James McCulloch

Isotomurus only has the macrosetae on the last 3 abdominal segments.

In terms of species, I’d guess that this is Isotoma anglicana given the colour, but I’d need a microscope to be totally sure!

It looks close to Vertagopus, but a subtle detail is that Vertagopus only has a coat of quite short hairs (although it’s a dense coat). Here there are some much longer hairs (macrosetae), and it looks like they’re on all abdominal segments, indicating Isotoma.

It was such a privilege to work with @juliet-turner.bsky.social on this project while I was a research assistant in the West group @biology.ox.ac.uk. It's wonderful to see our paper in its final form! 🐜

Thank you to @nmaybury4.bsky.social for support during the sampling and for accurately translating the original Latin description, and to @jstgerlach.bsky.social for permission to study @peterhousecam.bsky.social's springtail fauna!

Finding a colony of Hypogastrura springtails on this wall in Peterhouse, Cambridge started me on a trail through old papers, concluding that there may be another - morphologically distinguishable! - species in Britain.

The story is in the latest issue of BJENH:

www.researchgate.net/publication/...

I do think you are right with Proisotoma minuta!

Sorry for the delayed response! The mucro does look sufficiently narrow (and the anal spines sufficiently small) for me to be happy for this to be Hypogastrura manubrialis!

Congratulations! 🥳

A photo from the side would help if possible!

Regarding the mouthparts, my technique is usually to clear the specimen using NaOH or KOH, and then squash under a coverslip. Usually then, if the specimen is cleared well enough, you can see the mouthparts through the head without any fiddly work!

You're certainly right that this is in the Hypogastrura/Ceratophysella group! With small anal spines it'll be Hypogastrura, but I'm not 100% confident that the shape of the mucro is definitely manubrialis - it can be hard to judge depending on angle, but in photo 4 it looks a little broader

366 days ago I started my PhD at the @sangerinstitute.bsky.social. No better time to publish my profile on the Sanger website ⬇️

www.sanger.ac.uk/person/mccul...

I tend to have my taxonomic hat on when posting here, but there is a bigger picture!

(S. trinotatus has these setae, while bimaculatus does not)

Finding hyper-specific details like this to back up an identification never fails to make me smile!

YouTube video by Dominik Grimm Weiße Wasserkugelspringer (Sminthurides aquaticus) beim Paarungsritual 💕

I will finish by sharing this beautiful and romantic video of Sminthurides courtship. One of my favourite things!

www.youtube.com/watch?v=p7IV...

🧵7/7

Finally, this is the tiny Sminthurides bifidus. These are synanthropic aquatic springtails found on the edge of glasshouse water features and fish tanks. The dorsal black marking is quite variable.

The males are smaller and have antennal clasping organs to grasp the females in courtship! 🧵6/7

This is Seira domestica, a slender springtail almost never found outdoors (in the UK, at least). Lepidocyrtus have similar iridescent scales but have 2 teeth on the mucro (furca apex), not 1.

When assembled, this will be the first reference-quality genome from the subfamily Seirinae! 🧵5/7

This is Sminthurinus igniceps, a relative but less distinctive. It can be told from dark S. aureus by having a head paler than the body, and from S. domesticus by having mostly orangey antennae.

This species is also synanthropic, but seemingly moving out more into the wider countryside. 🧵4/7

Despite its spots which seem to glow among the woodchips, S. bimaculatus is very similar to S. trinotatus. You need to look for a pair of hairs called subapical ventral setae on the dens, part of the springing organ (furca) that gives springtails their name. This arrow shows where they'd be! 🧵3/7

This beautiful species, Sminthurinus bimaculatus, has been the British springtail I've most wanted to see. As with the other 3 spp., it's primarily synanthropic, meaning it's associated with human habitats like this flowerpot. 🧵2/7

Sminthurinus bimaculatus.

Sminthurinus igniceps.

Seira domestica.

Sminthurides bifidus.

I've reached 100 British springtail species! This was helped by a recent glasshouse sampling trip, where I added these 4 species.

