Cockroach Anatomy PDF

Periplaneta americana, Blatta orientalis, Blattella germanica COCKROACH Cockroach Cockroach  Phylum : Arthropoda  Class : Insecta  Subclass : Pterigota ( two pairs of wings )  Order : Orthoptera ( dissimilar wings )  Genus : Perip...

Periplaneta americana, Blatta orientalis, Blattella germanica COCKROACH Cockroach Cockroach  Phylum : Arthropoda  Class : Insecta  Subclass : Pterigota ( two pairs of wings )  Order : Orthoptera ( dissimilar wings )  Genus : Periplaneta americana...34 to 53 mm long with wings which extend beyond the tip of the abdomen in males.  Blatta orientalis  Blattellla germanica....smallest cockroach..females have vestigial wings while males have proper wings. Cockroach  Zero parental care. Can show cannibalism if food is not available.  Either brown or black bodied and sometimes bright yellow, red and green coloured.  Cursorial habit. ( fast runners, less capacity to fly )  Chromosomes 34 and best found in tropical climate.  Serious pests and vectors of various diseases.  0.6 to 7.6 cm long Cockroach  Nocturnal and Omnivorous in nature.  Body divided in to 3 parts called “ Tegmata “.  3-Tegmata Embryo stage} Head 6 segment..Thorax 3 segment.. Abdomen 11 segment  Total= 20 some of them fuse in adult stage.  Head – 1  Thorax – 3  Abdomen - 10......6 segments fused Total= 14. Cockroach  Chitinous exoskeleton....chitinous plates are called as “ Sclerites “.  Sclerites joined with each other by “membrane” called “Arthrodial or Articular Membrane”.  Dorsal side sclerites known as Tergum/Tergite  Ventral side sclerites known as Sternum/Sternite.  Sclerites of lateral side – Pleurites/Pleurons Head Head  Head  Hypognathous Condition : Bent downwards at an angle of 90 degrees from the long axis of the body.  Sclerites of the head joined fully and form head capsule. ( formed by the fusion of six segments ).  Top part of the head is called as “vertex” and on the vertex a chitinous plate is found which is known as “Occiput”.  On the lateral side of head apex1 pair of compound eye.  Each eye is made up of 2000 units called “Ommatidia”.  Light colured spot called fenestra/occelar spot is located upon dorsal surface close to each eye. It is a photoreceptor organ, it is known as “vestigial simple eye”.  Head  Lateral side of head apex bear of 1 pair of antennae, main receptor of touch, temp. Vibration in cockroach.  Antennae : Long , filiform, un-branched and have sensory receptors that help in monitoring the environment.  Each antenna extending forwards from an antennal socket located dorsally upon head capsule near the compound eye of its side. They are free moving.  Frons/forhead: A big chitin plate below vertex.  Gena or Cheek: Two long flattened chitin plates laterally. Head  Clypeus : A big chitin plate present in the anterior part of frons.  A movable chitin plate joined with anterior part of clypeus known as ‘Labrum” or “Upper lip”.  Occipital formamen : A big pore situated in the ventral part of head called “Occipital foramen”.Neck is joined with head on Occipital foramen. Mouth Parts  Mouth Parts  Mouth parts are “biting, cutting and chewing type”.  Mouth cavity is know as “Pre-oral cavity”/ “Cibarium”.  Mouth parts are as follows....  Labrum/upper lip : It is dorsally overhanging part which is chitinous in nature which is the terminal sclerite. Commonly called as Upper lip as its position is dorsal.  Mandibles : Jaw..one pair of mandibles forming lateral wall of the pre-oral cavity. First maxillae  First maxillae : One pair forming lateral wall of the pre-oral cavity. With the help of maxillary palp part of first maxillae cockroach picks up its food and put it in pre-oral cavity for chewing.  It is also used as brush to clean antenna and wings.  Labium/second maxilla : It forms floor of pre-oral cavity and covers the ventral side.  Hypopharynx/Tongue :Small, non chitinous, flexible and connected with the floor of the pre-oral cavity.  It has several sensory setae at its free end and the common salivary duct opens at the base of hypopharynx. THORAX  Thorax  Neck/Cervicum : It is short extension of pro- thorax.Thorax is divided in to three segments... 