scholarly journals Between-lake variation in the trophic ecology of an invasive crayfish

2017 ◽  
Vol 62 (9) ◽  
pp. 1501-1510 ◽  
Author(s):  
Michelle C. Jackson ◽  
Charlotte Evangelista ◽  
Tian Zhao ◽  
Antoine Lecerf ◽  
J. Robert Britton ◽  
...  
Keyword(s):  
Trophic Ecology ◽  
Invasive Crayfish ◽  
Lake Variation

Trophic Ecology

2015 ◽  
Keyword(s):  
Trophic Ecology

Neonatal nutritional strategy of a viviparous elasmobranch with extremely low reproductive output

2020 ◽  
Vol 638 ◽  
pp. 107-121 ◽  
Author(s):  
BS Rangel ◽  
NE Hussey ◽  
Y Niella ◽  
LA Martinelli ◽  
AD Gomes ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Reproductive Strategies ◽  
Trophic Ecology ◽  
Essential Fatty Acids ◽  
Physiological State ◽  
Maternal Investment ◽  
Early Life History ◽  
Nutritional State ◽  
Disc Width ◽  
Biomarker Analysis

Throughout evolutionary history, elasmobranchs have developed diverse reproductive strategies. Little focused work, however, has addressed how neonatal nutritional state is affected by differing degrees of maternal investment associated with these markedly different reproductive strategies. To investigate the effect of maternal investment on the nutritional quality of pups during the early life history of an extremely viviparous elasmobranch, quantitative biomarker analysis including lipids, fatty acids and stable isotopes was conducted. Using the cownose ray Rhinoptera bonasus (histotrophic viviparous) as a model, we found that pups were initially born in a positive nutritional state, enriched in physiologically important essential fatty acids and nitrogen and carbon stable isotope values (δ15N and δ13C), a result of maternal intrauterine transfer. A systematic decrease in some fatty acids and δ15N values, as well as a decrease in cholesterol with growth, confirmed that these substrates were derived from maternal resources and used in initial metabolic processes following birth. An observed increase in condition factor, plasma essential fatty acids and triglyceride:cholesterol ratio with increasing body size identified a progression towards successful independent foraging with pups not displaying marked nutritional deficiency or fasting phases. Our multi-tracer approach allowed the identification of 2 size classes of young rays (<50 and <70 cm disc width) that displayed distinct physiological states. Since prenatal maternal investment is critical for offspring condition and to promote successful foraging post birth, understanding the trophic ecology and physiological state of pups during their first year is critical to guide management and conservation within nursery grounds.

Biometric relationships of the invasive crayfish Procambarus clarkii to the Egyptian freshwater drainage canals

2015 ◽  
Vol 7 (1) ◽  
pp. 53-65
Author(s):  
El-Sayed M. ◽  
Al-Damhougy A. ◽  
Zaakouk A. ◽  
Amer, A.
Keyword(s):  
Procambarus Clarkii ◽  
Drainage Canals ◽  
Invasive Crayfish

TROPHIC ECOLOGY AND BIOEROSION OF MOLLUSCAN FAUNAS FROM THE LOWER WACCAMAW FORMATION AT PRINCE'S QUARRY IN SOUTHEASTERN NORTH CAROLINA

2016 ◽  
Author(s):  
Laura C. Streib ◽  
◽  
Christy C. Visaggi ◽  
Morgan E. Oldham ◽  
Austin B. Rickles ◽  
...  
Keyword(s):  
North Carolina ◽  
Trophic Ecology

Estimating native and invasive crayfish distributions in relation to culvert barriers with environmental DNA

2019 ◽  
Vol 38 (3) ◽  
pp. 629-641 ◽  
Author(s):  
Kousuke Ikeda ◽  
Hideyuki Doi ◽  
Shigeharu Terui ◽  
Atsuko Kato ◽  
Takashi Mitsuzuka ◽  
...  
Keyword(s):  
Environmental Dna ◽  
Invasive Crayfish

scholarly journals Integrating multiple chemical tracers to elucidate the diet and habitat of Cookiecutter Sharks

