21 Amazing Gastropod Facts Revealed About Species Of Snails And Slugs

Nidhi Sahai
Nov 10, 2022 By Nidhi Sahai
Originally Published on Apr 12, 2022
Edited by Lara Simpson
Fact-checked by Shreya Yadav
Gastropod facts to know more about snails and slugs.
Age: 3-18
Read time: 11.1 Min

The class Gastropoda consists of slugs and snails that consist of more than 60,000 species.

Slugs and snails abound in abundance in some areas. Millions of freshwater species and brackish-water marine species can exist on small mudflats.

Ponds, lakes, marshes, and streams have an abundance of freshwater snails. You will often spot only a few species in a single place, but these species will usually have a large population. These species feed on dead plants and algae. Water bodies like Lake Baikal in Siberia, Lake Ohrid on the North Macedonia–Albania border, Lake Titicaca in South America, and the Mekong basin in Southeast Asia have an extensive range of snails.

Land snails are terrestrial only to a small extent, but they do so quite successfully. They are constantly losing water when they are vigorously moving. When water is scarce, they withdraw into their shells and stay dormant until conditions improve. They hibernate in the winter when water is trapped under snow or ice, and they aestivate in summer droughts. Land snails were discovered above the snow, and Vitrina species have been found crawling on snowbanks in the Alpine meadows. Many species live in arid deserts, where they must go dormant for years between showers.

Across most of North America, fewer than ten species coexist in the same location. On the other hand, inhospitable environments such as New Zealand, northeastern India, Jamaica, and Queensland's wet forests (Australia), 20-30 various species can coexist. In some places of Western Europe, up to 30 species can be seen coexisting. In many arid environments, just one or two species exist, and they have remarkable dietary specializations.

A British acre of grassland could have 2,50,000 slugs, whereas a Panamanian montane forest could have 65,00,000 modern land snails per acre. Despite their abundance, slugs and snails are sometimes overlooked. Species on land and in freshwater often hide throughout the day and emerge at night. The majority of marine species are also nocturnal. Many of their shells are so severely encrusted with algae and other encrusting organisms that they may mistake for fragments of rock. The number of fossil gastropods was very less during the Paleozoic era, and most of them belonged to primitive groups. Their evolution started after that era.

Humans have eaten a variety of snail species since the dawn of time. The most commonly consumed marine snails are periwinkles (Littorina) in South Africa and Europe, abalones (Haliotis) in Japan and California, and queen conchs (Strombus gigas) in West Indies, and turban shells (Turbo) in the Pacific. Whelks and Limpets are occasionally eaten, but they are usually used as fish bait. Snails from freshwater bodies are rarely consumed.

Since prehistoric times, land snails of the Helicidae family have been consumed in Europe and the Middle East. Researchers and excavators have discovered many gastropod fossils and fossil shells. Many tonnes of H. pomatia and Helix aspersa (the most common species used to produce escargot) are now raised in snail farms or harvested wild throughout Europe. Several Eobania Otala species are from Algeria and Morocco.

Collectors cherish the shells of particular snails. Earring is made from the operculum of various Turbo species, while cameos are made using the shell of the Red Sea snail Cassis rufa. Abalone shells are used for decoration in multiple cultures; the golden cowrie (Cypraea aurantium) shell was once used as a chief's insignia in Fiji. Shell strings have been used as currency.

What are gastropods?

Gastropods are a group of animals that includes snails and sea slugs. They are classified as mollusks, which is a large group of invertebrates that also includes clams, octopuses, and squids. Gastropods have a hard shell that protects their soft body. Gastropods are found all over the world in both freshwater and saltwater aquatic habitats.

Gastropods are known for their slow movement. This is because they have muscular feet that they use to move themselves along. Gastropods also have a tongue-like organ called a radula, which they use to scrape food off of surfaces. Gastropods are primarily herbivores, but some species are carnivorous.

Gastropods have two main types of reproduction: sexual and asexual. In sexual reproduction, gastropods produce eggs that are fertilized by sperm. Asexual reproduction occurs when a gastropod produces offspring without fertilization. Gastropods can reproduce both sexually and asexually, depending on the species.

They are characterized by their spiraling shell, which is caused by torsion, a process during embryonic development in which the body twists around the axis of the visceral mass. This gives gastropods the ability to move in a distinctive sideways motion.

