scholarly journals Feeding habits variability of Lutjanus synagris and Lutjanus griseus in the littoral of Campeche, Mexico: an approach of food web trophic interactions between two snapper species

2020 ◽  
Vol 48 (4) ◽  
pp. 552-569 ◽  
Author(s):  
Paloma G. Juárez-Camargo ◽  
Atahualpa Sosa-López ◽  
Yassir Edén Torres-Rojas ◽  
Edgar Fernando Mendoza-Franco ◽  
Sergio Aguiñiga García
Keyword(s):  
Trophic Interactions ◽  
Feeding Habits ◽  
Relative Importance ◽  
Long Term Effects ◽  
Important Species ◽  
Δ13c And Δ15n ◽  
Spatial And Temporal Scales ◽  
Lutjanus Griseus ◽  
Coastal Marine ◽  
Isotopic Analyses

The study of the feeding habits variability (spatial and temporal scales) allows us to evaluate the trophic interactions between species, thus, the short and long-term effects of the removal of different species by the presence of different phenomena. In this study, we carried out stable isotope (δ13C and δ15N) and stomach content analyses to infer the trophic linkages between two snapper species (Lutjanus synagris and Lutjanus griseus) captured in the littoral of Campeche, Mexico. In total, 781 specimens were collected (528 L. synagris and 253 L. griseus) and based on relative importance index [%PSIRI] both snapper species consumed based on the prey-specific index of relative importance (PSIRI), Penaeidae family (PSIRI = 23.41%) was the most important species in the diet of Lutjanus synagris, while Callinectes sapidus (PSIRI = 21.45%) was the primary prey of Lutjanus griseus. The isotopic analyses indicated that both snapper species feed in the coastal-marine (δ15N: 10.6 to 12.1‰ and δ13C: -15.7 to -12.7‰); however, according to PERMANOVA, low diet similarity was found between snapper species (R = 0.07, P < 0.01), also, significant differences was detected in the δ15N and δ13C values between L. synagris, and L. griseus. Therefore, despite both snapper species presents similar trophic positions (L. synagris: 4.2 ± 0.2; L. griseus: 3.9 ± 0.1) and feeding behavior (according to SIBER = opportunistic predators), a low trophic overlap was observed, probably associated with the differential use of habitat in the coastal zone; where L. synagris is ecologically fed in areas of seagrass, while L. griseus is probably intermittent between pasture and mangrove areas, therefore, the role of each species is crucial in the dynamics of coastal-marine ecosystems as predators and potential structuring of the populations of their prey.

scholarly journals Ecosystem engineering strengthens bottom-up and weakens top-down effects via trait-mediated indirect interactions

2017 ◽  
Vol 284 (1863) ◽  
pp. 20170894 ◽  
Author(s):  
Zhiwei Zhong ◽  
Xiaofei Li ◽  
Dean Pearson ◽  
Deli Wang ◽  
Dirk Sanders ◽  
...  
Keyword(s):  
Trophic Interactions ◽  
Large Scale ◽  
Field Experiments ◽  
Ecosystem Engineering ◽  
Relative Importance ◽  
Top Down ◽  
Bottom Up ◽  
Spatial And Temporal Scales ◽  
Natural Systems ◽  
Ecological Scale

Trophic interactions and ecosystem engineering are ubiquitous and powerful forces structuring ecosystems, yet how these processes interact to shape natural systems is poorly understood. Moreover, trophic effects can be driven by both density- and trait-mediated interactions. Microcosm studies demonstrate that trait-mediated interactions may be as strong as density-mediated interactions, but the relative importance of these pathways at natural spatial and temporal scales is underexplored. Here, we integrate large-scale field experiments and microcosms to examine the effects of ecosystem engineering on trophic interactions while also exploring how ecological scale influences density- and trait-mediated interaction pathways. We demonstrate that (i) ecosystem engineering can shift the balance between top-down and bottom-up interactions, (ii) such effects can be driven by cryptic trait-mediated interactions, and (iii) the relative importance of density- versus trait-mediated interaction pathways can be scale dependent. Our findings reveal the complex interplay between ecosystem engineering, trophic interactions, and ecological scale in structuring natural systems.

scholarly journals Cultivation of the Acidophilic Microalgae Galdieria phlegrea with Wastewater: Process Yields

