scholarly journals Eco-Evolutionary Perspectives on Mixoplankton

2021 ◽  
Vol 8 ◽  
Author(s):  
Joost Samir Mansour ◽  
Konstantinos Anestis
Keyword(s):  
Aquatic Ecosystems ◽  
Prey Availability ◽  
Evolutionary Mechanisms ◽  
Current Review ◽  
Single Organism ◽  
Limiting Nutrients ◽  
Active Transcription ◽  
Species Specific ◽  
Marine Protists ◽  
Evolutionary Perspectives

Mixotrophy, i.e., the capability of both phototrophy and phagotrophy within a single organism, is a prominent trophic mode in aquatic ecosystems. Mixotrophic strategies can be highly advantageous when feeding or photosynthesis alone does not sustain metabolic needs. In the current review, we discuss the functional types of mixotrophic marine protists (herein mixoplankton) within the context of evolution. Permanent plastids have been established in large due to gene transfer from prey and/or endosymbionts to the host cell. In some kleptoplastidic mixoplankton, prior gene transfers and active transcription of plastid related genes in the host can help maintain and extend retention of the current kleptoplast. In addition to kleptoplasts, the prey nucleus is also sometimes retained and actively transcribed to help maintain and even replicate the kleptoplasts. Endosymbiotic relations vary considerably in the extent to which hosts affect symbionts. For example, some endosymbionts are heavily modified to increase photosynthetic efficiency, or are controlled in their cell division. It can be proposed that many kleptoplasts and endosymbionts are in fact en route to becoming permanent plastids. Conditions such as increased temperature and limiting nutrients seem to favor phagotrophy in mixoplankton. However, responses of mixoplankton to changing environmental conditions like light irradiance, temperature, nutrient, and prey availability are variable and species-specific. Studying mixotrophs with temporary plastids could elucidate past and future evolutionary mechanisms and dynamics of processes such as phagotrophy and the establishment of (secondary) permanent plastids.

scholarly journals Crab Diets Differ Between Adjacent Estuaries and Habitats Within a Sheltered Marine Embayment

2021 ◽  
Vol 8 ◽  
Author(s):  
Theo I. Campbell ◽  
James R. Tweedley ◽  
Danielle J. Johnston ◽  
Neil R. Loneragan
Keyword(s):  
Aquatic Ecosystems ◽  
Prey Availability ◽  
Dietary Composition ◽  
Recreational Fisheries ◽  
Seasonal Differences ◽  
Diverse Range ◽  
Bivalve Shell ◽  
Marine Embayment ◽  
Macroinvertebrate Fauna ◽  
High Calorie

Portunid crabs contribute to significant commercial and recreational fisheries globally and are commonly fished in estuaries and/or marine embayments, which are amongst the most degraded of all aquatic ecosystems. Portunus armatus were collected seasonally between April and February from five locations across three systems in temperate south-western Australia. The dietary composition of crabs was quantified and compared between two estuaries (Peel-Harvey and Swan-Canning) and a sheltered marine embayment (Cockburn Sound) containing three distinct habitats: shallow seagrass, shallow sand and deep sand. Overall, crabs ingested large volumes of bivalves (both live organisms and dead shell), polychaetes, crustaceans (e.g., amphipods, small decapods), and smaller volumes of teleosts, echinoderms and plant material (seagrass, algae). Analysis of Similarities showed that dietary composition varied significantly among the five locations (two estuaries and three habitats within Cockburn Sound) and seasons, with greater location than seasonal differences in the two estuaries. Diets were most distinct in the Cockburn Sound seagrass due to greater volumes of decapods and teleosts and smaller volumes of bivalve shell consumed in this habitat. Crabs from both estuaries consumed greater quantities of bivalves than those from Cockburn Sound. Seasonal differences in both estuaries were greatest between summer and winter, with a more diverse range of prey and large quantities of bivalves ingested in summer, whereas small bivalves and bivalve shell in the Peel-Harvey and polychaetes and other crustaceans in the Swan-Canning, were consumed in greater quantities in winter. The summer diet in the Peel-Harvey Estuary in the current study was compared to that 20 years previous and with documented change in the benthic macroinvertebrate fauna. Currently, crabs consume smaller volumes of high-calorie prey, i.e., polychaetes, small bivalves and teleosts, and instead ingest greater proportions of calcareous material than previously. This marked shift in dietary composition parallels changes in benthic macroinvertebrates in the Peel-Harvey Estuary. Overall, prey availability appears to be the major factor influencing the spatial and temporal differences in P. armatus diets in these three coastal systems.

