scholarly journals Feeding Habits and Trophic Level of the Panama GruntPomadasys panamensis, an Important Bycatch Species from the Shrimp Trawl Fishery in the Gulf of California

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
José A. Rodríguez-Preciado ◽  
Felipe Amezcua ◽  
Brian Bellgraph ◽  
Juan Madrid-Vera
Keyword(s):  
Trophic Level ◽  
Gulf Of California ◽  
Niche Breadth ◽  
Diversity Index ◽  
Feeding Habits ◽  
Trophic Niche ◽  
Important Species ◽  
Trawl Fishery ◽  
Shrimp Trawl ◽  
Commercially Important

The Panama grunt is an abundant and commercially important species in the southeastern Gulf of California, but the research undertaken on this species is scarce despite its ecological and economic importance. We studied the feeding habits of Panama grunt through stomach content analyses as a first step towards understanding the biology of this species in the study area. Our results indicate that the Panama grunt is a benthic predator throughout its life cycle and feeds mainly on infaunal crustaceans. Diet differences among grunt were not found according to size, diet, or season. Shannon diversity index results indicate that Panama grunt has a limited trophic niche breadth with a diet dominated by a limited number of taxa as crustaceans. The estimated trophic level of this species is 3.59. Overall, the Panama grunt is a carnivorous fish occupying the intermediate levels of the trophic pyramid.

Feeding habits of the toothed flounder Cyclopsetta querna (Paralichthyidae) of the south-east Gulf of California

2010 ◽  
Vol 91 (6) ◽  
pp. 1225-1230 ◽  
Author(s):  
Felipe Amezcua ◽  
Alfonso Portillo ◽  
Felipe Amezcua-Linares
Keyword(s):  
Gulf Of California ◽  
Diet Composition ◽  
Niche Breadth ◽  
Feeding Habits ◽  
Demersal Fish ◽  
Trophic Niche ◽  
The South ◽  
Top Predators

Feeding habits of the toothed flounder Cyclopsetta querna caught in the south-east Gulf of California were studied. Specimens were collected via demersal fish surveys. Results of this study show that C. querna is a predator that focuses on fish inhabiting the bottom and in particular on tonguefish (Symphurus sp.), midshipman fish (Porichthys sp.) and moray eels (Muraenidae). The diet of the toothed flounder did not vary significantly throughout the period of study, and neither size nor sex-related variations in diet composition were observed. Simpson's index indicates a limited trophic niche breadth with a diet dominated by a limited number of taxa. The estimated TROPH value for C. querna is similar to that estimated for other demersal top predators from the studied area; therefore, the toothed flounder can be considered a top carnivore from the demersal community in the Gulf of California.

Feeding habits and trophic level of the smooth hammerhead shark, Sphyrna zygaena (Carcharhiniformes: Sphyrnidae), off Ecuador

2018 ◽  
Vol 99 (3) ◽  
pp. 673-680 ◽  
Author(s):  
Colombo Estupiñán-Montaño ◽  
Luis Cedeño-Figueroa ◽  
José F. Estupiñán-Ortiz ◽  
Felipe Galván-Magaña ◽  
Alejandro Sandoval-Londoño ◽  
...  
Keyword(s):  
Trophic Level ◽  
Feeding Habits ◽  
Trophic Niche ◽  
Commercial Fishing ◽  
Dosidicus Gigas ◽  
Apex Predators ◽  
Marine Food Webs ◽  
Fishing Vessels ◽  
Marine Food ◽  
Index Of Relative Importance

As apex predators, sharks are known to play an important role in marine food webs. Detailed information on their diet and trophic level is however needed to make clear inferences about their role in the ecosystem. A total of 335 stomachs of smooth hammerhead sharks, Sphyrna zygaena, were obtained from commercial fishing vessels operating in the Ecuadorian Pacific between January and December 2004. A total of 53 prey items were found in the stomachs. According to the Index of Relative Importance (%IRI), cephalopods were the main prey (Dosidicus gigas, Sthenoteuthis oualaniensis, Ancistrocheirus lesueurii and Lolliguncula [Loliolopsis] diomedeae). Sphyrna zygaena was thus confirmed to be a teutophagous species. The estimated trophic level of S. zygaena was between 4.6 and 5.1 (mean ± SD: 4.7 ± 0.16; males: 4.7; females: 4.8). Levin's index (BA) was low (overall: 0.07; males: 0.08; females: 0.09), indicating a narrow trophic niche. We found that sharks <150 cm in total length consumed prey of coastal origin, whereas sharks ≥150 cm foraged in oceanic waters and near the continental shelf. The analyses indicate that S. zygaena is a specialized predator consuming mainly squids.

