Biology subjects

Adriaens, D.

Publications and source records attributed to Adriaens, D..

4 recordsLinked to original sources

bioRxiv2026

A Novel Computational Framework to Investigate the Biomechanics of Burrowing

Head-first burrowing likely imposes strong mechanical demands on the skull of fossorial vertebrates, but how cranial tissues respond to these loads remains obscure. Here, we developed a computational framework integrating the discrete element method (DEM) with finite element analysis (FEA) to investigate cranial biomechanics during burrowing. We used Blanus cinereus, a round-headed amphisbaenian, as a model to establish DEM predictions that were validated and calibrated against in vitro experiments across three substrates and compared with in vivo push forces. DEM-calibrated particle contact forces were then transferred to an anatomically detailed finite element model to quantify cranial loading. The analyses suggested that soft tissues accommodated substantial deformation, while the skull transmitted burrowing loads from the premaxilla towards the occipital region. Cranial sutures further redistributed stresses and strains within the skull. This validated DEM-FEA framework links particle-scale substrate interactions with internal cranial biomechanics and provides a quantitative approach for investigating the mechanics of head-first burrowing across fossorial vertebrates.

bioengineering↗

bioRxiv2022

A comparative analysis of the ontogeny of syngnathids (pipefishes & seahorses) reveals how heterochrony contributed to their diversification

BackgroundSyngnathids are a highly derived and diverse fish clade comprising the pipefishes, pipe-horses and seahorses. They are characterized by a plethora of iconic traits that increasingly capture the attention of biologists, including geneticists, ecologists and developmental biologists. The current understanding of the origins of their derived body plan is, however, hampered by incomplete and limited descriptions of the early syngnathid ontogeny. ResultsWe provide a comprehensive description of the development of Nerophis ophidion, Syngnathus typhle, Hippocampus erectus from early cleavage stages to release from the male brooding organ and beyond, including juvenile development. We comparatively describe skeletogenesis with a particular focus on dermal bony plates, the snout-like jaw morphology, and appendages. ConclusionsThis most comprehensive and detailed account of syngnathid development to date suggests that convergent phenotypes (e.g. reduction and loss of the caudal fins), likely arose by distinct ontogenetic means in pipefish and seahorses. Comparison of the ontogenetic trajectories of S. typhle and H. erectus provides indications that characteristic features of the seahorse body plan result from developmental truncation. Altogether this work provides a valuable resource and framework for future research to understand the evolution of the outlandish syngnathid morphology from a developmental perspective. Bullet pointsO_LISyngnathids (pipefish, pipe-horses and seahorses) are a highly derived and diverse fish taxon and many of their most iconic traits - and these traits variation across species - develop during their early ontogeny. C_LIO_LIThis study provides a detailed description and staging table of the entire pre-release development (and beyond) of three distinct syngnathids (two phylogenetically distinct pipefishes and a seahorse) with a focus on the skeletal elements forming the cranium, axial skeleton, appendages and the plate armor. C_LIO_LIThe data provided in this study suggests that developmental heterochrony, i.e. alterations in the rate and timing of developmental processes between lineages, might be a central evolutionary process shaping the morphological diversity found in syngnathids today. C_LI

developmental biology↗

bioRxiv2020

Do substrate type and gap distance impact gap-bridging strategies in arboreal chameleons?

Chameleons are well-equipped for an arboreal lifestyle, having zygodactylous hands and feet as well as a fully prehensile tail. However, to what degree tail use is preferred over autopod prehension has been largely neglected. Using an indoor experimental set-up, where chameleons had to cross gaps of varying distances, we tested the effect of substrate diameter and roughness on tail use in Chamaeleo calyptratus. Our results show that when crossing greater distances, C. calyptratus is more likely to use its tail for additional stability. The animals were able to cross greater distances (up to 1 75 times the shoulder-hip length) on perches with a rougher surface. We saw that depending on the distance of the gap, chameleons would change how they use their prehensile tails when crossing. With shorter gaps the tails either do not touch, or only touch the perch without coiling around it. With larger distances the tails are fully coiled around the perch, and with the largest distances additionally they reposition the hind legs, shifting them towards the end of the perch. Males were able to cross relatively greater distances than females, likely due to their larger size and strength.

animal behavior and cognition↗

bioRxiv2018

Social organization and biting performance in Fukomys mole-rats (Bathyergidae, Rodentia)

A caste system, based on work activity and reproduction, has been proposed in the two African mole-rat species which are generally considered eusocial, Heterocephalus glaber and Fukomys damarensis. Social behaviour in other Fukomys species is key to understanding evolution of sociality within bathyergids, which display a social continuum among species from solitary to eusocial. Furthermore, insight in the social structure of colonies may be instrumental in understanding the observed, extensive intraspecific morphological variation and ultimately help species delimitation. For the first, time social organisation was studied in a colony of wild-caught Fukomys micklemi (Sekute cytotype) from Zambia. Data were collected on work behaviour and analysed against morphological variables and biting performance. Although there was considerable variation in the amount of work performed by each individual, clearly distinguishable castes were not found. Castes might represent an artificial subdivision, which does not necessarily reflect the dynamic changes within a colony. Variation in work may be the result of an ongoing process of continuous change, whereby a colony undergoes a certain evolution that is reflected in developmental patterns of individuals. Ecological factors will undoubtedly play an important role in colony evolution. Consequently, predictions made according to the Aridity Food Distribution Hypothesis should be tested, taking into account the possibility of a dynamic model as described here. The relation between biting performance and behavioural traits was investigated for the first time. Whereas differences in biting performance were strongly correlated with morphological parameters, relation between work and biting performance remains unclear.

evolutionary biology↗