scholarly journals Reconstructing the diet, trophic level and migration pattern of mysticete whales based on baleen isotopic composition

2021 ◽  
Vol 8 (12) ◽  
Author(s):  
Philip M. Riekenberg ◽  
Jaime Camalich ◽  
Elisabeth Svensson ◽  
Lonneke L. IJsseldijk ◽  
Sophie M. J. M. Brasseur ◽  
...  
Keyword(s):  
Trophic Level ◽  
Trophic Position ◽  
Feeding Habits ◽  
Trophic Levels ◽  
Isotopic Niche ◽  
Physiological Changes ◽  
Temporal Sampling ◽  
Fin Whales ◽  
And Migration ◽  
Migration Pathways

Baleen from mysticete whales is a well-preserved proteinaceous material that can be used to identify migrations and feeding habits for species whose migration pathways are unknown. Analysis of δ 13 C and δ 15 N values from bulk baleen have been used to infer migration patterns for individuals. However, this approach has fallen short of identifying migrations between regions as it is difficult to determine variations in isotopic shifts without temporal sampling of prey items. Here, we apply analysis of δ 15 N values of amino acids to five baleen plates belonging to three species, revealing novel insights on trophic position, metabolic state and migration between regions. Humpback and minke whales had higher reconstructed trophic levels than fin whales (3.7–3.8 versus 3–3.2, respectively) as expected due to different feeding specialization. Isotopic niche areas between baleen minima and maxima were well separated, indicating regional resource use for individuals during migration that aligned with isotopic gradients in Atlantic Ocean particulate organic matter. Phenylanine δ 15 N values confirmed regional separation between the niche areas for two fin whales as migrations occurred and elevated glycine and threonine δ 15 N values suggested physiological changes due to fasting. Simultaneous resolution of trophic level and physiological changes allow for identification of regional migrations in mysticetes.

scholarly journals Reconstructing the diet, trophic level, and migration pattern of Mysticete whales based on baleen isotopic composition

2020 ◽  
Author(s):  
Philip M. Riekenberg ◽  
Jaime Camalich ◽  
Elisabeth Svensson ◽  
Lonneke L. IJsseldijk ◽  
Sophie M.J.M. Brasseur ◽  
...  
Keyword(s):  
Trophic Level ◽  
Trophic Position ◽  
Feeding Habits ◽  
Trophic Levels ◽  
Isotopic Niche ◽  
Physiological Changes ◽  
Temporal Sampling ◽  
Fin Whales ◽  
And Migration ◽  
Migration Pathways

AbstractBaleen from mysticete whales is a well-preserved proteinaceous material that can be used to identify migrations and feeding habits for species whose migration pathways are unknown. Analysis of δ13C and δ15N from bulk baleen has been used to infer migration patterns for individuals. However, this approach has fallen short of identifying migrations between regions as it is difficult to determine variations in isotopic shifts without temporal sampling of prey items. Here we apply analysis of δ15N values of amino acids to five baleen plates belonging to three species, revealing novel insights on trophic position, metabolic state, and migration between regions. Humpback and minke whales had higher reconstructed trophic levels than fin whales (3.4-3.5 versus 2.7-2.9, respectively) as expected due to different feeding specialization. Isotopic niche areas between baleen minima and maxima were well separated, indicating regional resource use for individuals during migration that aligned with isotopic gradients in Atlantic Ocean particulate organic matter. δ15N values from phenylalanine confirmed regional separation between the niche areas for two fin whales as migrations occurred and elevated glycine and threonine δ15N values revealed physiological changes due to fasting. Simultaneous resolution of trophic level and physiological changes allow for identification of regional migrations in mysticetes.

scholarly journals Dual stable isotope abundances unravel trophic position of estuarine nematodes

