Collective movement of schooling fish reduces the costs of locomotion in turbulent conditions.

The ecological and evolutionary benefits of energy-saving in collective behaviors are rooted in the physical principles and physiological mechanisms underpinning animal locomotion. We propose a turbulence sheltering hypothesis that collective movements of fish schools in turbulent flow can reduce the total energetic cost of locomotion by shielding individuals from the perturbation of chaotic turbulent eddies. We test this hypothesis by quantifying energetics and kinematics in schools of giant danio (Devario aequipinnatus) and compared that to solitary individuals swimming under laminar and turbulent conditions over a wide speed range.

The role of hydrodynamics in collective motions of fish schools and bioinspired underwater robots.

Collective behaviour defines the lives of many animal species on the Earth. Underwater swarms span several orders of magnitude in size, from coral larvae and krill to tunas and dolphins. Agent-based algorithms have modelled collective movements of animal groups by use of , which approximate the behaviour of individual animals.

Directional takeoff, aerial righting, and adhesion landing of semiaquatic springtails.

Springtails (Collembola) have been traditionally portrayed as explosive jumpers with incipient directional takeoff and uncontrolled landing. However, for these collembolans that live near the water, such skills are crucial for evading a host of voracious aquatic and terrestrial predators. We discover that semiaquatic springtails, , can perform directional jumps, rapid aerial righting, and near-perfect landing on the water surface.

Fire ant rafts elongate under fluid flows.

Fire ants survive flash floods by linking their bodies together to build waterproof rafts. Most studies of fire ant rafts consider static water conditions, but here, we consider the influence of flow. In particular, when floating on shallow water, the raft can run aground on vegetation, generating stresses in the raft as the water continues to flow around it.

Metabolic scaling of fire ants (Solenopsis invicta) engaged in collective behaviors.

During flash floods, fire ants (Solenopsis invicta Buren) link their bodies together to build rafts to stay afloat, and towers to anchor onto floating vegetation. Can such challenging conditions facilitate synchronization and coordination, resulting in energy savings per capita? To understand how stress affects metabolic rate, we used constant-volume respirometry to measure the metabolism of fire ant workers. Group metabolic rates were measured in a series of conditions: at normal state, at three elevated temperatures, during rafting, and during tower-building.

Caenorhabditis elegans exhibits positive gravitaxis.

Background: Gravity plays an important role in most life forms on Earth. Yet, a complete molecular understanding of sensing and responding to gravity is lacking. While there are anatomical differences among animals, there is a remarkable conservation across phylogeny at the molecular level.

Terrain following and applications: Caenorhabditis elegans swims along the floor using a bump and undulate strategy.

Nematodes such as Caenorhabditis elegans are heavier than water. When submerged in water, they settle to the bottom surface. Observations reveal that the animals do not lie flat on the bottom surface, but remain substantially suspended above the surface through continuous collisions with the surface, while maintaining their swimming gaits.