Pila globosa, also known as the Indian apple snail, is a species of freshwater snail that belongs to the Ampullariidae family. It is a large freshwater mollusk that can be found in ponds, lakes, and streams. The snail is known for its importance in nutrient cycling in aquatic ecosystems, although it can become invasive in non-native areas, posing a threat to local flora and fauna. Additionally, Pila globosa exhibits unique behaviors, such as aerial respiration and a tendency to lay pink-colored egg clutches above the waterline.
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Pila Globosa (Apple snail)
William John Swainson gave the binomial nomenclature for the freshwater snail Pila globosa in 1822. The P. globosa, sometimes known as the “apple snail,” has a large, spherical shell that can reach the size of an apple. P. globosa is a member of the Mollusca phylum, Gastropoda class, and Ampullariidae family. It has a large geographical range and thrives in equatorial and tropical climates, where strong rains alternate with dry intervals.
Pila globosa is an ectothermic mollusk that can adapt to both water and land. It prefers areas with a lot of aquatic vegetation and can remain dormant for months during the winter and summer. Pila globosa is a herbivore that mainly eats plant material, including green algae, diatoms, etc. It is a common food source for some people, especially tribal groups and lower economic groups in India and Nepal.
Diagram of Pila Globosa (Apple snail)
The labelled diagram of Pila Globsa is given below:
Classification of Pila Globosa
The systematic classification of Pila Globosa is given below:
|
Classification |
Scientific Name |
|---|---|
|
Phylum |
Mollusca |
|
Class |
Gastropoda |
|
Sub-class |
Prosobranchia |
|
Order |
Mesogastropoda |
|
Family |
Pilidae |
|
Genus |
Pila (Roding, 1798) |
|
Species |
globosa (spherical or ball like) |
Habitat and Distribution
The apple snail, Pila globosa, is a freshwater mollusk that can also live in brackish water environments with low salinity. They are amphibious and can live on land and in water. The detail description of its habitat and distribution is as follows:
- Habit and Habitat: It is commonly found in low-salinity environments such as rivers, pools, ponds, tanks, streams, lakes, marshes, rice fields, ditches, irrigation canals, wetlands, and brackish water. It prefers clean, shallow waters. They are found in such areas which harbor succulent aquatic plants.
- Distribution: They are found in the Oriental (India, Sri Lanka, Pakistan, Myanmar, Thailand, Nepal, Malaysia, the Philippines, Vietnam, Indonesia) and Ethiopian (Africa, Madagascar, and Arabia) areas. It is found in Maharashtra, Uttarakhand, Uttar Pradesh, Madhya Pradesh, West Bengal, Jharkhand, Bihar, Odisha, Assam, Meghalaya, and Kerala.
- Pila Globosa is a voracious eater, so it feeds upon plant scrapping, which it cuts with the help of its chitinous jaws and regular teeth.
- They prefer clean water containing aquatic plants such as Pistia, Vallisnerria, etc. Herbivorous, amphibious being adapted for life in water and on land.
- The animal moves in the same way that planarians glide. During the rainy season, Pila emerges from the ponds and travels on land to breathe fresh air.
- Speed: It creeps very slowly by the muscular foot ( 5 cm/Min) and during movement it does not leave the shell but carries it on back.
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Adapted to an amphibious mode of life:
- Pulmonary sac (for aerial adaptation)
- Gill or Ctenidium (for aquatic respiration)
- Creeps with ventral muscular foot called “snail pace”. If the surface is dry for movement it secretes slime.
- When in danger it immediately shuts the aperture with the operculum or lid attached to its foot.
- Summer sleep or aestivation: Snails can tide over a long period of drought by remaining in inactive mode with the shell aperture tightly closed, it is called summer sleep or aestivation.
Features of Pila Globosa
The features of the Pila Globosa are described below:
- Shell or external skeleton: Pila do not contain any internal skeleton but they have an exoskeleton that is secreted by itself to form a shell, in which it lives, and in other words, it’s a house of this animal.
- The color of the shell varies from yellow, brownish, or black, and because it is spherical or ball-like in shape, that’s why the species name is globose.
- Shape of the shell: Elongated, consisting of tubular whorls, which are coiled around a central axis called the columella.
- Conspiral spire: Many whorls lie in different planes and give it a conical spire appearance. That’s why the shell is called conispiral.
- Body of Pila Borbosa has 3 parts:
- Head: The head is a fleshy part of the body and is found overhanging the foot.
- Mouth: It is in the form of a slit-like aperture and lies ventrally between the bases of the first pair of tentacles.
- Eye: At the base of each tentacle a small stumpy eye-stalk or ommatophore arises, its tip bears a small prominent eye.
- Foot: Foot are large, strong, muscular, ventral part of the body. When they expand itself then are triangular with the apex directed backward. The foot helps in the locomotion of the animal, is highly contractile, and inside contains numerous pedal gland cells.
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Two pairs of tentacles or labial palps:
- The first pair of tentacles arise from the sides of the head and are small, tapering, and highly contractile.
- The second pair of tentacles are long, fleshy, cylindrical arise from behind the snout, from the dorsal surface of the head, and are also contractile. They can remain in the form of invagination.
- Visceral mass: It’s a sort of hump-like structure on the dorsal side and contains visceral organs. It is soft and grey to dark brown. It is spirally coiled as the shell and covers the body whorls and the spire.
- Mantle: It’s a thin delicate covering called mantle or pallium formed by the skin of the visceral mass. The mantle is the characteristic feature of the Mollusca.
Importance of Pila Globosa
Importance of Pila Globosa is as follows:
- They play an important role in freshwater and grassland environments.
- Freshwater snails are important in the aquatic ecosystem as they provide food for many creatures.
- Snails serve a crucial role in maintaining healthy aquatic habitats by acting as biofilters and preserving biodiversity.
- They purify water by consuming algae, dead plant matter, and other organic debris.
- Because they are voracious eaters of aquatic plants, they can help reduce the amount of aquatic vegetation that clogs canals.
- They are useful for managing aquatic weeds.
- P. globosa’s shell has economic importance as a precursor for nanocrystalline hydroxyapatite. This suggests that it can be utilized to create eco-friendly and cost-effective ceramic products. Snail shell’s high calcium carbonate content makes it suitable for making slaked lime in the lime industry.
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FAQs on Pila Globosa
Why Pila Globosa is Called Apple Snail?
Ampullariidae is the family of fresh water snails which are commonly known as apple snails. Pila globosa also belongs to this family of snails. Some species can reach upto the size of apples so called apple snails.
What is the Economic Importance of Pila Globosa?
Pila globosa is an economically and commercially valued snail used as food in aquaculture, medicine, and food item in many regions of Bangladesh and other countries.
What is the Food of Pila Globosa?
Pila is herbivorous and it lives primarily on aquatic vegetation.
What is the Colour of Pila Globosa?
The shell of Pila globosa varies in colour from yellowish to brown or even blackish.
What is the Common Species of Pila Globosa?
Pila globosa, the common Indian apple snail, is a freshwater and terrestrial snail that is native to India, Bangladesh, Myanmar and Sri Lanka.
Is Pila Globosa Edible?
The common edible snails reported are Pila globose (Apple snail) have been collected from Jathi pond, Chapra. They are edible and obtain a protein rich delicacy. Apple snail has also number of medicinal importance.
What is the Habit and Habitat of Pila Globosa?
Pila globosa is found in ponds, pools, tanks, lakes and rice fields. Found in fresh water streams, rivers and even in brackish water of low salinity. They are herbivorous, abundant in waters, having succulent aquatic vegetation.