Ontogenetic adaptations in the visual systems of deep-sea crustaceans

For all visually competent organisms, the driving force behind the adaptation of photoreceptors involves obtaining the best balance of resolution to sensitivity in the prevailing light regime, as an increase in sensitivity often results in a decrease in resolution. A number of marine species have an additional problem to deal with, in that the juvenile stages live in relatively brightly lit shallow (100–200 m depth) waters, whereas the adult stages have daytime depths of more than 600 m, where little downwelling light remains. Here, I present the results of electrophysiological analyses of the temporal resolution and irradiance sensitivity of juvenile and adult stages of two species of ontogenetically migrating crustaceans ( Gnathophausia ingens and Systellaspis debilis ) that must deal with dramatically different light environments and temperatures during their life histories. The results demonstrate that there are significant effects of temperature on temporal resolution, which help to optimize the visual systems of the two life-history stages for their respective light environments. This article is part of the themed issue ‘Vision in dim light’.

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The visual ecology of Holocentridae, a nocturnal coral reef fish family with a deep-sea-like multibank retina

Journal of Experimental Biology ◽

10.1242/jeb.233098 ◽

2020 ◽

pp. jeb.233098

Author(s):

Fanny de Busserolles ◽

Fabio Cortesi ◽

Lily Fogg ◽

Sara M. Stieb ◽

Martin Luehrmann ◽

...

Keyword(s):

Visual System ◽

Reef Fish ◽

Deep Sea ◽

Colour Vision ◽

Ganglion Cells ◽

Light Sensitivity ◽

Fish Family ◽

Visual Systems ◽

Retinal Topography ◽

Dim Light

The visual systems of teleost fishes usually match their habitats and lifestyles. Since coral reefs are bright and colourful environments, the visual systems of their diurnal inhabitants have been more extensively studied than those of nocturnal species. In order to fill this knowledge gap, we conducted a detailed investigation of the visual system of the nocturnal reef fish family Holocentridae. Results showed that the visual system of holocentrids is well adapted to their nocturnal lifestyle with a rod-dominated retina. Surprisingly, rods in all species were arranged into 6-17 well-defined banks, a feature most commonly found in deep-sea fishes, that may increase the light sensitivity of the eye and/or allow colour discrimination in dim-light. Holocentrids also have the potential for dichromatic colour vision during the day with the presence of at least two spectrally different cone types: single cones expressing the blue-sensitive SWS2A gene, and double cones expressing one or two green-sensitive RH2 genes. Some differences were observed between the two subfamilies, with Holocentrinae (squirrelfish) having a slightly more developed photopic visual system than Myripristinae (soldierfish). Moreover, retinal topography of both ganglion cells and cone photoreceptors showed specific patterns for each cell type, likely highlighting different visual demands at different times of the day, such as feeding. Overall, their well-developed scotopic visual systems and the ease of catching and maintaining holocentrids in aquaria, make them ideal models to investigate teleost dim-light vision and more particularly shed light on the function of the multibank retina and its potential for dim-light colour vision.

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The visual ecology of Holocentridae, a nocturnal coral reef fish family with a deep-sea-like multibank retina

10.1101/2020.05.24.113811 ◽

2020 ◽

Author(s):

Fanny de Busserolles ◽

Fabio Cortesi ◽

Lily Fogg ◽

Sara M. Stieb ◽

Martin Luerhmann ◽

...

Keyword(s):

Coral Reef ◽

Visual System ◽

Reef Fish ◽

Coral Reef Fish ◽

Deep Sea ◽

Colour Vision ◽

Fish Family ◽

Visual Systems ◽

Dim Light ◽

Dim Light Vision

AbstractThe visual systems of teleost fishes usually match their habitats and lifestyles. Since coral reefs are bright and colourful environments, the visual systems of their diurnal inhabitants have been more extensively studied than those of nocturnal species. In order to fill this knowledge gap, we conducted a detailed investigation of the visual systems of the coral reef fish family Holocentridae (squirrelfish and soldierfish). In addition to their nocturnality, this family is particularly interesting for dim-light vision studies due to its ecological and evolutionary connection to deeper habitats. Results showed that the visual system of holocentrids is well adapted to their nocturnal lifestyle with a rod-dominated retina. Surprisingly, rods in all species were arranged into 6-17 well-defined banks, a feature most commonly found in deep-sea fishes, that may increase the light sensitivity of the eye and/or allow colour discrimination in dim-light. Holocentrids also have the potential for dichromatic colour vision during the day with the presence of at least two spectrally different cone types: single cones expressing the blue-sensitive SWS2A gene, and double cones expressing one or two green-sensitive RH2 genes. Some differences were observed between the two subfamilies, with Holocentrinae having a slightly more developed photopic visual system than Myripristinae. Moreover, retinal topography of both ganglion cells and cone photoreceptors showed specific patterns for each cell type, likely highlighting different visual demands at different times of the day, such as feeding. Overall, their well-developed scotopic visual systems and the ease of catching and maintaining holocentrids in aquaria, make them ideal models to investigate teleost dim-light vision and more particularly shed light on the function of multibank retina and its potential for dim-light colour vision.

