Animals belonging to phylum Chordata are fundamentally characterised by the presence of a notochord, a dorsalhollow nerve cord and paired pharyngeal gill slits . These are bilaterally symmetrical, triploblastic, coelomate with organ-system level of organisation. They possess a post anal tail and a closed circulatory system
Phylum Chordata is divided into three subphyla: Urochordata or Tunicata, Cephalochordata and Vertebrata.
Ascidia Subphyla Urochordata and Cephalochordata are often referred to as protochordates and are exclusively marine. In Urochordata, notochord is present only in larval tail, while in Cephalochordata, it extends from head to tail region and is persistent throughout their life. Examples: Urochordata – Ascidia, Salpa, Doliolum; Cephalochordata – Branchiostoma (Amphioxus or Lancelet)
The members of subphylum Vertebrata possess notochord during the embryonic period. The notochord is replaced by acartilaginous or bony vertebral column in the adult. Thus all vertebrates are chordates butall chordates are not vertebrates. Besides thebasic chordate characters, vertebrates have aventral muscular heart with two, three or four chambers, kidneys for excretion andosmoregulation and paired appendages which may be fins or limbs.
The subphylum Vertebrata is further divided as follows:
ACORN WORM• Acorn worms are simple, wormlike marine animals that burrow into wet sand or mud of shallow seafloors. Possibly representing an evolutionary link between vertebrates and invertebrates, they pass through stages in which they possess characteristics of each type of animal
• Tunicate, common name for any member of a subphylum of primitive marine chordates. There are about 2000 known species. The larval stage is characterized by the presence of a notochord and a dorsal nerve cord, both of which are lacking in the adult. The adult is characterized by a layer of protective secretion called a tunic. Tunicates are common in such habitats as rocky shores but can also be found at great depths. Species known as sea squirts make up one class in the subphylum, and most tunicates belong to this class. Tunicates are important because they are an evolutionary link between invertebrates and vertebrates
Cephalochordata• These animals, which look like very small fish, are about 5 cm (about 2 in) long and have a well-developed notochord that provides support for muscles used in swimming. Lancelets live in sand and feed with their gill apparatus. Although their bodies have a much simpler structure than that of fish—no heart or paired fins exist, and they have only a trace of a brain—the arrangement of parts is similar in these animals.
Introduction There are over 25650 species of fishes, divided into three groups: bony fish, cartilaginous fish and jawless fish. Bony fish which are most numerous have skeletons of bone, and swim bladders (gas filled organs) to keep them afloat. Cartilaginous fish, such as sharks, rays, and ratfish, are mostly marine hunters, they have skeletons made of cartilage, and sandpaper like skin. The primitive jawless fish have sucker like mouths, and include lampreys and hagfish.
They are marine animals with streamlined bodyand have cartilaginous endoskeleton. Mouth is located ventrally.Notochord is persistent throughout life. Gillslits are separate and without operculum (gillcover). The skin is tough, containing minuteplacoid scales. Teeth are modified placoidscales which are backwardly directed. Theirjaws are very powerful. These animals arepredaceous. Due to the absence of air bladder,they have to swim constantly to avoid sinking.
