Pila globosa - Diagram, Classification and Structure

Pila globosa is a freshwater snail that belongs to the Ampullariidae family of apple snails. They can be found in ponds, lakes, and streams, and during the rainy season, they can be found on land. Pila globosa common name is apple snail.

Pila is a soft, unsegmented, and globose mollusk. It is an economically and commercially valued snail that is used as food, in aquaculture, and medicine in many regions. In this article, we will discuss the classification, structure, and significance of the Pila globosa.

What is Pila globosa?

Pila globosa is an aquatic mollusc belonging to the family Ampullariidae.  It is a gastropod mollusk, meaning its body is coiled or twisted and inhabits freshwater bodies including lakes and ponds. Pila can survive severe droughts by entering a dormant state in the mud. They are ectothermic mollusks that can adapt to both water and land and prefer areas with lots of aquatic vegetation.

Pila is a soft, unsegmented, and globose mollusk. Their bodies can be divided into three parts: the head, visceral mass, and foot. The head has two pairs of tentacles, one pair of eyes, and a ventral slit mouth. Pila globosa's breeding process involves three steps: copulation, fertilization, and laying. Copulation occurs in water on moist land and takes about 3-4 hours. Fertilization is internal.

Also Read: Nematode – Structure, Classification and Characteristics

Pila globosa Classification

Pila globosa classification is given below:

Pila globosa Diagram

The well labelled diagram of the Pila globosa is given below:

👁 Pila-globosa-(Apple-Snail)

Pila globosa Characteristics

Characteristics of the Pila globosa is as follows:

• Shell: The Pila globosa is known for its unusually enormous, conical shell. The shell might be reddish, greenish, or brown in colour.
• Size: Although Pila globosa's dimensions are variable, on average, its diameter is between 5 and 7 centimetres, though some examples may grow larger.
• Habitat: Ponds, lakes, rivers, and rice fields are examples of freshwater settings where these snails are frequently found. They choose still, slowly flowing water that is surrounded by greenery.
• Feeding: As a herbivorous animal, the Pila globosa consumes algae, aquatic plants, and debris. In aquatic environments, they are involved in the cycling of nutrients.
• Reproduction: Pila globosa has the ability to reproduce both sexually and asexually, like many other snail species. Their eggs are laid in gelatinous masses, and they go through a larval stage before becoming adults.
• Ecological Significance: Similar to other freshwater snails, Pila globosa contributes to the cycling of nutrients in aquatic environments. They aid in the decomposition of organic debris and the recycling of nutrients.
• Economic Significance: Pila globosa is gathered for human food in some areas. In some cultures, it is regarded as a delicacy, and the meat is only eaten after being properly prepared.
• Environmental Indicator: In freshwater environments, the quantity and presence of Pila globosa can be used as a gauge for the quality of the water. Population fluctuations could indicate changes to the ecology.

Also Read: Fungi - Definition, Characteristics, Classification, Uses

Pila globosa Structure

Structure of the Pila globosa is as follows:

• Pila is a globose, soft, unsegmented mollusc whose body is divided into three parts: the head, the visceral mass, and foot.
• One set of eyes, two pairs of tentacles, and a ventral slit mouth—also referred to as an aperture—make up the head.
• The foot has a ventral, broad, flat, and nearly triangular form. Operculum is attached to the this.
• Every major organ in an animal is present in a visceral mass, which resembles a hump.
• The structure that covers the visceral mass is called the mantle. It creates a shell for the organism and secretes calcium carbonate.
• An operculum is Pila's most notable characteristic. Anatomically speaking, the operculum is a calcareous structure that is joined to the upper surface of the foot. As the animal's soft component is removed, it functions as a trapdoor that closes the shell's hole.

Also Read: Symmetry in Animals - Definition, Types and Importance

Pila globosa Nervous System

A gastropod's nervous system is made up of commissures, ganglia, connectives, and the nerves that connect to various organs.

Ganglia

A ganglion is a tiny, dense mass of connective tissue and nerve cells. Pila contains five different pairs of ganglia: buccal, supraintestinal, visceral ganglion, pleuropedal, and cerebral ganglia.