1. Pro-thorax. 2. Meso-thorax. 3. Meta-thorax.  Thoracic appendages are... 1. Legs. 2. Wings. Legs  Legs  One pair of legs present in each segment of Thorax.  Each leg has five main parts/podomeres.... 1. Coxa: Broadest segment. 2. Trochanter: Small segment. 3. Femur: Long segment. 4. Tibia: Longest segment. 5. Tarsus: Made up of five sub-segments called “pretarsus”. It has two structures...  Arolium/Pulvilus : Adehsive pads.  One pair of claws movable on smooth surface with the help of “arolium” and on rough surface with the help of claws. Wings  Two pairs of wings are present...  Fore wings : Located on Meso-thorax, long ,narrow, leathery, strong, opaque and dark. Fore wings cover abdomen. May project beyond the abdomen in males called Tegmina/Elytra. Also shows network of fine tubules called “Nurvures” on inner side of the wings.  Hind wings : Present on Meta-thorax and are small, broad, thin, soft, transparent and membranous. Helpful in flying. Abdomen-1  It shows 10 segments...9 clearly seen in males and 7 clearly seen in females.  Other segments modified and reduced.  7th Tergum is largest in male and female. In males it covers 8th while in females it covers 8th and 9th Tergum.  Stink gland is located between 5th and 6th and emits offensive odour.  10th Tergum...bifurcated and bowl shaped and shows the presence of “Anal Cerci” in both males and females. Abdomen-2  Each ‘anal cerci’ is 15 segmented—Main sound receptors.  Sternum- In male-9 sternum. In female-7 sternum.  Males show the presence of anal styles which are two spine like structures present one on either side of the 9th sternum. These are non-segmented and help in copulation and absent in female.  7th sternum of female is boat shaped. Free end divided in to two plates: Gynavulvular plates or apical lobes.  These plate surround a pore called “Ootheca Pore”.  Abdomen-3  In female, the 7th sternum is boat shaped and together with the 8th and 9th sterna forms a genital pouch whose anterior part contains female gonopore, spermathecal pore and collatereal glands.  In males, genital pouch or chamber lies at the hind end of abdomen bounded dorsally by 9th and 10th terga and ventrally by the 9th sternum.  It contains dorsal anus, ventral male genital pore and gonapophysis ( organ which helps in copulation in insects ) Body wall-1  Body wall-2  It shows three layers... 1. Outermost-Thick cuticle which is covered by waxy layer. It is made up of alternate layer of protein and chitin. 2. Hypodermis/Epidermis- Shows columnar epithelium. 3. Inner most layer- “Basement layer” which is made up of simple squamous epithelium. BODY CAVITY Body Cavity  It is called as haemocoel which is filled with blood/haemolymph. Not a true coelom.  Blood is colourless and has no respiratory pigment and hence has nothing to do with the respiration.  Trehalose sugar in blood is disaccharide.  In embryonic stage several small sinuses fuse to form a large blood sinus/blood cavity.  All Arthropods are True coelomates...True coelom is found in gonads/Testis and ovaries and the body cavity is highly reduced.  Heart of Cockroach ---- Its structure and location CIRCULATORY SYSTEM / VASCULAR SYSTEM Blood Circulatory system  Blood vascular system  Circulatory system is open type/ “Lacunar Type”..blood filled in blood sinuses.  True blood vessel is absent but Anterior Aorta, a blood vessel which is half broken is present.  Blood filled cavity is known as “haemocoel”.  Blood is known as “Haemolymph”...colourless plasma which contains haematocytes/blood corpuscles.  Haematocytes- 1. Phagocytosis of bacteria 2. Blood clotting  Blood  It can work as hydraulic skeleton.  Exchange of materials.  Presence of two horizontal septa inside haemocoel which divides the haemocoel in to three chambers or sinuses. 1. Dorsal sinus/Pericardial sinus-Shows heart and alary muscles. 2. Middle sinus/Perivisceral sinus- Shows general viscera/digestive system and related organs. 