Isopoda: locomotion and aggregation behavior
Isopods represent Arthropoda. But they are no insects, no arachnids and no myriapods, although the glomerids or pill-millipedes can have a similar shape. Isopods are indeed crustaceans. And the shape of pill-millipedes is a result of independent evolution (convergent evolution).
Isopoda represent a clade of the Malacostraca, whose members are originally native to aquatic habitats. Also isopods from the phylogenetic point of view represent aquatic/ marine organisms. But one clade, the Oniscidea, also named terrestrial isopods, evolved mechanisms to survive ashore.
The footage shows a species of Oniscidea of genus Porcellio from mediterranean habitats in Croatia. Land isopods retained their gills and thus usually prefer moist habitats. My model-isopods are reared in a terrarium, were they use to aggregate under moist pieces of bark.
As most terrestrial isopods, they are destruents and feed on decaying organic material. I add regularly pieces of fruits or vegetables and thus create conditions comparable with compost. Most of my footage is presented in slow motion.
I thank Jana Bedek, Croatian Biospeleological Society, for her determination of the isopods on a genus level.
Copyrights: Stefan F. Wirth, Berlin May 2017/ November 2018