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NEMATODES 10.​Digestive system is complete and straight with both mouth and anus. -​ thread/ Askos- bladder, 11.​Mouth is terminal and surrounded helminthes- worm by...

NEMATODES 10.​Digestive system is complete and straight with both mouth and anus. -​ thread/ Askos- bladder, 11.​Mouth is terminal and surrounded helminthes- worm by lips bearing sense organ. -​ They are commonly called thread 12.​Respiratory and circulatory organs worm or round worm. are absent. -​ It is a phylum of unsegmented, 13.​Respiration occurs through general triploblastic, pseudocoelomic, body surface. Respiration is cylindrical or thread-like worms aerobic in free-living forms and which are covered by a body wall anaerobic in parasitic form. having cuticle and epidermis. 14.​Excretory system consists of intracellular canal or lateral excretory ducts. (Renette cells) ASCHELMINTHES 15.​Nervous system is not much developed. -​ Zoologist consider this as a 16.​Nervous system consists of superphylum and its various circumpharyngeal nerve ring and groups as phyla (Rotifera, longitudinal nerve cords. Gastrotricha, Kinorhynca, 17.​Sense organs are poorly Nematomorph, Nematoda) developed in the form of papillae, -​ Phylum Nematoda is its large which are well defined as amphids group. (in mouth) and phasmid (in anus). GENERAL CHARACTERISTICS 18.​These are unisexual. Sexes are separate with sexual dimorphism. 1.​ Mostly parasitic. Few of them are 19.​Fertilization is internal, may be free-living. cross or self. 1.​ They are cylindrical, elongated, 20.​Development may be direct or slender worm like and tapers at indirect.​ both end. NOTE: Larval forms are 2.​ Triploblastic Rhabditiform, Filariform and 3.​ Bilaterally symmetrical. Micrifilaria. 4.​ Organ system level of 21.​Various lateral lines and pores are organization. present on the surface of body. 5.​ Body is unsegmented. 6.​ Body cavity is filled with muscle. 7.​ They are pseudocoelomate meaning, body cavity is not lined by mesodermal layer. 8.​ Internal cephalization is present but externally there is little differentiation between the anterior and posterior regions.​ Distinct head is lacking. However, mouth is present in anterior region. 9.​ Body is covered with tough and resistant cuticle THINGS TO REMEBER: 5. 2nd stage larva enters the lungs and 4th stage larva comes out of the ​ Things to Remember lungs ​ This is the first unisexual phylum. ​ The tail is often curved in male. ​ Excretory organ is H-shaped. ​ Amphids ​ Mode of transmission -​ are olfactory-receptors -​ contaminated food and ​ Phasmids water. -​ are chemoreceptors and ​ Infective stage glandulo-sensory. -​ embryonated eggs with ​ Resistant cuticle on the body rhabditiform larva. surface is adaptation for its parasitic life. PHYLUM ECHINODERMATA ​ Cuticle secreted by underlying epidermis is composed of ECHINODERM scleroprotein. -​ Is the most common of all marine ​ No segmentation. In some, the animals under this phylum. cuticle is striated and thus giving -​ Adults are distinct with their radial the appearance of segmentation symmetry. and called pseudo-segmentation. 1.​ Starfish ​ The pharynx is triradiate. 2.​ Sea urchins ​ Males are usually smaller than 3.​ Sea cucumbers females. 4.​ Sand dollars ​ During development volume of cell 5.​ Brittle stars increases (no increase in number 6.​ Sea lily of cells). -​ Exclusively marine ASCARIDS LUMBRICODES Multicellular organisms with well – ​ Monogenetic life cycle, found in developed organ systems small intestine (jejunum) of man. -​ They share same characteristic ​ Cause Ascariasis. features. (marine organisms) ​ Male Ascaris are monarchic or -​ Colorful organisms with unique monodelphic (presence of single shapes testis). -​ Ecologically and geologically very ​ Female are diorchic or didelphic important (presence of pair of ovaries). -​ The water vascular system ​ In Ascaris, fertilization occurs in presents in echinoderms accounts uterus. for gaseous exchange, circulation ​ Moulting in life cycle occurs four of nutrients and waste elimination. times: -​ They have a star-like appearance 1.​ In soil and are spherical or elongated. 2.