Bioluminescence is the production of visible light by an organism. This phenomenon particularly widespread in marine animals, especially deep sea. While luminescent status numerous animals has been recently clarified thanks to advancements deep-sea exploration technologies and phylogenetics, that others become more obscure due dramatic changes systematics (themselves triggered molecular phylogenies). Here, we combined a comprehensive literature review with unpublished data establish...

Counterilluminating animals use ventral photogenic organs (photophores) to mimic the residual downwelling light and cloak their silhouette from upward-looking predators. To cope with variable conditions of pelagic environments they typically adjust luminescence intensity. Here, we found evidence that bioluminescent sharks instead emit a constant output move up down in water column remain cryptic at iso-luminance depth. We observed, across 21 globally distributed shark species, correlation...

Opsins — G-protein coupled receptors involved in photoreception have been extensively studied the animal kingdom. The present work provides new insights into opsin-based and photoreceptor cell evolution with a first analysis of opsin sequence data for major deuterostome clade, Ambulacraria. Systematic analysis, including time hemichordate sequences an expanded echinoderm dataset, led to robust phylogeny this cornerstone superphylum. Multiple genomic transcriptomic resources were surveyed...

Bioluminescence relies on the oxidation of a luciferin substrate catalysed by luciferase enzyme. Luciferins and luciferases are generic terms used to describe large variety substrates enzymes. Whereas luciferins can be shared phylogenetically distant organisms which feed producing them, have been thought lineage-specific Numerous light emission systems would then co-emerged independently along tree life resulting in plethora non-homologous luciferases. Here, we identify for first time...

Bioluminescence—i.e., the emission of visible light by living organisms—is defined as a biochemical reaction involving, at least, luciferin substrate, an oxygen derivative, and specialised luciferase enzyme. In some cases, enzyme substrate are durably associated form photoprotein. While this terminology is educatively useful to explain bioluminescence, it gives false idea that all luminous organisms using identical or homologous molecular tools achieve emission. As usually observed in...

Abstract The European brittle star Amphiura filiformis emits blue light, via a Renilla -like luciferase, which depends on the dietary acquisition of coelenterazine. Questions remain regarding luciferin availability across seasons and persistence luminous capabilities after single boost To date, no study has explored seasonal, long-term monitoring these or tracking luciferase expression in photogenic tissues. Through multidisciplinary analysis, we demonstrate that evolve according to...

The development of luminous structures and the acquisition luminescence competence during ontogeny velvet belly lantern shark Etmopterus spinax , a deep‐sea squalid species, were investigated. sequential appearance nine different zones embryogenesis established, new terminology for them given. These form complex pattern observed in free‐swimming animals. organogenesis photophores (photogenic organs) from was followed, photophore maturation marked by green fluorescent vesicles inside...

As top predators in many oceanic communities, sharks are known to eat large prey and supposedly able generate high bite forces. This notion has, however, largely gone untested due the experimental intractability of these animals. For those species that have been investigated, it remains unclear whether their forces simply a consequence body size or result diet‐related adaptation. aquatic poikilotherms, can grow very large, making them ideal subjects with which investigate effects on force....

The velvet belly lantern shark (Etmopterus spinax) emits a blue luminescence from thousands of tiny photophores. In this work, we performed pharmacological study to determine the physiological control these luminous organs. Isolated photophore-filled skin patches produced light under melatonin (MT) and prolactin (PRL) stimulation in dose-dependent manner but did not react classical neurotransmitters. alpha-melanocyte-stimulating hormone (alpha-MSH) had an inhibitory effect on...

Bioluminescence is a common feature in the permanent darkness of deep-sea. In fishes, light emitted by organs containing either photogenic cells (intrinsic photophores), which are under direct nervous control, or symbiotic luminous bacteria (symbiotic whose controlled secondary means such as mechanical occlusion physiological suppression. The intrinsic photophores lantern shark Etmopterus spinax were recently shown an exception to this rule since they appear be hormonal control. Here, we...

