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Importance and curiosities of scientific collections

Atualizado: 9 de jul. de 2021

Between the end of my master's degree and the beginning of my doctorate, I spent a year and a half participating in the assembly of the Biological Collection Prof. Edmundo F. Nonato - ColBio at the Oceanographic Institute of the University of São Paulo. I spent months looking through bottles filled with biological samples, including fish, zooplankton, and otoliths, and entering all of their information on the computer. Information like collection dates, locations, collection depths, the type of sampler used, the vessel, etc. all needed to be recorded electronically. It was during this period that I realized the importance of scientific collections, which, when preserved and recorded carefully, can be used for countless scientific studies.

While doing this work, I noticed that there were many samples of eggs and larvae from a species of fish (Engraulis anchoita) spanning from 1974 to 2010. This collection would allow me to analyze the distribution and abundance of this fish species over a long period of time, helping to verify the influence of environmental factors that could not otherwise be done with only a few months of collection. Citing what Silvia Gonsales (previously an illustrator for Chat with Neptune) told me, "the collections store pieces of relevant information to a puzzle, to be assembled and unveiled by the researchers." That is why when an accident occurs, like the fire at the Butantã Institute in 2010, it is not just dead snakes that are lost, but relevant, irreplaceable information that will leave holes in these puzzles, which may become impossible to assemble.

Preserved organisms deposited in ColBio.

(Picture: Gabriel Monteiro, under license CC 4.0 SA-BY)

Another benefit of biological collections is the financial savings they can provide. Often, we do not realize the high cost of a field trip for an institution or a funding agency. The campaign is even more expensive if a research vessel is necessary, especially if the area studied is far from the coast or very large. In my own doctoral project, I did not spend a single dollar on collecting samples, thanks to the material available in ColBio.

Now suppose you do a survey in which you want to know which species of fish occur within a certain region. You identify the species and, at the time of publication or later, a researcher asks if you have correctly identified species X. If your species X has at least one individual stored for biological collection, the questioning researcher can analyze the “test specimen” for themself to verify the species identification.

The same is true going the opposite direction; Say you are identifying a collected individual and have doubts about its classification. One of the easiest ways to identify this is to consult a scientific collection and analyze the possible species that your individual could belong to. During my master's degree, I went countless times to the Zoology Museum of the University of São Paulo - MUZUSP to see individuals deposited in the ichthyological (fish) collection. If you thought that University Museums and Natural History Museums were merely exhibitions for visitors to look around, you were wrong! In many cases, the scientific collections not on display are much larger, and, in my opinion, more important than what is on display.

Oh, and if the museum archives the holotype of a species, the collection becomes even more precious. A holotype or type specimen is an individual of a species which researchers designate as the basis for the description of a new species. We are constantly discovering new species and designating new holotypes, especially in the ocean, which is still so under explored!

While exploring the database of the Natural History Museum in London, I found several holotypes from Brazil. One of these holotypes that caught my attention was a kind of sponge (read more about sponges here) collected in 1996 in the São Sebastião region, SP. For the curious reader here is the link to the scientific collection of the Natural History Museum in London. I particularly thought it was amazing to be researching species collected by Darwin and Linnaeus in Brazil, whose specimens are today kept on another continent!

It is important to clarify that the holotype does not always need to be the entire individual, especially in cases of extinct species, whose descriptions are often based on fossils (for example, a holotype of a described dinosaur may be only a femur). In some cases the hpe molotyay even be an illustration!

Holotype of Marocaster coronatus, an extinct species of starfish. The material is held in the Toulouse Muséum, France.

(Photographer: Didier Descouens, under license CC-SA 4.0)

Speaking of illustration, Silvia Gonsales briefly mentioned on her profile here on the blog the importance of scientific illustrations: “drawing helps researchers represent and/or explain their ideas with something other than words. For example, when a new species is discovered, someone needs to describe it, that is, make an accurate record of what it looks like. Scientific illustration complements and synthesizes these recordings, showing all its important characteristics that often do not appear clearly in photographs”. Thus, the drawings of the described species help researchers to identify the species or even the stage of development in which it is found. In her Course Completion Work, Silvia Gonsales uses scientific drawings to describe and characterize the larval phases of a fish species (see the drawings below as an example of 3 stages). And in Claudia Namiki's post she shows how scientific drawing was used to describe otoliths. The originals of scientific drawings are also kept in scientific collections, available for consultation.

Scientific drawings showing 3 larval stages of a fish species.

(Illustration: Silvia Gonsales, under license CC 4.0 SA-BY)

Drawings are easy to store in high quality for a long time, but how are the other materials kept? Well, it all depends on what is being “deposited.” Otoliths and bones only need to be cleaned and labeled to be deposited, plankton samples are usually placed in glass jars and preserved in 4% formaldehyde, and fish in 70% alcohol. Plants are pressed, dried in a dehydrator and fixed on cardboard, called exsiccatae, like those in the collection of the Botanical Gardens of São Paulo and Rio de Janeiro. Taxidermy is the popular way to preserve larger animals. In the past, straw was used to stuff the skin of the animal that was being mounted. Nowadays, a material similar to diapers is used, such as the taxidermied animals in the Fisheries Museum of Santos. I bet many readers never thought that “stuffed” animals could be used to progress science, not just used by hunters to display animals in their living rooms (yikes!).

Examples of fish in 70% alcohol, taxidermied sea birds, the skeleton of a bird (Photos: Jana M. del Favero, under license CC 4.0 SA-BY) and botanical exsiccatae.

(Photo: Richieri Sartori, under license CC 4.0 SA-BY)

Two of the collections that I visited that really caught my attention were the flower and invertebrate glass collections from Harvard University’s Natural History Museum and Museum of Zoology. The collections were initially created to be used in classrooms, given that the pressed plants and fixed organisms (preserved in formaldehyde or alcohol) are not always a good representation of their living form (invertebrates may lose color and form when fixed). In the case of the glass organisms, even being within a close range, I would swear they were real animals, even though the models were made between 1887 and 1936! A true work of art for the university! More information about the glass flower collection can be obtained here and about marine invertebrates here. At the end of both pages there is a film with beautiful images, telling the story of how these glass organisms were made.

Glass organisms from the collection of the Museum of Natural History at Harvard University. (Photo: Jana M. del Favero, under license CC 4.0 SA-BY)

Museums can also store bibliographic treasures in their collections, such as the books with descriptions by Carolus Linnaeus maintained by the Museum of Zoology of the University of São Paulo. Linnaeus was one of the pioneering scientists in the identification of animals, and he is considered the “father of taxonomy.” This material is so rare and of such importance that it needs to be handled with gloves.

A survey from 2015 reported that only 12% of respondents visited a science and technology museum in the past 12 months. Although low, this percentage increased compared to the same survey in 2006, in which only 4% said they had visited a museum in the last year, and 8% in 2010. Among those who did not go to any museum, only 14.2% justified it with a lack of interest, 32.2% did not have time, and 31.1% stated that they did not go because one was not available in their region. According to the website that released the survey, the lack of access to a museum, or lack of knowledge about it, was more common than a general lack of interest, showing the importance of increasing access to and knowledge of these important places. The survey has since been updated, but there has been little improvement in these numbers.

So, after the curiosities presented here, how about planning a trip (even a virtual one!) to a museum and trying to see it in a different way?!


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