Locomotion behavior of Schizomida (Arachnida)
They look without magnification more like very motile and fast running ants or very tiny grasshoppers than like arachnids. But they indeed represent relatives of the web spiders and scorpions: Schizomida, a clade of whip scorpions. They are the sister taxon of Thelyphonida, the rather well known „big whip scorpions“, which are often kept as pets in terraria around the world. Schizomida are only rarely filmed in a higher resolution quality, which is due to their small size and their almost invisibility due to their semi-transparent cuticle and their very fast way of walking or even jumping. They are additionally difficult to be filmed as they strictly avoid all lights and tend to dry out quickly, when they cannot hide themselves by time in a slightly moist substrate.
Closeups of behaviors of a Schizomid species from a greenhouse in Germany. Copyrights Stefan F. Wirth
Schizomida in Greenhouses
Schizomids represent mostly tropical or subtropical organisms. But some species are regularly dispersed into greenhouses around the world. The filmed species might be Stenochrus portoricensis, but was not systematically studied in detail so far. As all known species, which appear in greenhouses, also S. portoricensis reproduces (apart from their original habitats) parthenogenetically with females producing females without mating procedures (thelytoky). I never found males so far.
S. portoricensis: native to subtropical Zones
The specimens, which I kept since months in a small terrarium, were collected in autumn 2016 at the famous fun and wellness bath „Tropical Islands“ South of Berlin. There they are a natural part of the world’s biggest indoor rainforest. The species S. portoricensis is originally native to Florida, Mexico, Cuba, Nicaragua, Porto Rico and other localities in similar tropical zones. These microscopical tiny organisms are predators and do not harm human beings at all. According to the available organisms in a suitable size in my terrarium, they might feed on the numerous collembolans and/or mites. Especially mites of the Gamasina appear in greater numbers in my substrate, which represents the original substrate from the greenhouse. I enriched this substrate regularly by smaller pieces of fruits or vegetables to stimulate the growth of microorganisms. I keep them at room temperature (about 20°C) and with not too much moisture. I do not know, whether they reproduced within these months, but the specimens of my recent video footage represent all sub-adults.
Film set and topic locomotion
Focus of my film is to present the different ways of locomotion, cleaning behaviors and burrowing activities of these fascinating animals. During the filming procedure, I used two cold-light-lamps for a suitable illumination and an ILCE-6300 (internal 4K mode), connected to a stereomicroscope and a lightmicroscope (with uplight).
Berlin December 2019/ March 2017, Copyrights Stefan F. Wirth
Es ist schon faszinierend, was da alles so kreucht und fleucht. Ich habe vor kurzem irgendwo gelesen, daß nur etwa 20 bis 25% aller vermeintlichen Insektenarten bekannt sind. Ich weiß nicht, ob die Arachnida mit eingeschlossen waren, aber ich kann mir vorstellen, daß es bei ihnen ähnlich aussieht.
Very cool! How do they come to be in greenhouses – are they imported in the soil of plant pots?
Hey thanks for your comment. Yes there are a few species dispersed via tropical plants and appear worldwide in greenhouses