Cockroach | Classification, Reproductive system, Anatomy

Hello friends, today we are going to talk about cockroaches what is a cockroach? Today you are going to know completely about this, if you cockroach, then you have to read step by step completely so that you understand it well, so let’s start.

What is a cockroach?

First of all, we know about the classification of cockroaches so we will get some important information about them.

Classification of cockroach –


Now let us know what is the scientific name of Cockroach.

What is the Scientific name of a Cockroach?

The scientific name of cockroach –

The scientific name of the cockroach is Periplaneta americana. The scientific name of any organism is taken together with the name of its genus and species.

This is very important information that is always asked in exams. Let’s go ahead.

The cockroach is a uniquely omnivorous insect that is found throughout the world and class Insecta exhibits all of the basic characteristics Or does it happen? Generally, cockroaches are reddish-brown or black in color with light brown margins in the first torso or thoracic segment.

Cockroaches are omnivores and are nocturnal. They live in damp and warm places, as well as in kitchens, hotels, bakeries, restaurants, warehouses, sewage, and public places. You guys must know this. Periplaneta is a fast-running animal. It is a dioecious and egg-laying animal and exhibits parental care.

With it, cholera, diarrhea, tuberculosis, and typhoid as various bacteria They carry harmful germs of diseases and are therefore known as “Vectors.

Also, read – What is a cell?

Morphology –

Adult or young cockroaches are about 2 to 4 cm in length and about 1 cm in width. cockroach’s body is dorso-ventrally, bilaterally symmetric, segmented, and divided into three distinct regions – the head, thorax, and abdomen. Their entire body is covered with a hard, brownish, chitinous skeleton.

In each of these segments, the skeleton consists of rigid plates called sclerites, which are held together by a soft and flexible articular membrane or arthrodial membrane. The sclerites of their dorsal side are called tergites.

And the sclerites on their abdominal or abdominal side are sternites and the sclerites on their lateral sides are pleurites.

The cockroach head is small, and triangular located at right angles to the longitudinal axis of the body. Their mouth parts are directed downwards so it is called hypognathous.

It is formed by the fusion of 6 segments and its neck is flexible due to that it can see easily in all directions. The head region has large, sessile, and reniform compound eyes, a pair of antennae, and appendages around the mouth.

Antennae contain sensory receptors that help in monitoring the environment. The oral appendages are for biting and chewing (mandibulate or orthopterous type).

The mouth region consists of a labrum (upper lip), a pair of mandibles, a pair of maxillae, a labium (lower lip), and a hypopharynx (tongue) or lingua.

The thorax consists of three sections – the prothorax, mesothorax, and metathorax. The prothoracic segment is the largest. The head is attached to the torso by a small extension of the prothorax called the neck or cervix.

Each thoracic segment has a pair of legs for walking. They have three pairs of legs for walking, due to which, are also called Hexapoda (Hexa-six, pod-foot), all three pairs of walking legs are the same and each foot has five segments – coxa ( Large), trochanter (short), femur (long and broad), tibia (long and thick) and tarsus.

The last segment of the foot – the tarsus consists of five movable joints or the podomeres or tarsomeres. Cockroaches have two pairs of wings, the first pair emerging from the mesothorax and protecting the hind wings at rest, and are called elytra or tegmina.

The second pair of wings emerge from the metathorax and are used in flight. Both males and females have 10 segments in their abdomen or abdomen. Each segment is covered by the dorsal trachea, the ventral sternum, and between them by a narrow membranous pleura on each side.

Also, read – What is taxonomy?

In females, the 7th sternum is boat-shaped and, together with the 8th and 9th stern, forms a brood or genital sac, the front parts of which contain the female gonopore, the spermatic cord, collateral glands, and the posterior portion of the ophthalmic chamber. Build in which cocoons are made.

In males, the genital sac is located at the posterior end of the abdomen, dorsally by the 9th and 10th terga, and in the abdomen by the 9th sternum. It contains the dorsal anus and the ventral male genital orifice. In both sexes, the genital pores are surrounded by sclerites called gonapophysis. The male bears a pair of short and thin anal sacs in the 9th sternum which are absent in the female.

In both sexes, the 10th segment consists of a pair of combined filamentous structures called anal cerci and a sense organ that is receptive to vibrations in air and land. The male’s 7th sternum has a pair of large and oval apical lobes or non-valvular plates that form a boat or ship’s bottom structure that separates the male from the female.

The cockroach is the fastest insect on land, it can run at 5.4 km.

Let us now study the digestive system of cockroaches.

Anatomy of Cockroach

Digestive System of cockroach –

cockroaches consist of the alimentary canals and digestive glands. The alimentary canal is present in the body cavity and is divided into three regions: the anterior gut, the middle intestine, and the posterior gut. The foramen includes the pre-ophthalmic cavity, mouth, pharynx, and esophagus.