2005 ◽  
Vol 85 (6) ◽  
pp. 1401-1407 ◽  
Author(s):  
Tom Moens ◽  
Steven Bouillon ◽  
Fabiane Gallucci
Keyword(s):  
Empirical Evidence ◽  
Trophic Level ◽  
Trophic Position ◽  
Feeding Habits ◽  
Nematode Species ◽  
Trophic Levels ◽  
Food Sources ◽  
Feeding Mode ◽  
Nematode Communities ◽  
Carbon And Nitrogen

The role and quantitative importance of free-living nematodes in marine and estuarine soft sediments remain enigmatic for lack of empirical evidence on the feeding habits and trophic position of most nematode species. Here we use natural abundances of carbon and nitrogen stable isotopes of some abundant nematode species/genera from estuarine intertidal sediments to assess their trophic level and major food sources. In all stations, δ15N of different dominant nematode species/genera spanned a range of 3.6 to 6.3 ppt, indicating that at least two trophic levels were represented. The large nematodes Enoplus brevis, Enoploides longispiculosus and Adoncholaimus fuscus consistently had high δ15N, in line with mouth-morphology based predictions and empirical evidence on their predacious feeding modes. Daptonema sp., Metachromadora remanei, Praeacanthonchus punctatus and ‘Chromadoridae’ (dominated by Ptycholaimellus ponticus) had comparatively lower δ15N, and δ13C suggesting that microphytobenthos (MPB) is their major carbon source, although freshly sedimented particulate organic matter may also contribute to their nutrition in silty sediments. The trophic position of Sphaerolaimus sp., a genus with documented predacious feeding mode, was ambiguous. Ascolaimus elongatus had δ15N signatures indicating a predacious ecology, which is at variance with expectations from existing feeding type classifications. Our study shows that—despite limitations imposed by the biomass requirements for EA-IRMS (elemental analyser—isotope ratio mass spectrometry)—natural isotope abundances of carbon and nitrogen are powerful tools to unravel trophic structure within nematode communities. At the same time, the prominence of different trophic levels results in a large span of δ15N, largely invalidating the use of nitrogen isotope abundances to assess food sources and trophic level of whole nematode communities.

Trophic ecology of the chihuil sea catfish (Bagre panamensis) in the south-east Gulf of California, México

2017 ◽  
Vol 98 (4) ◽  
pp. 885-893 ◽  
Author(s):  
Víctor M. Muro-Torres ◽  
Felipe Amezcua ◽  
Raul E. Lara-Mendoza ◽  
John T. Buszkiewicz ◽  
Felipe Amezcua-Linares
Keyword(s):  
Gulf Of California ◽  
Trophic Ecology ◽  
Trophic Position ◽  
Feeding Habits ◽  
Isotope Analysis ◽  
Demersal Fish ◽  
Trophic Levels ◽  
High Plasticity ◽  
Combined Use ◽  
Ecosystem Based Fisheries Management

The trophic ecology of the chihuil sea catfish Bagre panamensis was studied through high-resolution variations in its feeding habits and trophic position (TP) in the SE Gulf of California, relevant to sex, size and season. The combined use of stomach content (SCA) and stable isotope analysis (SIA) allowed us to perform these analyses and also estimate the TP of its preys. Results of this study show that the chihuil sea catfish is a generalist and opportunistic omnivore predator that consumes primarily demersal fish and peneid shrimps. Its diet did not vary with climatic season (rainy or dry), size or sex. Results from the SIA indicated high plasticity in habitat use and prey species. The estimated TP value was 4.19, which indicates a tertiary consumer from the soft bottom demersal community in the SE Gulf of California, preying on lower trophic levels, which aids in understanding the species' trophic role in the food web. Because this species and its prey are important to artisanal and industrial fisheries in the Gulf of California, diet assimilation information is useful for the potential establishment of an ecosystem-based fisheries management in the area.

scholarly journals Examining predator–prey body size, trophic level and body mass across marine and terrestrial mammals