In metazoans, opsins are photosensitive proteins involved in both vision and non-visual photoreception. Echinoderms have no well-defined eyes but several opsin genes were found the purple sea urchin (Strongylocentrotus purpuratus) genome. Molecular data lacking for other echinoderm classes although many species known to be light sensitive.In this study focused on European brittle star Amphiura filiformis, we first highlighted a blue-green sensitivity using behavioural approach. We then...

The mesopelagic zone is a visual scene continuum in which organisms have developed various strategies to optimize photon capture. Here, we used light microscopy, stereology-assisted retinal topographic mapping, spectrophotometry and microspectrophotometry investigate the ecology of deep-sea bioluminescent sharks [four etmopterid species (Etmopterus lucifer, E. splendidus, spinax Trigonognathus kabeyai) one dalatiid (Squaliolus aliae)]. We highlighted novel structure, translucent area present...

Abstract Bioluminescence is a prominent functional trait used for visual communication. A recent quantification showed that in pelagic ecosystems more than 75% of individual macro-planktonic organisms are categorized as able to emit light. In benthic ecosystems, only few censuses have been done, and were based on limited number observations. this study, our dataset observations from remotely operated vehicle (ROV) dives conducted 1991–2016, spanning 0–3,972 m depth. Data collected the...

Bioluminescence is the production of visible light by living organisms thanks to a chemical reaction, implying oxidation substrate called luciferin catalyzed an enzyme, luciferase. The luminous brittle star Amphiura filiformis depends on coelenterazine ( i . e ., most widespread in marine ecosystems) and luciferase homologous cnidarian Renilla produce blue flashes arm’s spine. Only few studies have focused ontogenic apparitions bioluminescence organisms. Like ophiuroids, A displays...

We report the discovery of light organs (photophores) adjacent to dorsal defensive spines a small deep-sea lanternshark (Etmopterus spinax). Using visual modeling based on in vivo luminescence recordings we show that this unusual display would be detectable by shark's potential predators from several meters away. also demonstrate spine-associated photophores (SAPs) can seen through mineralized spines, which are partially translucent. These results suggest SAPs function, either mimicking...

The smalleye pygmy shark (Squaliolus aliae) is a dwarf pelagic from the Dalatiidae family that harbours thousands of tiny photophores. In this work, we studied organisation and physiological control these photogenic organs. Results show they are mainly situated on ventral side shark, forming homogeneous area appears well suited for counterillumination, well-known camouflage technique organisms. Isolated skin patches containing photophores did not respond to classical neurotransmitters nitric...

The velvet belly lanternshark (Etmopterus spinax) is a small deep-sea shark commonly found in the Eastern Atlantic and Mediterranean Sea. This bioluminescent species able to emit blue-green ventral glow used counter-illumination camouflage, mainly. In this study, paired-end Illumina HiSeqTM technology has been employed generate transcriptome data from eye skin tissues of lanternshark. About 64 49 million reads were generated respectively. assembly allowed us predict 119,749 total unigenes...

Next generation sequencing (NGS) technology allows to obtain a deeper and more complete view of transcriptomes. For non-model or emerging model marine organisms, NGS technologies offer great opportunity for rapid access genetic information. In this study, paired-end Illumina HiSeqTM has been employed analyse transcriptomes from the arm tissues two European brittle star species, Amphiura filiformis Ophiopsila aranea. About 48 million reads were generated 136,387 total unigenes predicted A....

In the darkness of ocean, an impressive number taxa have evolved capability to emit light. Many mesopelagic organisms a dim ventral glow that matches with residual environmental light in order camouflage themselves (counterillumination function). Sharks use their luminescence mainly for this purpose. Specific lateral marks been observed Etmopteridae sharks (one two known luminous shark families) suggesting inter/intraspecific recognition. Conversely, dorsal patterns are rare within these...

Bioluminescence has often been seen as a spectacular yet uncommon event at sea but considering the vastness of deep and occurrence luminous organisms in this zone, it is now more obvious that producing light depth must play an important role structuring biggest ecosystem on our planet. Three species deepwater sharks ( Dalatias licha , Etmopterus lucifer granulosus ) were collected from Chatham Rise, off New Zealand, for first time, we documented their luminescence. Comparison glowing shark...