It might seem obvious that a camouflaged animal must generally match its background whereas to be conspicuous an organism must differ from the background. However, the image parameters (or statistics) that evaluate the conspicuousness of patterns and textures are seldom well defined, and animal coloration patterns are rarely compared quantitatively with their respective backgrounds. Here we exa...

Body patterning behavior in unshelled cephalopod molluscs such as squid, octopuses, and cuttlefish is the ability of these animals to create complex patterns on their skin. This behavior is generated primarily by chromatophores, pigment-containing organs that are directly innervated by central motoneurons. The present study focuses on innervation patterns and location of chromatophore motoneuro...

This research was aimed at characterizing the daily rhythms of locomotor activity of cuttlefish Sepia officinalis (Linnaeus, 1758), a promising aquaculture species, in a captive environment. Cuttlefish were distributed within two tanks equipped with infrared photocells, allowing the monitoring of locomotor activity continuously from August to February. Results showed a preference of cuttlefish ...

Polar lipids of the cephalopods Eledone moschata, Sepia officinalis and Todarodes sagittatus mantle, represent 50.5%, 66.1% and 74.2% of wet tissue respectively. On the other hand the polar lipids of these three species of cephalopods constitute of 80.8%, 94.8% and 93.7% of phospholipids, respectively. The main phospholipids identified were phosphatidylcholine (52.2, 51.3 and 58.4% of total pho...

Cephalopods are new evolutionary and ecological models. By their phylogenetic position (Lophotrochozoa, Mollusca), they provide a missing master piece in the whole puzzle of neurodevelopment studies. Their derived and specific nervous system but also their convergence with vertebrates offer abundant materials to question the evolution and development of the nervous system of Metazoa (evo-devo s...

mRNA from two molluscs, the snail Levantina hierosolima and the cuttlefish Sepia officinalis, and one arthropod, the scorpion Leiurus quinquestriatus, were found to contain species that hybridize with an oligodeoxynucleotide sequence corresponding to the six-amino-acid sequence His-His-Trp-His-Trp-His postulated to carry binuclear copper in arthropod haemocyanins. The duplexes formed between th...

Unshelled cephalopods have a remarkable ability to alter their appearance, using textural, postural, and chromatic elements to generate a myriad of body patterns. Of the unshelled cephalopods, it is generally acknowledged that cuttlefish express the most detailed and widest range of body patterns, including static and dynamic patterns. In this paper we present data on the neuronal mechanisms un...