Camouflage during movement in the European cuttlefish (Sepia officinalis)

A moving object is considered conspicuous because of the movement itself. When moving from one background to another, even dynamic camouflage experts such as cephalopods should sacrifice their extraordinary camouflage. Therefore, minimizing detection at this stage is crucial and highly beneficial. In this study, we describe a background-matching mechanism during movement, which aids the cuttlefish to downplay its presence throughout movement. In situ behavioural experiments using video and image analysis, revealed a delayed, sigmoidal, colour-changing mechanism during movement of Sepia officinalis across uniform black and grey backgrounds. This is a first important step in understanding dynamic camouflage during movement, and this new behavioural mechanism may be incorporated and applied to any dynamic camouflaging animal or man-made system on the move.info:eu-repo/semantics/publishedVersio

Discovery of an unrecognized nidovirus associated with granulomatous hepatitis in rainbow trout

Rainbow trout (Oncorhynchus mykiss) is the principal species of inland-farmed fish in the Western hemisphere. Recently, we diagnosed in farmed rainbow trout a disease in which the hallmark is granulomatous-like hepatitis. No biotic agents could be isolated from lesions. Still, unbiased high-throughput sequencing and bioinformatics analyses revealed the presence of a novel piscine nidovirus that we named “Trout Granulomatous Virus” (TGV). TGV genome (28,767 nucleotides long) is predicted to encode non-structural (1a and 1 ab) and structural (S, M, and N) proteins that resemble proteins of other known piscine nidoviruses. High loads of TGV transcripts were detected by quantitative RT-PCR in diseased fish and visualized in hepatic granulomatous sites by fluorescence in situ hybridization. Transmission electron microscopy (TEM) revealed coronavirus-like particles in these lesions. Together, these analyses corroborated the association of TGV with the lesions. The identification and detection of TGV provide means to control TGV spread in trout populations

Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases

The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular "reactive oxygen species" (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation). The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible. This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference

From the ocean to a reef habitat: How do the larvae of coral reef fishes find their way home? A state of art on the latest advances

peer reviewe

Deepwater Oil and Gas Production in the Gulf of Mexico and Related Global Trends

The marine oil industry in the Gulf of Mexico (GoM) began in 1938 with the construction of the first oil well platform built in 4 meters of water, a mile off the Louisiana coast. The Mexican marine oil industry began in the 1950s with exploration and low-level production off the city of Tampico in the state of Tamaulipas. The discovery of the massive Cantarell oil field off Campeche in 1976 led to rapid expansion of the Mexican industry, surpassing US production of GoM-derived oil. Total annual oil production from the GoM peaked in 2003 at 1.6 billion barrels, but has since declined to about 1.2 billion barrels. Production at the Cantarell field peaked in 2004 and has since declined by 90%. Both the US and Mexican oil industries have focused more recently on deepwater plays to support production. The US oil production by lease depth showed a steady offshore migration through the 1990s but a dramatic rise in ultra-deep (e.g., ≥1500 m water depth) production beginning in the 2000s. In 2017, 52% of US oil production was from ultra-deep wells. Beginning in 2013, Mexico liberalized its policies to allow international cooperative ventures for exploration and production, particularly focusing on deepwater sources. Several large discoveries off Mexico since 2015 portend higher offshore production in the 2020s when these fields come online. In the US GoM, marine-derived natural gas production has declined by 79% since 1997, to about 1 trillion ft3 in 2017, reflecting rapid increases in land-based gas sources from hydraulic fracturing, which are less expensive to produce that marine-derived gas. Over the next decade, shallow-water sources of oil and gas in the US GoM will be phased out or reduced in importance as additional ultra-deep sources are developed. In the US GoM these include plays in depths to 3000 m and potentially deeper off Mexico. Ultra-deep sources occurring in the “Golden Triangle” between West Africa, Brazil, and the GoM will likely dominate global ultra-deepwater production, but other frontier regions will doubtlessly be explored. The inherent risks of catastrophic well blowouts at extreme depths will increase as the productivity of oil facilities increases exponentially with water depth

From the ocean to a reef habitat: how do the larvae of coral reef fishes find their way home

International audienceAs it is unlikely that successful settlement is solely a matter of chance (i.e. tofind a suitable habitat), one of the greatest challenges facing the fish larvae is how to locate therelatively rare patches of coral reef habitat on which they settle and ultimately reside as adults.The answer must lie partly in the sensory modalities of fishes at settlement. Habitat selection isonly possible if fish larvae could detect some environmental cues to select a suitable reef habitatat settlement. The present review aims at providing the latest works dealing with informationperception in coral reef fish larvae at settlement. Two decades ago, it was generally assumedthat larval behaviors and sensory abilities at settlement were considered too feeble to significantlyaffect dispersal outcomes. Several recent studies showed that recognition of suitable reefhabitats by fish larvae at settlement is based on a combination of visual, chemical and acousticcues. The first part of our review shows the main advances in the knowledge of visual, chemicaland acoustic cues used by fish larvae to detect an island, a reef, a micro-habitat, a conspecific orsome predators. The second part of our review deals with the effect of imprinting and/or innatecapabilities. The third part focuses on the different cues used at different scales and underlinessome contradictory results about the distance of transmission and detection of chemical andacoustic cues in coral reefs. Finally, as global and regional environmental changes have stressedcoral reefs to such an extent that they are either destroyed or in decline, the fourth part presentsthe effects of both anthropogenic and environmental stressors on information perception andresponse capacities in coral reef fish larvae. If polluted seawater disrupts the larval abilities tofind a suitable reef habitat, fish larvae may spend more time in the planktonic environment,resulting in increased energetic costs and predation risk, and consequently a lower larval settlement.We hypothesise that as the stability of fish communities is dependent, in part, on the stabilityof social interactions, the disruption of “larvae-habitat relationships” can have major consequencesfor larval settlement into adult population with further repercussions for the ecosystemas a whole. Overall, larval settlement of coral reef fish is an excellent example of the complexityof interactions between an organism and its environment as without perceiving environmentalcues, fish larva would have very little chance of selecting a suitable reef habitat. Moreover,understanding the relationship between reef state and settlement potential will allow managementplanning for the maintenance of coral reefs that are increasingly degraded