General Characters Boat shaped body Dermal scales Fins Endoskeleton Gills Venous Heart Cold Blooded Vertebrates Lateral line sense organs Internal ear
Chondrichthyes Placiod Scales Body Heterocercal caudal Fin Cartilaginous Endo Skeleton Five or more pairs of gills No air bladder A pair of claspers for males
Different types of Chondrichthyes Shark (Scoliodon) Viviparous fish ranging from 1 to 7 feet in length Body divisible into head , trunk and tail
Narcine (Torpedo) A Bottom dwelling fish Dorsoventrally flattened body Ventrally positioned mouth and gills Head bears a pair of electric organs other than eyes and spiracles Short tail with two dorsal fins Carnivorous
Trygon (Stingray) Dorsoventrally flattened body Ventrally positioned mouth and gills Head bears a pair of eyes and spiracles Pectoral fins are confluent with the sides of the head Whip like tail with serrated spines Males have a pair of claspers Carnivorous
Pristis (Saw Fish) Shark like body Head and skull are prolonged into a long flattened rostrum with toothed margin Anal fin is absent Carnivorous
Osteicthyes Bony endoskeleton Body is covered by cycloid, ctenoid or ganoid scales Terminal mouth Homoceral caudal fin Four pairs of gills operculum Presence of air bladder No copulatory organs External fertilization
Different types of Osteicthyes Catla(Indian Carp) Stout and elongated body Blackish gray body colour Wide mouth Pectoral fins are placed low down Large Dorsal fins Bilobed Caudal fin
Anabas (Climbing Perch) Laterally compressed body Small paired fins Dorsal and anal fins are long and spinous Operculum possesses spines Presence of labyrinthiform
Exocoetus (Flying fish) Elongated and compressed body Black spots on pectoral fins Wide mouth Wing like pectoral fins
Tuna (Tunnies) Streamlined body Two dorsal fins 6-9 finlets behind second dorsal and anal fins
Hippocampus (Sea horse) Body covered by bony scutes Mouth at tip of the snout Very small pectoral fins Pelvic fins are absent Prehensile tail Brood pouch for males Swim in vertical plan
Remora (sucker fish) Depressed head First dorsal fin modified into sucker Second dorsal and anal fins are long and extended up to tail Not a parasite
Cybium (Seer fish) Elongated and coloured body Pectoral fins are inserted high upon the sides First dorsal fin is spiny Anal fin is broken up into finlets
Pomfret Laterally compressed body with grey brown colour Protruded lower jaw Falcate dorsal and anal fins Long pectoral fin Forked caudal fin
Etroplus( Pearlspot) Light green in colour with yellowish transverse bands Oblong and laterally compressed body Dorsal fins with 18 spines Anal fin with 13 fines
Tilapia Black or brown body with round snouts Long spinous and single dorsal fin Long pectoral fin
Sardine Oblonge and laterally compressed body Head devoid of scales Terminal mouth One dorsal fin Moves in groups called Shoals
Mackeral (Rastrellinger) Laterally compressed body Length of the head and width of the body are equal Two dorsal fin Finlets are present in second dorsal and anal fins Occur in shoals
Aquatic adaptations of fishes Streamlined boat shaped body and slimy skin offers a least resistance while swimming Paired and unpaired fins for locomotion and balancing Lateral line sense organs for detecting the movements of other fishes and pressure variations in the surrounding water Swim bladder acts as buoyancy regulatory Gills for aquatic respiration Eyes are covered by nictitating membrane which gives protection without affecting normal vision
Economic importance of fishes Used as food Used for the preparation of liver oil Used for the preparation of fish meal Dried shark skin is used for making shagreen Air bladder is used for making isinglass, which is used for the preparation of ink, leather, cement etc.
INTRODUCTION Amphibian is the class of tetrapoda whichhave aquatic larval stage and terrestrial adultstage. They were the first tetrapoda to evolveduring Devonian. Tetrapoda is the super classof four footed animals where the limbs arepentadactyl or with 5 digits. There are about3000 species at present.
Amphibian includes anornenotes [without amnion] poikilothermic animals, which live both in fresh water and moist. Skin is without scales. It has glands and is kept moist. Limbs are pentadactyl for walking and swimming. Digits do not have nails. Heart is three chambered. Both renal and hepatic portal systems are absent RBC are nucleated. Gills occur in larval stages which may also posses unpaired fins. Gills occur in some adults in addition to lungs. Respiration can also occur through skin and bucal cavity. Both middle and inner ears are present. Eyes have eyelids. Nitrogenous excretory product is usually urea. Kidney is mesonerphic but tadpole has pronephric one. Skull is dycondylic.
CANE The much maligned venomous cane toads TOADearned their bad reputation shortly after beingreleased into the Australian ecology in 1935 withthe hope that they would control thedestructive cane beetle population. They turnedout to be Type: Amphibianfailures at controlling beetles, but remarkably Diet: Omnivoresuccessful at reproducing and spreading Average lifespanthemselves. in the wild: 5 to 10 years Cane toads are large, stocky amphibians with Size: 4 to 6 indry, warty skin, and are native to the southern (10 to 15 cm)United States, Central America, and tropical South Weight: 2.9 lbsAmerica. Their numbers are manageable in their (1.3 kg)natural range, but they have thrived in Australiabecause there are few natural predators, theybreed easily, and they have abundantfood, including even pet food, which they stealfrom feeding bowls left outside of homes.