This in turn opens into a sac-like structure called a sac or crop. Which is used for storing food. The crop is followed by the gizzard or proventriculus. which there is an outer layer of thick circular muscles and a thick inner cuticle.

Which makes up the six highest chitinous plates called teeth, which help in grinding the particles of food. The midgut is a short and narrow tube at the back of the gizzard and is glandular in nature. The Gizzard’s junction area consists of eight finger-like tubular blind processes called hepatic ceca or enteric.

The posterior gut contains 100-150 yellowish thin filamentous Malpighian tubules which aid in removing excretory products from the hemolymph. The hindgut is wider than the midgut and is differentiated into the ileum, colon, and rectum. The rectum opens through the anus.

cockroaches consist of salivary glands, glandular cells, and liver mosses. A pair of salivary glands are found on either side of the crop in the thorax. The glandular cells of the midgut and hepatic or gastric caecal produce digestive juices.

Now we will learn about the respiratory system of cockroaches.

The respiratory system of cockroaches –

compared to other terrestrial insects respiratory system is well-developed. Their branched tubes are known as trachea, which opens through 10 pairs of small holes called spiracles or stigmata present in the lateral part of the body. The terminal branches or branches of the tracheal tubes are called trachea.

Which carries oxygen throughout the body. The spiracles are open and closed by valves controlled by the sphincter or the spiracular muscles. Each trachea is filled with a watery fluid through which the exchange of gases takes place.

During high muscle activity, a portion of the fluid is drawn into the tissues to enable greater oxygen intake and faster a passage of air in the tracheal system –


First the air Spiracles then it Trachea and then Tracheoles after that in the Tissues. 

What is the circulatory system of a cockroach?

Circulatory system –

Periplaneta has an open type of circulatory system, in which blood vessels are not well developed and they are open in the hemocoel in which blood or hemolymph flows freely. The organs of the intestine located in the hemocoel are bathed in blood.

Hemolymph is colorless and consists of plasma and hemocytes which are ‘phagocytic‘ in nature. Their heart is a long tube in which the muscular wall is located dorsally in the middle below the thorax. Their heart consists of 13 chambers or chambers with ostia on either side.

Blood from the sinuses enters the heart through the ostia and is pumped again into the sinus. The triangular muscles responsible for blood circulation in cockroaches are called the Alary muscles.

These muscles have 13 pairs and one pair is found in each segment on either side of the heart. In cockroaches, each antenna has an accessory vibrating vesicle on its root that also pumps blood.

Important information about cockroaches –

Did you know that a cockroach can live without its head for about a week? This is because of their open circulatory system and the fact that they breathe through tiny pores on each segment of their body as they do not depend on the mouth or head for breathing. But later the cockroach dies of hunger. Because food can be eaten only through the mouth.

Do you know that a cockroach 45 minutes can hold its breath for half an hour and can survive even after being submerged in water they often hold their breath to control the loss of water in their bodies.

Let us now study the nervous system of cockroaches.   

What is the Nervous System of cockroaches?

cockroaches consist of a nerve ring and a ganglionated double ventral nerve cord, sub-oesophageal ganglion, circum-oesophageal connectives, and double ventral nerve cord. The nerve ring is present in the head capsule surrounding the esophagus and formed by the supra-oesophageal ganglion called the ‘brain.

The brain is primarily a sensory and endocrine center and is located above the esophagus. A sub-oesophageal ganglion is the motor center that controls the movement of the mouth, legs, and wings.

It is located below the esophagus and is formed by the fusion of paired ganglia of the mandibular, maxillary, and labial segments of the head. A pair of circum-oesophageal connectives are present around the esophagus, which connects the supra-oesophageal ganglia to the sub-oesophageal ganglion.

The double ventral nerve cord is a solid, ganglion, that arises from the sub-oesophageal ganglion and extends to the 7th abdominal segment. There are three thoracic ganglia, one in each thoracic segment, and six abdominal ganglia in the abdomen.

In cockroaches, the sense organs are antennae, (antennae), compound eyes, labrum, maxillary pulps, labial palps, and anal cerci. The receptors for touch (thigmoreceptor) are located in the antennae, maxillary palps, and cerci.

The receptor for odor (olfactory receptors) is found on the antennae. Taste receptors (taste receptors) are found on the palate of the maxilla and labium.

Thermoreceptors are found on the first four tarsal segments on the feet. anal chordotonal that responds to vibrations produced by wind or earth. The photoreceptors of cockroaches have a pair of compound eyes on the dorsal surface of the head.

Each eye is made up of about 2000 simple eyes called ommatidia (singular ommatidium), through which the cockroach can obtain multiple images of an object. This type of vision is known as mosaic vision with greater sensitivity but lower resolution.