scholarly journals  Pain in domestic animals and how to assess it: a review

2012 ◽  
Vol 57 (No. 4) ◽  
pp. 185-192 ◽  
Author(s):  
L. Landa
Keyword(s):  
Pain Management ◽  
Animal Welfare ◽  
Pain Assessment ◽  
Domestic Animals ◽  
Current Review ◽  
Adult Humans ◽  
Clinical Responses ◽  
General Signs ◽  
Species Specific ◽  
Pain Recognition

 In recent years more attention has been paid to the issue of pain in animals, particularly in association with increasing awareness of animal welfare. It is therefore necessary for veterinarians to be able recognise unambiguously whether an animal suffers from pain. Adult humans suffering from pain can more or less characterise their painful experiences, including the site and intensity of the pain. However, pain in animals is in some aspects more complex and it can be rather difficult to evaluate the seriousness and impact of painful events. Therefore, in animals we have to recognise the signs of pain according to indirect markers which involve behavioural, physiological and finally clinical responses. Moreover, in particular the behavioural changes associated with pain can be along with the general signs also species-specific, and hardly recognisable (and for an inexperienced observer seemingly unimportant) which makes pain assessment even more complicated. Therefore, the current review formulates definitions of pain, its classification and is focused on methods that may facilitate pain recognition in animals, which is crucial for an effective pain assessment and consequent effective pain management. The review combines recent knowledge with well proven facts concerning pain and furthermore also highlights the author’s own research on pain assessment.    

scholarly journals UPLC–MS/MS Identification of Sterol Sulfates in Marine Diatoms

Marine Drugs ◽  
2018 ◽  
Vol 17 (1) ◽  
pp. 10 ◽  
Author(s):  
Genoveffa Nuzzo ◽  
Carmela Gallo ◽  
Giuliana d’Ippolito ◽  
Emiliano Manzo ◽  
Nadia Ruocco ◽  
...  
Keyword(s):  
Ultra Performance Liquid Chromatography ◽  
General Role ◽  
Specific Distribution ◽  
Field Samples ◽  
Different Strains ◽  
Species Specific ◽  
Marine Protists ◽  
Eukaryotic Organisms ◽  
Promising Source ◽  
Derivatives Of

Diatoms are unicellular eukaryotic organisms that play a key ecological and biogeochemical role in oceans as major primary producers. Recently, these microalgae have also attracted interest as a promising source of functional products with widespread relevance. Progress in the knowledge of cell and molecular biology of diatoms is envisaged as a key step to understanding regulation of their life cycle in marine environments as well as facilitating their full and profitable exploitation by biotechnological platforms. Recently, we identified sterol sulfates (StS) as regulatory molecules of cell death in the diatom Skeletonema marinoi. As these compounds may have a general role in diatom physiology and chemical signals in aquatic systems, we investigated a suitable tool for their analysis in laboratory and field samples. Herein, we describe a sensitive, fast, and efficient ultra performance liquid chromatography–mass spectrometry (UPLC–MS) method for qualitative and quantitative analysis of StS from crude extract of diatoms and other microalgae. The method was applied to 13 different strains of our collection of marine protists. This first study suggested a species-specific distribution of StS and identified the sulfated derivatives of 24-methylene cholesterol and 24-methyl cholesterol as the most common members in diatoms.

scholarly journals Selection following Gene Duplication Shapes Recent Genome Evolution in the Pea Aphid Acyrthosiphon pisum

