We´ve set up a Planarian lab!
This page reports on and shares some images of our "Planarias on the road" day, when we obtained and learned how to care for our first specimens of Girardia tigrina, a species of planaria with which we have set up our first planarian lab at the CBR.
Planarians for what?
The Lit Up Program was challenged by a teacher from Escola Secundária Quinta do Marquês, in Oeiras, to help support a research project that insisted on not "taking off". Teacher Maria dos Anjos Tomaz and her student, Laura, wanted to establish in their school a culture of planarians, small flat worms that live in freshwater bodies, so that Laura could carry out a research project on climate change.
Laura is very interested in studying the effects that two consequences of climate change could have - the increase in pollution (due to human activity) and the increase in salinity (due to the rise in average sea level) - on the organisms that make up our ecosystems, and would like to use planarians as indicators. Planarians are invertebrate animals, with bilateral symmetry, from the phylum Platyhelminthes: they are flat worms, whose bodies have the appearence of a ribbon. Due to their particular sensitivity to polluting substances, they are often used as bioindicators of water quality.
It seemed like a very pertinent question, so I contacted Dr. João Pestana, a researcher who works with planarians at the Center for Environmental and Marine Studies (CESAM) at the University of Aveiro, to find out if this idea had a leg to stand on, or better yet, to glide on :) Dr. João Pestana was immediately available to collaborate and make Laura's project a reality. He shared with us that he works on ecotoxicology studies with, among other organisms, a species of planarian called Girardia tigrina or Dugesia tigrina, also called brown planarian. Girardia tigrina is a dugesid, a family of free-living freshwater planarians, whose adults are 6 to 15 mm in length. It has a triangular head, with 2 "eyes" or ocelli, and 2 lateral auricles, chemoreceptors that project from the lateral area of the head (anterior area) of the animal and detect chemical substances in the external environment, in addition to being sensitive to touch and water currents. They are predators or scavengers, and move via cilia located on their ventral surface.
Figure 1. Visit to Dr. João Pestana´s ecotoxicology laboratory at the University of Aveiro: acquiring the necessary know-how to culture and manipulate planarians. We admired the aquaria with capsules (within which are planaria eggs), juveniles and adults of the planarian species Girardia tigrina or Dugesia tigrina - also called brown planarian. Planarians are invertebrate animals, with bilateral symmetry, from the phylum of flatworms: their body has the appearance of a ribbon. They are distributed in marine environments, but also occur in terrestrial and freshwater environments, with the majority of planarian species being predatory and benthic. Girardia tigrina is a dugesid, a family of free-living freshwater planarians, and a species that is easy to propagate in the laboratory. Adults are 6 to 15 mm long and are gray to brown in color, with darker pigmentation - similar to the stripes of a tiger (hence the name tigrina). In the laboratory, Dr Pestana taught Laura and teacher Maria dos Anjos Tomaz how to care for planarian cultures in the laboratory, how to identify the morphological characteristics of these fascinating animals under a magnifying glass or stereo microscope, and how to carry out locomotion and regeneration assays, which will be necessary for Laura´s project on climate change and possible future projects.
We were only missing perhaps the most important thing: the planarians, and the indispensable know-how to grow and maintain them and to make use of them as research organisms. The planaria we desperately wanted for Laura´s project were in Aveiro, but we were in Oeiras....
Planarians on the road!
This is when the Oeiras Valley Science and Innovation Office sprung into action and saved the day, by providing us with a vehicle and a driver to travel with us the ~ 270 km that separate the Quinta do Marquês school and the Center for Environmental and Marine Studies (CESAM) at the University of Aveiro!
On a beautiful March morning, Mr Milton, our CMO driver for the day, picked us up from the school and we hit the road. We arrived in the laboratory at the University of Aveiro where Dr. Pestana works around 10 am and spent the rest of the day learning everything we could about planaria. Dr. Pestana was incredibly patient and thorough, and showed and told us everything we ever wanted to know about planarians: we were able to learn the methodology necessary to grow and maintain planarians, to produce their culture medium, and to carry out the various tests - also called assays - common in typical ecotoxicology and stress biology experiments employing planaria. Laura was even able to do her first locomotion and regeneration assays! At the end of the day, Dr Pestana helped Laura and Mrs Tomaz collect around 2 hundred Dugesia tigrina adults to bring with us and start our planarian colony.
Figure 2. Planarians on the road: collection of specimens and trip to Aveiro from Oeiras. Dr João Pestana, Laura and teacher Maria dos Anjos Tomaz collected eggs and adults of the planarian Girardia tigrina that we transported with us with extreme care, in Falcon tubes, on the car journey to Oeiras. We had to chance to see even more organisms in the lab, such as Daphnia, duckweed, and fireflies. Further highlights of the trip: the delicious focaccia that Mrs Tomaz brought for us to snack on during our road trip and the wonderful Mr. Milton, who drove the car. Mr Milton got "schooled" by Mrs Tomaz on flatworms and other benthic invertebrates, and an earfull from me on various science and health literacy topics! A very special thank you to Oeiras City Hall, particularly Elisabete Brigadeiro and Maria José Amândio, of the Science and Innovation office at Oeiras Valley.
And so the Planaria Project takes off...
At the moment, we already have a planarian laboratory established at CBR, where we are cultivating and propagating the animals! Soon, Laura will be able to come and collect part of the colony and take it to the Quinta do Marquês school, where she can keep the organisms and carry out experiments with them for her project on climate change. However, because the CBR labs are able to keep environmental conditions well controlled, Lit Up will keep part of the colony here, in case the colony does less well at the school.
Figure 3. The brand new Planarian Laboratory at the CBR. We are open for business! The business of maintaining and testing Girardia tigrina organisms for any project Oeiras teachers and students might be interested in. Our recently relocated planaria got their first visitors: Laura, her colleague Miguel and teacher Maria Tomaz came by to check on their study objects.
(Text by Joana Loureiro; photographs by Joana Loureiro and Maria dos Anjos Tomaz)