http://www.collembola.org/publicat/photogr.htm - Last updated on 2008.04.13 by Frans Janssens

Keith Brocklehurst, 114, Leicester Lane, Leamington Spa, Warwickshire, CV32 7HH, UK
Frans Janssens, Department of Biology, University of Antwerp, Antwerp, B-2020, Belgium

The minute size of Collembola and their rapid unpredictable movements are obvious problems in their live photography. Perhaps their illumination is also a critical factor - cold fibre-optic light is best though expensive, and not a complete answer by any means. Nevertheless, if they can be made to remain still for a minute or so success will be more frequent. This is a behavioural method of making them "sit" fairly still and all in one or more chosen spots in a culture dish for a minute or more.

Fig.Ei. Entomobrya intermedia from the UK
Specimens drinking with eversed vesicles of collophore
2007 © Brocklehurst, K.

The images of Entomobrya intermedia (L = 2 mm) illustrate the spectacular and rapid response they give after 72 hours dehydration in culture at comfortable room temperature when a few drops of distilled water are quickly placed on the dry culture medium. The DIY filler forming the base of the culture vessel is whiter when dry and darker when wet; it contains tiny amounts of activated carbon, which avoids a difficult white background. The live specimens were collected by net and pooter from small garden plants. After dehydration five tiny drops of water, spaced well apart in the culture, were added from a fine pipette, and a few seconds later the springtails were all still and distributed as in the photographs. Head movements when this species is eating can be seen with magnification, but none was detected even from the occasional individual which was near the fish food. So, my guess is that they were applying their two-lobed ventral tube to the wet medium and absorbing water, presumably through fine tubes. Further work should suggest a method !

Fig.Ds. Dicyrtomina saundersi from the UK
Specimens drinking with eversed tubular vesicles of collophore
2007 © Brocklehurst, K.

The same behaviour occurs in Dicyrtomina saundersi, but here 2 vesicles are suddenly extruded from the ventral tube and laid out flat on the moist filler. The vesicles are fine and transparent with fine openings, and are usually seen extended in preserved Dicyrtomids and sometimes tangled round legs.

Taking photographs from the dorsal side by this method is straightforward with modern digital cameras - it would be interesting to somehow get ventral views. The images were made with a Nikon 995 camera.

Comments would be welcome.

Fig.Do. Dicyrtomina ornata from France
Drinking with eversed tubular vesicles of collophore
2008.04.10 © Lebeaux, P.

This specimen of Dicyrtomina ornata from France presses its everted tubular collophore vesicles against the wet substrate to 'drink'.

Acknowledgements