2020 ◽  
Vol 37 (9) ◽  
pp. 2601-2615 ◽  
Author(s):  
Rosa Fernández ◽  
Marina Marcet-Houben ◽  
Fabrice Legeai ◽  
Gautier Richard ◽  
Stéphanie Robin ◽  
...  
Keyword(s):  
Gene Duplication ◽  
Acyrthosiphon Pisum ◽  
High Capacity ◽  
Chromatin Accessibility ◽  
Pea Aphid ◽  
Specific Gene ◽  
Gene Duplications ◽  
Evolutionary Mechanisms ◽  
Ancestral Gene ◽  
Species Specific

Abstract Ecology of insects is as wide as their diversity, which reflects their high capacity of adaptation in most of the environments of our planet. Aphids, with over 4,000 species, have developed a series of adaptations including a high phenotypic plasticity and the ability to feed on the phloem sap of plants, which is enriched in sugars derived from photosynthesis. Recent analyses of aphid genomes have indicated a high level of shared ancestral gene duplications that might represent a basis for genetic innovation and broad adaptations. In addition, there are a large number of recent, species-specific gene duplications whose role in adaptation remains poorly understood. Here, we tested whether duplicates specific to the pea aphid Acyrthosiphon pisum are related to genomic innovation by combining comparative genomics, transcriptomics, and chromatin accessibility analyses. Consistent with large levels of neofunctionalization, we found that most of the recent pairs of gene duplicates evolved asymmetrically, showing divergent patterns of positive selection and gene expression. Genes under selection involved a plethora of biological functions, suggesting that neofunctionalization and tissue specificity, among other evolutionary mechanisms, have orchestrated the evolution of recent paralogs in the pea aphid and may have facilitated host–symbiont cooperation. Our comprehensive phylogenomics analysis allowed us to tackle the history of duplicated genes to pave the road toward understanding the role of gene duplication in ecological adaptation.

scholarly journals Pan-mammalian analysis of molecular constraints underlying extended lifespan

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Amanda Kowalczyk ◽  
Raghavendran Partha ◽  
Nathan L Clark ◽  
Maria Chikina
Keyword(s):  
Dna Repair ◽  
Single Species ◽  
Bowhead Whale ◽  
Individual Species ◽  
Evolutionary Constraint ◽  
Unexpected Finding ◽  
Evolutionary Mechanisms ◽  
Genetic Changes ◽  
Extended Lifespan ◽  
Species Specific

Although lifespan in mammals varies over 100-fold, the precise evolutionary mechanisms underlying variation in longevity remain unknown. Species-specific genetic changes have been observed in long-lived species including the naked mole-rat, bats, and the bowhead whale, but these adaptations do not generalize to other mammals. We present a novel method to identify associations between rates of protein evolution and continuous phenotypes across the entire mammalian phylogeny. Unlike previous analyses that focused on individual species, we treat absolute and relative longevity as quantitative traits and demonstrate that these lifespan traits affect the evolutionary constraint on hundreds of genes. Specifically, we find that genes related to cell cycle, DNA repair, cell death, the IGF1 pathway, and immunity are under increased evolutionary constraint in large and long-lived mammals. For mammals exceptionally long-lived for their body size, we find increased constraint in inflammation, DNA repair, and NFKB-related pathways. Strikingly, these pathways have considerable overlap with those that have been previously reported to have potentially adaptive changes in single-species studies, and thus would be expected to show decreased constraint in our analysis. This unexpected finding of increased constraint in many longevity-associated pathways underscores the power of our quantitative approach to detect patterns that generalize across the mammalian phylogeny.

Relationships between Mercury Concentrations in Walleye (Stizostedion vitreum) and Northern Pike (Esox lucius): Implications for Modelling and Biomonitoring

1994 ◽  
Vol 51 (9) ◽  
pp. 2090-2104 ◽  
Author(s):  
J. W. Parks ◽  
P. C. Craig ◽  
G. W. Ozburn
Keyword(s):  
Aquatic Ecosystems ◽  
Northern Pike ◽  
Esox Lucius ◽  
Stizostedion Vitreum ◽  
Empirical Relationships ◽  
Site Specific ◽  
Pike Esox Lucius ◽  
Species Specific ◽  
A Site ◽  
New Reservoir

