Tag: Isopoda

I think I found a new species, now how do I illustrate it?

When aiming to express a concept or convey a message, the use of visual material is certainly a clearer and more understandable method compared to a text-only description.

Images facilitate the reading of a text by providing an easy and immediate visual explanation. In biosystematics, descriptions of new plant and animal taxa are always combined with figures and plates in order to illustrate the anatomical parts and body details.

Taxonomists need images of good quality in describing taxa. As a rule, drawings are better detailed than stereo or light microscope photographs since some details, which are often barely visible in a photograph, can be highlighted in the drawing.

Nowadays only digital figures (drawings or photographs) are accepted by the most important journals of taxonomy. The usual method used so far to digitalise a conventional drawing is by scanning, however a simple scan does not always represent correctly the complex ink figure.

The new method, developed by Dr. Giuseppe Montesanto in the University of Pisa (Italy), to produce digitised drawings straight on your computer using specialised software.

The paper published in ZooKeys provides simple step-by-step instructions for users to produce noteworthy results with this easy method.

The procedure in short makes use of bitmap graphics with the GNU Image Manipulation Program (GIMP). The method is very accurate, producing detailed lines at the highest resolution and the raster lines appear as realistic ink-made drawings.

Additional advantages are that it is faster than the traditional way of making illustrations and everyone can use this simple technique. The method is also completely free as it does not use expensive and licensed software and it can be used with different operating systems.

‘When you describe a new species for scientific literature, the illustrations are not an addition to your description. They are an integral part of it. You may not be a great artist (although many biologists are talented artists), but with this method you can learn to do adequate drawings’. adds Dr. Montesanto.

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Original source:

Montesanto G (2015) A fast GNU method to draw accurate scientific illustrations for taxonomy. In: Taiti S, Hornung E, Štrus J, Bouchon D (Eds) Trends in Terrestrial Isopod Biology.ZooKeys 515: 191-206. doi: 10.3897/zookeys.515.9459

The bold and the shy one: Could woodlice have personalities?

Unlike larger animals and even other invertebrates, the theory for the presence of personality traits in terrestrial isopods had not been studied before the research conducted by Dr. Ivan Tuf’s team.

Known to react to an external impact with varying in its duration death feigning, or tonic immobility, several hundreds of Common rough woodlice were observed while responding to random sequences of touch, squeeze and drop. When compared, the results showed there is in fact a significant individual pattern of defensive behaviour. The study is published in the open-access journal ZooKeys.

In order to prove that the tested P. scaberwoodlice actually possess personalities, the scientists had to look for repetitiveness in their reactions to external impacts. Over the three-week observations, consisting of five experimental sets and four-day breaks, Dr. Tuf and his team recognised consistency in the reactions in the individuals. They even managed to identify some of them as “more ‘bold'” and others – “more ‘shy’.”

However, a number of other factors were found to influence the woodlice’ protective reactions such as habituation and body size. Ten minutes in a particular environment proved enough for a woodlouse to habituate it. As a result, their sensitivity towards the same stimuli decreased.

Similarly, it was not as noticeable with the larger specimens. Unlike their tinier relatives, they are capable of using chemical protection due to their better developed physiology. Nevertheless, the longest reaction time being measured in a medium-sized woodlice proves that body size is not of such importance.

Yet, it is still unclear whether the woodlice’ behaviour changes over time. If such a trend is present, then their reactions to the external stimuli is also likely to change.

“Investigation of long-time stability of behavioural traits in terrestrial isopods should be a possible goal of future studies,” the scientists suggest in conclusion.

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Original source:

Tuf IH, Drábková L, Šipoš J (2015) Personality affects defensive behaviour of Porcellio scaber(Isopoda, Oniscidea). In: Taiti S, Hornung E, Štrus J, Bouchon D (Eds) Trends in Terrestrial Isopod Biology. ZooKeys 515: 159-171. doi: 10.3897/zookeys.515.9429