Feeding habits and trophic level of the shovelnose guitarfish (Pseudobatos productus) in the upper Gulf of California

The shovelnose guitarfish (Pseudobatos productus) is the most abundant and economically important batoid in Gulf of California fisheries. Despite the importance of the guitarfish in the demersal ecosystem, its trophic relationships are poorly understood. Results from stomach content and stable isotope analysis indicate P. productus is a specialist predator that feeds on coastal benthic organisms, mainly crustaceans, followed by fishes and cephalopods in the Upper Gulf of California. Males and females did not differ in dietary composition and isotopic values. Pseudobatos productus displayed ontogenetic changes in the diet, with smaller, immature individuals having a more specialized diet and mature individuals becoming generalist predators. Size classes I (<570 mm) and II (>570 mm) fed almost exclusively on crustaceans (99.78% and 82.37 %IRI, respectively). Size class III (>832 mm) increased consumption of fishes (22.11 %IRI) and squid (6.54 %IRI). Ontogenetic diet shifts were strongly supported by the SIAR mixing model. Stomach content and stable isotope analyses classify P. productus as a second-order predator.

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Feeding habits of juvenile yellowfin tuna ( Thunnus albacares ) in Ecuadorian waters assessed from stomach content and stable isotope analysis

Fisheries Research ◽

10.1016/j.fishres.2017.05.017 ◽

2017 ◽

Vol 194 ◽

pp. 89-98 ◽

Cited By ~ 10

Author(s):

José Luis Varela ◽

Ketty María Intriago ◽

Julio César Flores ◽

Cristhian Ronald Lucas-Pilozo

Keyword(s):

Stable Isotope ◽

Stable Isotope Analysis ◽

Stomach Content ◽

Feeding Habits ◽

Isotope Analysis ◽

Yellowfin Tuna ◽

Thunnus Albacares

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Seasonal and developmental diet shifts in sympatric and allopatric intertidal gobies determined by stomach content and stable isotope analysis

Journal of Fish Biology ◽

10.1111/jfb.14463 ◽

2020 ◽

Vol 97 (4) ◽

pp. 1051-1062

Author(s):

Penelope S. Carbia ◽

Culum Brown ◽

Joo M. Park ◽

Troy F. Gaston ◽

Vincent Raoult ◽

...

Keyword(s):

Stable Isotope ◽

Stable Isotope Analysis ◽

Stomach Content ◽

Isotope Analysis ◽

Diet Shifts

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Assessment of trophic relationships between symbiotic tropical ophiuroids using C and N stable isotope analysis

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315406014494 ◽

2006 ◽

Vol 86 (6) ◽

pp. 1443-1447 ◽

Cited By ~ 3

Author(s):

D. Fourgon ◽

G. Lepoint ◽

I. Eeckhaut

Keyword(s):

Stable Isotopes ◽

Potential Benefit ◽

Feeding Habits ◽

Isotope Analysis ◽

Tracer Experiment ◽

Trophic Relationships ◽

Nitrogen Stable Isotopes ◽

Carbon And Nitrogen ◽

C And N ◽

The One

Analyses of the natural abundance of carbon and nitrogen stable isotopes were performed to investigate the feeding habits of two ophiuroids, Ophiomastix venosa and Ophiocoma scolopendrina, and to assess the potential benefit obtained by the symbiotic Ophiomastix venosa juveniles. A tracer experiment was also carried out to clarify the contribution of algae to the nitrogen uptake amongst the tested ophiuroids. Our results suggest that Ophiocoma scolopendrina adults occupy a higher position in the food web than Ophiomastix venosa and mainly feed on neuston. In contrast, O. venosa adults feed on the alga Sargassum densifolium and on organic matter associated with sediment. Free juveniles and symbiotic juveniles of O. venosa have intermediate δ13C values between both adult species. The high proportion of 13C in the symbiotic juveniles compared to the one in their conspecific adults indicates that their diet slightly differs from the latter and is closer to that of Ophiocoma scolopendrina. This raises the hypothesis that symbiotic juveniles steal neuston from their associated host, O. scolopendrina.

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

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315417000170 ◽

2017 ◽

Vol 98 (4) ◽

pp. 885-893 ◽

Cited By ~ 1

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.

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Trophic relationships in a tropical stream food web assessed by stable isotope analysis

Freshwater Biology ◽

10.1111/j.1365-2427.2008.02149.x ◽

2009 ◽

Vol 54 (5) ◽

pp. 1028-1041 ◽

Cited By ~ 36

Author(s):

SOPHIE COAT ◽

DOMINIQUE MONTI ◽

CLAUDE BOUCHON ◽

GILLES LEPOINT

Keyword(s):

Stable Isotope ◽

Food Web ◽

Stable Isotope Analysis ◽

Isotope Analysis ◽

Trophic Relationships ◽

Tropical Stream

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Trophic relationships of the platypus: insights from stable isotope and cheek pouch dietary analyses

Marine and Freshwater Research ◽

10.1071/mf15004 ◽

2016 ◽

Vol 67 (8) ◽

pp. 1196 ◽

Cited By ~ 7

Author(s):

Melissa Klamt ◽

Jenny A. Davis ◽

Ross M. Thompson ◽

Richard Marchant ◽

Tom R. Grant

Keyword(s):

