Disruptive body patterning of cuttlefish (Sepia officinalis) requires visual information regarding edges and contrast of objects in natural substrate backgrounds

Author Posting. © Marine Biological Laboratory, 2005. This article is posted here by permission of Marine Biological Laboratory for personal use, not for redistribution. The definitive version was published in Biological Bulletin 208 (2005): 7-11.Cuttlefish (Sepia officinalis Linnaeus, 1758) on mixed light and dark gravel show disruptive body patterns for camouflage. This response is evoked when the size of the gravel is equivalent to the area of the "White square," a component of its dorsal mantle patterns. However, the features of natural substrates that cuttlefish cue on visually are largely unknown. Therefore, we aimed to identify those visual features of background objects that are required to evoke disruptive coloration. At first, we put young cuttlefish in a circular experimental arena, presented them with natural gravel and photographs of natural gravel, and established that the animals would show a disruptive pattern when presented either with three-dimensional natural gravel or its two-dimensional photographic representation. We then manipulated the digital photographs by applying (i) a low-pass filter to remove the edges of the fragments of gravel, and (ii) a high-pass filter to remove the contrast among them. The body patterns produced by the cuttlefish in response to these altered visual stimuli were then video-recorded and graded. The results show that, to evoke disruptive coloration in cuttlefish, visual information about the edges and contrast of objects within natural substrate backgrounds is required.We are grateful for funding from the Sholley Foundation and Anteon contract #USAF-5408-04-SC-0002

Editorial: vision in cephalopods: part II

No description supplie

Quantification of cuttlefish (Sepia officinalis) camouflage : a study of color and luminance using in situ spectrometry

Author Posting. © The Author(s), 2012. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Journal of Comparative Physiology A 199 (2013): 211-225, doi:10.1007/s00359-012-0785-3.Cephalopods are renowned for their ability to adaptively camouflage on diverse backgrounds. Sepia officinalis camouflage body patterns have been characterized spectrally in the laboratory but not in the field due to the challenges of dynamic natural light fields and the difficulty of using spectrophotometric instruments underwater. To assess cuttlefish color match in their natural habitats, we studied the spectral properties of S. officinalis and their backgrounds on the Aegean coast of Turkey using point-by-point in situ spectrometry. Fifteen spectrometry datasets were collected from seven cuttlefish; radiance spectra from animal body components and surrounding substrates were measured at depths shallower than 5m. We quantified luminance and color contrast of cuttlefish components and background substrates in the eyes of hypothetical di- and trichromatic fish predators. Additionally, we converted radiance spectra to sRGB color space to simulate their in situ appearance to a human observer. Within the range of natural colors at our study site, cuttlefish closely matched the substrate spectra in a variety of body patterns. Theoretical calculations showed that this effect might be more pronounced at greater depths. We also showed that a non-biological method (“Spectral Angle Mapper”), commonly used for spectral shape similarity assessment in the field of remote sensing, shows moderate correlation to biological measures of color contrast. This performance is comparable to that of a traditional measure of spectral shape similarity, hue and chroma. This study is among the first to quantify color matching of camouflaged cuttlefish in the wild.This study was funded by ONR grant N000140610202 to RTH.2013-12-2

How visual edge features influence cuttlefish camouflage patterning

AbstractRapid adaptive camouflage is the primary defense of soft-bodied cuttlefish. Previous studies have shown that cuttlefish body patterns are strongly influenced by visual edges in the substrate. The aim of the present study was to examine how cuttlefish body patterning is differentially controlled by various aspects of edges, including contrast polarity, contrast strength, and the presence or absence of “line terminators” introduced into a pattern when continuous edges are fragmented. Spatially high- and low-pass filtered white or black disks, as well as isolated, continuous and fragmented edges varying in contrast, were used to assess activation of cuttlefish skin components. Although disks of both contrast polarities evoked relatively weak disruptive body patterns, black disks activated different skin components than white disks, and high-frequency information alone sufficed to drive the responses to white disks whereas high- and low-frequency information were both required to drive responses to black disks. Strikingly, high-contrast edge fragments evoked substantially stronger body pattern responses than low-contrast edge fragments, whereas the body pattern responses evoked by high-contrast continuous edges were no stronger than those produced by low-contrast edges. This suggests that line terminators vs. continuous edges influence expression of disruptive body pattern components via different mechanisms that are controlled by contrast in different ways

Impact of Lidocaine on Pain-Related Grooming in Cuttlefish

Nociception is the neural process of encoding noxious stimuli and is typically accompanied by a reflex withdrawal response away from the potentially injurious stimulus. Studies on nociception in cephalopods have so far focused on octopus and squid, with no investigations to our knowledge on cuttlefish. Yet, these are an important species both in scientific and commercial use. Therefore, the present study demonstrated that a standard pain stimulus, acetic acid, induced grooming behaviour directed towards the injection site in cuttlefish and that the injection of lidocaine reduces grooming behaviours in acetic-acid-injected cuttlefish. Wound-directed behaviour demonstrates that the animal is aware of the damage; thus, when subjecting these animals to any painful treatments in the laboratory, researchers should consider alleviating pain by the administration of pain-relieving drugs

Cuttlefish camouflage: The effects of substrate contrast and size in evoking uniform, mottle or disruptive body patterns