GOLDEN TOADThe Golden Toad of Monteverde, Costa Rica wasamong the first casualties of amphibian declines.Formerly abundant, it was last seen in 1989.Dramatic declines in amphibianpopulations, including population crashes andmass localized extinction, have been noted in thepast two decades from locations all over theworld, and amphibian declines are thus perceivedas one of the most critical threats to globalbiodiversity. A number of causes are believed to beinvolved, including habitat destruction andmodification, over-exploitation, pollution, introduced species, climatechange, destruction of the ozone layer (ultravioletradiation has shown to be especially damaging tothe skin, eyes, and eggs of amphibians), anddiseases like chytridiomycosis. However, many ofthe causes of amphibian declines are still poorlyunderstood, and amphibian declines are currentlya topic of much ongoing research.
BULL FROGThe largest of all North American frogs, this giantcan grow to a length of 8 inches (20 centimeters)or more and weigh up to 1.5 pounds (750 grams).Even the tadpoles of this species can reach 6.75inches (17.2 centimeters) in length.They are among the most wide-ranging of allNorth American amphibians, found in freshwaterponds, lakes, and marshes from Nova Scotia,Canada, throughout the continental United States, Type: Amphibianand as far south as Mexico and Cuba. Diet: Carnivore Average lifespanBullfrogs are typically green or gray-brown with in the wild: 7 to 9brown spots and have easily identifiable circular yearseardrums, or tympanum, on either side of their Size: (adultheads. female) 3.5 to 6 in (9 to 15 cm)Nocturnal predators, they will ambush and eat Weight: 1.1 lbjust about anything they can fit in their ample (0.50 kg)mouths, including insects, mice, fish, birds, and Group name:snakes. They sit quietly and wait for prey to pass Army or colonyby, then lunge with their powerful hind legs,mouths open wide.
LEOPARD FROGNorthern leopard frogs are so named for the arrayof irregularly shaped dark spots that adorn theirbacks and legs. They are greenish-brown in colorwith a pearly white underside and light-coloredridges on either side of their backs. They areconsidered medium-size, reaching lengths of 3 to Type: Amphibian5 inches (7.6 to 12.7 centimeters), nose to rump. Diet: CarnivoreFemales are slightly larger than males. Average lifespan in the wild: 2 to 4Leopard frogs will eat just about anything they can yearsfit in their mouths. They sit still and wait for prey Size: 3 to 5 into happen by, then pounce with their powerful (7.6 to 12.7 cm)legs. They eat beetles, ants, flies, worms, smaller Group name:frogs, including their own species, and even birds, Armyand garter snakes.The northern leopard frog is perhaps mostrecognizable as the formaldehyde-soakedspecimen in the high school lab tray.
HYLA – TREE FROGHyla is commonly known as a tree frog. It isan arboreal frog. Fingers and toes areprovided with adhesive pads which are usedfor climbing. Some species have poisonousglands in the skin. Upper jaw is toothed, whilelower jaw is toothless. Female carries theeggs, on its back till hatching and showsparental care. Hyla is not found in india.
RHACOPHORUS – FLYING FROGThe overachieving Wallaces flying frog wasntcontent to just hop and swim. Thousands of yearsof watching birds navigate the rain forest andavoid predators by taking to the sky appears tohave convinced this unique amphibian that airtravel is the way to go. Type: Amphibian Diet: CarnivoreAlso known as parachute frogs, Wallaces flying Size: 4 in (10 cm)frogs inhabit the dense tropical jungles of Malaysia Group name: Armyand Borneo. They live almost exclusively in thetrees, descending only to mate and lay eggs.When threatened or in search of prey, they willleap from a branch and splay their four webbedfeet. The membranes between their toes and looseskin flaps on their sides catch the air as theyfall, helping them to glide, sometimes 50 feet (15meters) or more, to a neighboring tree branch oreven all the way to the ground.
