CLASSIFICATION OF SEAL (PHOCA)
PHYLUM :- CHORDATA (Notochord, dorsal tubular nerve cord present and gill slits present)
Group :- CRANIATA (Definite head. Cranium with brain present)
Sub-phylum :- VERTEBRATA (vertebral column present)
Division :- GNATHOSTOMATA (Jaws and paired appendages present)
Super class :- TETRAPODA (Paired limbs, lungs, bony skeleton and cornified skin).
Class :-MAMMALIA (Body covered with hairs. females have mammary glands).
Sub-class :- THERIA (Viviparous).
Infra class :- EUTHERIA (Placental mammals, vagina single).
Order :- Carnivora (Carnivorous).
Genus : Phoca
- Found mouth in arctic and antarctic regions.
HABIT AND HABITAT
Essentially marine but not completely aquatic like whales. They spend substantial part of their life-cycles ashore mainly for breeding.
GENERAL CHARACTERSTICS OF SEAL : PHOCA
- Commonly called as earless common seal or sea lion. flipper-like forelimbs
- Body streamlined having more or less fish-like appearance. Body divisible into head, neck, back, chest and abdomen.
- Head contains mouth, nostril and vibrissae.
- Both forelimbs and hind limbs adapted for swimming and modified as flippers which act like oars. Feet webbed.
- Annual movement of seals starts towards warmer water. Earless seals have limited seasonal migration.
- Males larger than females.
- Seals spend much of their life in water, but they mate, give birth to babies and take care of them on the shore.
- Thick fur and blubber offer protection against freezing temperatures.
- When they dive, they decrease the heart rate for 50-80%. Elephant seal will decrease number of heart beats from 112 to 20-50 during diving.
- They can dive up to 1000-1300 feet deep when they are searching for food.
- Seals have whiskers that help them detect the vibration of the prey under water.
Seals show some degree of territorial behaviour. Adult male fur seals arrive a month before at a breeding ground called as rookeries and establish a territory for females they copulate. Female gives birth to a single young seal. At seashore, seals by their play actions, amuse man and children. Other seals are ,eared seals, walrus seals and elephants seals
Since the animal has webbed feet and above features, hence it is Phoca.