p1: Rosana what is your specialty or your research area in Biological Sciences?
p1: I am an expert in taxonomy of tunicates, more specifically ascidians.
p1: Ascidians are animals that attach to substrates. They are invertebrates,
p1: marine invertebrates, they attach to substrates. When I go to the field, I
p1: collect many different species and then in the lab, I have to dissect them to study
p1: their characters, their morphology, their anatomy, and then I'm going to compare
p1: these characters with descriptions of other species in the world.
p1: If there is no match with described species then I can describe them as new species.
p1: I also work on ecology, mainly ecology of bioinvasions because ascidians usually
p1: are transported by ships and vessels and spread in different sites of the world
p1: and then we have to understand what are their roles in the new communities
p1: that they invade.
p1: So why do you use tunicates as an experimental model, and which
p1: advantages could you get by using these organisms?
p1: Well, I started studying tunicates actually
p1: as uh a suggestion of an advisor
p1: I started studying ecology and then- but this advisor always said to have a model
p1: group that we were more comfortable and were able to identify species and everything
p1: and I just decided to work on tunicates because they were very common in the
p1: region I was studing which was in South Brazil and it happened to be a very diverse
p1: group and I got very interested afterwards, and many of the species
p1: in this region are actually introduced species, they are not native in that
p1: region because we had a port nearby.
p1: But tunicates got very interesting along the years just because they're really diverse,
p1: not many people study them, and very few researchers in each continent actually.
p1: But they are our sister group in evolution, tunicates are very close to vertebrates.
p1: In the point of view of bioinvasion, tunicates are very interesting because
p1: they attach to substrates, the adults attach to substrates and substrates can
p1: float or can be transported in the sea, and now we know that at least 70 species of
p1: tunicates have been transported worldwide.
p1: So uh we have colonial species and solitary, we have different kinds of
p1: families with species that have been transported so this is what made this group
p1: itself the tunicate as a really interesting model for studying how they affected the
p1: new environment, how they change evolutionarily when they get transported
p1: and enter a new community or a new environment of different kinds of
p1: temperatures, salinities, and other environmental characteristics, uh
p1: and um how they are going to, if they are going to evolve as isolated populations
p1: and since tunicates are also- most of the species are hermaphrodite so they can
p1: sometimes they can fertilise their own eggs, just one individual can start a
p1: whole population. This also makes them very interesting.
p1: Could you tell us a short story on a funny experiment with tunicates?
p1: Well, trying to work on bioinvasion, we want to understand how the species
p1: are transported and which species can be transported and actually I think that
p1: usually tunicates are very, very delicate and I would not expect them to be
p1: transported by very fast vessels and
p1: so we did once one experiment and we tried
p1: to see which species were being transported but we couldn't use a boat
p1: that's actually in the sea with a small community on its hull because that community
p1: will be very adapted to transportation if the boat is going around all the time.
p1: So what we did was we put some plates inside the water, let them colonise for four
p1: months and then we tried to attach those plates to the boat hull
p1: to mimic a hull that has been colonised by species, and that was not that easy
p1: because you can imagine how to fix a plate to a motor boat with fiberglass
p1: we could not use screws or even glue
p1: and we tried to make a small frame with PVC
p1: tubes and put the plates on the frame and attach the frame to the boat
p1: with ropes and we had our system all set, but when the boat started to go, we saw
p1: the dragging of the water with really strong and our system just went by so we had to
p1: think of many more ropes and weights to maintain the plates in place and then I
p1: realised how much those animals on the plates were suffering from dragging it's
p1: amazing that they still-
p1: they could stay on the plates for so long, and they actually did and this is how they
p1: were transported then now we understand better how strong they are, and why they
p1: are transported even by small boats in a uh
p1: local uh scale, not only by the big boats
p1: in an international scale.
p1: How do you imagine the future of these organisms in experimental biology
p1: and/or teaching?
p1: Bioinvasion is actually an ongoing process, it is not something that has occurred and
p1: it stopped, it's going to occur since we have more and more ships around the world.
p1: So I guess tunicates are going to be used for long periods in the future as models
p1: to better understand what are the roots, what are the impacts of bioinvasions?
p1: And also we are realising that more places we survey
p1: we find lots and lots of new species,
p1: so diversity is very great and there is lots of room for research on
p1: ascidians, both in taxonomy, and ecology.
p1: So ascidians are very interesting animals, not only because they are a sister group of
p1: vertebrates, but because they are sessile groups, they are filter feeding animals
p1: so they have a lifestyle that is very different from ours.
p1: So uh, I think we are going to continue to
p1: talk about them in undergrad courses
p1: because of their relationship with vertebrates, but I think they are
p1: very fascinating animals to talk about even in elementary schools.
p1: If you could say a few words on the tunicate scientific community.
p1: The scientific community that works on ascidians is not very large and working on
p1: taxonomy is even smaller. We're just a handful of people working
p1: but it's a really open field, as I told that we have lots of different species.
p1: We have- we know about 3,000 different species by now,
p1: but we're supposed to have at least 5,000
p1: and we have many sites in the world that have not been studied.
p1: And so I think that there is a lot of opportunities for new students to start
p1: working on tunicates and the community is usually very friendly and everybody
p1: loves to have new students in their labs, so I guess I can also invite you to start
p1: on taxonomy on ecology and I will be
p1: more than glad to help people that
p1: contact me to start studying ascidians.