I spied-a spider: Microscope work isn’t as daunting as it appears!

Lorna Drake is a PhD student at Cardiff University studying the variation in the diet of British Otters.  She won a place on the "Tomorrow's Invertebrate Recorders" course - a week long residential programme for young people (aged 18-25) run by the FSC BioLinks project and A Focus On Nature providing an introduction to surveying invertebrates.  Here, she tells us about her introduction to spider identification on the course and how it's not as scary as it seems! Since the course Lorna has bought a USB microscope to continue improving her identification skills so she can record invertebrates in her area. 

 

I spied-a spider: Microscope work isn't as daunting as it appears!

 

There are around 650 species of spider in the UK alone. That’s a lot! Some spiders can be identified by eye, others require hand lenses and many even require microscopes to correctly identify them to species level. Most people find spiders creepy though, so never get close enough to identify them in the field, let alone choose to look at them down a microscope. Earlier this year, however, I attended the Tomorrow’s Invertebrate Recorders course run by the FSC Biolinks team during which I chose to spend a whole day learning microscopic identification of spiders. 

 

To help get us started, we were given specimens stored in ethanol that had already been identified by an expert. This allowed us to try identifying the spider ourselves and then we checked the cheat sheet later to see if we got it correct. Before we got started though, we had to set up our equipment; this involved focussing our microscopes, adjusting our light sources and filling a little dish with glass beads and ethanol. The glass beads were to help keep the spider in place whilst the ethanol stops the spider drying out and allows the specimen to be manipulated more easily. 

Microscope set-up ready to start identifying some spiders!

 

Once everything was set up, we were ready to start identifying. I used a combination of two keys; the AIDGAP guide to British spiders and the Collin’s spider ID guide. The AIDGAP guide only achieves family level identification but was written with beginners in mind, I therefore found it easier to follow and used this to get my specimen to family level before switching to the Collin’s guide to get to species level. The guides describe morphological features that distinguish one species from another. For example, in the AIDGAP guide, question eight is about spider eyes where it says if your spider has six eyes proceed to question nine, but if it has eight eyes go to question 12. You follow the path until you reach a dead end, denoting what your specimen is. It’s kind of like those personality quizzes in comics you read as a teenager.

 

The candy-striped spider (Enoplognatha ovata) photographed down the microscope.

The candy-striped spider (Enoplognatha ovata) photographed down the microscope.

 

 

We were recommended to keep track of which options we picked (e.g. 1a, 2b, 3b, etc) and circle options where we weren’t sure whether we were correct or not, that way if when we got to the end we were wrong we could back track a couple of steps and correct our identification. The first few steps were quite simple as the features were very specific and easy to spot. This meant that after a few attempts you became very quick at getting through the first few features. After this you had to start manipulating the spider with tweezers a lot more; flipping it over to look at the underneath, then back over to look at the top of the abdomen and then trying to position it looking into the microscope so you could see its eye arrangement and if the eyes were solid black or glassy. I quickly found out how important delicate hand work is for microscopic spider identification.

 

Once I had got a specimen to family level, I moved onto the Collins guide and attempted to identify the particular species. Getting to species level with spiders often focuses on the genitalia. In females this is known as the epigyne, a fold in the exoskeleton on the underneath of the abdomen (a friend told me to look at this on Amaurobius similis as it looks like the pringles man’s moustache). In males the genitalia are at the end of the palps, which often look like little boxing gloves. 

These features are very distinctive between each species but they are also very small, so it can be difficult to spot the specific differences. I found this much more difficult than family identification and I’ll need a lot more practice before I can be confident getting spiders down to species. 

 

Spider genitalia circled in blue: on the left is the epigyne of a female garden spider (Araneus diadematus) and on the right are the palps of the missing sector orb weaver (Zygiella x-notata).

 

 

Spider genitalia circled in blue: on the left is the epigyne of a female garden spider (Araneus diadematus) and on the right are the palps of the missing sector orb weaver (Zygiella x-notata)

 

 

Spider identification isn't as hard as it seems

Looking down a microscope all day at the slightest of features was very tiring on my eyes and could take a long time; however, I felt a real sense of achievement when I successfully identified it and soon started getting quicker at the process. Whilst going out into the field and looking for spiders is fun, I personally prefer microscopic identification because you can take your time with the identification. I learnt that spider identification isn’t as hard as it seems - getting to family level is especially accessible for a beginner! I really enjoyed spending time identifying the spiders and definitely plan on keeping it up (I’ve even bought myself a USB microscope), so a massive thank you to the tutors at the Tomorrow’s Invertebrate Recorders course for showing me that invertebrate identification isn’t as daunting as it seems. 

 

Some of the spiders I have found since the Tomorrow’s Invertebrate Recorders course. From left to right starting with the top row: Nursery web spider (Pisaura mirabilis), cave spider (Meta menardi), common zebra jumping spider (Salticus scenicus), lace-weaver spider (Amaurobius similis), garden spider (Araneus diadematus), sheet web spider (Linyphia triangularis), daddy long legs spider (Pholcus phalangioides), Lobed Argiope (Argiope lobata) in Portugal and a jumping spider (family: Salticidae) in portugal with the most incredible palps!

 

Some of the spiders I have found since the Tomorrow’s Invertebrate Recorders course. From left to right starting with the top row: Nursery web spider (Pisaura mirabilis), cave spider (Meta menardi), common zebra jumping spider (Salticus scenicus), lace-weaver spider (Amaurobius similis), garden spider (Araneus diadematus), sheet web spider (Linyphia triangularis), daddy long legs spider (Pholcus phalangioides), Lobed Argiope (Argiope lobata) in Portugal and a jumping spider (family: Salticidae) in portugal with the most incredible palps!

 

Lorna Drake
Tomorrow's Invertebrate Recorder 2019

To find out about more opportunties for young people with the FSC check out our Young People webpage.

 

 

Comments

Wow Lorna, what a great blog! Thanks for sharing your experiences.