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.

scholarly journals Trophic niche breadth of pond zooplankton species using stable isotope analysis and the relationship with the abiotic and biotic factors

2019 ◽  
Vol 6 (1) ◽  
pp. 180917 ◽  
Author(s):  
Hideyuki Doi ◽  
Kwang-Hyeon Chang ◽  
Shin-ichi Nakano
Keyword(s):  
Stable Isotope ◽  
Niche Breadth ◽  
Resource Competition ◽  
Feeding Habits ◽  
Zooplankton Biomass ◽  
Trophic Niche ◽  
Zooplankton Species ◽  
Carbon And Nitrogen ◽  
Ecosystem Size ◽  
The Relationship

Zooplankton species have different feeding habits, but the diversity of their food resources and the factors governing them are still largely unknown. We here estimated the differences in the trophic niche breadths of dominant zooplankton species in ponds, using stable isotopes. To understand the differences in trophic niches of different zooplankton species, we measured the carbon and nitrogen stable isotope ratios and calculated the nearest-neighbour distance (NND), and standard deviation of NND (SDNND) of the bi-plot space of stable carbon and nitrogen isotopes in pond zooplankton. We tested the relationship between the NND/SDNND and environmental factors, as well as the zooplankton biomass, using generalized linear models (GLMs). For cladocerans, including Bosmina, Ceriodaphnia and Daphnia, the NNDs were significantly correlated with the biomass, pond morphology (volume and depth), total phosphorous (TP) and fish presence. For copepod species, including Eodiaptomus and cyclopoids, NNDs were significantly correlated with pond morphology, TP and fish presence, but not with biomass. In GLMs of SDNND, significant correlated factors were less than those for NND, and for some species, pond morphology and TP were significantly correlated with SDNND. Here, we found that the NND and SDNND of zooplankton species were related to various factors, including their biomass, predator presence, pond size and water quality. For cladocerans, biomass may be supported by trophic niche breadth, probably because of the consequences of resource competition. Also, predation and ecosystem size may influence trophic niche breadth due to changes in zooplankton behaviours.

Diets and trophic guilds of demersal fishes of the south-eastern Australian shelf

2001 ◽  
Vol 52 (4) ◽  
pp. 537 ◽  
Author(s):  
C. Bulman ◽  
F. Althaus ◽  
X. He ◽  
N. J. Bax ◽  
A. Williams
Keyword(s):  
Fish Species ◽  
Abundant Species ◽  
Trophic Guilds ◽  
The South ◽  
Important Species ◽  
Trawl Fishery ◽  
South Eastern ◽  
Total Fish ◽  
Wet Weight ◽  
Commercially Important

A total of 8200 stomach samples was collected from 102 fish species caught by trawl or gillnet during research surveys on the south-eastern Australian shelf from 1993 to 1996. Diet compositions were analysed based on percentages of wet weight of prey. Of the total fish examined, 70 species had sufficient stomach samples (i.e. >10) for further analysis. Ten trophic guilds were identified from cluster analysis. Benthic prey dominated the diets. However, analysis on a subset of 28 abundant species that were commercially and ecologically important, showed that pelagic prey was dominant, particularly for 12 quota species. This suggests that pelagic production contributes significantly to the trawl fishery production. Further analysis on the diets of these 28 species found that although fish was more important than invertebrate prey, there was no evidence of significant predation on commercially important species (quota species)by other fish species. A food web diagram was constructed, mostly based on the diet compositions, guild structure and relative abundance of commercially and ecologically important fish species, to show major trophic interactions of the shelf ecosystem.

scholarly journals Feeding habits of the spotted rose snapper, Lutjanus guttatus, (Actinopterygii, Perciformes, Lutjanidae), in the central Gulf of California, BCS, Mexico