2021 ◽  
Vol 18 (5) ◽  
pp. 2291
Author(s):  
Maria Rosa di Cicco ◽  
Maria Palmieri ◽  
Simona Altieri ◽  
Claudia Ciniglia ◽  
Carmine Lubritto
Keyword(s):  
Municipal Wastewater ◽  
Lipid Fraction ◽  
Total Lipid Content ◽  
Phosphate Removal ◽  
Total Carbon ◽  
Δ13c And Δ15n ◽  
Metabolic Versatility ◽  
Working Volume ◽  
Isotopic Analyses ◽  
Consistent Performance

Algal based wastewater treatment offers the opportunity to recover, in the form of biomass, the nutrients and internal chemical energy of wastewater. Recently, there has been a growing interest in the use of extremophilic microalgae, as they can easily adapt to difficult and often pollutant-rich environments. The thermo-acidophilic microalga Galdieria phlegrea is a species of recent discovery and great metabolic versatility, but it has still been poorly studied. Here, G. phlegrea was cultivated using raw municipal wastewater in 1 L Erlenmeyer flasks with 700 mL working volume at 37 °C for up to nine days. During the cultivation phase, biomass growth, phycocyanin content, ammonium and phosphate removal from the wastewater, lipid fraction, total carbon and nitrogen in the biomass, and variation in δ13C and δ15N isotopic ratios (a novel analytical contribution in these experiments) were monitored. Results indicated that G. phlegrea was able to grow in raw effluent, where it removed more than 50% ammonium and 20% phosphate in 24 h; total lipid content was in the range of 11–22%, while average C-N content was of 45% and 6%, respectively; isotopic analyses proved to be a useful support in identifying C and N metabolic pathways from effluent to biomass. Overall, G. phlegrea showed consistent performance with similar Cyanidiophyceae and is a potentially viable candidate for municipal wastewater valorization from a circular economy perspective.

scholarly journals Feeding habits of Cocobolo Andinoacara pulcher in the cienaga Grande de Lorica, Colombia

2016 ◽  
pp. 5189-5197
Author(s):  
Charles W Olaya-Nieto ◽  
Liquey Camargo-Herrera ◽  
Vanessa Díaz-Sajonero ◽  
Fredys F Segura-Guevara
Keyword(s):  
River Basin ◽  
Stomach Content ◽  
Feeding Habits ◽  
Frequency Of Occurrence ◽  
Relative Importance ◽  
Food Groups ◽  
Total Length ◽  
Length Relationship ◽  
Importance Index ◽  
Gut Length

ABSTRACTObjective. The feeding habits of Cocobolo (Andinoacara pulcher) in the cienaga Grande de Lorica, Sinu river basin, were studied. Materials and methods. The stomach content was analyzed using the Proportion of empty stomachs, Grade of digestion, Frequency of occurrence, numerical Frequency, Gravimetry, relative importance Index (RII) and the gut length-total length relationship. Results. 39.8% of stomachs were empty, 47.1% of preys were fresh and five food groups were identified. Vegetable remains was the most frequent group (63.8%) and the prey with greatest composition in weight (33.5%), while Rest of fishes was the most abundant group (34.7%). It was observed that in low and rising waters, fishes was the most consumed prey, while that in high and falling waters the most consumed prey was vegetable remains. Vegetable remains, detritus and fishes were food groups of secondary relative importance, while Insects and Others were circumstantial or incidental groups. Conclusions. The results achieved indicate that Cocobolo is a fish with omnivores feeding habits with a preference for fishes and vegetable remains. RESUMEN Objetivo. Se estudiaron los hábitos alimentarios de Cocobolo (Andinoacara pulcher) en la ciénaga Grande de Lorica, cuenca del río Sinú, Colombia. Materiales y Métodos. El contenido estomacal se evaluó con el Coeficiente de vacuidad, Grado de llenado, Grado de digestión, Frecuencia de ocurrencia, Frecuencia numérica, Gravimetría, Índice de importancia relativa y la relación longitud intestinal- longitud total. Resultados. El 39.8% de los estómagos se encontró vacío, el 47.1% de las presas en estado fresco y se identificaron cinco grupos alimentarios. Material vegetal fue el grupo más frecuente (63.8%) y con mayor composición por peso (33.5%), mientras que Restos de peces fue el más abundante (34.7%). Se observó que en aguas bajas y en aguas ascendentes, peces fue la presa más consumida, mientras que en aguas altas y aguas descendentes, fue material vegetal. Material vegetal, detritos y restos de peces fueron grupos alimentarios de importancia relativa secundaria, mientras que insectos y otros fueron circunstanciales o incidentales. Conclusiones. Los resultados alcanzados indican que Cocobolo es un pez de hábitos alimentarios omnívoros con preferencia por peces y material vegetal.