2014 ◽  
Vol 281 (1797) ◽  
pp. 20142103 ◽  
Author(s):  
Marlee A. Tucker ◽  
Tracey L. Rogers
Keyword(s):  
Community Structure ◽  
Body Size ◽  
Body Mass ◽  
Marine Environment ◽  
Trophic Level ◽  
Marine Mammals ◽  
Trophic Position ◽  
Trophic Levels ◽  
Predator Prey ◽  
Terrestrial Mammals

Predator–prey relationships and trophic levels are indicators of community structure, and are important for monitoring ecosystem changes. Mammals colonized the marine environment on seven separate occasions, which resulted in differences in species' physiology, morphology and behaviour. It is likely that these changes have had a major effect upon predator–prey relationships and trophic position; however, the effect of environment is yet to be clarified. We compiled a dataset, based on the literature, to explore the relationship between body mass, trophic level and predator–prey ratio across terrestrial ( n = 51) and marine ( n = 56) mammals. We did not find the expected positive relationship between trophic level and body mass, but we did find that marine carnivores sit 1.3 trophic levels higher than terrestrial carnivores. Also, marine mammals are largely carnivorous and have significantly larger predator–prey ratios compared with their terrestrial counterparts. We propose that primary productivity, and its availability, is important for mammalian trophic structure and body size. Also, energy flow and community structure in the marine environment are influenced by differences in energy efficiency and increased food web stability. Enhancing our knowledge of feeding ecology in mammals has the potential to provide insights into the structure and functioning of marine and terrestrial communities.

The trophic role of Octopus insularis at a pristine tropical atoll in southwest Atlantic: a potential keystone predator?

2019 ◽  
Author(s):  
Renato Junqueira de Souza Dantas ◽  
Tatiana Silva Leite ◽  
Cristiano Queiroz de Albuquerque
Keyword(s):  
Food Web ◽  
Trophic Position ◽  
Feeding Strategy ◽  
Isotope Analysis ◽  
Carbon Sources ◽  
Trophic Levels ◽  
Isotopic Niche ◽  
Southwest Atlantic ◽  
Trophic Role

In the present study, we evaluated the trophic role of Octopus insularis Leite and Haimovici, 2008 in the food web of Rocas Atoll, a preserved insular territory in the southwest Atlantic. Using stable isotope analysis of C and N, we showed that the local trophic web comprises at least four trophic levels, where the octopus presents d13C values from -12.1 to -6.1‰, d15N values from 6.4 to 11.0‰ and occupies a trophic position (TP) between the second and third trophic levels (mean ± SD TPadditive = 3.08 ± 0.36; TPBayesian = 3.12 ± 0.17). Among other benthic/reef-associated consumers, this cephalopod stood out for its much wider isotopic niche (SEAB = 4.7890), pointing to a diet diversified in carbon sources, but focused on prey in lower TPs. Time-minimizing feeding strategy seemed almost permanent throughout the life cycle, given the great niche overlap between small and large octopuses (large: SEAB = 4.59, small: SEAB = 4.03) and their very similar trophic positions (TPadditive/TPBayesian: large = 3.27/3.26; small = 2.89/2.99). Also, as a prey, O. insularis composed 16%-24% of the diet of some benthic/demersal predators. Overall, exerting great predatory pressure on bottom-associated organisms and serving as a relevant food source for top and mesopredators, O. insularis represented a top consumer of the benthic portion of the food web and an important link between its benthic and demersal strata with potential for keystone species.

scholarly journals Spatial variation in the stable isotopes of 13C and 15N and trophic position of Leporinus friderici (Characiformes, Anostomidae) in Corumbá Reservoir, Brazil

2007 ◽  
Vol 79 (1) ◽  
pp. 41-49 ◽  
Author(s):  
Alexandre L. Pereira ◽  
Evanilde Benedito ◽  
Cássia M. Sakuragui
Keyword(s):  
Stable Isotopes ◽  
Carbon Source ◽  
Isotopic Composition ◽  
Spatial Variation ◽  
Food Web ◽  
Trophic Level ◽  
Trophic Position ◽  
Trophic Levels ◽  
C3 Plants ◽  
The One