Site-specific and interlake models are developed and tested for predicting mercury levels in walleye (Stizostedion vitreum) and northern pike (Esox lucius). The models are based on empirical relationships from coexisting fish in waters impacted by atmospheric loadings, contaminated sediments, and new reservoir formations. The sizes of fish used in the model (39-cm walleye and 55-cm northern pike) are typical of those caught by sport and commercial fishermen. The relative importance of a number of environmental factors to the accumulation of mercury in coexisting populations was examined by regression of the Biotic Mercury Partitioning Index (BMPI: mercury in species 1 (39-cm walleye)/mercury in species 2 (55-cm northern pike)) on pH, alkalinity, dissolved organic carbon, and other variables that have been identified as important to the accumulation of mercury in either or both species. No species-specific differences in mercury bioavailability were identified. We postulate that development of other biotic relationships on a site-specific, watershed, or broader geographic basis will assist in attempts to model mercury in aquatic ecosystems and reduce sample requirements for biomonitoring programs.

scholarly journals Mechanistic insights into molecular evolution of species-specific differential glycosaminoglycan binding surfaces in growth-related oncogene chemokines

2017 ◽  
Vol 4 (9) ◽  
pp. 171059 ◽  
Author(s):  
Khushboo Gulati ◽  
Minal Jamsandekar ◽  
Krishna Mohan Poluri
Keyword(s):  
Mammalian Species ◽  
Three Dimensional ◽  
Purifying Selection ◽  
Tissue Growth ◽  
Binding Domain ◽  
Dimensional Structure ◽  
Evolutionary Analysis ◽  
Evolutionary Mechanisms ◽  
Species Specific ◽  
Positively Selected Sites

Chemokines are chemotactic cytokines involved in leucocyte trafficking to infected tissue. Growth-related oncogene (GRO) chemokines namely CXCL1, CXCL2 and CXCL3 are neutrophil activating chemokines sharing a conserved three-dimensional structure, but encompassing functional diversity due to gene duplication and evolutionary events. However, the evolutionary mechanisms including selection pressures involved in diversification of GRO genes have not yet been characterized. Here, we performed comprehensive evolutionary analysis of GRO genes among different mammalian species. Phylogenetic analysis illustrated a species-specific evolution pattern. Selection analysis evidenced that these genes have undergone concerted evolution. Seventeen positively selected sites were obtained, although the majority of the protein is under purifying selection. Interestingly, these positively selected sites are more concentrated on the C-terminal/glycosaminoglycan (GAG) binding and dimerization segment compared to receptor binding domain. Substitution rate analysis confirmed the C-terminal domain of GRO genes as the highest substituted segment. Further, structural analysis established that the nucleotide alterations in the GAG binding domain are the source of surface charge modulation, thus generating the differential GAG binding surfaces and multiple binding sites as per evolutionary pressure, although the helical surface is primordial for GAG binding. Indeed, such variable electrostatic surfaces are crucial to regulate chemokine gradient formation during a host's defence against pathogens and also explain the significance of chemokine promiscuity.

scholarly journals Seabirds vary responses to supplemental food under dynamic natural prey availability and feeding aggregation composition

The Auk ◽  
2019 ◽  
Vol 137 (1) ◽  
Author(s):  
Laurie D Maynard ◽  
Paloma C Carvalho ◽  
Gail K Davoren
Keyword(s):  
Prey Capture ◽  
Prey Availability ◽  
Food Sources ◽  
Forage Fish ◽  
Flock Size ◽  
Foraging Success ◽  
Northern Fulmar ◽  
Supplemental Food ◽  
Natural Prey ◽  
Species Specific