3. Ventral sinus/Perineural sinus- Shows nerve cord. Heart of Cockroach-1  Heart of Cockroach-2  It is located in the dorsal sinus/pericardial sinus.  It is tube shaped and consists of 13 chambers which are supported by 12 pairs of alary muscles.  Each chamber looks like an inverted funnel.  Each chamber opens inside Pericardial sinus by two openings called Ostia which are present, one on either side, posteriorly. Their openings are guarded by auricular valves.  Blood enters the heart through ostia from pericardial sinus.  Heart of Cockroach-3  Each chamber opens in to a chamber in front of it only whose entrance is guarded by ventricular valve.  Hence the flow of the blood is always from posterior to anterior chamber or in forward direction only.  Heart wall shows special cells called “Nephrocytes”....whose functions are 1. To control heart beat..49/min. 2. “Storage Excretion”--- Storage of Uric Acid.  Tergosternal Muscles also help in blood circulation mainly concerned with respiration.  Heart of Cockroach-4  Pulsatile ampulla which is located at the base of each antennae and base of each wing. It helps in blood circulation in antennae and wings.  Heart Anterior Aorta Head Sin Pericardial Sinus Perineural Sinus Perivisceral Si Single Circulatory System of Cockroach RESPIRATORY SYSTEM IN COCKROACH Respiratory system: Cockroach Respiration: Cockroach  Respiratory Organ : Respiratory Tubules.  Body has a network of respiratory tubules.  Opening of the system outside the body is known as Spiracle/ small holes.  Total 10 pairs of spiracles ( 2 in the Thorax and 8 in the abdomen region ). Respiration : Cockroach  All spiracles are located on “Pleurone”/lateral side of the body.  First pair is on the lateral side of the Tergum.  Each spiracle is guarded by a valve and a cilia like bristles for filtering the air.  Valves are absent in the 1st pair of spiracles in the Thorax and the 1st as well as 3rd pair in abdomen Respiration : Cockroach  Each spiracle opens in to a chamber called tracheal chamber or “Atrium”.  It is connected with several main tracheal trunks which branch in to diffuse network of trachea.  Last branch of Trachea is known as “Tracheal Capillaries or Tracheoles”.  Tracheal capillaries- “ Intra-cellular”.  Tracheal capillaries closed in a cell called “Tracheal en cell”. Respiration : Cockroach  Long process found in tracheal end cell.  These process deeply merge in tissues of the body.  Each cell of body is directly in contact with processes, blood does not related with respiration, in blood respiratory pigment absent.  Exchange of gases take place at the tracheoles by diffusion. Breathing  Several Tergo- Sternal muscles extend between the tergites and sternites of all abdominal segments.  When the abdomen expands, atmospheric air gets filled in the tracheal system through spiracles. This is inspiration.  When the abdomen contracts, the air is forced out. This is expiration. Expiration takes place through first pairs of spiracles of thorax and first pairs spiracles abdomen.  The spiracular valves control and regulate the in and out passages of the air in thorax and abdomen. DIGESTIVE SYSTEM OF COCKROACH Digestive system: Cockroach  Digestive system : Cockroach  It is divided in to... 1. Fore gut/ Stomodaeum ( Ectodermal ) 2. Mid gut/ Mesenteron ( Endodermal ) 3. Hind gut/ Proctodaeum ( Ectodermal )  Fore gut: Formed by the invagination of body wall.Cuticle present in inner side of foregut.  Mouth to gizzard is foregut mouth open in the small buccal cavity.  Buccal cavity opens in tubular pharynx.  Pharynx- Opens near occipital foramen in “Oesophagus”.  Digestive system : cockroach  In thorax oesophagus expand and called “crop”( used for food storage ).  Crop opens in to thick walled gizzard or proventriculus.  Wall of gizzard : Circular muscle layer well developed. 1. Cavity of gizzard called- “armarium”. 2. Six cuticular teeth occur in cavity. These made up of longitudinal muscle layer and sharp cuticle. 3. Fine grinding of food occurs with the help of cuticular teeth. 4. Cuticular hairs present in the posterior part of gizzard these form “sieve”. 