Snorkling in the Seerhein

Today after work I went snorkeling with some friends from work. We decided to start near the heart of Konstanz and swim down the Seerhein for about one and a half kilometer. I must say people looked a bit surprised to see three guys walking in wetsuit across the street. Although the water was not as clear as I hoped we still managed to see a couple groups of huge Carp, a number of single adult Pike of 1m+ at about 5-8m depth on the river floor, and some huge stickleback schools swimming in the shallows.

A huge Carp, my friend Ziga, and a large adult Pike somewhere in the green of the Seerhein

New sticklebacks from the Bodensee

Went out again with the boat yesterday to catch sticklebacks. A cold but beautiful day. At first we couldn’t find them where I saw them last week, but soon enough it was clear they were still there but just very well camouflaged against the pebbled background!

With the three of us we managed to catch about 300 of them in half an hour by wading through the shallow waters. Most of the fish are likely 1st-years, but we also caught a couple older individuals that were huge, close to 10 cm!

After mooring the boat, we moved all fish to a large social housing tank at the Limnological institute where they will undergo a anti-parasite treatment for a couple weeks. After that I will move them to our fish lab at the University of Konstanz as well as to outside mesocosms. There they will ‘participate’ in a range of my behavioural experiments focused on individual differences in collective behaviour.

First boating trip on the Bodensee

The past summer, I successfully completed a motorboat course to enable me to drive a motorboat on the Bodensee, required for my ongoing research on fish collective behaviour. I got my “Sportbootführershein” in the post a couple weeks ago, and finally this weekend was able to ‘take the boat out’.

driving-the-motor-boat

In the cold rainy weather of early November, I set-off with with a good friend on one of the motorboots from the Limnological Institute. The water was considerably clearer than during the summer, providing a visibility of just over 5 meters. It was beautiful being out on the water. However, in the first hour almost being out, we still hadn’t seen our first fish!

view-over-the-lake

We navigated around the island of Mainau, and started exploring the very shallow areas near the mainland. I was a bit annoyed I hadn’t seen any fish yet, let alone any sticklebacks, but when we decided to cross under the bridge leading to Mainau we suddenly found thousands of them!

The water was so shallow that it was necessary to take the motor out, and continue by oars. But this also meant we could observe the swarming fish from very close. Despite sticklebacks being very abundant in the Bodensee, in the autumn and early winter most of them move to deeper waters, likely following the movements of their invertebrate prey. These remaining fish were apparently some of the last ones remaining in the shallows, likely seeking shelter in the shadow of bridge, and I was therefore very happy to have found them.

We spent about half an hour observing their movements and behaviour and I got some good ideas to come back for some more quantitative field measures of their group sizes and compositions. After that we decided to go for a quick snorkel before going back to the harbour.

with-wetsuit-on-the-boat

With my freediving wetsuit, the 11 degrees C actually still felt very comfortable, and I was enjoying the relatively clear waters of the lake. The Bodensee has a very interesting geology, with relatively shallow water on its edges that can suddenly drop almost vertically tens and tens of meters into the deep.

We only snorkeled a bit above a drop-off near the harbour to check our wetsuits and the visisbility, which both passed our expectations. I therefore can’t wait to go back again and take the boat out the lake to catch wild individuals for my experiments, get some more quantitative observations of the sticklebacks and their predators, and explore underwater.

New stickleback in the lab

For my new research projects on the role of individuality in collective movements and decision making at the University of Konstanz, I have been getting new sticklebacks from the Bodensee. Last weekend I went to see them together with my 10mo son! I think it was the first time he actually ever saw moving fish. Although I showed him fish in aquaria before, he was too young to react to them, but this time he was amazed by the large school of fish swimming back and forth. The sticklebacks from the lake were absolutely huge, I estimate up to about 9cm, much bigger than the ones I ever saw in Cambridge and the ones in the ponds near the University here. I hope to go on a trip soon to observe the collective behaviour of the sticklebacks in lake Konstanz, the ponds, and streams in the area to set-up some exciting experiments on the population-specific differences of this amazing species.

Here I am showing my son a school of Moderlieschen

Here showing my excited son a school of Moderlieschen

Drawing sticklebacks

I have been trying to improve my drawing skills to better illustrate how my sticklebacks behave and in what way personalities matter in collective behaviour. I still have a far way to go but this is my latest quick sketch that shows four sticklebacks with different morphologies. When I get more time on my hands after I hand in I will try to get some more elaborate drawings done!

stickleback-drawing

Three-spine stickleback close-up photo

I have been taking quite a lot of photos and videos of the sticklebacks recently for public engagement and wanted to share this large close-up photo with you. Although it is a three-spine stickleback, it actually only has two spines, a feature that is common amongst this species.

Stickleback-closeup

Click the image to get the full-size photo! 

New stickleback project finished

taggedfishTwo part II Zoology students of mine have just finished an exciting new project with the sticklebacks! I can’t say too much about it yet but the photo can give an idea ;-) In short, it involved large numbers of tagged three-spine sticklebacks.

Stickleback spine-use project

Very recently two part IB students of mine finished a nice little experiment on the spine-use of three-spine sticklebacks. We were interested to see how personality might be related to the raising of the spines of three-spine sticklebacks as it helps them in protection against predators. Watch this close-up video that I took that nicely shows one individual stickleback raising its spines and lowering them again after feeling threatened by my presence. Hopefully soon we have the manuscript out with the findings of our study!

Last experimental work of PhD finished!

stickleback-testing-JollesToday I finished my last experiment that will be part of my PhD! I have been locked away in the lab for a couple weeks, testing hundreds of fish on their personality and collective behaviour, but now analysis and writing can fully start. I must have tested close to a thousand fish in the two and a half year since the start of my PhD, most of which are now enjoying a happy end of their lives back in the wild. I have all the data of a number of exciting projects that will not need me to go back to the lab for at least half a year but I can actually not wait to test my next hypothesis! The three-spine stickleback is an amazing species to work with and I will definitely continue working with them after my PhD.

New video of three-spine stickleback in my lab

Today I took a new video of the stickleback in my lab to use to talk about my work and these amazing fish during public lectures and conference presentations!

What you can see really well in this short little video is the large morphological and behavioural variation of the fish. Despite being similar in age the fish are quite different in body size as well as their colouration. Also pay attention to the spines, you can see individual fish often raising their spines at the moment they feel threatened by my presence.

One of the social housing tanks I use to house some of my hundreds of little stickebacks

One of the social housing tanks I use to house some of my hundreds of little stickebacks