AbstractCuttlefish are cephalopod molluscs that achieve dynamic camouflage by rapidly extracting visual information from the background and neurally implementing an appropriate skin (or body) pattern. We investigated how cuttlefish body patterning responses are influenced by contrast and spatial scale by varying the contrast and the size of checkerboard backgrounds. We found that: (1) at high contrast levels, cuttlefish body patterning depended on check size; (2) for low contrast levels, body patterning was independent of “check” size; and (3) on the same check size, cuttlefish fine-tuned the contrast and fine structure of their body patterns, in response to small contrast changes in the background. Furthermore, we developed an objective, automated method of assessing cuttlefish camouflage patterns that quantitatively differentiated the three body patterns of uniform/stipple, mottle and disruptive. This study draws attention to the key roles played by background contrast and particle size in determining an effective camouflage pattern

Male alternative reproductive tactics and associated evolution of anatomical characteristics in loliginid squid

© The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Marian, J. E. A. R., Apostólico, L. H., Chiao, C. C., Hanlon, R. T., Hirohashi, N., Iwata, Y., Mather, J., Sato, N., & Shaw, P. W. Male alternative reproductive tactics and associated evolution of anatomical characteristics in loliginid squid. Frontiers in Physiology, 10, (2019): 1281, doi: 10.3389/fphys.2019.01281.Loliginid squids provide a unique model system to explore male alternative reproductive tactics (ARTs) and their linkage to size, behavioral decision making, and possibly age. Large individuals fight one another and the winners form temporary consortships with females, while smaller individuals do not engage in male-male agonistic bouts but use various sneaker tactics to obtain matings, each with varying mating and fertilization success. There is substantial behavioral flexibility in most species, as smaller males can facultatively switch to the alternative consort behaviors as the behavioral context changes. These forms of ARTs can involve different: mating posture; site of spermatophore deposition; fertilization success; and sperm traits. Most of the traits of male dimorphism (both anatomical and behavioral) are consistent with traditional sexual selection theory, while others have unique features that may have evolved in response to the fertilization environment faced by each temporary or permanent male morph.JM acknowledges the funding provided by FAPESP (São Paulo Research Foundation – proc. 2013/02653-1, 2014/11008-5, 2015/15447-6, 2017/16182-1, and 2018/19180-2), CNPq (National Council for Scientific and Technological Development – proc. 477233/2013–9), and CAPES (Coordination for the Improvement of Higher Education Personnel – Finance Code 001)

The Arabidopsis Malectin-Like/LRR-RLK IOS1 is Critical for BAK1-Dependent and BAK1-Independent Pattern-Triggered Immunity

Plasma membrane-localized pattern recognition receptors (PRRs) such as FLAGELLIN SENSING2 (FLS2), EF-TU RECEPTOR (EFR) and CHITIN ELICITOR RECEPTOR KINASE 1 (CERK1) recognize microbe-associated molecular patterns (MAMPs) to activate pattern-triggered immunity (PTI). A reverse genetics approach on genes responsive to the priming agent beta-aminobutyric acid (BABA) revealed IMPAIRED OOMYCETE SUSCEPTIBILITY1 (IOS1) as a critical PTI player. Arabidopsis thaliana ios1 mutants were hyper-susceptible to Pseudomonas syringae bacteria. Accordingly, ios1 mutants showed defective PTI responses, notably delayed up-regulation of the PTI-marker gene FLG22-INDUCED RECEPTOR-LIKE KINASE1 (FRK1), reduced callose deposition and mitogen-activated protein kinase activation upon MAMP treatment. Moreover, Arabidopsis lines over-expressing IOS1 were more resistant to bacteria and showed a primed PTI response. In vitro pull-down, bimolecular fluorescence complementation, co-immunoprecipitation, and mass spectrometry analyses supported the existence of complexes between the membrane-localized IOS1 and BRASSINOSTEROID INSENSITIVE1-ASSOCIATED KINASE1 (BAK1)-dependent PRRs FLS2 and EFR, as well as with the BAK1-independent PRR CERK1. IOS1 also associated with BAK1 in a ligand-independent manner, and positively regulated FLS2-BAK1 complex formation upon MAMP treatment. In addition, IOS1 was critical for chitin-mediated PTI. Finally, ios1 mutants were defective in BABA-induced resistance and priming. This work reveals IOS1 as a novel regulatory protein of FLS2-, EFR- and CERK1-mediated signaling pathways that primes PTI activation

Novel Nanohybrids of Silver Particles on Clay Platelets for Inhibiting Silver-Resistant Bacteria

We develop a novel nanohybrid showing a strong antibacterial activity on all of the tested pathogens, including methicillin-resistant Staphylococcus auerus and silver-resistant E. coli. The nanohybrid consists of silver nanoparticles (AgNPs) supported on 1 nm-thick silicate platelets (NSPs). The AgNP/NSP nanohybrid enables to encapsulate bacteria and triggers death signals from the cell membrane. The geographic shape of the NSPs concentrates AgNPs but impedes their penetration into attached cells, mitigating the detrimental effect of silver ion deposition in applied tissues. Moreover, the tightly tethered AgNPs on NSP surface achieve a stronger biocidal effect than silver nitrate, but bypassing Ag+ mechanism, on silver-resistant bacteria. This nanohybrid presents an effective and safe antimicrobial agent in a new perspective