The mollusk collection was initiated through the efforts of T. van Hyning, the first director of the museum, and was small and composed mostly of local taxa until 1965.

Fred G. Thompson joined the museum faculty in 1966. He has served as curator of Malacology 1966-2016. In 1973, the Florida Museum of Natural History mollusk collection consisted of 22,174 catalogued lots and ranked 19th in the US (Solem, 1975). The collection has grown rapidly since, through numerous field surveys and acquisition of relinquished collections. Gustav Paulay joined the division in 2000 as Marine Malacologist. Since his hire, the collection was expanded to cover all marine invertebrates.

Malacology is devoted to the study of mollusks, the second largest phylum of animals in terms of described species. About 100,000 species of mollusks are known, and the Florida Museum holds >40,000 species among >560,000 lots of specimens (2023).  The mollusk collection is especially strong in terrestrial and freshwater mollusks. Overall marine mollusks comprise 38% of catalogued holdings, freshwater species make up 18%, and terrestrial taxa 44%. Gastropods comprise 83%, bivalves 16%, while all other mollusk classes combined <1% of the collection. Three quarters of the collection is from the New World, while 18% is from tropical Australasia and surrounding Pacific and Indian Ocean islands. The mollusk collection has unique strengths in land, freshwater and marine mollusks.

The Florida Museum has the largest land snail collection in the world from Hispaniola, Mexico-Central America, Pakistan and Thailand, and also has especially large holdings from the southeastern United States, West Indies, Andean South America, Madagascar, SE Asia, and Oceania. Freshwater mollusk collections are strong for the southeastern United States, Mexico, Central America, Andean South America, and the Philippines. Large subtropical and tropical West Atlantic and Indo-West Pacific holdings characterize the marine collection, and tropical marine collections are undergoing rapid growth.

These strengths reflect a former regional focus of the museum and research focus of the curators: on terrestrial and freshwater mollusks of Middle America and Southeast Asia, and on tropical marine mollusks, respectively.

The marine invertebrate collection (other than mollusks) was initiated in 2000 and currently (2023) holds 140K digitized specimen lots and another 20K curated lots soon to be available online. The bulk of the holdings have resulted from large-scale biodiversity surveys carried out by our staff, students and associates, mostly in the Indo-West Pacific, tropical West Atlantic, and Northeast Pacific. These include the collections behind the Marine Biodiversity Survey of Guam and the Marianas (1991-2000), the Moorea Biocode project (2006-2012), BIOTAS in the SW Indian Ocean (2007-2008), Census of Coral Reefs (CReefs) in French Frigate Shoals, Hawaii (2006) and Australia (2009-2010), the Marine Biodiversity Surveys of Oman (2019-2024, with preambles before that) and extended surveys in the Red Sea (2013-) and NE Pacific (California, Oregon, Washington, British Columbia, 2007-), as well as biodiversity surveys in Hong Kong, Philippines, Ryukyus, Palau, New Caledonia, Kiribati, Line Islands, Phoenix Islands, Hawaii, French Polynesia, Panama, St. Martin, Curacao, Bahamas, Florida, and Virginia.  Numerous other islands and reefs have also been sampled on a more limited basis. Surveys from the 1990’s on have included extensive live photographic coverage of sampled species, and from the early 2000’s also increasingly extensive tissue sampling and DNA barcoding.

Several relinquished collections have also been incorporated, notably the University of Guam collection (Guam and Micronesia), voucher collection of Continental Shelf Associates (mostly Florida and Gulf of Mexico), and the NOAA ARMS collection from their Pacific Reef Assessment and Monitoring Program.