Habitat Mapping for Human Well-Being: a tool for reducing risk in disaster-prone coastal environments and human communities

2021 ◽  
pp. SP505-2021-26
Author(s):  
Yuri Oki ◽  
Hiroshi Kitazato ◽  
Toyonobu Fujii ◽  
Soichiro Yasukawa
Keyword(s):  
Salt Marshes ◽  
Scale Up ◽  
Well Being ◽  
Coastal Ecosystems ◽  
Indian Ocean Tsunami ◽  
Important Species ◽  
Coastal Marine ◽  
Coastal Species ◽  
Northeastern Japan ◽  
The Pacific

AbstractCoastal ecosystems consist of diverse habitats, such as reed beds, salt marshes, mangrove swamps, tidal flats, river deltas, seagrass fields, coral reefs, sandy/rocky-shore beaches and other habitats that harbour biodiversity. The Great East Japan Earthquake of March 2011 caused severe damage to one-third of the fishing communities along the Pacific Ocean of northeastern Japan. Coastal species, such as seagrasses, function as nursery areas for commercially important species. Coastal ecosystems provide natural infrastructure for the prevention and reduction of hazardous events, a process known as ecosystem-based disaster risk reduction (Eco-DRR). The preparation of topographic and thematic maps of coastal marine environments is essential to establish and visualise the concept of Eco-DRR. Experience gained following the Japanese earthquake, as well as examples from Indonesia and Thailand in the wake of 2004 Indian Ocean tsunami showed that Eco-DRR is an affordable and sustainable approach. Dissemination of habitat maps should be further promoted as a means to ‘Build Back Better’. To scale up and promote Eco-DRR, scientists must work in a transdisciplinary manner and engage with society through understanding the roles of ecosystems by monitoring and analysing, providing solutions and raising the awareness of community and policy makers, enabling them to better implement Eco-DRR.

Biology and Management of Dogfish Sharks

2009 ◽  
Keyword(s):  
Stable Isotope ◽  
Isotope Composition ◽  
Feeding Habits ◽  
Important Species ◽  
Isotopic Signatures ◽  
Ecological Changes ◽  
Varied Diet ◽  
Commercially Important ◽  
C And N

Abstract.—Spiny dogfish <em>Squalus acanthias </em>are an abundant and commercially important species of fish off both the Atlantic and Pacific coasts of North America. They are opportunistic feeders and have a varied diet that can include many fish species, especially small forage fish such as herring, capelin, and sand lance as well as crustaceans, worms, euphausiids, gelatinous zooplankton, and cephalopods. The purpose of our present study is to investigate the utility of the second dorsal spine in providing multiyear information on the feeding habits of dogfish using stable isotope (C and N) analysis. The outer dentine and enamel layers of a spine from three dogfish (caught off the coast of British Columbia) were analyzed to obtain their stable nitrogen and carbon isotope composition (δ<sup>15</sup>N and δ<sup>13</sup>C, respectively). Each sample had annuli from multiple years, allowing possible seasonal migrations to be averaged over samples. The δ<sup>15</sup>N ranged from a low of 11.6‰ to a high of 14.9‰ over the three spines and δ<sup>13</sup>C ranged from –11.5‰ to –18.4‰. The variable isotopic signatures along the spine indicate that the method may be used to assess ecological changes. Stable isotope measurements of dogfish spines could be a valuable means of determining long-term changes in habitat usage and feeding ecology.

Feeding ecology of free-living nematodes.

2021 ◽  
pp. 185-215
Author(s):  
Nabil Majdi ◽  
Tom Moens ◽  
Walter Traunspurger
Keyword(s):  
Feeding Ecology ◽  
Trophic Interactions ◽  
Feeding Habits ◽  
Food Sources ◽  
Environmental Constraints ◽  
Feeding Rates ◽  
Feeding Selectivity ◽  
Free Living ◽  
Aquatic Nematodes ◽  
Food Recognition

Abstract This chapter provides overview of the feeding habits and food sources of aquatic nematodes. The environmental constraints on feeding, food recognition, and feeding selectivity are also addressed, together with the complex, indirect trophic interactions between nematodes and their microbial prey. To raise awareness of the inherent methodological and/or interpretational problems in studies of nematode feeding ecology, the chapter ends with a brief look at the methods that have been adapted to quantify feeding rates in nematodes.

