scholarly journals Feeding habits and dietary overlap during the larval development of two sandperches (Pisces: Pinguipedidae)

2017 ◽  
Vol 81 (2) ◽  
pp. 195 ◽  
Author(s):  
Javier A. Vera-Duarte ◽  
Mauricio F. Landaeta

Two species of sandperch (Pinguipedidae: Perciformes), Prolatilus jugularis and Pinguipes chilensis, inhabit the coastal waters of the South Pacific. Both species have pelagic larvae with similar morphology, but their diet preferences are unknown. Diet composition, feeding success, trophic niche breadth and dietary overlap were described during larval stages for both species. In the austral spring, larval P. jugularis (3.83-10.80 mm standard length [SL]) and P. chilensis (3.49-7.71 mm SL) during their first month of life had a high feeding incidence ( > 70%) and fed mostly on copepod nauplii ( > 80% IRI), Rhincalanus nasutus metanauplii and Paracalanus indicus copepodites. The number of prey ingested was low (mean: 4-5 prey per gut) and independent of larval size; total prey volume and maximum prey width increased as larvae grew. Mouth opening and ingested prey were greater in larval P. jugularis than in P. chilensis, leading to significant differences in prey composition among larval species, in terms of prey number and volume. Pearre’s trophic niche breadth was narrow for both species (0.159±0.07 for P. jugularis; 0.156±0.03 for P. chilensis) and independent of larval size. Dietary overlap was high inter- and intra-species in larvae with a mouth gape < 900 μm. These results suggest the relative importance of both larval species as primary consumers of the pelagic web in nearshore environments of rocky temperate areas.

2019 ◽  
Vol 6 (1) ◽  
pp. 180917 ◽  
Author(s):  
Hideyuki Doi ◽  
Kwang-Hyeon Chang ◽  
Shin-ichi Nakano

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.


2012 ◽  
Vol 69 (8) ◽  
pp. 1340-1351 ◽  
Author(s):  
Hannah M. Murphy ◽  
Gregory P. Jenkins ◽  
Paul A. Hamer ◽  
Stephen E. Swearer

Larval snapper ( Chrysophrys auratus , Sparidae) sampled over 7 years had different diets and feeding strategies between years with lower versus higher larval and 0+ abundances. We analysed stomach contents of snapper larvae from each year to determine diet composition, prey selectivity, prey quality, and trophic niche breadth and compared larval diet with prey availability. Snapper larvae from higher abundance years were specialized foragers selecting for calanoid nauplii at 2–4 mm standard length (SL) and calanoid copepodites and cladocerans at >4 mm SL. These larvae were characterized by either a constant or dome-shaped trophic niche breadth and an increase in prey quality (size of consumed prey) with increasing larval size. Snapper larvae from lower abundance years were generalist foragers characterized by an increase in trophic niche breadth, but not prey quality, with increasing larval size. Changes in foraging strategies were concordant with changes in the prey environment, with low zooplankton densities corresponding with generalist diet (lower larval abundance) years and high zooplankton densities with specialist diet (higher larval abundance) years. These findings suggest that snapper larval survival and juvenile recruitment strength is linked to changes in larval diet that relate to prey abundance and composition.


2010 ◽  
Vol 91 (6) ◽  
pp. 1225-1230 ◽  
Author(s):  
Felipe Amezcua ◽  
Alfonso Portillo ◽  
Felipe Amezcua-Linares

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.


2021 ◽  
pp. 45-45
Author(s):  
Milica Jacimovic ◽  
Jasmina Krpo-Cetkovic ◽  
Stefan Skoric ◽  
Marija Smederevac-Lalic ◽  
Aleksandar Hegedis

The black bullhead is an invasive species that forms dense populations and has a negative impact on the native ichthyofauna. Recent studies indicate that it is one of the most dominant invasive fish species in Serbian waters. Feeding habits based on stomach contents of individuals caught in Lake Sava were analyzed as a first step towards evaluating its possible negative impact on the native fish fauna of the lake. The following indices for diet analysis were applied: vacuity index, frequency of occurrence, numerical abundance and prominence value. Trophic niche breadth and seasonal trophic diversity were calculated using the Shannon?s index. The diet spectrum comprised 16 different prey categories from five groups: Mollusca, Crustacea, Insecta, Teleostei and plants. Fish were the main prey in all seasons, followed by aquatic invertebrates. Plant material and terrestrial insects were used as food in relatively small quantities. Predation on fish eggs was also detected. Our research confirmed that this species is an opportunistic generalist. An ontogenetic diet shift was also detected. The lowest value of trophic diversity was found in age 1+ individuals (H=1.39), while the highest was found in age 3+ individuals (H=2.00). The widest niche breadth was recorded in spring 2011 (H=2.12).


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
José A. Rodríguez-Preciado ◽  
Felipe Amezcua ◽  
Brian Bellgraph ◽  
Juan Madrid-Vera

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.


