Cockroach: Reproductive System, Fertilisation, Development and Economic Importance, Practice Problems and FAQs

Do you know, in some countries cockroaches are used as food? Why?

This is because cockroaches are a good source of proteins. They have antioxidant properties which are then transferred to the humans when they consume it. The cockroaches are cooked properly so that the bacteria present on their skin are killed. There are several dishes of cockroaches that give a crunchy texture and taste.

Let’s take a deep dive into the reproductive system and economic importance of cockroaches. 

Table of Contents:

• Reproductive System
• Fertilisation
• Ootheca
• Development in Cockroaches
• Economic Importance
• Practice Problems of Cockroach: Reproductive System
• FAQs Cockroach: Reproductive System 

Reproductive System

Cockroaches exhibit sexual dimorphism. They have distinct male and female members. Cockroaches have well-developed reproductive organs in both males and females.

Male Reproductive System

The male reproductive system consists of different parts like testes, vas deferens, seminal vesicle, ejaculatory duct, male gonopore, gonapophysis and accessory glands.

Testes

One pair of trilobed testes is present in male cockroaches. It is located in the 4th to 6th abdominal segments.

Vas Deferens

Vas deferens arises from testis. It opens into the ejaculatory duct through a seminal vesicle.

Seminal vesicle

Seminal vesicle is a sac-like structure that stores sperm in the form of bundles called spermatophores. They secrete fluid in the semen.

Ejaculatory Duct

It carries sperm from the seminal vesicle to male gonopore.

Male Gonopore

Male gonopore is a genital pore through which sperms pass into the vagina.

Male Gonapophysis

It is surrounded by chitinous and asymmetrical structures. Male gonapophysis is also known as phallomeres. Three gonapophysis are present like ventral phallomere, left phallomere and right phallomere.

Accessory Glands

Two types of accessory glands are present in male cockroaches. They are the mushroom gland and phallic gland.

Mushroom Gland - It is present in the 6th and 7th segments. It is present at the junction of the vasa-deferentia and the ejaculatory duct. They are also called utricular glands. They are small and long tubules that help in nourishing the sperms.

 Phallic Gland - It is also called the conglobate gland. It is present in the 6th and 7th segments. It lies beneath the mushroom gland. They help in the formation of spermatophores.

Female Reproductive System

It consists of different parts like ovaries, oviduct, common oviduct, genital chamber, gonapophysis and accessory glands. The accessory glands include spermatheca and collateral glands.

Ovaries

One pair of ovaries is present in the 2nd to 6th abdominal segments. Each ovary consists of 8 ovarian tubules or ovarioles with a developing ova.

Oviduct

Each ovary leads to the oviduct.

Common Oviduct

Oviducts join to form a single median oviduct or vagina. Vagina opens into a genital chamber.

Genital Chamber

Its role is to pass ova and sperm. Vagina and spermatheca open into it.

Gonapophysis

It is the external genitalia. It consists of three pairs of plate-like chitinous processes. It is arranged around the female genital apertures. It is also called ovipositor. 

Accessory Glands

In female cockroaches, the accessory glands are of two types. They are the spermatheca and collateral glands.

Spermatheca - One pair of spermatheca is present in the 6th abdominal segment. It opens into genital chamber. It stores sperm during copulation.

Collateral Glands - They open into the genital chamber. The secretion of collateral glands helps in the formation of egg cases or ootheca.

Fertilisation

The male cockroach deposits the sperm into the genital chamber of the female during copulation with the help of phallomeres. Internal fertilisation takes place, that means the fusion of sperm and ova takes place inside the female body. Sperms once released reach the spermatheca. Ova are also released into the genital chamber. The sperms stored in spermatheca are released into the genital chamber. Fertilisation takes place in the genital chamber of the female cockroach.

Ootheca (Egg Case)

Post fertilisation, the fertilised eggs are encased in capsules known as egg cases (ootheca). They are dark reddish to blackish brown in colour. Vary in size from about ⅜ inches or 8 mm long. Female cockroaches drop ootheca at places of high humidity with availability of food sources. A female lays around 9 – 10 ootheca. Each ootheca has 14 – 16 fertilised eggs.

