Cockroach

STRUCTURAL ORGANISATIONS IN ANIMALS
COCKROACH
The slide contain about-
1. Classification of cockroach
2. Feature of cockroach
3. Morphology- Head , Thorax , Abdomen
4. Difference between male and female cockroach
5. Anatomy- Digestive system, Blood vascular system, Respiratory system , Excretion , Nervous system , Reproductive system , Questions with answers

1. Structural Organisation In Animals Cockroach

2. Classification of Cockroach PHYLUM Arthropoda CLASS Insecta ORDER Blattodae GENUS Periplaneta SPECIES Americana

3. Features Of Cockroach Cockroaches are brown or black bodied animals. Bright yellow , red and green coloured cockroaches have also been reported in tropical region. Their size ranges from ¼ inches to 3 inches (0.6-7.6 cm) and have long antenna , legs and flat extension of the upper body wall that conceals head. They are nocturnal omnivores that live in damp places throughout the world. They are serious pests and vectors of several diseases. (Cockroaches are nocturnal omnivore means they are active at night and they can eat both plant and animal products)

4. Morphology Periplaneta Americana are about 34-53 mm long with wings that extend beyond the tip of the abdomen in males. Its body is divided into head, thorax and abdomen. The entire body is covered by hard chitinous exoskeleton. Exoskeleton has hardened plates called sclerites that are joined to each other by a thin and flexible articular membrane

5. Head It is pear shaped and is six segmented. It lies at right angle to the body with the broad side upwards. It articulates with the thorax by flexible neck. On each side of the head is a large compound eye. They have a pair of antennae articulate in pits close to the notches of the compound eyes. The top of the head is termed as vertex. Antennae have sensory receptors that helps in monitoring the environment .

6. Mouth parts are chewing and surrounded by five kinds of appendages. These include the labrum (upper lip) , mandibles, first maxillae , second maxillae and hypopharynx (tongue).

7. Thorax The thorax consists of three segments – Prothorax, Mesothorax and metathorax. The head is connected with the thorax by a short extensions of the prothorax known as neck. Each thoracic segment bear a pair of walking legs. The first pair of wings arises from mesothorax and the second pair from metathorax. Forewings called tegmina are opaque dark and leathery and cover the hind wings when at rest. The hind wings are transparent , membranous, and are used in flight.

8. Abdomen In both males and females abdomen consists of 10 segments. In females, the 7 th sternum is boat shaped and together with the 8 th and 9 th sterna forms a brood or gential pouch whose anterior part contains female gonopore , spermathecal pores and collateral glands. In males, gential pouch or chamber lies at the hind end of abdomen bounded dorsally by 9 th and 10 th terga and ventrally by the 9 th sternum. It contains dorsal anus, ventral male gential pore and gonapophysis . Males bear a pair of short, thread like anal styles which is absent in females. In both sexes, the 10 th segment bears a pair of jointed filamentous structures called anal cerci.

9. Difference Between Male And Female Cockroach Male Cockroach Female cockroach A . The abdomen is long and narrow. A . The abdomen is short and broad B . Brood pouch is absent. B . Brood pouch is present. C . Male have longer antenna. C . Female have shorter antennae D . Anal styles are present D . Anal styles are absent.

10. Anatomy In anatomy of cockroach we will learn about Digestive system Blood circulatory system Respiratory system Excretion Nervous system Reproductive system

11. Digestive System Alimentary canal divided into three regions;  foregut, midgut and hindgut. The mouth opens into short  pharynx  leading to  oesophagus. Oesophagus opens into a sac like  crop,  which store food. Crop is followed by  gizzard  or  proventriculus. Gizzard contains chitinous teeth for grinding the food. The entire fore gut is lined by  cuticle. A ring of 6-8 blind tubules called  hepatic or gastric   caecae  present at the junction of foregut and midgut, which secretes  digestive juices . Midgut is long tube like structure. At the junction of midgut and hindgut, another ring of 100-150 yellow coloured thin filamentous  Malpighian tubules are present. Malpighian tubules are meant for excretion from haemolymph. The hindgut is broader and differentiated into  ileum, colon  and  rectum.

12. Blood Vascular System Blood vascular system is open type. Blood vessels are poorly developed and open into space called  haemocoel. Visceral organs located in the haemocoel and bathed in blood called  haemolymph. The haemolymph composed of colourless plasma and haemocytes. Heart is elongated multichambered, funnel shaped with ostia. Blood enter into the heart through ostia and is pumped anteriorly into the sinuses. The haemocoel differentiated into three sinuses; Pericardial sinus. Perivisceral sinus. Perineural sinus.

13. Respiratory System The respiratory system consists of a network of trachea. Trachea opens to outside by 10 pairs of small holes called spiracles on lateral side of the body. Trachea gives rise to branching tubes called tracheal tubes which subdivided into tracheoles. Opening of spiracles regulated by valves. Movement of air takes place by diffusion and directly to the body cell.

14. Excretion Excretion is performed by malpighian tubules. Each tubule is lined by glandular and ciliated cells. They absorb nitrogenous wastes from the haemocoel and converted into uric acid and poured into the hindgut. Hence cockroach is  uricotelic  in nature. Nephrocytes and uricose glands also assist in excretion.

15. Nervous System Consists of a series of segmentally arranged ganglia joined by paired longitudinal double ventral nerve cord. Three ganglia lie in thorax and six in the abdomen. Head contain a bit of nervous system. The brain is represented by supra-oesophageal ganglion which innervates the compound eye and antennae. The sense organs are antennae, eyes maxillary palps, labial palps, anal cerci etc. Each compound eye consists of about 2000 hexagonal ommatidia. Each ommatidium forms a part of the image, called mosaic vision.

16. Reproductive System Cockroaches are dioecious and sex organs are well developed. Male reproductive system consists of a pair of testes lying one on each in 4th and 6th segments. Vas deferens arises from each testis, opens into ejaculatory duct through seminal vesicle. Ejaculatory duct opens into the male gonopore situated ventral to anus. Accessory reproductive gland called mushroom gland present on 6th-7th segment. External genitalia represented by male  gonopophysis  or  phallomere. Sperms are sorted in the seminal vesicles and are glued together in the form of bundles called  spermatophores which are discharged during copulation.

17. The female reproductive system consists of two large ovaries present in 2nd – 6th abdominal segments. Each ovary is formed a group of eight ovarian tubules or ovarioles, containing chain of developing ova. Oviduct of each ovary fused to form single median oviduct or vagina, which opens into genital chamber. A pair of spermatheca is present in the 6th segment which opens into genital chamber. Sperms are transferred through spermatophores. The fertilized eggs are encased in capsules called oothecae. Ootheca is dark reddish to blackish brown capsule about 3/8” long. On average, female produce 9-10 oothecae, each containing 14-16 eggs. Development is pourometabolous i.e development through nymphal stages. The nymph grows by molting about 13 times to reach the adult form.

18. Male Reproductive System

19. Female Reproductive System

20. Quiz Time What is the scientific name of cockroach? What is the position of ovaries in cockroach? How many segments are present in the abdomen of cockroach? What is the function of malpighian tubules? Name the locomotory appendages of cockroaches on the basis of external morphology

21. Answers Periplaneta Americana Ovaries in cockroaches lie in the 4 th , 5 th and 6 th segment. Ten segment The malpighian tubules help in the removal of excretory product present in the haemolymph of the cockroach Three pairs of legs and 2 pairs of wings.

22. THANK YOU By - Samriddhi Singh XI A Kendriya Vidyalaya No.1 Hubli