2021 ◽  
Vol 51 (1) ◽  
pp. 95-105
Author(s):  
Filius L. Valle-Lopez ◽  
Xchel G. Moreno-Sánchez ◽  
Marina S. Irigoyen-Arredondo ◽  
Leonardo A. Abitia-Cárdenas ◽  
Emigdio Marín-Enríquez ◽  
...  
Keyword(s):  
Gulf Of California ◽  
Trophic Ecology ◽  
Feeding Habits ◽  
Feeding Strategy ◽  
Trophic Niche ◽  
Trophic Plasticity ◽  
Important Prey ◽  
Management Measures ◽  
Reported Study ◽  
Santa Rosalia

The spotted rose snapper, Lutjanus guttatus (Steindachner, 1869), is an important resource for the coastal fisheries of the Gulf of California, mainly due to its high commercial value. Despite this, there are no management measures for this species, owing in part to a lack of information on its basic biology and its trophic ecology in the area. In this context, the presently reported study had as objective to describe the feeding habits of L. guttatus through stomach content analyses, as well as to describe possible changes linked to sex, size, and season. Specimens were caught monthly from June 2016 to September 2017 with gillnets in Santa Rosalía, BCS, Mexico. The abundance, weight, and frequency of occurrence of each prey were assessed, and these parameters were integrated into the index of relative importance (%IRI) to determine the importance of each prey item in the L. guttatus diet. The Levin’s index was used to assess the trophic niche width of the species, the feeding strategy was evaluated using Costello’s graphic method and the trophic level was calculated. Finally, to establish whether there were significant differences in the diet by sex, size, or season a PERMANOVA test was used with a 95% confidence level. A total of 202 L. guttatus stomachs were analyzed, 191 of which contained food. A total of 26 prey items were identified. According to the %IRI, the most important prey were the teleost fishes Harengula thrissina (Jordan et Gilbert, 1882) (45.7%) and Sardinops sagax (Jenyns, 1842) (34.8%), the euphausiid Nyctiphanes simplex (13.4%), and the crustacean Penaeus spp. (5.6%). The PERMANOVA analysis resulted in significant differences between the analyzed categories; however, there were no significant differences in the interactions among the categories. According to Levin’s index, L. guttatus had a narrow trophic width, with changes in the main prey consumed by the different categories. According to our results, L. guttatus can be considered a benthopelagic opportunistic carnivorous predator with a narrow trophic niche, presenting mostly quantitative variations in its diet according to sex, size, and season. Its trophic plasticity allows it to take advantage of the most available and abundant food resources.

Zeros as a result in diet studies, is this really bad? Rhinoptera steindachneri as a case study

2019 ◽  
Vol 99 (7) ◽  
pp. 1661-1666 ◽  
Author(s):  
N. R. Ehemann ◽  
L. A. Abitia-Cardenas ◽  
A. F. Navia ◽  
P. A. Mejía-Falla ◽  
V. H. Cruz-Escalona
Keyword(s):  
Eating Habits ◽  
Feeding Habits ◽  
Stomach Contents ◽  
Geographic Location ◽  
La Paz ◽  
Important Species ◽  
Mexican Pacific ◽  
Important Prey ◽  
Commercially Important ◽  
Prey Handling

AbstractRhinoptera steindachneri is a commercially important, medium-sized, pelagic migratory batoid fish with benthic feeding habits. It has been considered a specialized predator that feeds on molluscs as well as benthic ophiurids and arthropods off the Mexican Pacific coast. Most biological aspects of this species in La Paz Bay are unknown, despite its being a commercially important species of conservation interest. Therefore, the aim of this study was to characterize the feeding habits of R. steindachneri based on specimens caught in artisanal fisheries. The stomach contents of 310 specimens (146 females and 164 males) were analysed, all captured from 2013 to 2015. The vacuity index was 97.1%, and the most important prey species were Mysidium spp. and Cylichna spp. Because of the high frequency of empty stomachs recorded, it was not possible to describe with precision the general diet of the species. Three hypotheses were developed to try to explain why this characteristic occurred in this species, ranging from eating habits to physiology and prey digestion and geographic location of the study. However, considering the mechanical process of prey handling of R. steindachneri, several hypotheses were formulated, with the hour of capture, chemical processes and physiology and prey digestion being the most probable to explain this high vacuity index reported in this study.

scholarly journals A simple method for the genetic identification of commercially important species in the Opisthonema genus Gill, 1861 in the southern Gulf of California