Stable isotopes of carbon (delta13C) and nitrogen (delta15N) were used to describe sources of energy and trophic position for adult Leporinus friderici in the area of the Corumbá Reservoir, Brazil. Samples were collected from April 1999 to March 2000. Spatial variations were not identified in the isotopic composition. The maximum and minimum contribution of C4 plants calculated integrating the variation of plants and fish were 47.7% and 2.4%, respectively. Among C3 plants, periphyton presented closer isotopic values to those observed for fishes, corresponding to an important carbon source. The proportion of ingested plant item is larger in rivers upstream from the reservoir (42.7%), which justifies the smaller trophic level among there. However, in the reservoir, the ingestion of fish was 81.4%, while ingested plants contributed with 18.6%. Downstream from the dam, participation of plant item was even smaller (14.4%). Although the trophic position calculated with diet data was proportional to the one calculated with delta15N values, the former elevated the trophic level of L. friderici in the food web, because estimated trophic positions were based on fish items belonging to the 2nd (a) and to the 3rd (b) trophic levels.

scholarly journals Not all jellyfish are equal: isotopic evidence for inter- and intraspecific variation in jellyfish trophic ecology

2015 ◽  
Author(s):  
Nicholas E.C. Fleming ◽  
Chris Harrod ◽  
Jason Newton ◽  
Jonathan D.R. Houghton
Keyword(s):  
Trophic Ecology ◽  
Functional Group ◽  
Trophic Position ◽  
Seasonal Succession ◽  
Deep Ocean ◽  
Trophic Levels ◽  
Foraging Strategies ◽  
Isotopic Niche ◽  
Ecosystem Models ◽  
Temporal Shifts

Jellyfish are highly topical within studies of pelagic food-webs and there is a growing realisation that their role is more complex than once thought. Efforts being made to include jellyfish within fisheries and ecosystem models are an important step forward, but our present understanding of their underlying trophic ecology can lead to their over-simplification in these models. Gelatinous zooplankton represent a polyphyletic assemblage spanning >1,400 species that inhabit coastal seas to the deep-ocean and employ a wide variety of foraging strategies. Despite this diversity, many contemporary modelling approaches include jellyfish as a single functional group feeding at one or two trophic levels at most. Recent reviews have drawn attention to this issue and highlighted the need for improved communication between biologists and theoreticians if this problem is to be overcome. We used stable isotopes to investigate the trophic ecology of three co-occurring scyphozoan jellyfish species (Aurelia aurita, Cyanea lamarckii and C. capillata) within a temperate, coastal food-web in the NE Atlantic. Using information on individual size, time of year and δ13C and δ15N stable isotope values we examined: (1) whether all jellyfish could be considered as a single functional group, or showed distinct inter-specific differences in trophic ecology; (2) Were size-based shifts in trophic position, found previously in A. aurita, a common trait across species?; (3) When considered collectively, did the trophic position of three sympatric species remain constant over time? Differences in δ15N (trophic position) were evident between all three species, with size-based and temporal shifts in δ15N apparent in A. aurita and C. capillata. The isotopic niche width for all species combined increased throughout the season, reflecting temporal shifts in trophic position and seasonal succession in these gelatinous species. Taken together, these findings support previous assertions that jellyfish require more robust inclusion in marine fisheries or ecosystem models.

scholarly journals STRUKTUR TINGKAT TROFIK KOMUNITAS IKAN DI WADUK WADASLINTANG KABUPATEN WONOSOBO, JAWA TENGAH

2015 ◽  
Vol 7 (3) ◽  
pp. 155
Author(s):  
Khoirul Fatah ◽  
Susilo Adjie
Keyword(s):  
Trophic Level ◽  
Feeding Habits ◽  
Trophic Levels ◽  
Fish Feeding ◽  
Fish Samples ◽  
Percentage Weight ◽  
Recorded Data ◽  
Fish Group ◽  
The Difference

