; the body
dorsally olivaceous, whitish ventrally; 41-45 black cross
bars; scale rows on body 33 to 55, ventrals 209 to 312.
Ventral shield twice as broad as the adjoining Scales.
Length of specimens ranges from 1065 mm to 1822 mm;
juvenile 310 mm.
Recorded from Pakistan near coast of Astola Island and
Karachi coast near Hawksbay.
Adult has a very small head, elongated, depressed, body is
yellowish or grayish, tail is black with six or more light
rings. Scale rows at mid body 31 to 40; ventrals 302 to
390. Total length 655 mm to 1150 mm.
it inhabits muddy mangrove swamp and sandy beaches.
535 mm to 880 mm
Recorded in Sindh from Karachi coast and in Balochistan
headed banded sea snake
Head very small, body long, slender anteriorly; 488
to 71 black bands. Scale rows on mid body total length
range 470-1200 mm.
It inhabits shallow water where the bottom is sandy or
Sindh and Balochistan coast.
toothed sea snake
Head small; anterior part of body is slender; body
bluish or grayish blue dorsally, yellow ventrally;
35 to 58 deep bluish black bands; scale rows at
midbody 38-54, ventrals 253-334. Total length of
705 mm -1210 mm.
It inhabits muddy creeks with mangrove swamps.
Gulf sea snake
Head olive brown; body elongated, slender anteriorly; top
of the head has curved yellow marks, 45 black bands
uniting at the ventral side. Scale rows on neck 29-35;
midbody 43-51; ventrals 314-372. Snout-Vent length of our
specimens ranged 685 mm to 1130mm.
It inhabits muddy mangrove swamps.
Balochistan Mekran Coast), Sindh (Hawksbay).
large; body stout and cylindrical anteriorly;
ground colour yellowish or pale brown; head dark
olivaceous; body with broad black or dark brown bands
which are 32-34 in number. No specimen
Writer is Marine Biologist at
Survey Department, Karachi