Leo Margolis, (December 18, 1927 – January 13, 1997) was a Canadian

parasitologist Parasitology is the study of parasites, their hosts, and the relationship between them. As a biological discipline, the scope of parasitology is not determined by the organism or environment in question but by their way of life. This means it f ...

. He was a pioneer in the use of parasites for identification of Pacific Ocean fish stocks. His discoveries became a crucial point in negotiations over

pacific salmon ''Oncorhynchus'', from Ancient Greek ὄγκος (''ónkos''), meaning "bend", and ῥύγχος (''rhúnkhos''), meaning "snout", is a genus of ray-finned fish in the subfamily Salmoninae of the family Salmonidae, native to coldwater tributarie ...

fisheries Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life or, more commonly, the site where such enterprise takes place ( a.k.a., fishing grounds). Commercial fisheries include wild fisheries and fish farm ...

, as it could now be determined where each individual fish spawned, in the rivers of

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

or the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

. Born in

Montreal Montreal is the List of towns in Quebec, largest city in the Provinces and territories of Canada, province of Quebec, the List of the largest municipalities in Canada by population, second-largest in Canada, and the List of North American cit ...

Quebec Quebec is Canada's List of Canadian provinces and territories by area, largest province by area. Located in Central Canada, the province shares borders with the provinces of Ontario to the west, Newfoundland and Labrador to the northeast, ...

, he received a B.Sc. in 1948, a M.Sc. in 1950, and a Ph.D in 1952 from

McGill University McGill University (French: Université McGill) is an English-language public research university in Montreal, Quebec, Canada. Founded in 1821 by royal charter,Frost, Stanley Brice. ''McGill University, Vol. I. For the Advancement of Learning, ...

. He joined the Pacific Biological Station in

Nanaimo, British Columbia Nanaimo ( ) is a city of about 100,000 on the east coast of Vancouver Island, in British Columbia, Canada. "The Harbour City" was previously known as the "Hub City", which was attributed to its original layout design with streets radiating fr ...

, where was a government scientist, advisor, and diplomatic representative. He became Head of the Fish Health and Parasitology Section of the Station in 1967 and was appointed Senior Scientist in 1990. He suffered a heart attack in 1997 while walking home from work and died several days later, at the age of 69, after being airlifted to a

Vancouver Vancouver is a major city in Western Canada, located in the Lower Mainland region of British Columbia. As the List of cities in British Columbia, most populous city in the province, the 2021 Canadian census recorded 662,248 people in the cit ...

hospital.

Research

Margolis published a number of papers on fish parasites, but he is famous in the whole community of parasitologists for a paper on "the use of ecological terms in parasitology" published in 1982. In 1981, the

American Society of Parasitologists Founded in 1924, the ''American Society of Parasitologists'' comprises a diverse group of about 500 scientists from academia, industry, and government involved in the study and teaching of the scientific discipline of parasitology. Society members ...

appointed an ad hoc committee "to establish working definitions of a few terms used and misused by parasitological ecologists", and Margolis was the chairman of this committee. The paper contains the definition of widely used terms such as

prevalence In epidemiology, prevalence is the proportion of a particular population found to be affected by a medical condition (typically a disease or a risk factor such as smoking or seatbelt use) at a specific time. It is derived by comparing the number o ...

and has subsequently been cited thousands of times.

Honours

* Fellow of the

Royal Society of Canada The Royal Society of Canada (RSC; , SRC), also known as the Academies of Arts, Humanities, and Sciences of Canada (French: ''Académies des arts, des lettres et des sciences du Canada''), is the senior national, bilingual council of distinguishe ...

, 1975 * Officer of the

Order of Canada The Order of Canada () is a Canadian state order, national order and the second-highest Award, honour for merit in the system of orders, decorations, and medals of Canada, after the Order of Merit. To coincide with the Canadian Centennial, ce ...

, 1990 * Honorary Member Atlantic Canada Society of Parasitologists, 1992 * Honorary Member British Society of Parasitology, 1994 * Gold Medal Professional Institute of the Public Service of Canada, 1995 * Distinguished Service Award American Society of Parasitologists, 1995 * Honorary D.Sc., St. Mary's University, 1995

Eponymous taxa

A number of

taxa In biology, a taxon (back-formation from ''taxonomy''; : taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and ...

have been named in the honour of Leo Margolis. These include

genera Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial s ...

such as '' Margolisia'' Bray, 1987 (

Digenea Digenea (Gr. ''Dis'' – double, ''Genos'' – race) is a class of trematodes in the Platyhelminthes phylum, consisting of parasitic flatworms (known as ''flukes'') with a syncytial tegument and, usually, two suckers, one ventral and one or ...

Opecoelidae Opecoelidae is a family of trematodes. It is the largest digenean family with over 90 genera and nearly 900 species, almost solely found in marine and freshwater teleost fishes.Bray, Rodney A., Cribb, Thomas H., Littlewood, D. Timothy J. & Waesch ...

), '' Margolisianum'' Blaylock & Overstreet, 1999 (

Nematoda The nematodes ( or ; ; ), roundworms or eelworms constitute the phylum Nematoda. Species in the phylum inhabit a broad range of environments. Most species are free-living, feeding on microorganisms, but many are parasitism, parasitic. Parasitic ...

, Philometridae) and '' Margolisius'' Benz, Kabata & Bullard, 2000 (

Copepoda Copepods (; meaning 'oar-feet') are a group of small crustaceans found in nearly every freshwater and saltwater habitat. Some species are planktonic (living in the water column), some are benthic (living on the sediments), several species have ...

Lernaeopodidae Lernaeopodidae is a family of parasitic copepods. The females are typically large and fleshy, and attach to the host permanently using a plug made of chitin called the ''bulla''. The males cling on to the females using their antennae. They paras ...

), and

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

, such as '' Allopodocotyle margolisi'' Gibson, 1995 (

), '' Steringophorus margolisi'' Bray, 1995 (

, Fellodistomatidae), '' Acanthochondria margolisi'' Kabata, 1984 (

Chondracanthidae Chondracanthidae is a family of parasitic copepods, usually found infecting the branchial chamber of demersal fishes. It comprises the following genera: *'' Acanthocanthopsis'' Heegaard, 1945 *'' Acanthochondria'' Oakley, 1930 *'' Acanthochondr ...

), and ''

Philometra margolisi ''Philometra'' is a genus of nematodes, which are parasites of marine and freshwater fishes. The genus was erected by Oronzio Gabriele Costa in 1845. Species in this genus are worldwide. They parasitize the body cavities, tissues and ovaries of ...

'' Moravec, Vidal-Martínez & Aguirre-Macedo, 1995 (

, Philometridae). All these are parasites.

References

Leo Margolis
{{DEFAULTSORT:Margolis, Leo 1927 births 1997 deaths Anglophone Quebec people Canadian parasitologists Fellows of the Royal Society of Canada Fisheries scientists McGill University alumni Officers of the Order of Canada Scientists from Montreal 20th-century Canadian zoologists Scientists from British Columbia Presidents of the Canadian Society of Zoologists