This document summarizes information about sea snakes. It describes their scientific classification, with 64 species divided among 7 genera. It provides details about their physical adaptations like paddle-shaped tails that allow swimming. They can remain submerged for hours and breathe air through lungs and skin. Reproduction involves live birth for most, with the exception of sea kraits that lay eggs. Threats include habitat loss, climate change, and fishing/harvesting. The document lists several rare or endangered sea snake species.

1. Vinod Kumar
FSM – 2021 – 20 – 10
MFSc FRM
KUFOS

2. SCIENTIFIC CLASSIFICATION
Kingdom : Animalia
Phylum : Chordata
Class :Reptilia
Order : Squamata
Sub order : Serpentes
Family : Elapidae
Sub family : Hydrophiinae
: Laticaudinae
Hydrophiinae includes Australasian terrestrial snakes, whereas
Laticaudinae only includes the sea kraits (Laticauda). There are 64
species of sea snakes divided between 7 genera.

4. Range of sea snakes shown in lime green, except the widespread,
pelagic yellow-bellied sea snake

6. Aypisurus laevis
Olive sea snake
Ephalophis greyae
Grey's mudsnake
Emydocephalus ijimae
Ijima's turtleheaded sea snake

7. Hydrelaps darwiniensis
Black-ringed mangrove snake
Hydrophis platurus
Yellow-bellied sea
Laticauda laticaudata
Blue-lipped sea krait
Parahydrophis mertoni
Northern mangrove sea

8. Hydrophis platurus
Yellow Bellied Sea
Snake
Laticauda colubrina
Banded sea krait
Laticauda
laticaudata
Blue lipped sea krait
Enhydrina
schistose
Hydrophis annandalei
Annendeil’s Sea snake
Lapemis curtus
Spine bellied sea snake

9. DESCRIPTION
• The majority of adult sea snakes species grow to between 120 and 150 cm (4
and 5 ft) in length, with the largest, Hydrophis spiralis.
• Most sea snakes are venomous, except the genus Emydocephalus, which
feeds almost exclusively on fish eggs.
• Sea snakes are extensively adapted to a fully aquatic life and are unable to
move on land, except for the sea kraits, which have limited land movement
• All sea snakes have paddle-like tails and many have laterally compressed
bodies that give them an eel-like appearance.
• They are cold blooded animals

10. • There are several features that have allowed sea snakes to adapt
more readily to the marine environment than other reptiles. Marine
adaptations include swimming, respiration, salt excretion, and marine
fouling & skin shedding.

11. PADDLE SHAPED TAIL
They have been reported swimming at depths over 90 m (300 ft), and can
remain submerged for as long as a few hours, possibly depending on
temperature and degree of activity

12. Sea snakes are able to avoid excess salt accumulation from sea water using a salt
excreting gland, the posterior sublingual gland that sits under the tongue.
Skin of sea snakes are very resistant to water, and does not let water in the body
easily

13. RESPIRATION
• Sea snakes are air breathing reptiles and must come to the surface to breathe,
however they can spend from 30 minutes to 2 hours diving between breaths
• The lung has become very large and extends almost the entire length of the body.
The extended lung possibly also serves to store air for dives.

14. • Something else that helps a sea snake stay underwater for so long without
getting a fresh gulp of air is a small air sac at the bottom of their right
lung.This lung stretches all the way down a snake’s body and into its tail.
• Cutaneous respiration : This is a process in which gases are exchanged
through the snake’s skin. Performed during sleeping or brumation

15. • Since the absence of rod cells, vision has a limited role for
catching prey and mate selection, but sound vibrations and
chemoreception may be important
• Tongue can fulfill its olfactory function more easily under water
• The olive sea snake, Aipysurus laevis, has been found to have
photoreceptors in the skin of its tail, allowing it to detect light and
presumably ensuring it is completely hidden, including its tail,
inside coral holes during the day.

