Zoology

  MOLLUSCA General Characteristics • They are mostly found in marine and freshwater , very few are terrestrial and found in moist soil. •They exhibit organ level of organization. •Their body has a cavity. Bilaterally symmetrical. •Body is divided into head, visceral mass , muscular foot and mantle. • Head comprises of tantacles and compound eyes. •Body is covered by calcareous shell. •Muscular foot help in locomotion. •They have a well developed digestive system, the radula is respire through organ for feeding. • They respire through the general body surface, gills or pulmonary sac. • The blood circulates through open circulatory system. •Nervous system consist of number of paired ganglia . •The sexes are separate in most of the molluscs but some species are hermaphrodite. •Fertilization may be external or internal. •Generally oviparous with indirect development.

PERIPATUS CLASSIFICATION: PHYLUM:  ONYCHOPHORA (contain annelida & arthropoda character). COMMENTS: •It is referred as " living fossil". • Body of the animal is cylindrical & elongated caterpillar like & measuring 4-6 cm in length. •Outer covering of the body is thin,velvety, chitinous showing transverse, wrinkles, numerous small papillae or tubercles. •Anterior end is marked by pre-antennae & ventral mouth & posterior end by anus. •There is a head of three segments. •Post-oral segment of the head bear pair of hooked jaws, a pair of oral papillae, a pair of simple eyes & a pair of segmented antennae. • There are about 15 pairs of walking legs, •There is a tracheal system for respiration with spiracles scattered irregularly over the body surface. •Crural gland is absent & genital pore is posterior. •Connecting link between arthropoda & annelida.

  BOMBYX CLASSIFICATION : PHYLUM ARTHROPODA (Jointed appendage). SUB-PHYLUM UNIRAMIA (single branch appendage). CLASS: INSECTA ( 3 pair of legs ). COMMENTS: • Bombyx is commonly called as silk moth. • Body consists of head, thorax & abdomen. •Head bears a pair of antennae & a pair of compound eyes. •Thorax bears three pairs of legs and two pairs of rings which are covered with scales. • Hindwings are smaller than forewings. • Abdomen consists of 10 segments. •Mouth parts of siphoning type. •Moths are nocturnal,they come in the night during rainy season. •Various stages of life cycle are egg, larva, pupa, adult male & female •Larva feeds mulberry leaves by its mandibles & mouth parts & undergoes moulting as it grows. • Habit & Habitat: They are reared for silk. Adults have short life span & do not feed. • Distribution : cosmopolitan.

APIS CLASSIFICATION: PHYLUM:  ARTHROPODA (Jointed appendage). SUB-PHYLUM:  UNIRAMIA (single branch appendage). CLASS:  INSECTA (3 pair of legs). COMMENTS: •Commonly called as Honey bee . •Body divisible into head, thorax & abdomen in all castes. •Queen is largest & fertile. Worker is smallest. Head triangular, containing compound eyes and many jointed antenna besides ocelli. •Clypeus, labrum & other mouth parts visible in lateral position. Mouth parts are rasping & lapping type. •Thorax is divided into prothorax, mesothorax & metathorax each containing a pair.Thorax contains a pair of wings. •Abdomen has 6 segments. Last segment contain stings. spiracles are found over abdomen. •Worker act as repairers, store keeper, cleaner, honey collector & defenders. •Drone are male members. They fertilise the eggs laid by queen • Habit & Habitat: They are social/colonial insect living in bee hives.

TERMITE CLASSIFICATION: PHYLUM:  ARTHROPODA (Jointed appendage). SUB-PHYLUM: UNIRAMIA (single branch appendages). CLASS: INSECTA (3 pair of legs). COMMENTS: •Body is divided into head, thorax & abdomen. •Head contains paired compound eyes, paired antennae & a pair of small maxillary palp. • Thorax divisible into prothorax, mesothorax and metathorax. Tergum of prothorax (pronotum) doesn't cover head. •Thorax contains a pair of short reduced wing stubs & 3 pairs of legs. • Head & thorax comparatively shorter while abdomen is much elongated & swollen accomodating large no. of legs. Last abdominal segments contain a pair of anal cerci. •Mouth larts are of bitting types . • Habit & Habitat: The termites may be wood dwelling or subterranean. They form nest which contains numberless chambers and galleries having moderately hard walls . • Geographical distribution: They are found throughout temperate & tropical countries. They are cosmopolitan.