Waduk Wadas lintang memiliki potensi perikanan yang cukup besar baik perikanan tangkap maupun perikanan budidaya. Kegiatan penangkapan ikan di waduk Wadaslintang saat ini sudah cukup tinggi, yang akan berdampak langsung pada struktur komunitas ikan yang menyebabkan pergeseran pola hubungan antara pemangsa,mangsa atau pesaing pada berbagai tingkat trofik. Tujuan penelitian ini untukmengetahui pola hubungan antar kelompok ikan berdasarkan tingkat trofik dari tingkat trofik terendah sampai kepada ikan karnivor, sehingga diperoleh gambaran peran kelompok ikan dalam komunitas. Penelitian ini dilaksanakan pada bulan April, Juni, September dan Nopember 2013 di perairan waduk Wadaslintang. Analisa data mencakup komposisi hasil tangkapan dan kebiasaan makan ikan serta tingkat trofik komunitas ikan. Analisis sidik ragam untuk mengetahui perbedaan antar tingkat trofik. Ikan contoh diperoleh dari nelayan dengan alat tangkap jaring, mulai dari ukuran 0,75 – 4,5 inchi. Hasil penelitian diketemukan sebanyak 15 jenis ikan yang didominasi oleh ikan nila dengan persentase berat mencapai 56,45%. Struktur komunitas ikan di perairan waduk Wadaslintang tersusun atas tiga kelompok tingkat trofik yaitu ikan patin, nila, tawes dan nilem mempunyai jenjang trofik terendah (<2,5), ikan bader dan brek mempunyai nilai jenjang trofik sedang (2,5 – 3,49) dan ikan beong, betutu, palung dan lelemempunyai nilai jenjang trofik tertinggi (>3,5). Kelompok ikan pada tingkat trofik rendah < 2,5 sangat penting dalam menyokong komunitas ikan di perairan waduk Wadaslintang karena akan mempengaruhi kelompok ikan dengan tingkat trofik tinggi.Wadaslintang reservoirs was considered have high potential for fisheries and aquaculture. Fishing Activities in the Wadaslintang reservoir is currently quite high, which may gave a direct impact on the trophic levels structure of fish community and would change composition of predators, preys, and competitors on various trophik levels. The objective of research was focused on the pattern of relationship among trophic groups from the lowest level of trophic to the highest level of carnivorous fish, to find out the role of each fish group in the community. This research was carried out in April, June, September and November 2013 at Wadaslintang reservoir waters. The recorded data were analysed to find out the composition of the fish, feeding habits and trophic levels, and followed by statistical analysis of variance to evaluate the difference among trophic level. Fish samples obtained from a capture tool gillnets, ranging from size 0.75 – 4.5 inches. The results shows that Wadaslintang Reservoir was habited by 15 species of fish where Nile Tilapiais is the dominance species with percentage weight is 56,45%. The structure of fish communities in the water of the Wadaslintang reservoir composed of three groups, namely trophic level of sutchi catfish, nile tilapia, silver barb and nilemhad the lowest trophic levels (< 2.5), barb and javaen barb had value trophic level moderat (2.5-3.49) and catfish, marble goby, hampala barb and walking catfish had the highest trophic level values (>3.5). Fish group on trophic level < 2.5 levels is very important group in supporting good community structure in Wadaslintang reservoir as a way to sustainability of populaion oh the other groups with higher trophic level.

scholarly journals Not all jellyfish are equal: isotopic evidence for inter- and intraspecific variation in jellyfish trophic ecology

2015 ◽  
Author(s):  
Nicholas E.C. Fleming ◽  
Chris Harrod ◽  
Jason Newton ◽  
Jonathan D.R. Houghton
Keyword(s):  
Trophic Ecology ◽  
Functional Group ◽  
Trophic Position ◽  
Seasonal Succession ◽  
Deep Ocean ◽  
Trophic Levels ◽  
Foraging Strategies ◽  
Isotopic Niche ◽  
Ecosystem Models ◽  
Temporal Shifts

