# Malacology

Malacology, from Ancient Greek μαλακός (malakós), meaning "soft", and λόγος (lógos), meaning "study", is the branch of invertebrate zoology that deals with the study of the Mollusca (molluscs or mollusks), the second-largest phylum of animals in terms of described species after the arthropods. Mollusks include snails and slugs, clams, and cephalopods, along with numerous other kinds, many of which have shells.
Fields within malacological research include taxonomy, ecology and evolution. Several subdivisions of malacology exist, including conchology, devoted to the study of mollusk shells, and teuthology, the study of cephalopods such as octopus, squid, and cuttlefish. Applied malacology studies medical, veterinary, and agricultural applications, for example the study of mollusks as vectors of schistosomiasis and other diseases.
Archaeology employs malacology to understand the evolution of the climate, the biota of the area, and the usage of the site.
Zoological methods are used in malacological research. Malacological field methods and laboratory methods (such as collecting, documenting and archiving, and molecular techniques) were summarized by Sturm et al. (2006).

## History

Malacology evolved from the earlier discipline of conchology, which focused solely on the collection and classification of shells. The transformation into a comprehensive field of biological study occurred over several key historical milestones.

### Early period pre-1795

Before the late 18th century, the study of mollusks was limited to conchology, emphasizing the aesthetic and taxonomic value of shells. During this time, the term "mollusks" referred only to shell-less species such as cephalopods and slugs. Organisms with shells were classified under "Testacea", reflecting a limited understanding of their broader biological characteristics.

### The contributions of Cuvier

In 1795, French naturalist Georges Cuvier introduced a new classification system for invertebrates based on anatomical observations. He proposed that mollusks represented a distinct group of organisms unified by common morphological traits. This approach laid the groundwork for the transition from conchology to malacology, as it highlighted the importance of internal anatomy over external shell features.

### Early 19th century

Following Cuvier’s work, the early 19th century saw an expansion of the field’s focus. Scientists began studying not only the external shells of mollusks but also their internal anatomy, physiological functions, and ecological roles. This marked a shift toward viewing mollusks as complete organisms, rather than merely as shell producers. The term "malacology" was officially introduced in 1825 by French zoologist and anatomist Henri-Marie Ducrotay de Blainville. Derived from the Greek word "malakos" (meaning "soft"), it reflected a broader interest in the biological and ecological characteristics of mollusks, including their soft body structures. This moment is considered the formal establishment of malacology as a distinct scientific discipline.

### Late 19th century and beyond

By the late 19th century, malacology had expanded further to encompass evolutionary biology, taxonomy, and ecology. Researchers investigated the relationships between mollusks and other invertebrates, as well as their roles in various ecosystems. The discipline continued to integrate new methodologies and technologies, solidifying its place within zoology.

## Malacologists

Those who study malacology are known as malacologists. Those who study primarily or exclusively the shells of mollusks are known as conchologists, while those who study mollusks of the class Cephalopoda are teuthologists.

## Societies

* Argentine Malacological Society [es] (Asociación Argentina de Malacología)
* American Malacological Society
* Association of Polish Malacologists (Stowarzyszenie Malakologów Polskich)
* Belgian Malacological Society (Société Belge de Malacologie) – French speaking
* Belgian Society for Conchology [nl] – Dutch speaking
* Brazilian Malacological Society (Sociedade Brasileira de Malacologia)
* Conchological Society of Great Britain and Ireland
* Conchologists of America
* Dutch Malacological Society
* Estonian Malacological Society
* European Quaternary Malacologists
* Freshwater Mollusk Conservation Society
* German Malacological Society (Deutsche Malakozoologische Gesellschaft)
* Hungarian Malacological Society (Magyar Malakológiai Társaság)
* Italian Malacological Society (Società Italiana di Malacologia)
* Malacological Society of Australasia
* Malacological Society of London
* Malacological Society of the Philippines, Inc.
* Mexican Malacological Society (Sociedad Mexicana de Malacología y Conquiliología)
* Spanish Malacological Society (Sociedad Española de Malacología)
* Western Society of Malacologists

## Journals

More than 150 journals within the field of malacology are being published from more than 30 countries, producing an overwhelming amount of scientific articles. They include:
* American Journal of Conchology (1865–1872)
* American Malacological Bulletin
* Archiv für Molluskenkunde
* Basteria
* Bulletin of Russian Far East Malacological Society
* Fish & Shellfish Immunology
* Folia conchyliologica
* Folia Malacologica
* Heldia
* Johnsonia
* Journal de Conchyliologie – volumes 1850–1922 at Biodiversity Heritage Library; volumes 1850–1938 at Bibliothèque nationale de France
* Journal of Conchology
* Journal of Medical and Applied Malacology
* Journal of Molluscan Studies
* Malacologia
* Malacologica Bohemoslovaca
* Malacological Review – volume 1 (1968) – today, contents of volume 27 (1996) – volume 40 (2009)
* Soosiana
* Zeitschrift für Malakozoologie (1844–1853) → Malakozoologische Blätter (1854–1878)
* Miscellanea Malacologica
* Mollusca
* Molluscan Research – impact factor: 0.606 (2007)
* Mitteilungen der Deutschen Malakozoologischen Gesellschaft
* Occasional Molluscan Papers (since 2008)
* Occasional Papers on Mollusks (1945–1989), 5 volumes
* Ruthenica
* Strombus
* Tentacle – The Newsletter of the Mollusc Specialist Group of the Species Survival Commission of the International Union for Conservation of Nature.
* The Conchologist (1891–1894) → The Journal of Malacology (1894–1905)
* The Festivus – a journal which started as a club newsletter in 1970, published by the San Diego Shell Club
* The Nautilus – since 1886 published by Bailey-Matthews Shell Museum. First two volumes were published under name The Conchologists’ Exchange. Impact factor: 0.500 (2009)
* The Veliger – impact factor: 0.606 (2003)
* 貝類学雑誌 Venus (Japanese Journal of Malacology)
* Vita Malacologica a Dutch journal published in English – one themed issue a year
* Vita Marina (discontinued in May 2001)

## Museums

Museums that have either exceptional malacological research collections (behind the scenes) and/or exceptional public exhibits of mollusks:
* Academy of Natural Sciences of Philadelphia
* American Museum of Natural History
* Bailey-Matthews Shell Museum
* Cau del Cargol Shell Museum
* Maria Mitchell Association
* Museum of Comparative Zoology at Harvard
* National Museum of Natural History, France
* Natural History Museum, London
* Rinay
* Royal Belgian Institute of Natural Sciences, Brussels: with a collection of more than 9 million shells (mainly from the collection of Philippe Dautzenberg)
* Smithsonian Institution