MALACOLOGY: HISTORY, PRACTICES, RESEARCH - BIOLOGY - 2025

The malacología is a derived branch of zoology that is responsible for the study of mollusks, which represent the second largest group of species of invertebrate world. It is believed that today there are about 200,000 species, dating their origin to approximately 500 million years.

The study of mollusks extends throughout the world and there are various societies in constant activity. There are also spaces, such as museums, dedicated to this animal group. Malacology focuses primarily on the study of the taxonomy (classification), ecology, and evolution of mollusk species.

Malacology studies mollusks, both those that have shells and those that do not.

Image by Mabel Amber from Pixabay

Mollusks are important historically, culturally and commercially. There are currently eight types of mollusks: gastropods, cephalopods, polyplacophores, monoplacophores, gastropods, cephalopods, bivalves and scaphopods. On the other hand, there is also knowledge of two more groups already extinct.

History

The antecedents of malacology go back to the 18th century when Georges Cuvier renewed the concept of the classification of animals called "mollusks". Previously, the term was used only for cephalopods, whose main characteristic is having their limbs or tentacles attached to the head. An example of cephalopods are octopuses and squid.

Cuvier's studies were based on the description of the anatomy of mollusks. In this, he joined the mollusks as a group of invertebrate animals in which both those with shells and those without shells were included. However, malacology was formally established by Ducrotay de Blainville, who was very close to Cuvier for a long time. This period of time marked the passage from conchology to malacology.

For its part, conchiliology refers to the study of the shells of mollusks. Shells are precisely one of the characteristics of mollusks that have had great importance in history and prehistory.

The influence of these dates even from the years 18,000 a. C. and have been found in caves from prehistoric times. In many cases they were part of cultural symbolism, being also used in an ornamental and artisan way.

Research sites for malacology

Mollusks have been part of human life both commercially, culturally and nutritionally. Due to this, the study of this group of the animal kingdom has become relevant in aspects of the economy, in terms of cultivation and sustainable development and for its great archaeological contribution.

Both universities and Malacology Societies are centers where various studies related to mollusks are periodically published. His activity is constant in this area of ​​research. Some of these most notable institutions are:

The Malacological Society of Molluscs

It is an organization located in London dedicated to the scientific study of mollusks. Among its contributions it should be noted that it has a journal of publications called the Journal of Molluscan Studies that works in conjunction with the Oxford University Press publishing house. The society equally supports studies in paleontology, biochemistry, neurology, aquaculture and more, only if they have a priority focus on mollusks.

The American Malacological Society

Another of the study communities focused on malacology, This also contains publications related to the study of mollusks as a contribution to those interested. His bulletin is known as The American Malacological Bulletin.

Among other associations there is also the world-wide Unitas Malacologica and the Latin American Malacology Association. Apart from promoting individual and group study of mollusks, they tend to organize world or regional conferences.

Malacology-related practices

There are a variety of techniques and areas of scientific research that serve malacology, and they may be closely related.

For example, sclerochronology, which is responsible for the study of the growth of mollusks with shells, specifically bivalves. In this case, special attention is paid to the skeleton rings to be able to keep track of time with respect to the growth of the animal.

Paleontological conservation is another example in which malacology makes use of paleontological techniques for its study purposes. In this case, the “conservation” factor is added because the object of study is the shells of extinct mollusks.

This allows obtaining information from groups that were already under danger and exempts those that are currently alive from any risk for their preservation.

Other techniques include limnology, which is responsible for studying waters and their physical, chemical and biological composition, and biogeography, which studies the influence of geographic conditions on the development of mollusks.

Mollusks can be found all over the world, however, there are areas with richer and more diverse fauna such as Cuba, the Philippines, Equatorial Guinea, the Iberian Peninsula and South America. There are also many collections and museums dedicated to different species, among which are both living and extinct.

Types of mollusks

Mollusks make up the second largest group in the animal kingdom after arthropods. They are characterized by having a soft invertebrate body. There are currently between 800,000 and 200,000 living species and they are presented in 8 categories.

Gastropods

Gastropods are made up of slugs and snails. They are the widest category of mollusks since they make up 80% of this animal group. It is the only classification that also contains terrestrial species.

Bivalves

The main characteristic of bivalves is the shape of their shell divided into two symmetrical halves. Some examples are oysters and scallops.

Cephalopods

Octopuses are part of the cephalopod mollusks, studied by malacology

Image by edmondlafoto from Pixabay

They are known for their composition of tentacles attached to the head, such as the octopus and squid.

Scaphopods

Among the other classifications are polylacophores, known as chiton or "sea cockroaches." One of its main characteristics is its shell composed of 8 overlapping flat layers.

Then there are the monoclapophores with just 11 species. They are similar to chitones with the difference that their shell is a single flat layer.

Finally, the aplacophores are mentioned, with a distinctive worm-like shape and the absence of a shell.

References

1. The Mollusk Collection of the MNCN. National Museum of Natural Sciences. Recovered from mncn.csic.es
2. Mollusk Classification - Advanced. Types of Mollusks. CK-12 Foundation. Recovered from ck12.org
3. Vinarski M (2014). The birth of malacology. When and how ?. Zoosystematics and Evolution 90 (1): 1-5. Recovered from zse.pensoft.net
4. Darrigan G (2011). Importance of mollusks for man. Thematic foundation. Chair: Malacology. pp 3. Recovered from fcnym.unlp.edu.ar
5. Heppell David (1995). The long dawn of malacology: a brief history of malacology from prehistory to the year 1800. National Museum of Scotland. Archives of Natural History 22 (3). 301. Recovered from euppublishing.com
6. Malacology, Conchology, Sclerochronology (Skeletochronology) & Conservation palaeobiology. Department of Geosciences and Geography. University of Helsinki. Recovered from helsinki.fi
7. Frey M (2018). What is Malacology ?. Burke Museum. Recovered from burkemuseum.org