POISON DART FROGPoison dart frogs, members of the Dendrobatidaefamily, wear some of the most brilliant and beautifulcolors on Earth. Depending on individual habitats,which extend from the tropical forests of Costa Ricato Brazil, their coloring can be yellow, gold, copper, Type: Amphibianred, green, blue, or black. Their elaborate designs Diet: Carnivoreand hues are deliberately ostentatious to ward off Average lifespanpotential predators, a tactic called anosmatic in the wild: 3 tocoloration. 15 years Size: 1 in (2.5Some species display unusual parenting habits, cm)including carrying both eggs and tadpoles on their Group name:backs. Although this "backpacking" is not unique Armyamong amphibians, male poison arrow frogs areexceptional in their care, attending to the clutch,sometimes exclusively, and performing vitaltransportation duties.Dendrobatids include some of the most toxic animalson Earth. The two-inch-long (five-centimeter-long)golden poison dart frog has enough venom to kill 10
REPRODUCTIONFor the purpose of reproduction most amphibians are bound to freshwater. A few tolerate brackish water, but there are no true seawateramphibians. Several hundred frog species in adaptive radiations(e.g., Eleutherodactylus, the Pacific Platymantines, the Australo-Papuanmicrohylids, and many other tropical frogs), however, do not need anywater whatsoever. They reproduce via direct development, an ecologicaland evolutionary adaptation that has allowed them to be completelyindependent from free-standing water. Almost all of these frogs live inwet tropical rainforests and their eggs hatch directly into miniatureversions of the adult, passing through the tadpole stage within the egg.Several species have also adapted to arid and semi-aridenvironments, but most of them still need water to lay their eggs.Symbiosis with single celled algae that lives in the jelly-like layer of theeggs has evolved several times. The larvae (tadpoles or polliwogs)breathe with exterior gills. After hatching, they start to transformgradually into the adults appearance. This process is calledmetamorphosis. Typically, the animals then leave the water and becometerrestrial adults, but there are many interesting exceptions to thisgeneral way of reproduction.
SPOTTED SALAMANDERDespite being fairly large and having an extremelybroad range, the spotted salamander is actuallypretty hard to, well, spot.They can reach 9 inches (23 centimeters) in lengthand are prevalent in mature deciduous forests from Type: Amphibianeastern Canada throughout the eastern and Diet: Carnivoremidwestern United States. But these secretive Average lifespansalamanders spend almost their entire lives hidden in the wild: Up tounder rocks or logs or in the burrows of other forest 20 yearsanimals. Size: 7 in (18 cm)They will populate upland forests and mountainousregions, but are most common in moist, low-lyingforests near floodplains.They emerge from their subterranean hiding spotsonly at night to feed and during spring mating. Theywill actually travel long distances over land after aheavy rain to mate and lay their eggs in vernal poolsand ponds.
TIGER SALAMANDERTiger salamanders markings are variable throughouttheir extensive range, but the most commonmarking resembles the vertically striped pattern oftheir mammalian namesake. Type: AmphibianThey are usually brown in color with brilliant yellow Diet: Carnivorestripes or blotches over the length of their bodies. Average lifespan inTheir base color, however, can also be greenish or the wild: 12 to 15gray and their markings can be yellow dots or brown yearssplotches. Some have no markings at all. Size: 7 to 14 in (18 to 35 cm)Thick-bodied amphibians with short snouts, sturdy Weight: 4.4 oz (126legs, and long tails, tigers are the largest land- g)dwelling salamander on Earth. They can grow to 14inches (35 centimeters) in length, but the averagesize is more like 6 to 8 inches (15.2 to 20.3centimeters).They are also the most wide-ranging salamanderspecies in North America, living throughout most of
AXOLOTLThe Mexican axolotl (pronounced ACK-suh-LAH-tuhl) salamander has the rare trait of retaining itslarval features throughout its adult life. Thiscondition, called neoteny, means it keeps itstadpole-like dorsal fin, which runs almost thelength of its body, and its feathery external gills, Type: Amphibianwhich protrude from the back of its wide head. Diet: Carnivore Average lifespan inFound exclusively in the lake complex of the wild: 10 to 15Xochimilco (pronounced SO-chee-MILL-koh) near yearsMexico City, axolotls differ from most other Size: up to 12 in (30salamanders in that they live permanently in cm)water. In extremely rare cases, an axolotl will Weight: 2.11 to 8 ozprogress to maturity and emerge from the water, (60 to 227 g)but by and large, they are content to stay on thebottom of Xochimilco’s lakes and canals..
