On springtails (Hexapoda: Collembola): phylogenetic history and morphofunctional study of the jumping apparatus

• Applicant: Dr. Fábio Oliveira, Ph.D.
• Subject Area: Systematics and Morphology (Zoology)
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 442589507

Springtails (Hexapoda: Collembola) are tiny organisms mostly inhabiting hidden places (such as deeper soil layers or litter residue), thus relatively little is known about their morphology and biology. Despite the general lack of knowledge about these animals, they are everywhere, displaying a multitude of patterns of body morphology. They are notorious organisms, mainly because the presence of a catapult-shaped structure that allows them to jump and escape from predators. This highly specialized jumping apparatus consists of a movable structure (furcula) that fits into a hook (retinaculum), when in repose, located on the ventral side of abdomen. The act of jumping happens via the propulsion provided by the furcula acting towards the posterior region of the body, as a result of a mechanical process involving the flexion and extension of a strong segmental musculature (ventral, dorsal, dorsoventral and transverse bundles). Among springtails, the morphology of the jumping apparatus is quite diverse, but convergence may occur as a result of selective pressures related to the different microhabitats occupied by these animals, such as soil layer, shrubs or even the surface of the water. The structural variability of the jumping apparatus including its musculature will be studied in the large groups of Collembola: Symphypleona, Neelipleona, Poduromorpha and Entomobryomorpha. The jumping apparatus and morphofunctional mechanisms will be studied (furcula and retinaculum, including musculature), and also its variations through the lineages of Collembola. The taxon sampling will be strategically chosen allowing a morphological and molecular comparative study allowing investigation of phylogenetic relationships within Collembola. Such morphological studies will be developed using new structural research techniques μCT, cLSM and digital 3D-reconstruction. The first morphological matrix using internal morphological characters of furcula and retinaculum will be generated. Hypotheses will be provided about the phylogenetic history of Collembola, as well as on the origin and diversification of the jumping apparatus. Such interpretations will be based on the results of phylogenetic analyzes using morphological and molecular data. We will study taxa representing the morphological diversity of the jumping apparatus in Collembola, capturing these traits in species that inhabit different forest habitats: deep and upper layers of soil, litter, shrubs and canopy.

• DFG Programme: Research Grants