16. BEHAVIOR
• Sea snakes are generally reluctant to bite
• On land, their movements become very erratic. They crawl awkwardly in these
situations and can become quite aggressive
• Sea snakes appear to be active both day and night
• They can sometimes be seen swimming in schools of several hundred

17. FEEDING
• All sea snakes are carnivores that mostly eat eels. They also eat small fish,
crustaceans, and eggs.
• H. platurus, which feed by simply gulping down their prey, are more likely to bite
when provoked because they seem to use their venom more for defense.
Others, such as Laticauda spp., use their venom for prey immobilization.

18. • Males have hemipenis
• Females have cloacal, a posterior orifice that serves as reproductive tract.
Mating through the cloaca is known as cloacal copulation.
• Most species reproduce every year. The
timing of the reproductive cycle varies
enomously between species and also
differs between geographical locations for
the same species.

19. • All sea snakes except the latidcaudids give birth to live young after
gestation periods that range from four to eleven months, depending
on the species.
• The one exception is the genus Laticauda, which is oviparous; its
five species all lay their eggs on land
• Young are born underwater and must be independent immediately
to swim to the surface to breathe. There is no parental care.

20. MARINE FOULING AND SHEDDING OF SKIN
All snakes shed their skins. Sea snakes shed every two to six week. The process
involves rubbing the lips against coral or other hard substrate to loosen the skin. The
snake then catches the skin against something to anchor it and crawls forward
leaving the skin turned inside out behind it.
Skin shedding allows sea snakes to rid
themselves of fouling marine organisms such
as algae, barnacles and bryozoans.

21. SEA SNAKE BARNACLE
They are often associated with the
sea snake barnacle (Platylepas
ophiophila), which attaches to their
skin

22. • The majority of the sea snakes are highly venomous, but rarely inject it when
biting
• The most important symptoms are rhabdomyolysis (rapid breakdown of skeletal
muscle tissue) and paralysis. Early symptoms include headache, a thick-feeling
tongue, thirst, sweating, and vomiting.
• Very few human fatalities have been reported.

23. • Sea snakes heart has three chambers
• Right atria
• Left atria
• Ventricle
• The right atrium purpose is to receive
deoxygenated blood from the systemic circulation,
and the left atria receive oxygenated blood from
the lungs.
• The ventricle chamber has internal ridges that
enable a significant functional separation between

24. • Paired kidneys are located in the dorsal caudal coelomic cavity
• Since no urinary bladder is present, urine is not stored and ureters empty directy
into the cloaca.
• Snakes excrete by eliminating all the liquid and solid wastes via cloaca

25. Mentioned In IUCN Red list
Hydrophis : 44
Aipisurus : 9
Laticauda : 8
Emydocephalus : 2
Hydraleps : 1
Total : 64
EN - Endangered (1)
VU - Vulnerable (3)
LR/cd - Lower Risk : Conservation Dependent (0)
NT or LR/nt - Near Threatened (4)
LC or LR/lc - Least Concern (33)
DD - Data Deficient (24)

26. Laticauda schistorhyncha
Katauli or flat tail sea snake found only
in the waters of Pacific island nation of
Niue
Hydrophis semperi
Lake Taal snake is a rare species of
venomous sea snake found only in a single
lake on the island of Luzon in the
Philippines

27. Laticauda crockei
Crocker's sea snake is endemic to a single
brackish lake (Lake Te-Nggano) on Rennell
Island in the Solomon Islands.
Aipysurus fuscus
Dusky sea snake or Timor Reef snake is
found in the Timor Sea between
Australia, Indonesia and East Timor

28. Residential & commercial development
Housing & urban areas
Commercial & industrial areas
Climate change & severe weather
Habitat shifting & alteration
Storms & flooding
Biological resource use
Fishing & harvesting aquatic
resources
Pollution
Agricultural & forestry effluents

29. https://en.wikipedia.org/wiki/Sea_snake
http://seasnakes.info/biology/#:~:text=Sea%20Snake%20Biology.%20Marine%20
adaptations.%20There%20are%20several,excretion%2C%20and%20marine%20
fouling%20%26%20skin%20shedding.%20Swimming.
https://faunafacts.com/snakes/sea-vs-land-
snakes/#:~:text=Dietary%20Differences%20Between%20Sea%20Snakes%20an
d%20Land%20Snakes,Amphibians%20%20%20Eggs%20%20%20Insects%20

30. THANK YOU…