COLLEMBOLA > PODUROMORPHA > HYPOGASTRUROIDEA > Hypogastruridae > Hypogastrurinae

The official 'Checklist of British and Irish Collembola' starts with the Hypogastruridae family, simply because the three PODUROMORPHA superfamilies are listed alphabetically as there's no specific taxonomic order at family level. I decided to move its position as I wanted the individual accounts to more or less follow the 'key' where Neanura muscorum and Monobella grassei are the first described species. The Ceratophysella genus doesn't appear for another fifty or so pages.

Although there are around a dozen Ceratophysella species listed, I believe that only five have actually been recorded in Britain and only three are normally considered. The most likely species is definitely Ceratophsella denticulata, but as positive identification can only be achieved by dorsal chaetotaxy (close examination of the length and position of body setae on abd4+5) it is common practice to leave unexamined individuals as either Ceratophysella sp. or as an unidentified specimen of the denticulata group - an assemblage of virtually identical species.

The individual featured below was found on the rim of our garden waste bin 'paddling' through a small pool of water before climbing up the lip so, although not a particularly attractive spot, it was a convenient location to try to get some photos. At a little under 2mm long these species are tiny and a real challenge to photograph, so in many ways it couldn't have been in a better place. It also gave me time to observe the way that it didn't try to shy away from the water; a benefit of a naturally water-repelling granular cuticle.

I don't profess to have any knowledge of these creatures other than what I've read and certainly wouldn't be able to identify some of the more obscure species without help, but I have learnt that within this particular family the two main genera Ceratophysella and Hypogastrura are distinguished by the size of the anal spines. Unfortunately, they're barely visible in these photos, but in Ceratophysella they're longer and more defined. I've also read that the primary underlying body colour, which is often described as greyish blue, is typically, apart from Hypogastrura purpurescens, more purplish than bluish in Ceratophysella than Hypogastrura. Neither of those facts though would have particularly helped me identifying this specimen, so once again I was grateful for the feedback I received from the FB 'UK Collembola' group.

For completeness, it's worth mentioning that whilst Ceratophysella denticulata is indeed the most likely candidate here, Ceratophysella gibbosa is another possibility as it's also a widespread species considered as moderately common in compost and rotting vegetation and, although my garden waste bin doesn't quite fit that description, it constitutes a similar 'habitat'.