Factors affecting colour change in ‘white’ western rock lobsters, Panulirus cygnus

Co-solvent Selection for Supercritical Fluid Extraction of Astaxanthin and Other Carotenoids from Penaeus monodon Waste

“…The amount of esterified astaxanthin was determined by the background color of the shrimp during the time of harvesting and the changed chemical form that affected the pigment s location in the chromophores 40 . In addition, the physiological and morphological color changes in crustaceans were related to the rapid and slow transformations resulting from the hormonal and environmental factors 41,42 . Astaxanthin is mainly found as carotenoproteins in the exoskeleton.…”

Control of shell colour changes in the lobster, Panulirus cygnus

“…Juvenile Australian western rock lobsters, Panulirus cygnus (George), within a size range of 65-85·mm carapace length congregate on inshore reefs and over a 3-4·week period undergo a highly synchronised moult that is associated with a colour change from a deep red to pale pink (Chubb and Barker, 2005;Gray, 1992;Melville-Smith et al, 2003). These juvenile lobsters are herein referred to as 'Prewhites' and the pale pink migratory phase referred to as 'Whites'.…”

“…Male and female White lobsters aggregate in equal numbers on these reefs until an unknown trigger signals their migration in early December each year to deeper waters and their future breeding grounds (Chubb and Barker, 2005;George, 1958). Upon reaching deeper waters, the White lobsters gradually return to their normal deep 'Red' colouration and become sexually mature over the forthcoming months for reproduction in the following year (George, 1958;Gray, 1992;Melville-Smith et al, 2003).…”

“…Pale-coloured animals are discovered occasionally in some spiny lobster species, such as the Australian southern rock lobster Jasus edwardsii captured in deep water (McGarvey et al, 1999); however, this colour change is thought to be caused by local availability of carotenoids and does not occur in a synchronised manner throughout a large population. In the case of the western rock lobster, the colour of Whites during their migration may provide protective colouration across open stretches of sand (Melville-Smith et al, 2003). It has therefore been suggested that the initial cause of the White phase in the western rock lobster is due to pre-moult dietary modification or adaptation to substrate colour.…”

“…It has therefore been suggested that the initial cause of the White phase in the western rock lobster is due to pre-moult dietary modification or adaptation to substrate colour. Although inducing a small change in shell colour, environmental factors such as dietary carotenoid content, background substrate colour, light intensity, incident light wavelength and photoperiod have been previously shown to be ineffective in rapidly returning White lobsters to their normal Red colouration (Melville-Smith et al, 2003).…”