Abstract While foraging, a predator can feed solitarily or in a group. The net energy gain of joining a group is predicted to vary with prey patch quality, species-specific prey capture behavior, and the size and species composition of the predator group. In coastal Newfoundland, Canada, capelin (Mallotus villosus), a key forage fish, migrates inshore to spawn during the summer, resulting in a dramatic shift in prey availability. During July–August 2015–2017, we examined the numerical and behavioral responses of procellarid (Great Shearwater [Ardenna gravis], Sooty Shearwater [A. grisea], Northern Fulmar [Fulmarus glacialis]), and gull species (Herring Gull [Larus argentatus], Great Black-backed Gull [L. marinus]) to fish offal under varying capelin availability as well as flock size and composition using an at-sea experiment on the northeast Newfoundland coast. The experiment consisted of providing offal every 30 s (10-min experimental period), along with 10-min control periods before and after. We recorded the species-specific number of birds on the water, the number of birds simultaneously attempting to capture offal, and the number of successful attempts (“foraging success”). The number of birds on the water was lower during high capelin availability for all species, except for Northern Fulmar. The number of conspecifics simultaneously attempting to capture offal increased with the number of conspecifics on the water, but plateaued at different numbers (4–17) for most species. The species-specific proportion of successful attempts (i.e. foraging success) varied with flock size and composition (i.e. number of conspecifics, heterospecifics, species). Foraging success of Herring Gulls and fulmars were moderately affected by flock size and composition, suggesting that they may be dominant competitors. Findings suggest that seabirds rely more heavily on supplemental food sources, such as fisheries discards and offal, when natural prey availability declines, potentially resulting in a higher risk of by-catch during fisheries activities as forage fish stocks decline.

Breeding ecology of Horned Puffins (Fratercula corniculata) in Alaska: annual variation and effects of El Niño

2003 ◽  
Vol 81 (6) ◽  
pp. 1004-1013 ◽  
Author(s):  
A MA Harding ◽  
J F Piatt ◽  
K C Hamer
Keyword(s):  
Food Availability ◽  
El Niño ◽  
Prey Availability ◽  
El Nino ◽  
Southern Oscillation ◽  
Breeding Ecology ◽  
Seabird Species ◽  
Breeding Parameters ◽  
Rate Of Increase ◽  
Species Specific

Both within and among seabird species, different aspects of breeding biology may respond to changes in prey availability in distinct ways, and the identification of species-specific breeding parameters that are sensitive to food availability is useful for monitoring purposes. We present data from a 5-year study (1995–1999) of the breeding ecology of Horned Puffins (Fratercula corniculata) in Alaska. The El Niño – Southern Oscillation event of 1997–1998 provided an opportunity to examine the sensitivity of various breeding parameters to a reduction in prey availability caused by the anomalous oceanographic conditions of 1998. Horned Puffins were able to maintain high fledging success (83–97%) over the 5 years of the study, despite the poor local feeding conditions in 1998. The rate of increase in chick mass was lowest in 1998, and evidence suggests that chicks also fledged at the youngest ages in that year. The impacts of reduced food availability on growth varied among body structures, suggesting differential allocation of energy and nutrients. There was no variation among years in either chick diet or the mass of food loads delivered by adults. We suggest that rates of chick growth, specifically mass increase, may be a good parameter to measure for use in monitoring Horned Puffins.

Explaining diet composition of North Sea cod (Gadus morhua): prey size preference vs. prey availability

2003 ◽  
Vol 60 (2) ◽  
pp. 140-150 ◽  
Author(s):  
Jens Floeter ◽  
Axel Temming
Keyword(s):  
North Sea ◽  
Diet Composition ◽  
Gadus Morhua ◽  
Prey Size ◽  
Prey Availability ◽  
Weight Ratio ◽  
Fish Prey ◽  
Gear Efficiency ◽  
Species Specific ◽  
Size Preference

The nature and significance of size preference for fish prey in the diet selection of North Sea cod (Gadus morhua L.) was analysed. The analysis combined information on size-specific abundance derived from bottom trawl surveys with prey size frequencies in cod stomachs from the International North Sea Stomach Database. To estimate the abundance of all potential fish prey in the sea, a length-based number spectrum was calculated, corrected for gear efficiency by the application of a species-specific correction factor, and weighted by local predator abundance to take the spatial–temporal overlap between cod and its prey into consideration. A prey size preference model for cod feeding on fish is presented. Results showed that the preferred predator-to-prey weight ratio is an exponentially increasing function of predator size and an exponentially decreasing function of the slope of the number spectrum. More than 75% of fish found in the stomachs of North Sea cod originated from the least preferred quartile of the prey size range, indicating that prey abundance is the main determinant of the diet composition.

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