Development in Cockroaches

Development is hemimetabolous in cockroaches. That means the embryo develops into a mature individual through sexually immature nymphal stages. The nymph moults (cast or shed a part of the body to make way for new growth) about 13 times to reach the adult form. No parental care given for nymphs. The stage before the last nymphal stage has wing pads but only adult cockroaches have wings.

Economic Importance

Every organism in this world contributes in one or another way. It may be negative or positive. 

Negative Impact

They are considered pests. They act as a vector for several bacterial diseases like cholera, diarrhoea etc. They damage household materials like clothes, papers etc. They pollute food. They create anxiety and stress in humans. They cause allergies in certain people. 

Positive Impact

It is used as food by certain people. It can be used as bait for fishes. It is part of the food chain. It is commonly used as an experimental animal in laboratories.

Practice Problems of Cockroach - Reproductive System

Ques:- In which segments, testes is present in male cockroaches?

A. 4th, 5th, 6th segments
B. 6th and 7th segments
C. 2nd to 6th segments
D. 7th and 8th segments

Solution: One pair of trilobed testes is present in male cockroaches. It is located in the 4th to 6th abdominal segments. Hence, the correct option is a.

Ques:- Which glands are also known as conglobate glands?

A. Mushroom glands
B. Phallic glands
C. Spermatheca
D. Collateral glands

Solution: Phallic glands are also called the conglobate glands. They are present in the 6th and 7th segments. It lies beneath the mushroom gland. They help in the formation of spermatophores. Hence, the correct option is b.

Ques:- The female cockroach generally lays how many oothecas?

A. 7-8
B. 6-7
C. 9-10
D. More than 10

Solution: Ootheca is a capsule in which fertilised eggs are encased. They are dark reddish to blackish brown in colour. They vary in size. A normal female lays around 9-10 ootheca. Hence, the correct option is c. 

Ques:- The development in cockroaches is _____________.

A. Hemimetabolous
B. Holometabolous
C. Both a and b
D. None of the above

Solution: The development in cockroaches is hemimetabolous. Here the embryo develops into a mature individual through sexually immature nymphal stages. There is no pupal stage. Hence, the correct option is a.

FAQs of Cockroach - Reproductive System

Ques:- How are cockroaches economically important?

Solution: Cockroaches are used as food by certain people. They can be used as bait for fishes. They are commonly used as experimental animals in laboratories. They also have a negative impact as they are considered pests that pollute the food and water.

Ques:-What is the site of fertilisation in cockroaches?

Solution: The fertilisation takes place in the genital chamber of the female reproductive tract. The male cockroach deposits the sperm into the genital chamber of the female during copulation with the help of phallomeres. Internal fertilisation takes place in them. Here the fusion of sperm and ova takes place inside the female body. 

Ques:-What different parts are involved in male reproductive system of cockroaches?

Solution: The male reproductive system of cockroaches have testes, vas deferens, seminal vesicle, ejaculatory duct, male gonopore, male gonapophysis and accessory glands. Two types of accessory glands are present and these are the mushroom glands and phallic glands.

Ques:- What is ootheca?
Solution: The fertilised eggs are enclosed in capsules known as egg cases or ootheca after fertilisation. They range in colour from dark reddish brown to blackish brown. Sizes range from 38 inches to 8 millimetres in length. Female cockroaches produce ootheca in areas with high humidity and food supplies. Around 9 – 10 ootheca are laid by a female. There are 14 – 16 fertilised eggs in each ootheca.

Related Topics to Reproductive System of Cockroach in Biology

• Morphology of Cockroach
• Respiratory system of cockroaches
• Digestive system of cockroach
• Connective Tissues
• Connective Tissue Blood
• Connective Tissue Bone
• Connective Tissue Cartilage

NCERT Class 11 Biology Chapters