MUDPUPPIES - WATERDOGSMudpuppies, also called waterdogs, are one ofonly a few salamanders that make noise. Theyget their name from the somewhat embellishednotion that their squeaky vocalizations sound likea dogs bark. Type: AmphibianAmong the largest of the Diet: Carnivoresalamanders, mudpuppies can exceed 16 inches Average lifespan in(41 centimeters) in length, although the average the wild: 11 yearsis more like 11 inches (28 centimeters). Their Size: 8 to 13 in (20range runs from southern central to 33 cm)Canada, through the midwestern UnitedStates, east to North Carolina and south toGeorgia and Mississippi.Mudpuppies live on the bottoms oflakes, ponds, rivers, and streams, and neverleave the water. They hide themselves invegetation and under rocks and logs, emerging atnight to feed on whatever prey they cancatch, including crayfish, worms, and snails.
ICHTHYOPHISIchthyophis is a blind tailless and limbless amphibianof 15-22cm length which lives in burrows in moist soil. The body is long and cylindrical. Skin is providedwith bony scales. Eyes are rudimentary. Head is smalland compact. Sensory tentacles between the eyesand nostril. Both jaws bear teeth. Male has aneversible copulatory organ bearing hooks. The femalecoils and the eggs. It is found in India.
The class name refers to their creeping or crawling mode of locomotion (Latin, repere or reptum, to creep or crawl).They are mostly terrestrial animals and their body is covered by dry and cornified skin, epidermal scales or scutes . They do not have external ear openings. Tympanum represents ear. Limbs, when present, are two pairs.Heart is usually three-chambered, but four-chambered in crocodiles. Reptiles are poikilotherms. Snakes and lizards shed their scales as skin cast. Sexes are separate. Fertilisation is internal. They are oviparous and development is direct.
The class aves includes birds characterized by thepresence of feathers and the power of flight. About 9000species of the birds are known. They are most beautifulanimals with a wide range of colours and behaviors suchas courtship, nest building, parental care and migration.They communicate by song and bird calls. Most of thebirds can fly. A few have lost the power of flight. The studyof birds is known as Ornithology.
1. Presence of wings: Fore limbs are modified into wings. They are powered by powerful flight muscles.2. Feathery covering: Body is stream lined and is covered with feathers.3. Pneumatic bones: Bones are hollow and filled with air.4. Beak: the upper and lower jaws are modified into beak.5. Four chambered heart: Heart is four chambered with two auricles and ventricles.6. Warm blooded: Birds are warm blooded animals with constant body temperature.7. Hind limbs are variously adapted for walking, hoping, perching, grasping, swimming etc.8. Alimentary canal has crop to store food and a muscular Gizzard for grinding.9. Double respiration: Lungs are adapted for double respiration.10. Brain: They have well developed brain.
11.They have no urinary bladder.12.Ovary: right ovary and oviducts disappear in the adults. It is to reduce the weight.13. Fertilization is internal. Development is direct.
Birds are evolved in the Jurassic period from bipedal reptiles. The following are the evidences to show that birds have a reptilian ancestry.1. Feathers are modified reptilian scales.2. Hind limbs have scales.3. Clawed toes.4. Amniotic membrane.5. Archaeopteryx, a reptile bird is considered as the connecting link between reptile and birds.
Birds are adapted for an aerial life. Every part of their body is suited for various purposes.1. Presence of wings.2. Body is covered by feathers.3. Well developed flight muscles.4. Well developed keel for the attachment of flight muscles.5. Four chambered heart with complete separation of oxygenated and deoxygenated blood.6. Pneumatic bones.7. Double respiration.8. Homeotherms (warm blooded) with a high body temperature.9. Sense of vision is great.10. Hind limbs supports the entire body.