​ & 3. In lungs -​ They are exclusively marine 4. In intestine animals. -​ The organisms are spiny-skinned. -​ They exhibit organ system level of organization. Most members have  a circulatory system as well as a organs, chemoreceptors, terminal digestive system. tentacles etc. -​ They are triploblastic and have a -​ Sexes are separate. coelomic cavity -​ They have an open circulatory CLASSIFICATION OF system (no heart or blood vessels) ECHINODERMATA -​ They respire through gills or cloacal respiratory tree. ASTEROIDEA -​ They have a simple radial nervous -​ They have a flattened, star-shaped system, and the excretory system body with five arms. are absent. -​ They have tube feet with suckers. -​ The body is unsegmented with no -​ They respire through papulae. distinct head. -​ The body comprises of calcareous -​ The mouth is present on the plates and movable spines. ventral side while the anus is on -​ Pedicellaria is present. the dorsal side. -​ examples: -​ · The tube feet aid in 1.​ Crown of thorns Starfish locomotion. -​ They reproduce sexually through gametic fusion and asexually through regeneration. -​ Development is indirect -​ They possess the power of regeneration. -​ They have poorly developed sense organs. These include chemoreceptors, tactile organs, terminal tentacles etc. -​ The larval forms show bilateral symmetry and adult forms show radial symmetry 2.​ Aster starfish -​ They have a true coelom. -​ The body is uniquely shaped. It can star like, elongated or spherical. -​ The body is unsegmented without a head. -​ The body surface is covered with calcareous spicules. -​ Body cavity has the distinguishing water vascular system -​ The brain is absent, but a nervous system is present with a nerve ring and radial nerve cords. -​ Respiration occurs through tube feet and gills. -​ Sense organs are poorly developed and include tactile OPHIUROIDEA -​ The body is flat with pentamerous discs. -​ The tube feet are devoid of suckers. -​ They respire through Bursae. -​ The long arms are demarcated from the central disc -​ Examples: 1.​ Brittle stars 3.​ Cake urchins ECHINOIDEA 4.​ Heart urchins -​ The body is hemispherical. -​ The tube feet contain suckers. -​ The body does not have arms. -​ The body has a compact skeleton and movable spines. -​ examples 1.​ Sand dollars HOLOTHUROIDEA -​ The body is long and cylindrical. -​ The arms, spines, and pedicellariae are absent. -​ They respire through the cloacal respiratory tree. 2.​ Sea urchins -​ They possess tube feet with suckers. -​ example: -​ 1. Sea cucumbers CRINOIDEA PHYLUM ANNELIDA -​ The body is star shaped. -​ Worm with series of identical -​ The tube feet have no suckers. segments that runs from their head -​ The arms are bifurcated. to their tails (Segmented worms) -​ Spines and pedicellariae are -​ Found in aquatic and terrestrial absent. environmen -​ examples a.​ Habitat: marine, freshwater, 1.​ Sea-lily terrestrial b.​ Body plan: similar shape as the Phylum Mollusca - The Mollusks: roundworm but the body is clams, snails, oysters, octopus segmented both internally and externally which allows for a a.​ Habitat: marine and fresh water; quicker response for movement. terrestrial c.​ Digestive system: Segmented b.​ Body plan: mollusks have a soft, worms have a complete digestive unsegmented body and often system, and this set-up is often move with a stung muscular foot referred to as a tube-within-a-tube on its ventral surface. body plan. c.​ Reproduction: hermaphrodites d.​ Reproduction: Hermaphrodites: (some) Sexual d.​ The radula: mollusks are well e.​ Symmetry: Bilateral; anterior and known for their tongue-like organ posterior ends; dorsal and ventral called the radula which has many surfaces. rows of teeth and is used to scrape f.​ Special features: i. Oxygen food from the surface of plants and diffuses through the skin. ii. Have rocks. “setae” external bristles for e.​ The mantle: is a fold of skin that movement. surrounds the body organs. The mantle acts like a gland because it GENERAL CHARACTERISTICS is capable of secretion. These secretions harden to help form the ​ Bilaterally symmetrical shells of mollusks. ​ Segmented body f.​ Symmetry; bilateral ​ Exhibit organ system level g.