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Evolutionary analyses of visual opsin genes in anurans reveals diversity and positive selection suggestive of functional adaptation to distinct light environments

10.1101/2021.08.27.457945 ◽

2021 ◽

Author(s):

Ryan K Schott ◽

Leah Perez ◽

Matthew A Kwiatkowski ◽

Vance Imhoff ◽

Jennifer M Gumm

Keyword(s):

Positive Selection ◽

Spectral Sensitivity ◽

Life Histories ◽

Visual Pigments ◽

Molecular Techniques ◽

Functional Adaptation ◽

Opsin Gene ◽

Visual Systems ◽

Opsin Genes ◽

Dim Light

Among major vertebrate groups, anurans (frogs and toads) are understudied with regards to their visual systems and little is known about variation among species that differ in ecology. We sampled North American anurans representing diverse evolutionary and life histories that likely possess visual systems adapted to meet different ecological needs. Using standard molecular techniques, visual opsin genes, which encode the protein component of visual pigments, were obtained from anuran retinas. Additionally, we extracted the visual opsins from publicly available genome and transcriptome assemblies, further increasing the phylogenetic and ecological diversity of our dataset. We found that anurans consistently express four visual opsin genes (RH1, LWS, SWS1, and SWS2, but not RH2) even though reported photoreceptor complements vary widely among species. We found the first evidence of visual opsin duplication in an amphibian with the duplication of the LWS gene in the African bullfrog, which had distinct LWS copies on the sex chromosomes. The proteins encoded by these genes showed considerable sequence variation among species, including at sites known to shift the spectral sensitivity of visual pigments in other vertebrates and thus mediate dim-light and color vision. Using molecular evolutionary analyses of selection (dN/dS) we found significant evidence for positive selection at a subset of sites in the dim-light rod opsin gene RH1 and the long wavelength sensitive cone opsin gene LWS. The function of sites inferred to be under positive selection are largely unknown, but a few are likely to affect spectral sensitivity and other visual pigment functions based on proximity to previously identified sites in other vertebrates. The observed variation cannot fully be explained by evolutionary relationships among species alone. Taken together, our results suggest that other ecological factors, such as habitat and life history, as well as behaviour, may be driving changes to anuran visual systems.

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Effects of Temperature and Pressure on Sulfate Reduction and Anaerobic Oxidation of Methane in Hydrothermal Sediments of Guaymas Basin

Applied and Environmental Microbiology ◽

10.1128/aem.70.2.1231-1233.2004 ◽

2004 ◽

Vol 70 (2) ◽

pp. 1231-1233 ◽

Cited By ~ 101

Author(s):

Jens Kallmeyer ◽

Antje Boetius

Keyword(s):

Sulfate Reduction ◽

Deep Sea ◽

Anaerobic Oxidation Of Methane ◽

Anaerobic Oxidation ◽

Guaymas Basin ◽

Oxidation Of Methane ◽

Hydrothermal Sediments ◽

Deep Sea Sediments ◽

Effects Of Temperature ◽

Temperature And Pressure

ABSTRACT Rates of sulfate reduction (SR) and anaerobic oxidation of methane (AOM) in hydrothermal deep-sea sediments from Guaymas Basin were measured at temperatures of 5 to 200°C and pressures of 1 × 105, 2.2 × 107, and 4.5 × 107 Pa. A maximum SR of several micromoles per cubic centimeter per day was found at between 60 and 95°C and 2.2 × 107 and 4.5 × 107 Pa. Maximal AOM was observed at 35 to 90°C but generally accounted for less than 5% of SR.