Gastropods can be found in nearly every habitat, from deep-sea hydrothermal vents to mountaintops. Gastropods are an essential part of many ecosystems and provide food for a variety of predators. Humans also harvest them for food, including escargot, a delicacy made from the cooked aquatic snail. Gastropods have a long and fascinating history, dating back to the early days of animal evolution.

Gastropods are often found in damp habitats such as gardens and forests. They can also be found in freshwater habitats, like ponds and lakes. Gastropods are an essential part of many food chains because they are eaten by so many different animals. Some animals that eat gastropods include birds, fish, mammals, reptiles, and other invertebrates. Gastropods are also eaten by humans! In some cultures, eating gastropods is considered a delicacy.

Gastropods have a very interesting way of moving around. They move by using their muscular foot to push themselves along surfaces. This type of movement is called 'slime propulsion.' Gastropods secrete slime from the bottom of their foot, which helps them to move and also protects them from predators.

Gastropods have two main types of defense mechanisms: camouflage and toxic secretions. Camouflage allows gastropods to blend in with their surroundings and avoid being eaten by predators. Toxic secretions are chemicals that gastropods produce that can make predators sick or even kill them.

Gastropods are the largest group of gastropod mollusks, with over 80,000 species. Gastropods can range in size from less than a millimeter to over two meters. Gastropods have been around for over 500 million years and are one of the oldest groups of animals on Earth. Gastropods are found in every continent except Antarctica. Gastropods are amazing creatures that come in all shapes and sizes. If you're ever lucky enough to spot one, take a moment to appreciate these unique animals!

Classification Of Gastropods In The Animal Kingdom

They belong to the kingdom Animalia, phylum Mollusca, and class Gastropoda. The Gastropoda taxonomy is constantly evolving, with two significant revisions published in the last two decades, and there will almost definitely be more revisions based on the DNA sequencing findings. At the moment, Gastropoda taxonomy varies from one author to the next.

Snails can be found in all depths of the water, but they are most prevalent below the tidal zones and along the sea floor, where there is an abundance of food. An estimate of an average population of 760 million Littorina (periwinkles) solely on a single square mile of rocky shore consumes 2,200 tonnes (19,95,806 kg) of material every year, only approximately 55 tonnes (49,895.2 kg) of which is organic materials, demonstrates the extent of their impact on a shoreline.

Limpets of all kinds have a more substantial presence in such environments, grazing and browsing on algae and the sessile invertebrates. The ability of limpets to homing is an intriguing trait. Several gastropod species have a tendency to congregate in one location and feed on the regular paths that radiate from it.

Specialization in food sources has contributed to the diversity of the mollusks in the ocean. Salinity and temperature are the primary physical factors that limit range expansion, usually by prohibiting successful mating rather than preventing settlement and young (larval stage) growth.

Snails' evolutionary transition from marine to freshwater and land habitats necessitated a number of unique adaptations. Snails had additional issues to deal with, such as their basic eating and reproductive habits. In the ocean, the dispersion can occur through the passive movement of a veliger stage by waves and currents. Such a dispersal method would only result in the downstream spread in rivers and streams.

The surface litter and higher soil zone are home to the small land snail. Food is abundant in the form of decomposing plants and animals, as well as fungi, in this microhabitat, which is generally damp. The gastropod shells of the garden snail are dull and unnoticeable. The shell's surface is frequently carved. Small arthropods prey on the tiny species [less than 0.1 in (3 mm) in diameter].

The snail's natural tendency to retreat into its shell is useless since the predator merely pursues the snail into its shell. Because this structure is seen in more than 12 pulmonate families, elaborate obstacles that constrict the shell entrance and small spines along the aperture must give some protection.

Physical Features Of Gastropods

Gastropods are one of the most diverse groups of animals on Earth. They come in all shapes and sizes and can be found in nearly every habitat imaginable. Though they may look very different from one another, gastropods share a few key physical features.

Gastropods have a muscular foot which they use for locomotion, and a unique organ called a pneumostome which allows them to take in oxygen from the water around them. They also have a well-developed head, which houses their eyes and sensory organs. Most gastropods have two pairs of tentacles on their head; one pair for sensing and one pair for locomotion.

The head also bears the mouth, which is usually surrounded by a fleshy proboscis. The gut of a gastropod winds several times through the body before opening at the anus, which is located at the posterior end of the animal.