Commissures

The term commissure refers to the nerve connections that exist between two ganglia. The ganglia pairs are positioned so that commissures can connect them on opposing sides of the body. There are three commissures that connect the ganglia: the cerebral commissure, the buccal commissure, and the pedal commissure, which connects the pleuropedal  ganglia.

Connectives

The neural pathways connecting two distinct ganglia include connectives. Ganglia can be located on either the same or opposite sides of the body. For example, the cerebral ganglia and the buccal ganglia are connected by cerebrobuccal connectives.

Nerves

Nerves are supplied to all body organs in the form of branches.

• The eye and the tentacles on either side of the body are innervated by the cerebral ganglia.
• The foot receives nerve impulses from the pedal ganglion.
• The mantle is innervated by the pleural ganglion.
• The pulmonary sac and the ctenidium receive nerve signals from the supra intestinal ganglion.
• The buccal mass receives nerve signals from the buccal ganglion.
• The kidney, gut, pericardium, and genitalia are innervated by the visceral ganglia.

Also Read: Human Brain

Pila globosa Digestive System

Pila globosa digestive system is explained in detail below.

The Alimentary Canal

• The mouth is the beginning and the anus is the end of the coiled alimentary canal.
• It is separated into three areas: the midgut, which contains the stomach and intestine, the hindgut, which includes the rectum, and the foregut, which is composed of the buccal cavity and oesophagus.
• The buccal cavity is a chamber that contains multiple muscle groups used to move the radula, or mouth.
• The oesophagus is a long, narrow tube that enters into the stomach after emerging from the buccal mass.
• The oesophagus enters the stomach, which is a U-shaped chamber that opens into
• abdomen.
• The oesophagus enters the stomach, which is a U-shaped chamber that opens into the intestine through the pyloric chamber.
• The intestine is a long, coil-shaped structure that ends where the rectum joins it, in between the gonads.
• The anus is reached by the rectum, a tube with thick walls.

Also Read: Human Digestive System

Digestive Glands

• Salivary glands are located on both sides of the buccal mass. Mucin-like compounds and carbohydrase enzymes are secreted by them.
• The coiled, triangular digesting glands are a feature. The digestive epithelium consists of secretory cells, resorptive cells, and lime cells. It is bordered by alveoli.
• The oesophageal pouches are rounded structures situated beneath the salivary glands, which facilitate the opening of tiny ducts at the interface of the buccal cavity and oesophagus. Digestive enzymes are secreted by these pouches.
• The structures at the roof of the buccal cavity are called buccal glands, and they serve as auxiliary digestive glands.

Also Read: Difference Between Enzymes And Hormones

Pila globosa Respiration

Pila can live on land as well as in the water. These are amphibians which exhibit double mode of respiration. This means they can breathe in atmospheric air when on land and use oxygen from the water for aerobic respiration. For water respiration, the animal has gills or a ctenidium, and for aerial respiration, it has pulmonary sacs or lungs. An additional set of respiratory glands are the nuchal lobes. Pila uses its gills to breathe in the water.

Gills

On the dorsolateral wall of the branchial or right chamber of the mantle cavity, a solitary ctenidium is located in Pila. The gill is made up of several triangular lamellae, or leaflets, which are grouped in a single row along the gill's central axis and run parallel to one another. We refer to this kind of gill as monopectinate type. Each lamella has a basal end that is fixed to the mantle wall's pallial epithelium and an end that hangs freely in the branchial chamber. The size of the lamellae diminishes towards the two ends of the gill while it is largest in the middle. Each branchial lamella is made up of two layers of epithelia that are supported by muscle and connective tissue.

Also Read:Difference Between Aerobic And Anaerobic Respiration

Conclusion - Pila

Pila, also called the apple snail, is a large family of freshwater snails that are amphibious. The body of a Pila is divided into three parts: the head, visceral mass, and foot. The head of a Pila has two pairs of tentacles, one pair of eyes, and a slit mouth. Pila snails have two respiratory adaptations that allow them to live both on land and in water. When in water they breathe through a ctenidium, and on land they breathe through a pulmonary sac. Pila snails are herbivores, and can be found in ponds, lakes, rivers, and brackish water environments. . It is indigenous to Bangladesh, India, Thailand, Sri Lanka, and other nations in the area.

Also Read:

• Classification Of Animals - Class 11 Biology
• Class Mammalia
• Amphibia