PERIPLANETA AMERICANA CLASSIFICATION: PHYLUM ARTHROPODA (Jointed legs). SUB-PHYLUM: UNIRAMIA (single branch appendage). CLASS: INSECTA (3 pair of jointed legs). COMMENTS: •Commonly called as cockroach. Body reddish brown in colour measuring 2.5cm in length. • Body elongated, bilaterally symmetrical & dorsoventrally flattened. •Body differentiated into dorsal & ventral surface & divided into head, thorax & abdomen. • Head is slightly movable containing a pair of antennae & compound eyes. •Thorax divisible into prothorax, mesothorax and metathorax. Thorax contains 3 pairs of walking legs, a pair of anterior forewing & a pair of posterior hindwings. •Abdomen contains 10 segments. Male & female cockroaches are distinguised by appendages in 10th abdominal segments. •Male has a pair of segmented anal cerci & a pair of segmented anal styles in 10th abdominal segment. •Female cockroach has anal cerci & ovipositor valves.

MUSCA DOMESTICA CLASSIFICATION : PHYLUM: ARTHROPODA (Jointed appendages) SUB-PHYUM: UNIRAMIA (single branch appendage). CLASS:  INSECTA( 3 pair of legs ) COMMENTS: •They are commonly known housefly. • Body is dark grey with yellowish tinge on ventral side, has four longitudinal lines on thorax and one black streak on abdomen. •Body is segmented & divisible into 3 regions:- Head, Thorax & Abdomen. •Head is small, semicircular in outline & consists of two short flexible & highly sensitive structure i.e., antennae, compound eyes consist of about 4,000 visual units or ommatidia. •Thorax is indistinctly segmented & bears a pair of strong membranous things dorsally and 3 pairs of jointed legs ventrally. •Abdomen is also covered with fine hairs and comprises 8 segments in male & 9 in females. • Habit & Habitat: The housefly is found in all climates. It is probably the insect with widest distribution.

JULU S CLASSIFICATION: PHYUM:  ARTHROPODA (jointed appendge). SUB-PHYLUM: UNIRAMIA (single branching appendage). CLASS:  DIPLOPODA (Trunk with 2 pair of legs). COMMENTS: • Commonly called as wire worm. •Body is differentiated into head, thorax and Abdomen . • Head is covered by cephalic sheets bend downward, head appendages are seven jointed delicate antennae, group of ocelli & mandibles. •Thorax has 4 segments & each of the last 3 segments is provided with one pair of walking legs. •Abdominal segments are double, each having one tergum, two small sterna, two pairs of walking legs & two pairs of obscure spiracles. •Sides of most terga have dark openings of odoriferous glands, secreting noxious substance. •There is no tracheal system. • Habit & Habitat: Julus is tropical, found in dark & damp places.  • Distribution : cosmopolitan.

  CANCER CLASSIFICATION PHYLUM: ARTHROPODA (Jointed appendages). SUB-PHYLUM:  CRUSTACEA (Biramous appendages). CLASS:  MALACOSTRACA (carapace cover head or thorax). COMMENTS: •Commonly known as "crabs" & are found buried under rocks, wood piece and in sand along sea shore. •Body is flat & covered by a carapace. It is comprised of a cephalothorax of 13 segments & abdomen is curved below the cephalothorex. • The cephalothorax is comprised of 13 (5+8) segments of cephalic & thoracic region. •Carapace in Callinectes is beautifully decorated and is produced into a pair of spines laterally. •The cephalothorax bears a pair of complex compound eyes, a pair of small antennule & antennae. •The 5 pairs of walking legs, 1st pair is chelate & is largest. • Abdominal appendages are degenerate, two pair of pleopods are present in males modified into coapulatory organs. •Sexes are separate and development is indirect.