The foot of a gastropod is a muscular structure that extends ventrally from the body. It is used for locomotion, as well as for anchoring the animal to surfaces. In some species, the foot can be modified into a pair of long flattened flaps (known as parapodia), used for swimming or crawling across muddy substrates. Though they may not look like it, gastropods are actually very good swimmers. They use their muscular foot to propel themselves through the water and along the sea floor. Some gastropods even have a unique organ called a pneumostome, which allows them to take in oxygen from the water around them.

One of the most striking features of gastropods is their coiled shell. This shell is made up of calcium carbonate and serves as protection for the animal's soft body. The shell also contains the gastropod's spiral-shaped intestine. Physical features such as their coiled shell and well-developed head make them unique among other groups of animals.

The food of gastropods varies depending on which category is being addressed. Herbivores, predatory carnivores, parasites, detritus feeders, scavengers, and a few ciliary feeders with decreased or nonexistent radulas are among the marine gastropods. Land animals can eat leaves, fruit, bark, and rotting animals, while marine animals can scrape algae from the sea floor's rocks. Certain species, like the Archaeogastropda, have slender marginal teeth in horizontal rows. Many of the typical gastropod traits have been reduced or eliminated in some endoparasite species, like the eulimid Thyonicola doglieli.

Gastropods are a fascinating group of animals, and there is still much to learn about them.

As much as they are beneficial for your garden, they can be harmful to you as well.

Examples Of Gastropods

Snails, Slugs, Periwinkles, Abalones, Conchs, whelks. The subclasses are Caenogastropoda, Heterobranchia, Neomphaliones, Neritimorpha, Patellogastropoda, and Vetigastropoda.

These animals play an essential role in the ecosystem by breaking down dead plant and animal matter, which helps to recycle nutrients back into the environment. Gastropods are also a source of food for other animals, such as fish, birds, and mammals. Gastropods have olfactory organs, statocysts, eyes, and mechanoreceptors as sense organs.

The olfactory organs, which are placed on the tips of four tentacles in terrestrial gastropods (land snails and slugs), are the most significant sensory organ. Rhinophores are the chemosensory organs of opisthobranch marine gastropods.

Although most marine gastropods breathe through their gills, many freshwater and terrestrial species have pallial lungs. Hemocyanin is the respiratory protein in almost all gastropods, although hemoglobin is the respiratory protein in one freshwater pulmonate family, the Planorbidae.

Most gastropods possess very basic visual organs in the form of eyespots on the tip of their tentacles. In gastropods, however, 'eyes' range from rudimentary ocelli, which only differentiate between light and shade, to more complicated pit eyes. Because land snails and slugs are primarily nocturnal species, eyesight is not the most crucial sense for them.

The central nervous system and peripheral nervous system make up the nervous system of the gastropods. The central nervous system is made up of ganglia that are linked together by nerve cells. The cerebral ganglia, parietal ganglia, osphradial ganglia, pedal ganglia, pleural ganglia, and visceral ganglia are all paired ganglia. Buccal ganglia are also seen on occasion.

The following are the most important components of a gastropod's life cycle, Gastrophonic eggs, egg-laying, the development of gastropod embryos, the expansion of gastropods, hibernations, and estivation. Some gastropods are trochophore or veliger in their larvae or larval stadium.

In gastropods, courtship and mating occur either internally or externally, depending on the species. In marine gastropods, external fertilization is prevalent.

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Written by Nidhi Sahai

Bachelor of Arts in Journalism and Mass Communication

Nidhi Sahai picture

Nidhi SahaiBachelor of Arts in Journalism and Mass Communication

Dedicated and experienced, Nidhi is a professional content writer with a strong reputation for delivering high-quality work. She has contributed her expertise to esteemed organizations, including Network 18 Media and Investment Ltd. Driven by her insatiable curiosity and love for journalism and mass communication, Nidhi pursued a Bachelor of Arts degree from Guru Gobind Singh Indraprastha University, graduating with distinction in 2021. During her college years, she discovered her passion for Video Journalism, showcasing her skills as a videographer for her institution. Nidhi's commitment to making a positive impact extends beyond her professional pursuits. Actively engaging in volunteer work, she has contributed to various events and initiatives throughout her academic career.

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