The House Crow (Corvus splendens), also knownas the Colombo Crow is a common Asian bird ofthe Crow family. It is between the Jackdaw and theCarrion Crow in size (40 cm in length) but isrelatively slimmer than either. The forehead, crown,throat and upper breast are a richly glossed black,whilst the neck and breast are a lighter grey-brownin colour. The wings, tail and legs are black. Thereare regional variations in the thickness of the billand the depth of colour in areas of the plumage
A common sight in urban areas throughout the world, theRock Pigeon was introduced into North America in theearly 1600s. City buildings and their window ledgesmimic the rocky cliffs used by wild pigeonsDescriptionSize: 29-36 cm (11-14 in)Wingspan: 50-67 cm (20-26 in)Weight: 265-380 g (9.35-13.41 ounces)Large pigeon.Color variable, but wild birds are gray.White rump.Rounded tail, usually with dark tip.Pale gray wings have two black bars.Wings broad with moderately pointed wingtips.
The term peafowl can refer to the two species of bird in thegenus Pavo of the pheasant family, Phasianidae. TheAfrican Congo Peafowl is placed in its own genus Afropavoand is not dealt with here. Peafowl are best known for themales extravagant tail, which it displays as part ofcourtship. The male is called a peacock, the female apeahen, though it is common to hear the female alsoreferred to as a "peacock" or "female peacock". The femalepeafowl is brown or toned grey and brown.
The chicken (Gallus gallus) is a type ofdomesticated fowl, believed to be descendedfrom the wild Indian and south-east Asian RedJunglefowl.The chicken is one of the most common andwide-spread domestic animals. With apopulation of more than 24 billion in 2003,there are more chickens in the world than anyother bird. Humans keep chickens primarily as asource of food, from both their meat and theireggs.
Members of the parrot genus Psittacula or Afro-Asian Ringnecked parakeets as they are commonlyknown in aviculture originates found from Africa toSouth-East Asia. It is a widespread group, with aclear concentration of species in south Asia, butalso with representatives in Africa and the islands ofthe Indian Ocean. This is the only genus of Parrotwhich has majority of its species in continental Asia.Of all the extant species only Psittacula calthropae,Psittacula caniceps and Psittacula echo do not havea representative subspecies in any part of mainlandcontinental Asia. The Rose-ringed Parakeet,Psittacula krameri, is one of the most widelydistributed of all parrots.
The Great Horned Owl, Bubo virginianus, is a verylarge owl native to North and South America. It is anadaptable bird with a vast range, though it is not aswidespread as the Barn Owl.
The Great Blue Heron, Ardea herodias, is awading bird in the heron family Ardeidae, commonover most of North and Central America as well asthe West Indies and the Galápagos Islands,except for the far north, or in deserts and highmountains where there is no water for it to feed in.
Milvus is a genus of medium-sized birds of prey.It is an Old World group consisting of three kiteswhich form part of the subfamily Milvinae. Itssystematics are under revision; it contains 3-4species
Kingfishers are birds of the three familiesAlcedinidae (river kingfishers), Halcyonidae (treekingfishers), and Cerylidae (water kingfishers).There are about 90 species of kingfisher. Allhave large heads, long, sharp, pointed bills,short legs, and stubby tails. They are foundthroughout the world.
The Ostrich (Struthio camelus) is a flightless birdnative to Africa. It is the only living species of itsfamily, Struthionidae, and its genus, Struthio. Itis distinctive in its appearance, with a long neckand legs and the ability to run at speeds of about65 km/h (40 mph), the top land speed of anybird.
A kiwi is any of the species of small flightlessbirds endemic to New Zealand of the genusApteryx (the only genus in family Apterygidae).At around the size of a domestic chicken, kiwi areby far the smallest living ratites. Most kiwi speciesare endangered. The kiwi is also a nationalsymbol of New Zealand.
They are found in a variety of habitats – polarice caps, deserts, mountains, forests, grasslands and dark caves. Some of them have adapted to fly orlive in water. The most unique mammalian characteristic is the presence of milk producing glands (mammary glands) by which the young onesare nourished. They have two pairs of limbs, adapted for walking, running, climbing, burrowing, swimming or flying The skin of
mammals is unique in possessing hair. External ears or pinnae are present. Different types of teeth are present in the jaw. Heart is four chambered.They are homoiothermous. Respiration is by lungs. Sexes are separate and fertilisation is internal. They are viviparous with few exceptions and development is direct.