You might wander, how many legs do cockroaches have. If you have seen one of those giant cockroach props that actors use on stage, you probably know that these insects have six legs. However, real cockroaches can have anywhere from 5 to 7 legs depending on the species and gender.
So why do all roaches have 6 legs? Keep reading to find out more about how many legs cockroaches have and why it is important to know.
What bug looks like a roach?
What is the Purpose of Having 6 Legs?
Cockroaches are insects, and insects are arthropods. Arthropods are invertebrates with external skeletons, segmented bodies, jointed legs, and a simple digestive system. Externally, arthropods have a hard, external covering called an exoskeleton. Exoskeleton means “outside skeleton.”
These exoskeletons are composed of a protein called collagen. This protein is very strong and resists breaking. However, it is also very flexible and can grow with the insect as it grows. Since exoskeletons are external, arthropods have to shed them periodically as they grow larger.
5 Legs in Cockroach Adults
Adults of most species have 5 legs. There are a few exceptions. The American cockroach has 6 legs in its adult form, but it can “lose” one of its legs at certain times during its life cycle. What happens is that the leg becomes dislocated from the body, and the blood vessels supplying it with blood rupture.
Then, the leg dies and falls off. The Australian cockroach has 5 legs in the adult form, but it has 6 legs in the nymph form.
The Indian cockroach has 5 legs in both the adult and the nymph form.
The German cockroach has 5 legs in both the adult and the nymph form.
The Oriental cockroach has 5 legs in the adult form, but it has 6 legs in the nymph form.
The smoky brown cockroach has 5 legs in both the adult and the nymph form.
7 Legs in Cockroach Nymphs
Nymphs of most species have 7 legs. Again, there are a few exceptions. The American cockroach has 7 legs in its nymph form, but it has only 5 legs in its adult form.
The Australian cockroach has 7 legs in its nymph form, but it has only 5 legs in its adult form.
The Indian cockroach has 7 legs in its nymph form, but it has 5 legs in the adult form.
The German cockroach has 7 legs in both the nymph form and the adult form.
The Oriental cockroach has 7 legs in the nymph form, but it has 5 legs in the adult form.
The smoky brown cockroach has 7 legs in both the nymph form and the adult form.
Why Do All Roaches Have 6 Legs?
As explained above, arthropods have an external skeleton made of collagen protein. This exoskeleton is very strong and resistant to breaking, but it is also very flexible and can grow with the insect as it grows.
Since the exoskeleton is external, it has to shed periodically as the insect grows larger. Once the exoskeleton has been shed, it breaks down and is reabsorbed by the insect’s body.
Once the exoskeleton is broken down and reabsorbed, there is no collagen protein left to make a new exoskeleton. Since there is no protein, there is no way for the insect to grow a new exoskeleton. Therefore, the insects have to modify their bodies to make the new exoskeleton.
Which Species of Cockroaches Have 6 Legs?
The American cockroach, Australian cockroach, Indian cockroach, German cockroach, smoky brown cockroach
Which Species of Cockroaches Have 7 Legs?
Oriental cockroach
What bug looks like a roach?
Conclusion
Cockroaches have external skeletons, so they periodically have to shed their exoskeletons and replace them with new ones as they grow larger. Since there is no protein left to make a new exoskeleton, the insects have to modify their bodies to make a new exoskeleton. As a result, the insects have to have at least 6 legs.
However, some species temporarily “lose” one leg during their life cycle, so they end up with only 5 legs in their adult form. Cockroaches are very common pests that can be found in both commercial and residential buildings across the world.
Although they are often associated with filth and squalor, they can also be found in clean and well-maintained buildings. Although they may seem repulsive, you should be aware that they are considered to be one of the most adaptive species on the planet.