EUPAGRUS CLASSIFICATION PHYLUM:  ARTHROPODA (Jointed appendages). SUB-PHYLUM: CRUSTACEA (Biramous appendages CLASS: MALACO STRACA (carapace covers head & thorax). Comment: • Commonly known as "Hermit crab ". •It is a peculiar crustacean having extreme modifications in order to adjust in the coils of molluscan shells. • Body is reduced in varying degrees and asymmetrical but shows usual divisions into head thorax & abdomen. •Carapace reduced & not found at the sides with epistome. It covers head Rostrum absent. •Head contains antennules, antennae & stalked eyes. Thoracic appendages protrude through the opening of the shell . First thoracic leg is chelate & the rest reduced. •Seventh & eighth thoracic appendages are reduced & remain inside the mollusc shell. •Uropods are hooked & notched in the shell. • Distribution: cosmopolitan.

  SCOLOPENDRA CLASSIFICATION : PHYLUM ARTHROPODA (Jointed appendages). SUB-PHYLUM UNIRAMIA (Single branching appendage). CLASS CHILOPODA (Body divided into head & trunk). COMMENTS: •Commonly called as centipede . • Body is elongated, dark greenish-brown in colour, dorsoventrally flattened & is divided into a distinct head & a long segmented trunk or body . •Head appendages are long antennal, ocelli & reduced maxillae & mandible visible on ventral side. •Mouth is guarded by labrum, mandibles & first maxillae. •Body segments have 21 pairs of walking legs. The first pair of legs are curved , clawed & forwardly directed to form maxillipedes or poison claws. •Each leg is composed of coxa, trochantea, femur, tibia & 3 tarsi ending in a single claw. •Paired, oral spiracles lie on the pleural areas. •It is harmful to mankind. •Habit & Habitat : It is a tropical animal, found in India & America.

PALAEMON CLASSIFICATION PHYLUM:  ARTHROPODA (Jointed appendages). SUB-PHYLUM:  CRUSTACEA (Biramous appendages). CLASS: MALACOSTACA (carapace covers head/thorax). Comment: •Commonly called as "prawn". •Body is elongated, spindle shaped, bilalerally symmetrical and deep orange coloured when preserved. •Division the body are cephalothorax, abdomen & telson." •Cephalothorax is made up of 5 head & 8 thoracic segments. Carapace is anteriorly produced into sawthoothed rostrum. •There are two prominent eyes on the head. • Abdomen is made up of 6 segments. •There are 19 pairs of appendages, one pair in each segment. The cephalic appendages comprises of antennules, antennal,mandibles, maxillal & maxillulae. •First abdominal somite is not reduced. Rest 5 abdominal segments contain paired biramous swimming pleopods.

  SACCULINA CLASSIFICATION PHYLUM:  ARTHROPODA (Jointed appendages). SUB-PHYLUM: CRUSTACEA (Biramous appendages). CLASS:  CIRRIPEDIA (Adult sessile or parasitic). COMMENTS : •Commonly called as "Root-headed barnacle". •Parasitizes crabs. Zoologists were able to discover its real crustacean nature by studyings it embryology having 1st stage nauplius larva. • Adult loses all arthropodan characters & appears like a fleshy tumour attached to the abdomen of the crab on ventral side & lead a parasitic life on decapod sructures. •It sends root like structures like mycelium of fungus through peduncle in each appendages of crab & in the body to derive nutrition. • Appendages, segmentation, mouth, anus, alimentation absent. •Hermaphroditic, • Presence of sacculina causes development of many changes in secondary sexual characters of the host.

BALANUS   CLASSIFICATION : PHYLUM:  ARTHROPODA (Jointed appendages) SUB-PHYLUM: CRUSTACEA (Biramous appendages) CLASS: CERRIPEDIA (Adults sessile /parasitic) COMMENTS: •Commonly called as Rock Barnacle. •Stalk is absent to the shell covering animal is directly attached to the substratum or rocks. •Head is short & broad. • Mantle surrounding the body is covered six calcareous plates, consisting of unpaired carina, rostrum & 2 pairs of carino-lateral plates. Edges of the plates overlap & fit together forming a cylinder. • opening of the shell is provided with a movable fourfold lid or operculum, composed of 2 scuta or 2 terga. •In water, the barnacle protrudes through the opening six pairs of delicate, curled, fringed & jointed thoracic legs to collect food. • Life cycle includes nauplius larva. •Distribution: It has cosmopolitan distribution.