5. Gizzard- Grinding in upper part- filteration in lower part.  Digestive system : Cockroach  Mesenteron/ Mid gut ( endodermal )  Anterior part is called Cardia.  Gizzard open in cardia by “stomadial valve”.  6-8 small and tubular, finger like blind processes called hepatic caecae or gastric caecae is present at junction of foregut and midgut, project freely in to the haemocoel form the front end of Cardia.  These secrete “digestive juice”.  Wall of mesenteron is muscular.  Digestive system : cockroach  “ Hind gut “ or Proctodaeum ( Ectodermal ) :  100 to 150 yellow coloured thin tubules attached at the junction of hind gut and mid gut called “ Malpighian tubules “ which are excretory organs ( removal of excretory products from haemolymph ).  Digestive system : cockroach  Hind gut has three parts : 1. Ileum- Its wall is thin and internally folded. Its cuticle bears minute spines, which serve to break the peritrophic membrane. 2. Colon- Longest and broader part. 3. Rectum- Last part, oval shaped and internally folded wall. Its wall -6 folds called rectal papillae which absorb water. 4. Anus- at the end of 10th abdominal segment. Salivary Glands : Cockroach  Salivary Glands : Cockroach  One pair and attached with oesophagus and occur in thorax.  Two parts of each salivary glands.. 1. Reservoir part 2. Glandular part  Common efferent salivary duct arises from both salivary gland.  This duct open in pre-oral cavity at the base of hypo-pharynx.  Saliva: It contains carbohydrate digestive enzymes ex: Amylase, Chitinase and Cellulase.  Food : Omnivorous..identification with the help of antennae. Digestion-1  Starts in pre-oral cavity.  Saliva- Enzymes of saliva act upon the food till it reaches the crop. Digestion of carbohydrates takes place.  In crop- Hepatic caecae- complete digestive juice reaches in crop through the gizzard.  Gizzard- Food thoroughly grinded in to a paste by the thick and sharp edged cuticle of internal folds and grooves.  Ground food enters in to the midgut through stomadial valve. Digestion-2  Wall of Cardia : A membrane secreted around the food called peritrophic membrane which is made up of Glycogen and protein.  Serves to protect the wall of mid-gut from friction with food particles.  Membrane is permeable to digestive enzymes and digestive food.  Bacteria present in mid gut which are helpful in digestion of cellulose. Digestion-3  Digestion is completed in the anterior part of the mid- gut while absorption in the posterior part.  Distribution of Digested food by “Haemocoelomic fluid”..... 1. Peritrophic membrane and undigested food enter in to the Ileum. 2. Spine break the peritrophic membrane, so undigested substance release in ileum. 3. Maximum absorption of water occurs in rectum by rectal papilla. NERVOUS SYSTEM OF COCKROACH Nervous system of Cockroach Nerve ring  Nervous system of Cockroach Three types of Nervous system... 1. Central Nervous System. 2. Peripheral Nervous System. 3. Autonomous Nervous System.  Central Nervous System : It consists of.. 1. Brain Ring: It is located around the pharynx and oesophagus. 2. Its dorsal part is thick and bilobed called “Supra pharyngeal Ganglion/ cerebral Ganglion”. It is formed by the fusion of three pairs of cephalic ganglia.  Central Nervous System of Cockroach  These three pairs are... 1. Protocerebrum 2. Deuterocerebrum 3. Tritocerebrum  Sub-oesophageal ganglion on ventral side of alimentary canal. Sub-oesophageal ganglion formed by the fusion of three pairs of ganglia.  Both ganglia connected to each other by circum-oesophageal connectives. Nervous System of Cockroach  Ventral Nerve Cord : Double, Solid and ladder like.  It has 9 segmental/abdominal ganglia out of which 3 large ganglia in thorax and six in abdomen. Last ganglia is located in the 7th abdominal segment.  All ganglia formed in embryo stage by the fusion of 2 ganglia. Last segmental ganglia is formed by the fusion of many ganglia.  Peripheral Nervous System of Cockroach  Three pair of nerve from cerebral ganglion  One pair from proto-cerebrum supplying compound eye.  One pair from deutero-cerebrum in antennae.  