Male Reproductive System of Cockroach

Male reproductive system

1.           In cockroach, sexes are separate. 
2.           In cockroach sexual dimorphic characters are indistinct. 
3.           Females are broader than the male and absence of anal style. 
4.           Male reproductive system of cockroach  consists of a pair of testes  
5.           Testis are lying on either side of ventral nerve cord lateral side in the 4th -6th    
         abdominal segments. 
6.           Each testis is tri-lobed structure. 
7.           From each testis arises a thin vas deferens, which opens into ejaculatory duct 
         through seminal vesicle. The ejaculatory duct opens into male gonopore situated 
         ventral to anus. 
8.           A characteristic mushroom shaped gland is present in the 6th-7th abdominal 
         segments which functions as an accessory reproductive gland.  
9.           The external genitalia are represented by male gonapophysis or phallomere  
         (these  are chitinous asymmetrical structures, surrounding the male gonopore). 
10.      The sperms are stored in the seminal vesicles and are glued together in the form  
        of bundles called  spermatophores  
11.      The sperms are discharged during copulation.

Alimentary Canal of Cockroach :

Alimentary Canal of cockroach :

The alimentary canal is in the form of tube  present in the body cavity

Alimentary canal of cockroach is  divided into three regions are as follows:

1.  Fore gut

2.  Mid gut

3.  Hind gut.

Fore gut- it is also called as stomodaeum. It consists of mouth, pharynx, oesophagus, crop chamber and gizzard.

The mouth is present to the anterior end which opens into a short tubular pharynx, leading to a narrow tube called oesophagus.

 The oesophagus leads into large sac like structure called crop. Crop is used for storing of food.

The crop is followed by gizzard. It has rounded highly muscular part. The lumen of crop chamber shows presence of Six  chitinous teeth. Gizzard helps in grinding the food particles.

At the junction of fore gut and mid-gut there is presence of 6-8 blind tubules called hepatic or gastric caecae which secrete digestive juice.

Mid-gut –It is in the form of elongated and coiled tube.  The digestion and absorption of food takes place in this part.  

Hind gut – it is also called as proctodium. It is coiled and pigmented part of alimentary canal.  The hindgut consist of  ileum, colon and rectum.

At the junction of mid-gut and hind-gut there is presence of ring of 100-150 yellow coloured thin filamentous Malpighian tubules. The malpighian tubules are the most important part of excretory system, help in removal of nitrogenous waste from the haemo-lymph.

The rectum is most posterior part of alimentary canal. The undigested food is temporarily  stored into the rectum.

Sexual Dimorphism in cockroach

                   

         Sexual Di-morphism in cockroach

Sr. No.	Male Cockroach	Female Cockroach
1.	Presence of anal style in the last segment is an important sexual dimorphic character.	Absence of anal style in the last segment
2	Antennae longer than the body.	Antennae longer than the body.
3.	Three podomers of antenna are smaller	Third podomers are smaller than 2nd podomer.
4.	Abdomen is long, narrow and dorso-ventrally flattened.	Abdomen is short, larger and broad.
5.	Wings are long and large, extending beyond the length of the body.	Wings are short and narrow i. e. smaller than a body.
6.	Male genital opening present at 9th and 10th segment	Female genital opening present in between the 6th and 9th segments.
7	Abdomen Long	Abdomen short and narrow
8	Abdomen shows nine distinct segments.	Only seven abdominal distinct segments.

Cockroach (Periplaneta americana) Systematic position, habits and habitat

    Periplaneta americana 

 Classification 

.

Phylum            -Arthropoda                 =Presence of Jointed Appendages 

Sub-phylum     -Mandibulata               -Mandibles are present

Class                -Insecta                       -Three pair of walking legs . Body is divisible into Head,

-Neck, Thorax and Abdomen.

Division           -Exopterrygota            -Presence of straight wing

Order               -Dictyoptera                - Presence of two pair of wing

Genus              -Periplaneta    

Species            -americana

           

Habits, Habitat and External morphology 

                Cockroaches are belong to the class insect of phylum Arthropod as they have jointed appendages.  They are found in tropical regions of the world.

They are nocturnal omnivores that live in dark and damp places where plenty of organic food is available. These insects lives with human habitation, they are serious pests and vectors of several diseases. 
Cockroach is omnivorous in feeding habit. The body measures about 34-53 mm long with wings that extend beyond the tip of the abdomen in males. The color of the body is brown or black and has long antenna, jointed appendages, three pairs of walking legs.  The body of cockroach is divisible into head, neck, thorax, and abdomen. Head bears mouth parts, pair of compound eyes, antennae.

The body of the cockroach is segmented. The body of cockroach is covered by a hard chitinous exoskeleton in the form of hardened plates called sclerites or sclerite plates. The sclerite plate present on dorsal side are called Tergal plates or tergites. The sclerite plates present on ventral side are called sternal plates or  sternites. The terga and sterna are laterally joined together by flexible articular membrane (arthrodial membrane). Sexes are separate. Sexual di-morphism in cockroach is distinct. In male there is presence of anul style, in female are absent.