The adaptive significance of chromatophores in the Arctic under-ice amphipod Apherusa glacialis

Abstract

Solar radiation is a crucial factor governing biological processes in polar habitats. Containing harmful ultraviolet radiation (UVR), it can pose a threat for organisms inhabiting surface waters of polar oceans. The present study investigated the physiological color change in the obligate sympagic amphipod Apherusa glacialis mediated by red-brown chromatophores, which cover the body and internal organs of the species. Short-term experimental exposure to photosynthetic active radiation (PAR) led to pigment dispersal in the chromatophores, resulting in darkening of the animal. Irradiation in the PAR range (400-700 nm) was identified as the main trigger with high light intensities evoking marked responses within 15 min. After exposure to high PAR, darkness led to a slow aggregation of pigments in the cell center after 24 h. Experiments revealed no statistically significant change in coloration of the animal when exposed to different background colors nor UV radiation. Our results point to a doseand time-dependent photoprotective role of chromatophores in the amphipod, presuming a shielding effect from harmful radiation in a dispersed state. The reversible nature of the physiological color change enables the species to adapt dynamically to prevailing light conditions and thereby minimize the cost of increased conspicuousness toward visually hunting predators.

Background matching in the brown shrimp Crangon crangon: adaptive camouflage and behavioural-plasticity

“…Among crustaceans, some species are transparent 1 and thus almost invisible, others allow the growth of epiphytes on their carapace 2 or match their colour with the background, to conceal themselves 3 – 6 . Indeed, the ability to rapidly change colour is a common strategy employed by many animals to tune and adjust their camouflage abilities to heterogeneous environments 7 – 11 , as well as to communicate with conspecifics, thermoregulate and gather protection from ultraviolet (UV) light 7 , 12 , 13 . Colour adaptations represent a complex and multifaceted topic which connects environmental factors, animal behaviour, visual perception and cell physiology 11 , 14 .…”

Possible Involvement of Cone Opsins in Distinct Photoresponses of Intrinsically Photosensitive Dermal Chromatophores in Tilapia Oreochromis niloticus

“…Changing the body color pattern is a strategy frequently used by lower vertebrates and invertebrates, allowing them to respond to biotic and abiotic stimuli. These color-changing mechanisms greatly impact physiological and behavioural aspects of animals, including UV protection [1], [2], thermoregulation [3], [4], concealed communication [5], [6], camouflage [7], [8], mate choice [9], [10], aggressive signaling [11], [12], and social status display [13], [14]. Chromatophores, dermal specialized pigment cells, are thought to be the primary agents that shape body patterns in many animals.…”

Efecto de diferentes intensidades de luz sobre la expresion de cromatoforos, crecimiento y supervivencia en juveniles de Macrobrachium tenellum

“…Factores como la temperatura, ac- tividad diurna, intensidad de luz recibida y color de fondo tienen como respuestas la dispersión de la pigmentación de los cromatóforos en el tegumento, para que los organismos se adapten a las condiciones impuestas por el entorno, ya que funcionan como un mecanismo de protección ante condiciones no óptimas de luz, oscureciendo el cuerpo para prevenir posibles daños a órganos internos (Fuhrmann et al, 2011). Los resultados de este estudio concuerdan con lo mencionado por estos autores, con la respuesta adaptativa adecuada al aumento de la intensidad de luz.…”