oceany: Squid

Evidence: 100 • authority: 72

A squid (pl. squid) is a mollusc with an elongated soft body, large eyes, eight arms, and two tentacles in the orders Myopsida, Oegopsida, and Bathyteuthida (though many other molluscs within the broader Neocoleoidea are also called squid despite not strictly fitting these criteria). Like all other cephalopods, squid have a distinct head, bilateral symmetry, and a mantle. They are mainly soft-bodied, like octopuses, but have a small internal skeleton in the form of a rod-like gladius or pen, made of chitin. Squid diverged from other cephalopods during the Jurassic and radiated at the beginning of the Late Cretaceous, and occupy a similar role to teleost fish as open-water predators of simil…

Evidence: 67 • authority: 92

Reflectin Proteins Form Net Charge Density-Tuned Multiphase Condensates That May Facilitate Spatial Organization in Squid Skin Bragg Lamellae.. The reflectins are cationic proteins that transduce neuronal signals tuning skin color for dynamic camouflage and communication in Loliginid squid. Neuronally released acetylcholine (ACh) activates phosphorylation of the reflectins, triggering their condensation, folding and hierarchical assembly. These changes drive proportional osmotic and Gibbs-Donnan dehydration of membrane-enclosed Bragg lamellae containing these proteins in skin cells called iridocytes, resulting in the calibrated, progressive change their refractive index and spacing to finel…

Evidence: 67 • authority: 92

Evidence: 67 • authority: 72

Camouflage is the use of any combination of materials, coloration, or illumination for concealment, either by making animals or objects hard to see, or by disguising them as something else. Examples include the leopard's spotted coat, the battledress of a modern soldier, and the leaf-mimic katydid's wings. A third approach, motion dazzle, confuses the observer with a conspicuous pattern, making the object visible but momentarily harder to locate. The majority of camouflage methods aim for crypsis, often through a general resemblance to the background, high contrast disruptive coloration, eliminating shadow, and countershading. In the open ocean, where there is no background, the principal m…

Evidence: 67 • authority: 72

Active camouflage, adaptive camouflage, or chameleonizing is camouflage that adapts, often rapidly, to the surroundings of an object such as an animal or military vehicle. In theory, active camouflage could provide perfect concealment from visual detection. Active camouflage occurs in several groups of animals, including reptiles on land, and cephalopod molluscs and flatfish in the sea. Animals achieve active camouflage both by color change and (among marine animals such as squid) by counter-illumination, with the use of bioluminescence. Military counter-illumination camouflage was first investigated during World War II for marine use. More recent research has aimed to achieve crypsis by us…

Evidence: 51 • authority: 80

Evidence: 51 • authority: 80

Evidence: 51 • authority: 80

Evidence: 51 • authority: 80

Evidence: 51 • authority: 80

Evidence: 51 • authority: 92

Situational motionless camouflage of a loliginid squid.. Coleoid cephalopods have the most elaborate camouflage system in the animal kingdom. This enables them to hide from or deceive both predators and prey. Most studies have focused on benthic species of octopus and cuttlefish, while studies on squid focused mainly on the chromatophore system for communication. Camouflage adaptations to the substrate while moving has been recently described in the semi-pelagic oval squid (Sepioteuthis lessoniana). Our current study focuses on the same squid's complex camouflage to substrate in a stationary, motionless position. We observed disruptive, uniform, and mottled chromatic body patterns, and we i…

Evidence: 51 • authority: 92

Metabolomic Profiling of Squid Chromatophores Reveals Differential Biochemical Fingerprints across Red, Yellow, and Brown Colors.. Cephalopods possess the ability to camouflage using specialized dermal organs, including chromatophores that modulate pigment-based color, iridophores that produce structural iridescence, and leucophores that scatter light to create diffuse white. Among these organs, chromatophores─present as yellow, red, and brown variants─contribute to rapid color changes during camouflage, as their multicellular architecture expands under neuromuscular control. While the general structure and function of chromatophores have been characterized, the specific biochemical feature…