​ FYI: second largest phylum; 3 organization main body parts: head visceral ​ Fluid filled internal cavity mass, & foot. ​ Absent of respiratory organs ​ Respire through their body surface ​ Nephridia are the excretory organs ​ Body cavity (coelom) is filled with CT ​ Has digestive system with a mouth and anus ​ Nervous system with a ventral nerve cord ​ Closed or well - developed circulatory system  ​ Their body contains hemoglobin, Family: Amphinomidae which gives them a red color ​ Regeneration is the most common Genus: Hermodice characteristics of the Annelids ​ Setae help them in movement Specie: carunculata ​ Asexual reproduction most of them ​ Marine worms and some are hermaphroditic/ ​ Large chaetae/ bristles hermaphrodite ​ The body is elongated and divided ​ Most common Annelids into segments. ​ Range from half inch in length up ​ They are found in the marine to 22 ft. ever recorded environment. ​ Single acre of soil is estimated to ​ These are true coelomates, have millions of earthworm bilaterally symmetrical worms. ​ Triploblast ​ They excrete through ​ A pseudo/ ecoelomate metanephridia and protonephridia. ​ Twenty- seven thousand kinds ​ Fertilization is external. ​ Complete digestive system ​ They have a well-developed ​ Protostome/ deuterostome (since nervous system. complete digestive system) ​ The circulatory system is closed CLASSIFICATION OF PHYLUM type. ANNELIDA ​ They are hermaphrodites. ​ They might possess fin-like ​ Polychaeta appendages called parapodia. ​ Oligochaeta ​ The organisms belonging to this ​ Hirudinea group lack clitellum and are ​ Archiannelida dioecious. ​ examples: Class Polychaeta 1.​ Sand worm 2.​ Tube worm -​ Poly means many & keta/ketae 3.​ Fireworms mean bristles. 4.​ Clam worms -​ Closed circulatory Fireworms system means blood is contained -​ produced stinging sensation inside blood -​ Female fireworm produced blue- vessels, circulating green mucus which glow when in direction they release their gametes into the (unidirectional) water -​ Open circulatory Scientific name: Hermodice system – blood carunculate open into spaces and not into Phylum: Annelida capillaries so that blood comes in Class: Polychaeta contact with tissues. Order: Aciculata CLAM WORM OR RAG/ PILE WORM/ ​ They exhibit no free larval stage, SANDWORM and the development takes place inside the cocoons. Scientific Name: Nereis ​ Example. 1.​ Earthworm Phylum: Annelida Clitellum Class: Polychaeta -​ little vein found in an earthworm Family: Nereididae and always closer to the edges -​ Thick saddle ring like structure Genus: Alitta found on the epidermis of an Species: succinea earthworm for cocoon formation Class Oligochaeta = oligo means few Metamerism/segmentation -​ body is divided into a number of segments which contain all body organs repeatedly, but the alimentary canal is long and straight tube extending through all the segments. ​ Earthworm ​ Very small chaetae Dioecious ​ Clitellum -​ little vein closer to the -​ having the male & female edges reproductive organs in separate individuals. closer to the mouth and farther from the anus Earthworm ​ Hermaphroditic Scientific name: Lumbricina ​ They are mostly freshwater and terrestrial organisms. Kingdom: Animalia ​ The body is segmented Phylum: Annelida metamerically. ​ Head, eyes and tentacles are not Class: Clitellata distinct. ​ They are hermaphrodites, but Order: Opisthopora cross-fertilization takes place. ​ Fertilization is external. Genus: Lumbricus ​ Cocoon formation occurs. ​ Setae are segmented. ​ They do not possess parapodia, but clitellum is present. ​ The organisms belonging to this class are monoecious. CLASS HURUDINEA Class Archiannelida ​ Most found in freshwater. Some ​ They are found only in the marine are marine, terrestrial, and environment. parasitic. ​ Minute, primitive with ciliated ​ The body is segmented. epidermis ​ The tentacles, parapodia, and ​ The body is elongated without setae are not present. setae and parapodia. ​ The animals are monoecious. ​ They are unisexual or ​ The body is dorsoventrally or hermaphrodite. cylindrically flattened. ​ Tentacles are present on the ​ They have an anterior and prostomium. posterior sucker on the ventral ​ Eg. side. 1.​ Dinophilus ​ The organisms lay eggs in 2.​ Protodrilus cocoons. ​ There is no larval stage during the PHYLUM CHORDATA development of the organism. ​ The mouth is located ventrally in ​ These are animals with flexible rod the anterior sucker, while the anus supporting their dorsal or back is present dorsally in the posterior sides sucker. ​ The phylum name derives from ​ Fertilization is internal. Greek root word chord – meaning ​ They are hermaphrodites. string ​ Example. ​ Most of their species are 1.