One pair from trito-cerebrum in labrum.  Three pairs of nerves connect the sub- oesophageal ganglion with mandibles, maxillae and labium and other parts of the head and neck.  Three ganglia lie in the thorax and six in the abdomen.  Peripheral Nervous System  Six pairs of nerves from Prothoracic and five pairs from each of the mesothoracic and metathoracic ganglia innervate different parts of their respective segments.  A single pair of nerves arises from each of the first five abdominal ganglia to innervate muscles, spiracles, heart chambers and other parts in their respective segments.  From the last abdominal ganglia three pairs of nerves arise.  Peripheral Nervous System  All nerves are mixed nerves.. Motor Nerve Sensory Nerve  Autonomous Nervous System  It is divisible in to.... 1. Stomogastric Nervous system. 2. Spiracular Nervous system. 3. Caudal Nervous system.  Stomogastric Nervous System : This includes the following five ganglia which are all interconnected with each other by nerves and the nerves arising from these ganglion to innervate the anterior part of gut... It regulates Involuntary activities of foregut.  Autonomous Nervous System  Frontal Ganglion : This is a small median ganglion located dorsally upon the pharynx just in front of the brain.  Hypocerebral Ganglion : This is also a small median ganglion located dorsally upon oesophagus behind the brain.  Visceral Ganglion : This is located mid-dorsally upon the crop at about its middle.  Proventricular ganglia : These are two small ganglia, one upon dorsal and the other upon ventral surface of gizzard. Each of these are connected to visceral ganglion by nerve. These regulate the activity of forgut as”peristalsis”  Spiracular Nervous System  It controls spiracles.  Nerve plexus is found around spiracles which are connected with segmental ganglia of nerve chord.  Caudal Nervous System : It regulates the activity of hindgut, gonads and abdominal appendages.  This nervous system formed by the last segmental ganglion of nerve chord/7th.  Compound Eyes : It is made up of 2000 units called Ommatidia. Mechanism  Two types of vision : 1. Mosaic Vision/Apposition Vision : It is formed in bright light. ( less resolution but more sensitivity). 2. Superposition Image : In dim light in nocturnal insects.  In cockroach only apposition images are formed ( day and night ) No contrction power in pigmented sheath.  FEMALE REPRODUCTIVE SYSTEM : COCKROACH Reproductive system : Cockroach ootheca ootheca  Female reproductive System  One pair of ovary situated in 2nd to 6th segment of abdomen.  Each ovary is made up of 8 long tubules called “Ovarioles”.  Only one egg formed in each ovariole. Hence total 16 ova are matured at a time in cockroach.  Both oviduct of ovaries fuse and form “Vagina”. ( single median oviduct ).  Vagina : It opens inside body in a genital chamber. Female reproductive system  Genital chamber : formation of genital chamber by the fusion of 3 abdominal sternum.  7th Sternum : Forms the floor of genital chamber.  8th and 9th Sternum : It turns inwards to form the roof and sides of this pouch, the pouch itself is divisible in to a genital chamber in front and oothecal chamber behind.  A pair of “Spermatheca”present in 6th segment associated with genital chamber. Spermatheca unequal in size. Female reproductive system  Both spermatheca open by a pore in genital chamber.  A platform in genital chamber just beneath spermatheca pore called “Spermatheca Papilla”.  One pair of collaterial glands associated with genital chamber. These are branched tubular gland’s left collaterial gland is more branched.  Both glands open in genital chamber by two different pore.  Three pairs of chitinous processes hanging from the roof of genital chamber in to its cavity are the external genitalia of female cockroach. Female reproductive system  These are called ovipositor processes because these serve to arrange the ova in a newly formed ootheca, and possible help in giving proper shape to the ootheca.  