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aaron B. Carlisle ◽  
Elizabeth Andruszkiewicz Allan ◽  
Sora L. Kim ◽  
Lauren Meyer ◽  
Jesse Port ◽  
...  
Keyword(s):  
Trophic Ecology ◽  
Foraging Ecology ◽  
Isotope Analysis ◽  
Environmental Dna ◽  
Small Sample ◽  
Apex Predators ◽  
Central Pacific ◽  
Chemical Tracers ◽  
Important Prey ◽  
Tracer Techniques

AbstractThe Cookiecutter shark (Isistius brasiliensis) is an ectoparasitic, mesopelagic shark that is known for removing plugs of tissue from larger prey, including teleosts, chondrichthyans, cephalopods, and marine mammals. Although this species is widely distributed throughout the world’s tropical and subtropical oceanic waters, like many deep-water species, it remains very poorly understood due to its mesopelagic distribution. We used a suite of biochemical tracers, including stable isotope analysis (SIA), fatty acid analysis (FAA), and environmental DNA (eDNA), to investigate the trophic ecology of this species in the Central Pacific around Hawaii. We found that large epipelagic prey constituted a relatively minor part of the overall diet. Surprisingly, small micronektonic and forage species (meso- and epipelagic) are the most important prey group for Cookiecutter sharks across the studied size range (17–43 cm total length), with larger mesopelagic species or species that exhibit diel vertical migration also being important prey. These results were consistent across all the tracer techniques employed. Our results indicate that Cookiecutter sharks play a unique role in pelagic food webs, feeding on prey ranging from the largest apex predators to small, low trophic level species, in particular those that overlap with the depth distribution of the sharks throughout the diel cycle. We also found evidence of a potential shift in diet and/or habitat with size and season. Environmental DNA metabarcoding revealed new prey items for Cookiecutter sharks while also demonstrating that eDNA can be used to identify recent prey in stomachs frozen for extended periods. Integrating across chemical tracers is a powerful tool for investigating the ecology of elusive and difficult to study species, such as meso- and bathypelagic chondrichthyans, and can increase the amount of information gained from small sample sizes. Better resolving the foraging ecology of these mesopelagic predators is critical for effective conservation and management of these taxa and ecosystems, which are intrinsically vulnerable to overfishing and exploitation.

scholarly journals Diversity and Diet Differences of Small Mammals in Commensal Habitats

Diversity ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 346
Author(s):  
Linas Balčiauskas ◽  
Laima Balčiauskienė ◽  
Andrius Garbaras ◽  
Vitalijus Stirkė
Keyword(s):  
Small Mammals ◽  
Small Mammal ◽  
Trophic Ecology ◽  
Mammal Species ◽  
Additional Food ◽  
Δ13c And Δ15n ◽  
Degree Of Separation ◽  
Kitchen Gardens ◽  
Dietary Plasticity ◽  
The Stability

The stability of diversity of syntopic (inhabiting the same habitat in the same time) small mammals in commensal habitats, such as farmsteads and kitchen gardens, and, as a proxy of their diet, their isotopic niches, was investigated in Lithuania in 2019–2020. We tested whether the separation of species corresponds to the trophic guilds, whether their diets are related to possibilities of getting additional food from humans, and whether their diets are subject to seasonal trends. We analyzed diversity, dominance and distribution of hair δ13C and δ15N values. Diversity and dominance was not stable and differed according to human influence. The highest small mammal species richness occurred in commensal habitats that provided additional food. The degree of separation of species was higher in homestead habitats than in kitchen gardens, where a 1.27 to 35.97% overlap of isotopic niches was observed between pairs of species. Temporal changes in δ13C and δ15N values in the hair of the mammals were not equally expressed in different species. The isotopic overlap may depend on dietary plasticity, minimizing interspecific competition and allowing co-existence of syntopic species. Thus, small mammal trophic ecology is likely related to intensity of agricultural activities in the limited space of commensal habitats.

Trophic ecology of a large-bodied marine predator, bluntnose sixgill shark Hexanchus griseus, inferred using stable isotope analysis

2020 ◽  
Vol 103 (2) ◽  
pp. 147-162
Author(s):  
Jonathan C. P. Reum ◽  
Gregory D. Williams ◽  
Chris J. Harvey ◽  
Kelly S. Andrews ◽  
Phillip S. Levin
Keyword(s):  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
Trophic Ecology ◽  
Isotope Analysis ◽  
Marine Predator ◽  
Hexanchus Griseus
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