Low Mortality of Larval Lampreys from Electrofishing, Suction-pumping, Anesthesia, and Handling

2017 ◽  
Vol 8 (2) ◽  
pp. 640-647 ◽  
Author(s):  
Jeffrey C. Jolley ◽  
Christina T. Uh ◽  
Gregory S. Silver ◽  
Timothy A. Whitesel
Keyword(s):  
Pacific Northwest ◽  
Control Group ◽  
Long Term Effects ◽  
Negative Effects ◽  
Short Term ◽  
Important Species ◽  
Pacific Lamprey ◽  
The Pacific ◽  
Delayed Mortality

Abstract Native lamprey populations are declining worldwide. In the Pacific Northwest focus on conservation and management of these ecologically and culturally important species has increased. Concern has emerged regarding the effects of sampling and handling of lamprey, with little to no attention given to the larval lifestage. We monitored the survival of larval Pacific Lamprey Entosphenus tridentatus and Lampetra spp. after backpack electrofishing, deepwater electrofishing and suction-pumping, anesthesia, and handling. We performed survival trials on wild-caught lamprey (n = 15 larvae in each trial) collected from the Clackamas River drainage in Oregon, USA, coupled with control group trials from lamprey sourced from a hatchery (n = 10 larvae). Short-term (96 h) survival was &gt;98% with only one observed mortality. Delayed mortality (1 wk) was observed for four individuals that had fungus; two of those were positive for the bacteria Aeromonas hyrdrophila. We recorded blood hematocrit as a secondary measure of stress. The baseline, nonstressed larvae hematocrit levels did not differ from those of fish that had undergone stress through electrofishing, suction-pumping, and handling without anesthesia. Electrofishing, suction-pumping, and anesthesia showed no short-term negative effects on larval lamprey although potential long-term effects remain unstudied. These techniques appear to provide efficient and relatively safe methods for collecting and surveying larval lamprey.

scholarly journals Global to USA County Scale Analysis of Weather, Urban Density, Mobility, Homestay, and Mask Use on COVID-19

2020 ◽  
Vol 17 (21) ◽  
pp. 7847
Author(s):  
Sajad Jamshidi ◽  
Maryam Baniasad ◽  
Dev Niyogi
Keyword(s):  
Transmission Rate ◽  
Climate Impact ◽  
Relative Importance ◽  
Urban Density ◽  
Spatial And Temporal Scales ◽  
Urban Dynamics ◽  
Causal Processes ◽  
The Impact ◽  
The Relationship

Prior evaluations of the relationship between COVID-19 and weather indicate an inconsistent role of meteorology (weather) in the transmission rate. While some effects due to weather may exist, we found possible misconceptions and biases in the analysis that only consider the impact of meteorological variables alone without considering the urban metabolism and environment. This study highlights that COVID-19 assessments can notably benefit by incorporating factors that account for urban dynamics and environmental exposure. We evaluated the role of weather (considering equivalent temperature that combines the effect of humidity and air temperature) with particular consideration of urban density, mobility, homestay, demographic information, and mask use within communities. Our findings highlighted the importance of considering spatial and temporal scales for interpreting the weather/climate impact on the COVID-19 spread and spatiotemporal lags between the causal processes and effects. On global to regional scales, we found contradictory relationships between weather and the transmission rate, confounded by decentralized policies, weather variability, and the onset of screening for COVID-19, highlighting an unlikely impact of weather alone. At a finer spatial scale, the mobility index (with the relative importance of 34.32%) was found to be the highest contributing factor to the COVID-19 pandemic growth, followed by homestay (26.14%), population (23.86%), and urban density (13.03%). The weather by itself was identified as a noninfluential factor (relative importance < 3%). The findings highlight that the relation between COVID-19 and meteorology needs to consider scale, urban density and mobility areas to improve predictions.

Early Post-Partum Contact and Later Attitudes

1980 ◽  
Vol 3 (3) ◽  
pp. 273-286 ◽  
Author(s):  
Peter de Chateau
Keyword(s):  
Post Partum ◽  
Postnatal Period ◽  
Child Rearing ◽  
Control Group ◽  
Maternal Behaviour ◽  
Relative Importance ◽  
Long Term Effects ◽  
Infant Behaviour

In a randomized, prospective study the long-term effects of early post-partum skin-toskin and suckling contact was studied. In follow-up studies 36 hours, 3 and 12 months after delivery maternal behaviour, infant behaviour, the duration of breast feeding and certain attitudes towards child rearing procedures were shown to develop differently in a group of mothers and infants with early post-natal contacts as compared to a control group. Three years after delivery parents with early contact appreciated their children's language development to be faster; the number of siblings born in these families was greater than in controls. In the discussion, the relative importance of the immediate postnatal period is emphasized, a more family oriented development seems to occur in the presence of early post-delivery interaction.

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