Category: Biology Second Paper

The star-shaped animals of the order Echinodermata are called starfish. They look like stars as they have five arms. Such as Asterias vulgaris, Astropecten euryacanthus, Ophiura ciliaris.

Tube fit is the moving part. The body of animals of the order Echinodermata is equipped with two rows of tubes called tube feet. Tube feet are narrow, hollow, muscular and elastic. Tube fits occur along the length of the ambulacral groove. For example, sea star (Asterias vulgaris).

A shallow groove along the digital midline of each arm is called an ambulacral groove in the phylum Echinodermata. These grooves arise from each side of the five corners of their mouth. For example, sea star (Asterias vulgaris).

A water circulation system is a water-filled cavity. Animals of the order Echinodermata have various shaped tubes filled with water inside the body called water circulatory system. A water circulation system is created by changing parts of the silo. It transports various types of objects through it.

Sea cucumber – Holothuria impatiens
Pink feather star – Antedon bifida
Brittle Star – Ophiothrix fragilis
Sea stars- Asterias vulgaris, Astropecten euryacanthus
Snake star- Ophiura ciliaris
Sea urchin- Echinus esculentus
Cucumaria- Cucumaria planci
Sea daisy- Xylopax medusiformes
Gorgonocephalus – Gorgonocephalus arcticus
Bristle star- Ophiocoma scolopendrina
Sea pentagon- Oreaster reticulatus
Aka sea star – Anthenea pentagonula

The order Echinidermata is divided into five classes.
1. Asteroids: Their bodies are star-shaped with five arms. Tube fit exists. Spines and pedicilli are present on the body. For example – sea star (Asterias vulgaris).
2. Ophuroidea: Their bodies are pentamerous discs. Tube fit and spine present on the body. Their arms are long. For example – Cucumaria (Cucumaria planci).
3. Echinoidea: Their bodies are hemispherical. Tube fit exists. The body has no arms. Spine present. For example, sea urchin (Echinus esculentus).
4. Holothuroids: Their bodies are long cylindrical in shape. The body has no arms, spines and pedicellariae. But tube fit exists. For example, sea cucumber (Holothuria impatiens).
5. Crinoid: Their bodies are star-shaped. The body does not have tube feet, spines, pedicillaries etc.

1. Their bodies are unsegmented, cylindrical or spherical or star-shaped or flower-shaped.
2. Their body is bilaterally symmetrical or pentalaterally symmetrical or orally symmetrical or divided into five equal parts.
3. Body skin prickly. The exoskeleton is composed of numerous ossicles composed of spines and pedicellaries and the endoskeleton composed of calcium carbonate. It is covered by ciliated membranes.
4. The body is organized into distinct verbal and non-verbal levels. Five ambulacral grooves are present on the oral floor.
5. They have a water circulatory system, which carries out respiration and locomotion.
6. There are ring vessels, radial canals, medriporites, stone canals and lateral canals for water transport.
7. Their moving parts are podia. It is responsible for respiration and food absorption.
8. The Himalayan and Perihimalayantra work on circulation.
9. The body does not have a brain, respiratory system, excretory system and circulatory system.
10. All animals are marine.
11. The life cycle consists of bipinaria, auricularia, ophiopluteus, echinopluteus larvae.

[Key words to remember features: unsegmented, bony, oral floor, bimucous, canaliculi, himal and perihimalatantra]

The word Echinodermata is formed from the Latin words Echinus meaning prickly, derma meaning skin and ata meaning bearing. Animals whose body is symmetrical, five-segmented, ciliated, headless, circulatory system and echinodermata are called Echinodermata. They are called conifers. Animals like sea star, sea cucumber, sea lilies, sea urchin, sand dollar etc. belong to this phase. The number of species is about 7,550. Jacob Klein (1734) named Echinodermata.

Characteristics of Bryozoa, Ectoprocta
1. They are colonial and look like moss plants.
2. They stick to submerged solids.
3. Each member of the colony is called a zooid. Zooids live in burrows called zoeciums.
4. Their bodies consist of polypides (lophophores) and cystids. Polypides consume food and form the exoskeleton of the cystid body.
5. The organ that surrounds the mouth is called lophophore.
6. On the outside of the lophophore is the anal pore.

