Microscope Imaging And Plankton Sampling

After completing the imaging for the Saudi Arabian specimens, we are starting the next material in our queue, the Argentina, Russia, and Costa Rica Global Malaise Projects.

The BIO Image lab gets a wide diversity of arthropods to photograph, of these specimens, a very large proportion are extremely small, ranging from 2 cm to 0.05 mm – almost invisible to the untrained eye. To acquire the best quality representative picture of the species we utilize an imaging microscope and z-stacking software.

There are several steps along the microscope imaging process at the BIO Imaging Lab. After the barcoding process and the specimens have been recovered by the Collections Team, we are given a list from the BOLD team that states which Barcode Index Number (BIN) requires an image for the BOLD Database. The specimens are then accepted into the Imaging Lab queue and are ready to be photographed. We place specimens in a frosted dish with ethanol and in their appropriate orientation (lateral or dorsal). The lowest and highest points at where parts of the specimen are still in focus are set, and then the microscope is set to take images at specific layers (depths of field) of the specimen. These images are then stacked together by the imaging software and a scale bar is attached and saved onto the final image prior to the editing process (reference the picture below for the visually representation of the steps).

The lowest (top left) and highest (top right) points of focus of the specimen, and the final image after z-stacking has combined all images (bottom middle). Argentina Global Malaise Project - Diptera, Dolichopodidae, Medeterinae, Thrypticus sp. (BOLD:ACN9594)*
The lowest (top left) and highest (top right) points of focus of the specimen, and the final image after z-stacking has combined all images (bottom middle). Argentina Global Malaise Project – Diptera, Dolichopodidae, Medeterinae, Thrypticus sp. (BOLD:ACN9594)*

This Dipteran belongs to Dolichopodidae family, DNA barcoding results showed that the species is within the Thrypticus genus. The species in the Thrypticus genus are known as [Water Hyacinth] petiole miners during their larval and pupal stages of development. This specimen was collected in Misiones, Argentina with a Malaise Trap.

In an effort to develop the methods for live aquatic sample imaging, Kareina and I set off to acquire live freshwater plankton and insects from the local Eramosa and Speed Rivers. We utilized a basic plankton tow net set in the current which collected an array of microscopic invertebrates. We then brought back the live samples to BIO as quickly as possible where the Collections Team promptly sorted the specimens to order level of taxonomy prior to imaging. The specimens’ movements were slowed down by being placed in a dish with club soda in order for the microscope to complete the Z-stack.

Kareina acquiring a plankton sample with the plankton tow net in flowing water at the Speed River collecting site - Crane Park, Guelph, Ontario.
Kareina acquiring a plankton sample with the plankton tow net in flowing water at the Speed River collecting site – Crane Park, Guelph, Ontario.

 

Acquiring a plankton sample with the plankton tow net in shallow flowing water at the Speed River collecting site - Crane Park, Guelph, Ontario.
Acquiring a plankton sample with the plankton tow net in shallow flowing water at the Speed River collecting site – Crane Park, Guelph, Ontario.

While we were at our last collecting site on the Speed River in Crane Park I had my first midday coyote sighting! Due to its larger body size and general appearance at first glance, there is a good chance that we saw a coywolf (coyote/wolf hybrid) instead of a coyote!

Thank you for reading!

-Adrian

*The BOLD ID can be used to look up the specimen on the Bold Systems Database

 

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