Stable Isotope ◽

Stable Isotope Analysis ◽

Isotope Analysis ◽

Trophic Relationships ◽

Cheek Pouch ◽

Insect Larvae ◽

Top Down ◽

Δ13c And Δ15n ◽

Eastern Australia ◽

Wide Range

The unique Australian monotreme, the platypus (Ornithorhynchus anatinus) potentially exerts a strong top-down influence on riverine food webs in eastern Australia. However, despite considerable interest in the evolutionary history and physiology of the platypus, little is known of its trophic relationships. To address this lack of knowledge we used stable isotope analysis, in combination with the analysis of food items stored in cheek pouches, to determine its position in a typical riverine food web. This was the essential first step in the process of designing a larger study to investigate the relative importance of top-down and bottom-up effects in rivers where the platypus occurs. We found that platypuses were feeding on a wide range of benthic invertebrates, particularly insect larvae. The similarity of δ13C and δ15N values recorded for the platypus, a native fish (Galaxias sp.) and the exotic mosquitofish (Gambusia holbrooki) indicated dietary overlap and potential competition for the same resources. Although cheek pouch studies identify most of the major groups of prey organisms, the potential for contribution of the soft-bodied organisms such as larval dipterans, is suggested by stable isotope analysis, indicating that the use of both techniques will be important in future ecological investigations.

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Use of epidermal mucus in elasmobranch stable isotope studies: a pilot study using the giant manta ray (Manta birostris)

Marine and Freshwater Research ◽

10.1071/mf16355 ◽

2018 ◽

Vol 69 (2) ◽

pp. 336 ◽

Cited By ~ 6

Author(s):

K. B. Burgess ◽

M. Guerrero ◽

A. J. Richardson ◽

M. B. Bennett ◽

A. D. Marshall

Keyword(s):

Stable Isotope ◽

Stable Isotope Analysis ◽

Time Course ◽

Feeding Habits ◽

Isotope Analysis ◽

Δ13c Values ◽

Significant Difference ◽

Manta Birostris ◽

Epidermal Mucus ◽

Manta Ray

Stable isotope analysis of tissues with different turnover rates allows for a broader temporal view of a species’ feeding habits. Epidermal mucus is a rapid to medium turnover ‘tissue’ in teleost fish, but its use in elasmobranch dietary studies is unknown. In the present study, we conducted stable isotope analysis on mucus and muscle from the giant manta ray Manta birostris. Mucus δ13C values were depleted and closer to surface zooplankton δ13C values compared with muscle, whereas there was no significant difference in δ15N values between these two tissue types. Using diet tissue discrimination factors from the literature, there was no significant difference in the expected prey profile between muscle and epidermal mucus. However, a broader range in δ13C values of expected prey was shown for mucus compared with muscle. The results suggest that if M. birostris mucus is indicative of recent dietary intake, resource use during aggregative behaviour off Ecuador is broader, but with no obvious resource switching. The present study is the first example of using bulk stable isotope analysis to evaluate mucus to investigate feeding ecology in elasmobranchs. However, the time course for the change in mucus isotope signature still needs to be determined through controlled feeding studies in an aquarium setting.

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Trophic ecology of the blue shark (Prionace glauca) based on stable isotopes (δ13C and δ15N) and stomach content

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315415001393 ◽

2015 ◽

Vol 96 (7) ◽

pp. 1403-1410 ◽

Cited By ~ 13

Author(s):

Sandra Berenice Hernández-Aguilar ◽

Ofelia Escobar-Sánchez ◽

Felipe Galván-Magaña ◽

Leonardo Andrés Abitia-Cárdenas

Keyword(s):

Stable Isotope ◽

Stomach Content ◽

Trophic Ecology ◽

Baja California ◽

Marine Ecosystem ◽

Isotope Analysis ◽

Trophic Levels ◽

Baja California Sur ◽

Δ13c And Δ15n ◽

Prionace Glauca

Occupying the upper levels of trophic webs and thus regulating prey at lower levels, sharks play an important role in the trophic structure and energy dynamics of marine ecosystems. In recent years, the removal of these individuals from upper trophic levels as a result of overfishing has negatively affected ecosystems. We analysed the diet of blue sharks (Prionace glauca) caught off the west coast of Baja California Sur, Mexico, during the months of February–June in 2001, 2005 and 2006. We employed both stomach content and stable isotope analyses as each method provides distinct yet important information regarding the role of blue sharks in marine food webs, allowing us to estimate the relative contribution of different prey items to this predator's diet. Of the 368 stomachs analysed, 210 contained food (57%) and 158 (43%) were empty. Based on stomach contents and the index of relative importance (IRI), the pelagic red crab (Pleuroncodes planipes) was the most important prey, followed by the squids Gonatus californiensis (34.1%) and Ancistrocheirus lesueurii (10.4%). The mean (±SD) values for δ15N (16.48 ± 0.94‰) and δ13C (−18.48 ± 0.63‰) suggest that blue sharks prefer feeding in oceanic waters. The trophic level based on stomach content analysis was 4.05, while that based on the stable isotope analysis was 3.8, making blue sharks top consumers in the marine ecosystem of Baja California Sur, Mexico.

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