Some animals of the order Bryozoa
Electra – Electra bengalensis
Antropora – Antropora minor
Crisia – Crisia eburnea
Pectinatella – Pectinatella magnifica

The term Arthropoda is formed from the Greek words arthros meaning jointed and podos meaning foot. Those animals whose body has jointed appendages, bilaterally symmetrical, free circulatory system, hemoceles and exoskeleton containing chitin are called Arthropoda. Arthropoda is the largest group of animals. 80% of animals in the fauna are arthropods. The number of species is about 12,57,040. They are herbivores, carnivores or omnivours. Von Siebold (1845) named the order Arthropoda.
Characteristics of Arthropoda
1. They are triploblastic organisms, bilaterally symmetrical and segmented.
2. The body is divided into tagmata. The body is divided into head, thorax and abdomen.
3. They are animals with jointed appendages. The head has a pair of antennae and a pair of antennae.
4. The appendages of the body are changed to form the mouth. It takes food.
5. The exoskeleton is made up of cuticles and regularly sheds or molts.
6. The body cavity is known as hemocele. It is filled with blood.
7. Their main excretory organ is the Malpighian duct. But excretion is also done by green gland, chyloe, coxal gland, antennal gland and maxillary gland.
8. The circulatory system is open type. It consists of the heart, arteries and hemocele.
9. Respiration is accomplished through their trachea, gills, skin, gills, or pectoral fins.
10. Men and women are separate animals. Their internal fertilization occurs. Turns into an explosion.
11. The life cycle consists of larva, pupa and nymph stage.
12. They live as terrestrial, aquatic, sessile, free-living, parasitic or symbiotic.
[Key words to remember features: triploblastic, tagmata, pujakshi, moulting, hemocele, malpighian duct, chest lung]

Classification of Arthropoda
The order Arthropoda is divided into several suborders.
1. Trilobitomorpha: These are invertebrate arthropods. Their exoskeleton is strong. They are the most diverse.
2. Crustacea: Their bodies are soft and three-layered. Real Siloam exists. Has two pairs of antennae. Has two compound eyes. The body is divided into segments. For example – Bagda shrimp (Penaeus monodon).
3. Calicerata: These are eight-jointed joints. The body is divided into head and torso. They don’t have wings. There are poison glands in the body. For example – Spider (Lycosa lenta)
4. Hexapoda: Their body is chitinous and divided into head, thorax and abdomen. The thorax has a pair of jointed legs and a pair of wings. Has a branched tracheal system. Respiration is done by air ducts. Free circulatory system exists. Excretion is accomplished by the Malpighian duct

Some animals of Arthropoda
Flies – Musca domestica
Lobster- Macrobrachium resenbergii
Shrimp – Penaeus monodon
Cockroach- Periplaneta americana
Horse-hoofed crab – Tachypleus tridentatus
Limulus- Limulus polyphenus
Mosquito – Culex pipiens
Dengue mosquito- Aedes aegypti
Bee – Apis mellifera
Spider- Lycosa lenta
Grasshopper – Oxya chinensis
Butterfly – Papilio xuthus
Centipede- Scolopendra laeta
Thousand feet – Julus terrestris
Crab- Scylla olivacea
Beetle- Scolopendra gigantea
Barnacle – Balanus balanus
Hunting Mantis – Mantis religiosa
Bookworm- Lepisma saccharina
Buthus- Buthus tamulus

How to Identify Butterflies
1. The body of the butterfly is thin and covered with soft hairs.
2. The pupa of the batyfly resides within the chrysalis.
3. Adults have slender antennae and head discs.
4. When sitting, the fins are erect.
Haemocoel
A body cavity filled with hemolymph is called a hemocele. It is divided into three chambers or sinuses by the dorsal membrane and digital membrane. Pericardial sinus above the dorsal membrane, perivisceral sinus below the dorsal membrane and perineural sinus below the ventral membrane.
Book lung
The chest and lungs are organs of the body. The outer skin of the digital floor of Arthropoda animals is folded and arranged like the pages of a book to form the respiratory organ called the book lung. Spider (Lycosa lenta).
Book gill
The chest gill is a sexual organ. In Arthropoda animals, the skin of the digital floor is folded and forms a breathing organ like a gill like a page of a book is called a chest gill. For example – Macrobrachium resenbergii.
Tagmata
Each region of the body of animals of Arthropoda class is called tagmata. The process by which the animal body is divided into tagmata is called tagmatization. The evolutionary process by which tagmatization is accomplished is called tagmosis. The bodies of animals of the class Insecta of the order Arthropoda are divided into three tagmas. Namely – head, chest and abdomen. For example, grasshopper (Poekilocerux pictus).