Wimbledon Common excursion
Saturday 20th May 2017
Several Quekett members took their microscopes, cameras and computers to the Information Centre on Wimbledon Common for another enjoyable day of pond dipping, microscopy and photography in the company of fellow microscopists. As in previous years, Dennis Fullwood had obtained permission from the Conservators for us to use the Centre and to collect specimens from the Common, a Site of Special Scientific Interest (SSSI) and a Special Area of Conservation (SAC).
Barry Wendon outside the Information Centre
This year, we collected aquatic specimens from 2 new sources, Hookhamslade pond and the cattle trough near the Centre, as well as from Queensmere.
Nigel Williams, Tony Pattinson and Dennis Fullwood collecting from Hookhamslade pond
Thanya Nirantasook and Noi Matthews examining the cattle trough
Greenish-brown layer at the bottom of the cattle trough
Back in the Information Centre, we used a variety of microscopes and cameras to observe and record our specimens, and explained them to some interested visitors.
Members and visitors in the Information Centre
Barry Wendon brought his Olympus CK inverted microscope and found lots of ciliates.
Thanya Nirantasook with Barry’s Olympus CK microscope
Dennis Fullwood brought his Nikon Labophot compound microscope and Olympus SZ4045 stereomicroscope and used them to observe pond life and insects caught in his yellow pan traps.
Nigel Williams (left), Fleur White and Dennis Fullwood
Graham Matthews has been using his Leitz DIC objectives and condenser on a Zeiss Standard microscope for several years, but they are now on his newly-acquired grey Leitz Dialux and were used to observe waterfleas and other organisms.
Graham Matthews with his Leitz Dialux
Graham Matthews and Irma Irsara with Dennis’s Olympus SZ4045
Mary Morris brought her trusty Watson stereomicroscope with its transmitted-light base and a selection of identification keys.
Mary Morris with her Watson stereomicroscope
Neil Henry used his Bresser Biolux AL attached to his laptop to record still and video images.
Neil Henry with his Bresser Biolux AL
Paul Smith brought his Olympus CX41 microscope that does not have a viewing head but a set of adapters and an EOS M mirrorless camera. The camera was connected via its HDMI output to a television for focusing and composition and was operated via an infrared remote control.
Paul Smith with his Olympus CX41
Tony Pattinson brought along his PZO stereomicroscope with an LED ring light and his trinocular Olympus CH-2 compound microscope. On the CH-2, he used a 5 megapixel C-mount camera attached to his laptop, capturing and stacking images with ToupView software. Tony is still experimenting with this camera set-up, and is currently using a Kyowa 10× eyepiece inside the Pentacon adapter and a Cosmicar 12.5mm lens on the camera. Tony found several species of Cladocera, a high concentration of Pediastrum, and larvae and pupae of Chaoborus.
Tony Pattinson with his Olympus CH-2
Tony has been producing images containing several photomicrographs of diatoms, all at the same scale, to help with comparing and identifying them.
One of Tony’s diatom identification charts
Alan Wood and Thanya Nirantasook brought their Olympus SZ4045 stereomicroscope and used it to observe Chaoborus larvae and pupae and other material collected from the ponds. Tony pointed out that the Chaoborus pupae were ready to hatch, and we were able to watch 3 adult midges emerging, slowly and carefully withdrawing their long thin legs from the exuviae.
Olympus SZ4045 stereomicroscope
Phil Greaves didn’t bring a microscope and spent most of the day collecting several tubes of Cladocera from the ponds and lakes on the Common and recording precise details of location. He took the specimens home to identify them.
Norman Chapman was there too. He does not share the enthusiasm for pond life and went looking for flowers to collect pollen.
Specimens from the ponds and cattle trough
We found all sorts of things, including Amoeba, Euglena, Paramecium, Pediastrum, Stylonychia, Daphnia, Scapholeberis, Simocephalus, Cyclops, snail eggs, nematodes, fly larvae, water mites, ostracods, ciliates, dinoflagellates, green hydra and rotifers.
More photos to come…
Daphnia pulex Leydig [by Graham Matthews]
Daphnia pulex with well-developed young in the brood pouch [by Graham Matthews]
Predatory Chaoborus larvae release a kairomone that causes juvenile Daphnia to develop neck teeth as a defence mechanism. There were lots of Chaoborus larvae in the samples, and Tony Pattinson photographed the neck teeth on a juvenile Daphnia.
Neck teeth on juvenile Daphnia [by Tony Pattinson]
Scapholeberis mucronata (Müller) [by Graham Matthews]
Simocephalus vetulus (Müller) [by Graham Matthews]
Most waterfleas (Cladocera), like Daphnia, Scapholeberis and Simocephalus shown above, swim around in clear water and are easy to find. A few waterfleas hide among debris and so they are difficult to find, and the debris sticks to them making it hard to observe the features necessary for identification. Ilyocryptus sordidus (Liévin), which we haven’t seen before at Wimbledon, is one that hides in debris.
Ilyocryptus sordidus (Liévin) [by Tony Pattinson]
Asellus aquaticus (L.) [by Tony Pattinson]
Crangonyx pseudogracilis Bousfield [by Tony Pattinson]
Hydra viridissima Pallas [by Tony Pattinson]
Pediastrum sp. [by Tony Pattinson]
Pediastrum spp. from the cattle trough [by Tony Pattinson]
Pediastrum spp. and diatoms [by Paul Smith]
Ceratopogonid larva (3 mm long) [by Tony Pattinson]
Video of amoeba [by Paul Smith]
Click the arrow at bottom left to start the video (34 seconds), click the symbol to the left of “vimeo” for full screen
We don’t always manage to identify everything that we find, and here is an example. We didn’t know what was living on this length of filamentous alga (Mougeotia sp.), so we asked for help on the QuekettMicro Facebook group. Mike Wot suggested the epiphytic diatom Cocconeis (but the colour seems wrong), Gianfranco Novarino suggested a sessile euglenoid such as Colacium, and Graham Matthews suggested the yellow-green alga Characiopsis.
Epiphytes on filamentous alga [by Tony Pattinson]
As part of the Club’s microscopy outreach programme, Quekett members will be back in the Information Centre on Wimbledon Common for the BioBlitz on Sunday 18th June 2017 and for Open Day on Sunday 10th September 2017.
Our thanks to Dennis Fullwood for organising another successful Quekett excursion, and to the Conservators for allowing us to use the Information Centre and to collect specimens.
Report and photographs by Alan Wood, photomicrographs by Graham Matthews, Paul Smith and Tony Pattinson