Oryctolagus Cunniculus, the rabbit is included in:
Phylum – Chordata,
Sub-phylum – Vertebrata,
Class – Mammalia.
The rabbit is brown in colour. It is about 40 cm in long and it weighs 2 to 4 pounds. The entire body is covered with a soft uniform hairy coat or fur. The body is divisible into four parts namely- head, neck, trunk and tail.
The head is elongated and produced into a pointed snout. The mouth is a transverse slit on the ventral side of the snout. It is bounded by two lips- upper lip and lower lip. The upper lip has a cleft interest middle through which the incisor teeth are clearly visible. Such a lip is called harelip. The sides of the upper lip produce stiff long thick hairs called vibrissae or whiskers. They are tactile sensory organs.
The external nares or nostrils are a pair of large oval slits just above the mouth. Two lines are present on the sides of the sides of the head. They are protected an upper and a lower eyelids. A third eyelid called nictitating membrane is also present on the inner corner of the eye. The top of the head bears a pair of sound collecting lobes called ear pinnae. The pinna acts as a radar antenna. The basal part of each pinna has tubular ear opening called external auditory meatus. This opening is closed below by a tympanic membrane or ear drum. The neck is short and permits the free movement of the head.
The Trunk is divisible into an anterior thorax and posterior abdomen. The ventral side of the abdomen is provided with 4 or 5 pair of teats or nipples. The teats are rudimentary in males. The anus is the present at the posterior end of the abdomen. On either side of the anus is a hairless depression called perineal pouches. The perineal scent glands lying inside open into these pouches. The secretions of these glands give the characteristics odour of the rabbit. In the male rabbit, the urinogenital aperture lies at the tip of penis (a muscular copulatory organ). The testes are lodged in two skin-bags called scrotal sacs which are present on either side of the penis. Instead in the female a vulva, the slit like aperture lies below the anus.
The trunk bears two pairs of limbs namely fore limbs and hind limbs. Each fore limb is divided into 3 parts namely a proximal upper branch (brachium), middle fore arm (antebrachium) and a distal hand (manus). The hand is further divided into 3 parts namely wrist (carpus) and the palm (metacarpus) and the digits (fingers) with claws. The hind limb is also divided into thigh, the shank (crus) and the foot (pes). The foot is further sub-divided into an ankle (tarsus), a metatarsus and five toes with claws. The tail is hort and bushy and is located at the posterior end of the trunk.