3 are now in the pipeline to have reference-quality genomes sequenced for the first time, by the @sangerinstitute.bsky.social. More info in the thread below! 🧵1/7

A slightly outdated group photo of the obacuromics group, at the tree of life programme, Wellcome Sanger Institute - so you know spot us at ESEB

We are excited to attending #ESB2025 find …
@arf-mln.bsky.social to chat about beetle genomics
@jamesimcc.bsky.social about sedges or springtails evolution
Sam Ebdon about distr. of dominance
Myself about diptera comparative genomics

And all of us to chat about any whacky reproduction #obscuromics

Yes, sorry for the delay!

Falling through the Cracks: iNaturalist Invertebrate Records in the UK Joss Carr discusses his MSc Research Project investigating the data quality of UK invertebrate records on iNaturalist.

I'm doing an online talk on 16/09 about my MSc thesis, which was all about iNaturalist data for invertebrates in the UK, and the alarmingly high proportion of it which 'falls through the cracks' due to data quality concerns. Please join if interested!

Link: www.eventbrite.co.uk/e/falling-th...

While the data are thin for signata and flavosignata, it’s the case that minuta, saundersi & ornata can be found under the same log. Despite apparent morphological identicalness, there could be other reasons they don’t outcompete each other, e.g. physiological/metabolic adaptations to different food

That's exciting! I'm on the look out for springtail samples from across the world for a future project - I'll direct message you!

Now that we have a name for this springtail, it is much easier for us to monitor its spread, analyse its interaction with the ecosystem, identify its origins, and study its populations & evolution through the lens of genomics.

Read the full description here: soil-organisms.org/index.php/SO...

A huge thank you to @persmiseth.bsky.social for showing me a population of these springtails when I was visiting Edinburgh earlier this year; some of them then became the type specimens. Also, Alex McDermott-Roberts and @jaiiiiiii1.bsky.social for providing specimens/photos from elsewhere.

A composite of illustrations of different body parts. Elements A and B show the dorsal and ventral pattern respectively; to the right of the dorsal pattern illustration is the chaetotaxy formula for the relevant body segments. Each of the five most taxonomically useful segments in terms of their chaetotaxy - the head, the 2nd thoracic segment, and the 2nd, 3rd, and 4th abdominal segments - has between 2 and 5 somewhat arbitrarily-chosen "compartments" with the formula detailing the number of macrosetae (the thickest type of "hair") in each compartment. Element C shows the configuration of a small part of the manubrium - the basal part of the furca (springing organ). This is a combination of pseudopores (two in this case - the open circles) surrounded by a number of setae (four here). Element D shows the shape of the "apical bulb" at the very tip of the fourth antennal segment. E. petri has a bilobate apical bulb. Element E shows the foot and the dentation of the claw - one of the ways in which E. petri differs from true E. imitabilis beyond colour pattern. Finally, element F shows the apex of the dens and the mucro (the other two parts of the furca other than the manubrium). The mucro of E. petri has two teeth and a basal spine which reaches the tip of the basal tooth.

This rather complicated looking figure provides the chaetotaxy (arrangement of setae (hairs)) for the taxonomically important body segments. These are the head, 2nd and 3rd thoracic segments, and 2nd, 3rd, and 4th abdominal segments (in order from A-F). The diagram of the head also includes the relative size and position of each ocellus which makes up the eye. The dotted boxes delimit the "compartments" of each segment, which is how you get the standard chaetotaxy formula as given in the other figure. This chaetotaxy scheme was first introduced by Jordana in his 2012 volume of the Synopses on Palaearctic Collembola, which covers the subfamily Capbryinae and tribe Entomobryini of the family Entomobryidae. The chaetotaxy of any of the members of these groups should, in theory, be able to be represented using this scheme.

While it appears similar to true E. imitabilis, described from a single Chinese specimen, the pattern of E. petri is unique. The chaetotaxy - the arrangement of hairs (setae) on different parts of the body - is also unique.

Click the Alt text on these images for explanations of what they depict!

Formerly known as Entomobrya nr imitabilis, this morphospecies was first spotted in 2015. Since then it has appeared across the whole length of the British Isles - the type specimens were found on an Edinburgh gravestone. Where it has come from and how it has spread so quickly is a mystery...

I'm so excited to share that this springtail, one that seems to have rapidly appeared in graveyards and gardens across the UK, now has a proper name: Entomobrya petri!

I hope this will be the first of many new species descriptions, allowing us to track our rapidly changing springtail fauna. 🧵⬇️