MALE REPRODUCTIVE SYSTEM : COCKROACH Male reproductive system Male reproductive system  One pair of testis in 4-6 abdominal segment. Each testis is formed of 3 or 4 lobes. Each lobe is divided in to many lobules.  Vasa deferentia : Vasa deferens arises from each testis which open in the ejaculatory duct.  Ejaculatory duct opens outside by male genital pore.  Seminal vesicle in form of vesicles located upon ejaculatory duct.  A gland associated with seminal vesicle called mushroom gland or utricular gland is present in the 6th-7th abdominal segment which functions as an accessory reproductive gland. Male reproductive system  Having two types of tubules.... 1. Small tubules on inner side – Utriculi brevivores. 2. Long tubules outside – Utriculi majores.  Tips of long tubules called “Uricose gland” These absorb excretory material from haemocoel. Male reproductive system Male reproductive system Male reproductive system  A gland located on mushroom gland called “Phallic Gland” or congloblate gland.  It opens out side by a long duct “Phallic aperture”.  Chitinous structures associated with phallic aperture and male genital pore called “phallomeres” or “gonapophysis”.  Phallomeres... 1. Left 2. Right 3. Ventral  Male reproductive system  Left phallomeres :- 1. Made up of flat chitinous plate. 2. Four types of lobes attached with it. 3. Lower most is known as Titilator with hooks. 4. “Pseudopenis”- long with bulbow apex. 5. Asperate lobe – Lobe of spiny surface, phallic duct opens at the base of asperate lobe. 6. Innermost lobe – Acutolobe with a hook.  Right Phallomere – It is a chitinous structure. Two large hooks present at the apex and a hook present on base of right phallomeres. Male reproductive system  Ventral phallomeres : 1. Simplest and formed of a flat chitinous plate hooks absent. 2. Hooks help in opening of ootheca pore of female. 3. Phallomeres :- “External genital organs”. 4. “Spermatogenesis” completely in Testis. 5. Seminal vesicle :- stored the sperms. 6. All sperms glue together to form a “sperm ball”. 7. Long tubules secrete a membrane around a sperm ball called spermatophore.  Male reproductive system 1. Small tubules secrete a nutritious fluid in spermatophore. 2. At the time of copulation spermatophore enters in to ejaculatory duct. 3. Ejaculatory duct secrete another coat on spermatophore. 4. “Spermatophore” – double layered. 5. When they go out side from male genital pore then phallic gland secretes another layer, so spermatophore becomes three layered.  COPULATION, FERTILIZATION, METAMORPHOSIS Copulation  Breeding Season : From March to September.  Copulation Time : One hour.  The females secretes a highly odorous and volatile “sex attracting scent from their scent glands called Pheromones/Ecto-hormones.  Male perceive the smell of this scent with the help of olfactory sensillae located upon their antennae. Fertilization  Internal Fertilization : After fertilization the left collaterial gland secretes a soluble “ milky protein “ while the right one secrete dihydroxy- phenol.  Both secretions mix to form a brownish scleroprotein.  Sclero protein forms a common egg case called Ootheca.  Ootheca is a dark reddish to blackish brown capsule, about 3/8” ( 8 mm ) long.  The female deposit it in some dark and dry places.  Development  One female may form 9-10 Ootheca and each ootheca contain 14- 16 fertilized eggs.  Development of egg inside Ootheca.  Ootheca are adaption of terrestrial life to prevent the “water loss”.  Development time- 4 to 8 weeks.  Juvenile stage inside Ootheca is called “Nymph” which appears like an adult except wings and reproductive organs.  Nymph changes in to an adult in one year.  During metamorphosis- 13 times moulting in one year. Metamorphosis  Incomplete or Paurometabulous : In insect, those have larva stage have complete or holometabolous metamorphosis.  Cleavage = “ superficial meroblastic “. Cytoplasm divides not the yolk  Egg- Megalecithal and centrolecithal  Endocrine Glands : 1. Prothoracic gland : Secretes ecdysone hormone which controls moulting. 2. Corpora Allata : Secrete juvenile hormone which maintains larval/juvenile characters.