#collophore

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Hexapoda part 2: Springtails!

First part here!

Springtails, or Collembola, are a much larger group than the two orders previously discussed, and they are absolutely everywhere. With over 100 thousand individuals per square meter, you can easily find some in the soil nearby, or even in flowerpots.

They get their name from their tail-like appendage, the furcula, usually folded under their abdomen. When released, it allows them to jump far away (a few centimeters) to escape predators.

Their second characteristic organ is the collophore, a kind of glue tube in front of the furcula. Believed to stabilize the springtail when landing a jump, it turned out to mostly help maintaining water balance, with springtail balance only being an afterthought.

Springtails were once split into the elongated springtails, or Arthropleona, and the globular springtails, or Symphypleona. Neither is likely monophyletic, and they have been split into two orders each.

Entomobryomorpha, the slender springtails

Pogonognathellus longicornis, AJC1, CC BY-SA 2.0

Entomobrya lanuginosa, Andy Murray, CC BY-SA 2.0

The default settings of the springtail world, these girls are the least specialized of our four orders. They are relatively insect-like in appearance, with a clear break between the thorax and abdomen, short hair across the body, and very long antennas.

They include some of the most adaptable and widespread species, being found from forest canopies all the way to Antarctica. Also the snow flea, whose anti-freeze proteins allow to survive sub-zero temperatures as very conspicuous black spots on the white snowscape.

Poduromorpha, the chubby springtails

Monobella grassei, Gilles San Martin, CC BY-SA 2.0

Holacanthella spinosa, Andy Murray, CC BY-SA 2.0

The perfect creatures. Plump, colorful, chubby springtails are the closest we've come to a living gummy bear (sorry, tardigrades!). They are characterized by short stubby legs and visible segmentation throughout their body. Their furcula is short and flat, or sometimes completely absent, which some species make up for with chemical defenses or even anal spikes!

Their water-repelling cuticles takes on a variety of unique shapes, and allows Podura aquatica to live its whole life on the surface of the water. Like other chubby springtails, it can be found in massive congregations of like-minded individuals. (see below)

We'll go over the globular springtails in the next post!

Anurida maritima, Wes Gapp, CC BY 4.0

[entomoblog]

Pourquoi les collemboles retombent (presque) toujours sur leurs pattes | Pour la Science

See on Scoop.it - EntomoNews

Contrairement à ce que l’on pensait, ces minuscules arthropodes contrôlent minutieusement leurs sauts.

  Pierre Giraudeau

01 février 2023

  "Souvent confondus avec leurs cousins les insectes, les collemboles forment un ordre d’arthropodes à six pattes mesurant quelques millimètres et dépourvus d’ailes, qu’on aperçoit parfois dans les jardins ou en bord de rivière. En cas de danger, plutôt que de s’envoler pour déguerpir, ils sautent, ou plutôt se catapultent grâce à un appendice en forme de fourche, la furca. Rabattu au repos sur la face ventrale du collembole, cet organe est capable de se déployer rapidement et de projeter son propriétaire à quelques centimètres, comme le ferait un ressort. On pensait jusqu’ici que ces sauts étaient incontrôlés et que les collemboles se projetaient au hasard – en tournoyant jusqu’à cinq cents tours par seconde ! –, pourvu que le danger s’éloigne. Mais en filmant au ralenti les sauts de collemboles de l’espèce Isotomurus retardatus, l’équipe de Victor Ortega-Jiménez, de l’université du Maine, aux États-Unis, a montré que ces animaux font preuve d’une remarquable agilité et contrôlent minutieusement leurs sauts."

(...)

  [Image] Sur cette photo d’un collembole Isotomurus retardatus, on aperçoit la furca, rabattue sous l’abdomen à son extrémité, et le collophore, plus près de la tête, à la base des pattes.

Crédit : Victor Ortega-Jiménez

  Directional takeoff, aerial righting, and adhesion landing of semiaquatic springtails | PNAS, 07.11.2022 https://www.pnas.org/doi/10.1073/pnas.2211283119

Bernadette Cassel's insight:

  Sur le même sujet

  Les collemboles ont la taille d'une tête d'épingle, mais ils peuvent contrôler leurs sauts comme des acrobates chevronnés - De www.nytimes.com - 8 novembre 2022, 19:09

[is-the-bug-video-cute]

do you know anything about globular springtails? i found them by chance looking through a photographers portfolio and im obsessed with them but theres like no information about them online

I sure do know some things about globular springtails! 

Springtails, or collembola, for the uninitiated, are non-insect hexapods, living mainly in soil and on/near the surface of still water. They’re very small, and very abundant, with some figures estimating that there are over 100,000 springtails for every square meter of soil on Earth. 

They're divided into three major orders, shown respectively in the image below: the Entomobryomorpha (slender springtails), the Poduromorpha (plump springtails), and the Symphypleona (globular springtails). 

Globular springtails get their name from their delightfully globular shape, having fused abdominal segments and a very round, near-spherical body. Like their fellow collembola, they are voracious omnivores, working to break down scraps of fungi, bark, and other decaying organic detritus into soil in whatever damp crevices they can find -- though globular springtails tend to prefer a higher humidity still, second only to some wholly aquatic species in Poduromorpha. 

All collembola, as their name suggests, have a collophore: an tube-like organ on their underside that helps them to regulate moisture and steady themselves on uneven surfaces. Unique to the globular springtails, however, is the presence of two long, eversible “tubes” that allow them to groom themselves, and coat their bodies in a waterproofing fluid so as to float more easily on the surface of puddles and ponds. This can be seen in great clarity in this excerpt from a BBC documentary. 

One of the most common genera of globular springtails, Sminthurides, contains a particularly interesting (and adorable) species: Sminthurides aquaticus (seen above). They live on or near the surface of water, and are notable for their wonderful courtship dance, in which the larger female will lift a smaller male by his antennae, and will spin him around. This can continue for some time and they are even capable of jumping while doing this dance. It’s one of my favorite tidbits of information about springtail behavior, and really shows how varied their behavior and lives can be. 

(all images sourced from and copyright Andy Murray)

Additionally, if you ever want to find more information abut springtails, I highly recommend the website of the world’s foremost collembola expert, Frans Janssens: collembola.org