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An experimental assessment of social tolerance and den ecology in a high-density octopus population

Marine Biology ◽

10.1007/s00227-021-03865-4 ◽

2021 ◽

Vol 168 (5) ◽

Author(s):

Duncan A. O’Brien ◽

Michelle L. Taylor ◽

Heather D. Masonjones ◽

Philipp H. Boersch-Supan ◽

Owen R. O’Shea

Keyword(s):

Deep Sea ◽

Marine Species ◽

High Density ◽

Behavioural Plasticity ◽

High Population Density ◽

Social Tolerance ◽

Potential Prey ◽

The Bahamas ◽

The Social ◽

Den Use

AbstractLong held notions of the universally asocial octopus are being challenged due to the identification of high-density and interacting octopus populations in Australia, Indonesia, Japan and the deep sea. This study experimentally assessed the social tolerance and presence of potential prey items of Caribbean reef octopus, Octopus briareus, in a tropical marine lake (25°21′40″N, 76°30′40″W) on the island of Eleuthera, The Bahamas, by deploying artificial dens in multi-den groups or ‘units’ in the months of May and June 2019. Fifteen octopus were observed occupying dens (n = 100), resulting in 13 den units being occupied (n = 40). Two examples of adjacent occupation within a single den unit were identified but with zero examples of cohabitation/den sharing. Ecological models showed den and den unit occupation was predicted to increase with depth and differ between sites. Octopus also displayed no preference for isolated or communal units but preferred isolated dens over dens adjacent to others. Additionally, 47 % of occupied dens contained bivalve or crustacean items with no epifauna on their interior surface. The lack of epifauna suggests that these items have been recently ‘cleaned’ by occupying octopus and so represent likely prey. This study presents evidence of possible antisocial den use by O. briareus, a modification of the default ‘asocial’ ignoring of conspecifics typically attributed to octopus. This is likely in response to the high population density and may imply behavioural plasticity, making this system appropriate for further scrutiny as a research location on the influence of large, insular environments on marine species.

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Introduction

Ecology of Marine Sediments ◽

10.1093/oso/9780198569015.003.0004 ◽

2009 ◽

Author(s):

John S. Gray ◽

Michael Elliott

Keyword(s):

Marine Sediments ◽

Deep Sea ◽

Marine Species ◽

Dark Side ◽

Marine Animals ◽

Linnaean System ◽

Lofoten Islands ◽

Linnaean Classification ◽

Marine Biologist ◽

New System

As the oceans cover 70% of the earth’s surface, marine sediments constitute the second largest habitat on earth, after the ocean water column, and yet we still know more about the dark side of the moon than about the biota of this vast habitat. The primary aim of this book is to give an overview of the biota of marine sediments from an ecological perspective—we will talk of the benthos, literally the plants and animals at the bottom of the sea, but we will also use the term to include those organisms living on the intertidal sediments, the sands and muds of the shore. Given that most of that area is below the zone where light penetrates, the photic zone, the area is dominated by the animals and so we will concentrate on this component. Many of the early studies of marine sediments were taxonomic, describing new species. One of the pioneers was Carl von Linnaeus (1707–1778), the great Swedish biologist who developed the Linnaean classification system for organisms that is still used today (but under threat from some molecular biologists who argue that the Linnaean system is outdated and propose a new system called Phylocode). Linnaeus described hundreds of marine species, many of which come from marine sediments. The British marine biologist Edward Forbes was a pioneer who invented the dredge to sample marine animals that lived below the tidemarks. Forbes showed that there were fewer species as the sampled depth increased and believed that the great pressures at depths meant that no animals would be found deeper than 600 m. This was disproved by Michael Sars who in 1869 used a dredge to sample the benthos at 600 m depth off the Lofoten islands in Norway. Sars found 335 species and in fact was the first to show that the deep sea (off the continental shelf) had high numbers of species. Following these pioneering studies, one of the earliest systematic studies of marine sediments was the HMS Challenger expedition of 1872–1876, the first global expedition. The reports of the expedition were extensive but were mostly descriptive, relating to taxonomy and general natural history.

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Vision using multiple distinct rod opsins in deep-sea fishes

Science ◽

10.1126/science.aav4632 ◽

2019 ◽

Vol 364 (6440) ◽

pp. 588-592 ◽

Cited By ~ 48

Author(s):

Zuzana Musilova ◽

Fabio Cortesi ◽

Michael Matschiner ◽

Wayne I. L. Davies ◽

Jagdish Suresh Patel ◽

...

Keyword(s):

Deep Sea ◽

Visual Information ◽

Dim Light ◽

Cone Opsins

Vertebrate vision is accomplished through light-sensitive photopigments consisting of an opsin protein bound to a chromophore. In dim light, vertebrates generally rely on a single rod opsin [rhodopsin 1 (RH1)] for obtaining visual information. By inspecting 101 fish genomes, we found that three deep-sea teleost lineages have independently expanded their RH1 gene repertoires. Among these, the silver spinyfin (Diretmus argenteus) stands out as having the highest number of visual opsins in vertebrates (two cone opsins and 38 rod opsins). Spinyfins express up to 14 RH1s (including the most blueshifted rod photopigments known), which cover the range of the residual daylight as well as the bioluminescence spectrum present in the deep sea. Our findings present molecular and functional evidence for the recurrent evolution of multiple rod opsin–based vision in vertebrates.

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