[Biology Class Notes] on Molt Pdf for Exam

Molt or also known as moult is the condition in many of the invertebrates in which they shed or cast off a part of their body, usually an outer layer, depending on the biological requirement which may be at specific times of the year or at the specific time of their life cycle. Molt synonym in this context is sloughing or shedding because the animals routinely dropped off the body parts of covering as part of their living conditions and physiological requirements. This process as identified by the moulting meaning can be stated as molted/moulted.

Concept Stated By Moulting Meaning

During certain points in their life cycle or annually animals belonging to the group of invertebrates shed their covering or certain body parts which are usually external parts of the body which is known as molting/moulting. The condition described by the moutling meaning is said to be molt or moult. For the animals belonging to the clade of Ecdysozoa, this process is known as ecdysis. The process typically involves the shedding of the epidermis i.e. the skin. Other parts of the animal body that may be involved in the shedding process include pelage which means shedding of hair, feathers, fur or wool, or any other external layer, wings in some insects, or entire exoskeletons in arthropods. 

This molted/moulted condition is further also observed in cats when they shed their hair, in chickens when they lose their feathers, dogs and canids shed fur, snakes shed their skins, lizards shed their skins, etc. These processes are further explained below more specifically. 

Moulting in Birds

In birds, the primary cases of moulting include the shedding of the body hair, feathers and furs if present. Generally it’s the periodic replacement of the feathers. This is carried out annually in most of the species, while in some it may occur twice and in a very few thrice in a year. The birds typically don’t shed all their feathers together at one time as they need them to regulate the body temperature. They may change the feathers present around the head region and may shed the feathers on the rest of the body at a different shedding period. In some of the birds only a few feathers are renewed during a single moulting period. 

During an annual “wing molt” season some birds shed all their feathers of the wings and thus become flightless and have to find accommodation that offers both easily available food and protection from the wilderness. The condition of shedding does not necessarily lead to balding or appearance of a bald patch on the skin. That might be due to any form of injury or a condition of illness caused by parasites, etc. In some cases the birds are observed to drop their tail feathers under fright conditions. This type of moulting condition is said to be “fright molt”. Injuries due to feather pecking, which is common in poultry birds, or in case of feather plucking do not come under the concept of being molted or moulted. 

The moulting process in the birds can be described as a circular phenomenon. The feathers of a bird become dead on maturity and need to be replaced. Hence, first the bird begins to molt some of the old feathers and then pin feathers arise taking the place of the old ones. When the pin feathers become full feathers and attain maturity they begin to shed thus causing a routinely cyclical series of events. Since, the feathers take up almost 4 – 12% of a bird’s body weight sufficient energy is required to molt. Therefore, the molting period in most of the birds comes after the breeding season under the condition that there is plenty of food available in the habitat. In some cases like the red-collared widowbirds, the males of the species shed their non-breeding feathers to acquire breeding feathers right before the breeding season. Although it is a significantly energy consuming process, some large birds with high body mass are known to replace their injured feathers at will. 

An image of the shedding and renewing of the feathers is visible in the given picture:

[]

Moulting in Reptiles

The two most common examples of molting in reptiles include the shedding of skin by the snakes and the lizards. The “shedding of skin” in snakes is quite well-known and so common across the world that it has found different meanings in many cultures. To shed the skin, the snake typically starts rubbing its head, or any part of its body near the head, on a hard object such as a rock or in-between two rocks. By this the skin that is already stretched splits or opens up, the portion near the head peels back on itself. It then crawls out of it effectively turning the skin inside out. Usually the molted/moulted skin is left in one-piece and it also includes the thin transparent layer present on the snake’s eye for protection. Contrastingly, in lizards the moulting process occurs in bits. Generally the skin of lizards falls off in pieces. 

Moulting in Arthropods and Other Animals

In arthropods, the moulting process is not only an annual process of shedding and renewing the covering but also in major cases as a life-cycle process. In many of the insects, moulting is a process by which there is metamorphosis from one stage of life to another. In such processes, after moulting insects may develop new organs such as new external lenses for the eyes. The new exoskeleton is initially soft and later on hardens and might not change again in one lifetime. This process in arthropods is also known as ecdysis. 

The common and widely lovable pets, the dogs, are also known to shed their hairs. Most of them moult twice a year, once in spring and another in autumn. But this shedding is dependent on the breed, the surrounding environment and temperature. The shedding in dogs is usually known as “blow coats” or “blowing of coats”. The process of molting is also observed among amphibians. Both the frogs and salamanders are known for regularly moulting and in some cases the frogs are found to consume their molted/moulted skin. Some species amongst them may molt in pieces while others may molt in one piece. 

The End of Moulting

It is clear from the above article that molt or moult is a condition of replacing the old body parts with new ones. This process is also known as shedding. When talking about this natural phenomenon, molt should not be confused with “molt be” an expression in catalan language. Molt be catalan expression means really good. Hence, whenever someone savours a delicious delicacy the expression molt be can be used. 

Leave a Reply

Your email address will not be published. Required fields are marked *