2020 ◽  
Vol 46 (3) ◽  
pp. 145-154
Author(s):  
Carlos Iván Pérez-Quiñonez ◽  
Casimiro Quiñonez-Velázquez ◽  
Francisco Javier García-Rodríguez
Keyword(s):  
Gulf Of California ◽  
Genetic Identification ◽  
Simple Method ◽  
Important Species ◽  
Commercially Important

scholarly journals Effect of a lateral square-mesh panel on the catch pattern and catch efficiency in a Mediterranean bottom trawl fishery

2020 ◽  
Vol 21 (1) ◽  
pp. 105
Author(s):  
SARA BONANOMI ◽  
JURE BRČIĆ ◽  
BENT HERRMANN ◽  
EMILIO NOTTI ◽  
ALESSANDRO COLOMBELLI ◽  
...  
Keyword(s):  
Mesh Size ◽  
Lateral Position ◽  
Bottom Trawl ◽  
Important Species ◽  
Commercial Fish ◽  
Trawl Fishery ◽  
Red Mullet ◽  
Commercially Important ◽  
The Mediterranean ◽  
Trawl Fisheries

The current legal codends used in Mediterranean bottom trawl fisheries are at high risk of retaining undersized individuals of several commercial fish species. This entails that codends alone are unable to provide the desired exploitation pattern. A simple technological measure that potentially can provide higher release efficiency of undersized fish are Square-Mesh Panels (SMPs). SMPs are often applied in the upper section of the trawl belly, just ahead the codend. However, recent studies in the Mediterranean have demonstrated that SMPs mounted in this position provided limited release efficiency, because very few fish came into contact with their meshes. In attempt to improve SMPs efficiency in the Mediterranean bottom trawl fisheries, we applied them on the lateral sides of the last tapered section of the trawl belly, just ahead of the codend, and fitted two guiding panels in the trawl belly to enhance fish-SMP contact. We compared the catch performance of a standard commercial trawl with a 52 mm diamond-mesh codend and of a similar trawl fitted with lateral SMPs (70 mm mesh size) in the belly using a twin trawl. The study focused on red mullet (Mullus barbatus), a commercially important species, but data for gurnard (Chelidonichthys lucerna and Chelidonichthys cuculus)  were also obtained and analysed. In contrast to previous research on SMPs mounted in the top panel of the trawl, in this study SMPs induced a significant effect on catch performance for red mullet, demonstrating that their lateral position involved greater fish-SMP contact. However, since the test trawl lost a significant amount of legal-sized red mullet compared with the standard trawl, the effect was not wholly positive, possibly due to an excessively large mesh size. Therefore, future studies should be encouraged to test lateral SMPs with smaller mesh sizes.

scholarly journals Feeding habits of the congeneric species Stellifer rastrifer and Stellifer brasiliensis (Acanthopterygii: Sciaenidae) co-occurring in the coast of the state of Santa Catarina, Brazil

2015 ◽  
Vol 75 (2) ◽  
pp. 423-430 ◽  
Author(s):  
LM. Sabinson ◽  
JL. Rodrigues-Filho ◽  
AC. Peret ◽  
JO. Branco ◽  
JR. Verani
Keyword(s):  
Feeding Habits ◽  
Brazilian Coast ◽  
Congeneric Species ◽  
Santa Catarina ◽  
Food Category ◽  
Trawl Fishery ◽  
Shrimp Trawl ◽  
Direct Competition ◽  
Seasonal Basis ◽  
Fishing Area

The objective of the present study was to investigate the feeding habits allowing the occurrence of the congeneric species Stellifer rastrifer and Stellifer brasiensis, collected on a seasonal basis, in the operating area of the artisanal seabob-shrimp trawl fishery in Porto Belo, an important fishing area on the southern Brazilian coast. Fish were collected seasonally from November 2009 to August 2010, in isobaths of 10, 20 and 30m. Of the 450 stomachs analyzed, 194 belongd to Stellifer rastrifer and 242 to Stellifer brasiliensis. From the totality of analyzed stomachs 33.49% were empty and 66.52% had some content. Crustacea were the predominant food category in the diet of S. rastrifer and S. brasiliensis, and the shrimp Acetes americanus was the most frequent crustacean in stomachs of both studied species. The overlapping in the diet of the species was high, however when analyzing the overlap in each season it was found that it occurred only during spring and winter. Although the most important items in the diet of these species are the same, the intake of each alternates in time, suggesting a difference in predation pressure, which leads to less direct competition in a given time.

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