​ Leeches vertebrates or animals with backbone (subphylum Vertebrata) Leech CHARACTERISTICS OF PHYLUM Scientific Name: Hirudinea CHORDATA Kingdom: Animalia Notochord Phylum: Annelida -​ It is a longitudinal, cartilaginous rod running between the nerve cord Class: Clitellata and the digestive tract. It acts as a support for the nerve cord and is Family: Hirudinidae replaced by the vertebral column after the embryonic stage in all Genus: Hirudo vertebrates. Specie: sp. Dorsal Nerve Cord -​ It is a bundle of nerves running along the “back” and splits into the brain and the spinal cord. It is hollow and lies dorsal to the notochord.  Classification Of Phylum Chordata(subphyla) Pharyngeal Slits -​ They are the openings which allow the entry of water through the Urochordata mouth without entering the digestive system viz. they connect ​ The adults are fixed to the mouth and throat. All Chordates substratum. have these openings on the lateral ​ It is also known as Tunicate sides of the pharynx at some stage because the body of an adult is of their life. enclosed within a tunic made up of cellulose-like substance known as Post anal Tail tunicin. ​ Notochord can be seen only in the -​ It is an extension of the body to the larval stage and disappears in anus. In chordates, the tail is adults. composed of skeletal muscles which help in locomotion in fish-like ​ The nerve cord present in larva is species. It is absent in most of the replaced by a dorsal ganglion in adult Chordates. adults. ​ The larva can move and undergoes a metamorphosis. ​ For e.g., 1.​ Ascidia, 2.​ Salpa, 3.​ Doliolum Other characteristics of Chordates include: Cephalochordata ​ Bilaterally symmetrical, ​ The atrium is present. triploblastic, coelomic and ​ Motile adult and larval stage. segmented body. ​ The tail is present throughout life. ​ The body design is complex and ​ They show progressive well-differentiated. metamorphosis. ​ The body has an organ system ​ The notochord is found throughout level of organization. life. ​ Numerous well-developed pharyngeal gill slits are present.  ​ Paired fins are generally absent. ​ Early species had heavy bony scales and plates in their skin, but these are not present in living species. ​ In most cases the skeleton is cartilaginous. ​ The embryonic notochord persists Vertebrata in the adult. ​ DSeven or more paired gill ​ These are advanced chordates pouches are present. and have cranium around the brain. ​ The notochord is replaced by a vertebral column in adults. This is why it is said that ‘all vertebrates are chordates but all chordates are not vertebrates ​ A high degree of cephalization is observed. ​ The epidermis is multi-layered. ​ They consist of three types of muscles-striped, unstriped and CLASS CHONDRICHTHYES cardiac. ​ They have a well-developed -​ “Cartilaginous fish” coelom. -​ Skeleton made of cartilage ​ The alimentary canal is complete. -​ Movable jaws with well developed ​ The heart is three or teeth four-chambered. -​ Rough sand paper like scales ​ They have well-developed made of the same composition of respiratory and excretory systems. the teeth. ​ Endocrine glands are present in all. SHARKS & RATFISH ​ They are unisexual and reproduce sexually, hagfish being an SHARKS exception. ​ For e.g. humans. -​ Adapted for fast swimming and to be predators Vertebrate Chordates RATFISH OR CHIMERAS -​ Are the chordates that have notochord and pharyngeal slits -​ Bottom dwellers have long “rat-lke” during the early stages of tails” development. As the animals mature, rings of bones called vertebrae replace the notochord. -​ Divided into seven classes ​ Jaws are absent. RAYS &SKATES they live, wings that are adapted for flight, and the beaks that are RAY adapted to the kind of food they eat. -​ Flattened bodies with gills on the bottom of their bodies. -​ Whip-like tail with stinging spines (venomous) SKATES -​ Very similar to rays but without the long tail or stinging spines. CLASS OSTEICHTHYES ​ Bony fish ​ Make of 98% of all fish and over half the vertebrates ​ Skeleton at least made partially of bone ​ Thin, flexible, overlapping scales ​ Mouth located at end of body ​ Presence of gas-filled sac called a swim bladder. CLASS MAMMALIA CLASS AMPHIBIA ​ Mamma = breasts ​ Included frogs, toads, and ​ The presence of breasts is a salamanders distinguishing feature of mammals. ​ Skin is moist and permeable to Another distinguishing feature of gases and water mammals is that their bodies are ​ Most lay eggs in water covered with hair. Almost all ​ Most have an aquatic larval stage mammals are vivaparous. ​ Mammals are divide into three REPTILES (CLASS REPTILIA) subclasses: 1.