Sharks
This reading profile brings together 7 source-linked articles that reference sharks.
Explore Fauna’s source-checked field guides and research articles covering sharks, or search the species catalog below for individual species profiles.Source-linked reading
- Field guideHow sharks sense electric fieldsSharks sample tiny voltage differences through the ampullae of Lorenzini. Arrays of surface pores connect to sensory chambers, letting the nervous system compare signals across space and distinguish external fields from some self-generated activity.
- Field guideHow animals detect magnetic fieldsExperiments support sensitivity to field direction, inclination, or intensity in multiple taxa; radical-pair chemistry, magnetic particles, and electromagnetic induction are leading mechanism classes, not one confirmed universal sensor.
- Field guideThe IUCN Red List: categories explainedThe IUCN Red List is the global standard for extinction risk. It sorts each assessed species into one of nine categories — every one a dated, evidence-based verdict in a stated geographic scope.
- Field guideConvergent evolution explainedCacti and some euphorbias independently evolved succulent, spiny forms in dry habitats; wings, streamlined bodies, and camera-like eyes offer other examples at different scales. Establishing convergence requires a phylogeny and evidence that similarity arose separately rather than being inherited unchanged from a common ancestor.
- Field guideHow animals see in low lightScarce photons are the central problem: anatomy can admit more light, rods and photopigments capture it, reflective layers offer a second pass, and neural circuits combine signals across space or time while accepting blur and noise.
- Field guideHow bioluminescence worksDifferent lineages make, obtain, or host different light-producing chemistries, package them in cells or photophores, and control flashes or glows for camouflage, prey capture, defense, communication, or mating.
- Field guideHow dolphins sleep with half their brainDuring unihemispheric sleep, strong slow waves occupy one cerebral hemisphere while the other remains in a more wake-like state. The sides alternate over time; this is neither total wakefulness nor a neat division in which exactly half of every brain system switches off.