Arthropod eyes are compound eyes because they are composed of repeating units, ommatidia, each of which acts as a separate visual receptor.

Now we will read about the excretory system of cockroaches.

Excretory system of cockroach –

 Malpighian tubules are the primary excretory organs of cockroaches which help to eliminate nitrogenous wastes from the body in the form of uric acid. Cockroaches excrete uric acid, so it is uricotelic.

In addition, the fat body, nephrocytes, epidermis, and uricase glands also perform excretory functions. Malpighian tubules are thin, long, fibrous, yellowish structures attached at the junction of the midgut and hindgut.

These are about 100-150 in number and are present in bundles of 6-9. Each duct is lined by glands and ciliated cells and waste is expelled through the posterior intestine. The glandular cells of the Malpighian tubules absorb water, salts, and nitrogenous wastes from the hemolymph and transfer them to the lumen of the tubules.

The cells of the tubules reabsorb water and some inorganic salts. By narrowing the tubules, nitrogenous waste is pushed into the ileum, where much of the water is reabsorbed. It moves into the rectum and almost solid uric acid passes out with the stool.

Marcello Malpighi – described these ducts and called them vasa varicose. Meckel later called them Malpighian tubules.

You will get information about the reproductive system of cockroaches. 

The reproductive system of cockroach –

The cockroach is bisexual. They have well-developed reproductive organs. The male reproductive system consists of a pair of testes, vasa deferentia, ejaculatory duct, utricular gland, phallic gland, and external genitalia. A pair of three-lobed testes are located on the lateral side of the 4th and 6th abdominal segments.

A thin spermatic cord emerges from each testis, which through the seminal vesicles opens into the ejaculatory duct. The ejaculatory duct is a long duct that opens into the abdomen of the anus through the male gonopore. The utricular or mushroom-shaped gland is a large accessory reproductive gland that opens into the anterior part of the ejaculatory duct.

The seminal vesicle is present on the abdominal surface of the ejaculatory duct. These sacs store spermatozoa in the form of bundles called spermatocytes. The duct of the phallic or conglobate gland also opens near the gonopore, the function of which is uncertain.

Surrounding the male genitalia are some chitinous and heterogeneous structures called phallometric or Gonapophys that help in copulation.

The female reproductive system of cockroaches consists of ovaries, vaginas, genital sacs, collateral glands, sperm, and external genitalia. A pair of ovaries are located laterally in the second and sixth abdominal segments. Each ovary is made up of a group of eight ovarian ducts, or ovaries, that contains a series of developing ovules.

The lateral oviducts of each ovary unite into a broad median common oviduct known as the vagina, which opens into the genital chamber. The vertical opening of the vagina is the female genital orifice. A pair of spermatozoa are present in the sixth segment, which is opened by a median orifice in the dorsal wall of the genital sac.

During copulation, the eggs descend into the genital chamber, where they are fertilized by sperm. A pair of white and branched collateral glands present at the back of the ovary form a hard egg case called the ootheca around the egg.

The genital sac is formed by the 7th, 8th, and 9th abdominal sterna. The genital sac consists of two chambers, a genital chamber into which the vagina opens and an ophthalmic chamber where the oothecae form. Surrounding the female genital orifice are three pairs of plate-like chitinous structures called Gonapophys.

These gonapophyses guide the ovum into the ootheca as ovipositors. The ootheca is a dark red to dark brown capsule about 12 mm long that contains about 16 fertilized eggs and is dropped or glued onto a suitable surface, usually near a food source of high relative humidity or a crevice. in the crack. On average, each female cockroach produces about 15 – 40 oothecae in her life span of about one to two years.

Embryo development takes place in the ootheca, which takes about 5 – 13 weeks. Cockroaches develop gradually through nymphal stages (paurometabolous). The nymph is similar to the adult and undergoes molting. The maiden grows about 13 times by ecdysis to reach the adult form.

Many species of cockroaches are found in the wild. About 30 of the 4,600 cockroach species are associated with human habitats. About four species are known as pests. They destroy the food and contaminate it with their unpleasant odor.

The mere presence of cockroaches is a sign of unhygienic conditions and they are also known as carriers of many bacterial diseases. Cockroach allergens can cause asthma in sensitive people.

Diploptera punctata, a live cockroach, produces a nutritionally dense crystalline “milk” to feed its live-born young. It is found in Myanmar, China, Fiji, Hawaii, and India. Scientists believe that cockroach milk may be the superfood of the future.

Some important questions and answers about cockroaches –

Question 1 – How many chambers are there in the cockroach’s heart?

Answer – There are a total of 13 chambers in the heart of cockroaches.

Question 2 – How long can a cockroach hold its breath?

Answer – A cockroach can hold its breath for 45 minutes.

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