Jellyfish are highly topical within studies of pelagic food-webs and there is a growing realisation that their role is more complex than once thought. Efforts being made to include jellyfish within fisheries and ecosystem models are an important step forward, but our present understanding of their underlying trophic ecology can lead to their over-simplification in these models. Gelatinous zooplankton represent a polyphyletic assemblage spanning >1,400 species that inhabit coastal seas to the deep-ocean and employ a wide variety of foraging strategies. Despite this diversity, many contemporary modelling approaches include jellyfish as a single functional group feeding at one or two trophic levels at most. Recent reviews have drawn attention to this issue and highlighted the need for improved communication between biologists and theoreticians if this problem is to be overcome. We used stable isotopes to investigate the trophic ecology of three co-occurring scyphozoan jellyfish species (Aurelia aurita, Cyanea lamarckii and C. capillata) within a temperate, coastal food-web in the NE Atlantic. Using information on individual size, time of year and δ13C and δ15N stable isotope values we examined: (1) whether all jellyfish could be considered as a single functional group, or showed distinct inter-specific differences in trophic ecology; (2) Were size-based shifts in trophic position, found previously in A. aurita, a common trait across species?; (3) When considered collectively, did the trophic position of three sympatric species remain constant over time? Differences in δ15N (trophic position) were evident between all three species, with size-based and temporal shifts in δ15N apparent in A. aurita and C. capillata. The isotopic niche width for all species combined increased throughout the season, reflecting temporal shifts in trophic position and seasonal succession in these gelatinous species. Taken together, these findings support previous assertions that jellyfish require more robust inclusion in marine fisheries or ecosystem models.

Trophic structure of the bathyal benthos at an area with evidence of methane seep activity off southern Chile (~45°S)

2014 ◽  
Vol 94 (4) ◽  
pp. 659-669 ◽  
Author(s):  
Germán Zapata-Hernández ◽  
Javier Sellanes ◽  
Andrew R. Thurber ◽  
Lisa A. Levin
Keyword(s):  
Trophic Structure ◽  
Trophic Position ◽  
Demersal Fish ◽  
Trophic Levels ◽  
Food Sources ◽  
Isotopic Niche ◽  
Methane Seep ◽  
Southern Chile ◽  
Close Proximity ◽  
Third Trophic Level

Through application of carbon (C) and nitrogen (N) stable isotope analyses, we investigated the benthic trophic structure of the upper-slope off southern Chile (~45°S) including a recent methane seep area discovered as part of this study. The observed fauna comprised 53 invertebrates and seven fish taxa, including remains of chemosymbiotic fauna (e.g. chemosymbiotic bivalves and siboglinid polychaetes), which are typical of methane seep environments. While in close-proximity to a seep, the heterotrophic fauna had a nutrition derived predominantly from photosynthetic sources (δ13C > –21‰). The absence of chemosynthesis-based nutrition in the consumers was likely a result of using an Agassiz trawl to sample the benthos, a method that is likely to collect a mix of fauna including individuals from adjacent non-seep bathyal environments. While four trophic levels were estimated for invertebrates, the fish assemblage was positioned within the third trophic level of the food web. Differences in corrected standard ellipse area (SEAC), which is a proxy of the isotopic niche width, yielded differences for the demersal fish Notophycis marginata (SEAC = 5.1‰) and Coelorinchus fasciatus (SEAC = 1.1‰), suggesting distinct trophic behaviours. No ontogenic changes were detected in C. fasciatus regarding food sources and trophic position. The present study contributes the first basic trophic data for the bathyal area off southern Chile, including the identification of a new methane seep area, among the furthest south ever discovered. Such information provides the basis for the proper sustainable management of the benthic environments present along the vast Chilean continental margin.

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