​ Monotremata ​ water -tight skin is made out of 2.​ Marsupialia scales - hard, overlapping layers of 3.​ Placetals protein. ​ Scales cannot expand, so to grow MONOTREMATA bigger a reptile must molt. ​ Most lay eggs, but some give birth ​ Trema = hole to live young ​ Have bodies covered with thick furs. They have breast that lack CLASS AVES (BIRD) nipples, but secrete milk. ​ These mammals are unique as -​ Aves have bodies covered with they are the only egg-laying feathers, scaly feet that are (ovaparous) mammals. Their adapted to the kind of environment  young lck the milk that oozes in General Characteristics of Phylum their thick fur. Arthropoda 1. Arthros; Jointed, podos; Foot) 2. Kingdom: Animalia 3. Habitat: mostly terrestrial, also aquatic MARSUPIALS 4. Insects are the most successful ​ Marsupium = bag or pouch life form on the planet: they make ​ Described as pouched mammals. up more than half of all living ​ Contains the nipples that secrete things on Earth milk. 1.​ Kangaroo 5. Body has Three-part: head, 2.​ Koala thorax, abdomen. 3.​ opossums 6. Body is metamerically segmented 7. Three pairs of jointed legs (6 legs). 8. Compound eyes which contain several thousand lenses leading PLACENTAL MAMMALS to a larger field of vision. ​ Placenta pertains to a part in the 9. They possess two antennae. womb where the young is nourished as it undergoes 10. Symmetry: bilateral development until birth. This group 11. Germ layer: triploblastic compromises the largest and the most divers forms of chordates. 12. Grade of organization: organ ​ Are divided into different orders system grade 13. Coelom: haemocoel 14. Chitinous (hard) exoskeleton, no bones or a skeleton 15. Respiratory system: by general body surface, by gills, tracheae or book lungs 16. Circulatory system: open type with dorsal heart. 17. Excretion: Malpighian tubules or green gland  18. Nervous system: dorsal brain Many appendages: Body is long with with ventral nerve cord numerous segments each having one or two pairs of legs. 19. Sexes are separate. Sexually dimorphism is present Head is distinct with antennae, a pair of eyes and two to three pairs of 20. Fertilization: internal. jaws. 21. Development: direct or indirect Excretion: by malpighian tubules. with larval stages Respiration: by trachea. Classification of Phylum Arthropoda Arthropoda Examples: Julus (Millipede), Scolopendra (Centipede), -​ is classified into five classes based Spirobolus etc on body divisions, body appendages, habitat, organs of Class 3 Insects respiration and modes of excretion. (Insectus: divided) Class 1 Crustacea Habitat: Mostly terrestrial and rarely (Crusta: shell) aquatic Habitat: They are mostly aquatic, Body divided into three regions: few are terrestrial and very few head, thorax and abdomen. are parasitic. Thorax has three segments, each Cephalothorex: Head is often fused bearing a pair of leg and a pair of with thoracic segments to form wings found on second and third cephalothorax. segments. Thorax and abdomen have a pair of Abdomen has 7-11 segments without biramous appendages in each appendages. segment. Respiration: by tracheae, gills etc. Respiration: through the gills or general body surface. Excretion: usually by malpighian tubules. Excretory organs are modified coelomoducts which may either Examples; Pieris (Butterfly), maxillary glands or antennary Periplaneta (Cockroach), glands. Tabernus (Housefly), Mosquiotes, Ants, etc. Examples: Cancer (crab), Palaemon (Prawn), Daphnia (water flea) Class 4 Arachnida etc. (Arachne: spider) Class 2 Myriapoda Habitat: mostly terrestrial and rarely (Myrios: ten thousand; podos: foot) aquatic Habitat: Mostly terrestrial.  Body is usually divided into cephalothorax and abdomen. There are four pairs of legs attached to the cephalothorax. Respiration: by tracheae or book lungs or gills. Excretion: by malpighian tubules or coxal gland or both. Examples: Aramea (Spider), Palamnaeus (Scorpion), Limulus (King Crab), etc Class 5 Onychophora (Onychos: claw; phoros: bearing) Habitat: mostly terrestrial Small sized arthropods Body is segmented Respiration: by tracheae. Excretion: by nephridia Examples: Paripatus