2018 ◽  
Vol 69 (10) ◽  
pp. 1614 ◽  
Author(s):  
Matthew D. Taylor ◽  
Michael B. Lowry ◽  
Alistair Becker

Responsible fisheries enhancement should include comprehensive monitoring programs to detect ecological effects of fish releases and support adaptive management. Competition for food and shelter is one such impact, and density-dependent effects may occur if release numbers are above levels that the ecosystem can support. Herein we present a novel application of trophic niche breadth estimated from stable isotope data to examine potential competitive interactions arising from eastern king prawn (Melicertus plebejus) stocking. Eastern king prawn and potential competitors (Macrobrachium intermedium, Atherinosoma microstoma, Leptatherina presbyteroides, Ambassis jacksoniensis and Gobiopterus semivestitus) were sampled from two stocked and two reference estuaries, before and after stocking. Stable isotope ratios were measured and used to model trophic overlap and trophic niche breadth. A statistically significant increase in niche breadth was evident for two competing species in one stocked estuary, and one competing species in another. M. intermedium, the species that had the greatest trophic overlap with eastern king prawn, did not show any change in niche breadth. The potential for competition and the role of environmental variability (including rainfall and run-off, mouth opening regime and seasonal changes) in driving the patterns observed are discussed. This approach shows promise for monitoring competitive effects arising from aquaculture-based fisheries enhancements in the future.


Author(s):  
Chiyuki Sassa

The feeding habits of myctophid larvae of Symbolophorus californiensis were examined in the southern transition region of the western North Pacific where the main spawning and nursery grounds of S. californiensis are formed. This species is a key component of the pelagic ecosystems of this region, and their larvae attain one of the largest sizes among myctophids. To analyse gut contents larvae, including most life history stages after yolk-sac absorption (3.7 to 22.2 mm body length (BL)), were collected in the upper 100 m layer in 1997 and 1998. Feeding incidence was higher during the day than at night (53.1–92.3% versus 0–5.6%), and daytime feeding incidence increased gradually with larval growth. Larvae fed mainly on copepods of various developmental stages. Larvae of S. californiensis showed an ontogenetic change in their diet: larvae ≤7.9 mm BL (i.e. preflexion stage) fed mainly on copepod eggs and nauplii, while the larvae ≥8 mm BL consumed mainly calanoid copepodites such as Pseudocalanus and Paracalanus spp. In the largest size-class (16–22.2 mm BL), the furcilia stage of euphausiids was also an important prey item. There was an increase in the average prey size with growth in larvae ≤11.9 mm BL, while the number of prey eaten positively correlated with growth in larvae ≥12 mm BL. The trophic niche breadth also increased with larval growth, which would ensure a wide range of available food resources for the larger size-class larvae.


2012 ◽  
Vol 23 (3) ◽  
pp. 282-292 ◽  
Author(s):  
Vivianne Eilers ◽  
Márcia Divina de Oliveira ◽  
Kennedy Francis Roche

AIM: The present study involved an analysis of the monthly variations in the population densities and body sizes of the different stages of planktonic larvae of the invasive golden mussel (Limnoperna fortunei), in the rivers Paraguay and Miranda; METHODS: The study was carried out between February 2004 and January 2005. Monthly collection of the plankton samples was accompanied by physical, chemical and biological analyses of the water; RESULTS: The Miranda River presented higher values of calcium, pH, alkalinity, conductivity and total phosphorous. Larval density varied from 0-24 individuals.L-1 in the Paraguay River, with a peak in March of 2004, while in the Miranda River, densities varied between 0-9 individuals.L-1 with a peak in February of 2004. No larvae were encountered during the coldest months, May and June. No significant correlations were found between environmental variables and larval density in either river. Only the valved larval stages were recorded. The "D" and veliger forms were most abundant; umbonate larvae were rare in the Miranda River samples. Mean body sizes of "D", veliger and umbonate larval stages were, respectively, 111, 135 and 152 µm, in the Paraguay River, and 112, 134 and 154 µm in the Miranda River. Principal Components Analysis indicated positive relationships between "D" larval stage size and the ratio between inorganic and organic suspended solids, while negative relationships were found between larval size and calcium and chlorophyll-<img border=0 width=7 height=8 src="/img/revistas/alb/2012nahead/ALB_AOP_230307car01.jpg">; CONCLUSIONS: The larvae were recorded in the plankton during most of the year, with the exception of the two colder months. Neither densities nor larval stage body sizes were significantly different between the two rivers. Possible positive effects of food and calcium concentrations on body size were not recorded. This species may be adapted to grow in environments with elevated sediment concentrations.


Author(s):  
Grace Madanire-Moyo ◽  
Annemariè Avenant-Oldewage

Cestodes are parasitic flatworms that live in the digestive tract of vertebrates as adults and often in the liver, muscle, haemocoel, mesentery and brain of various animals as larval stages. To identify the cestodes infecting Clarias gariepinus Burchell, 1822 (sharptooth catfish) in the Vaal Dam, a total of 45 host specimens were collected with the aid of gill nets between October 2011, January and April 2012. The fish were sacrificed and examined for cestode parasites. Two adult cestodes, Tetracampos ciliotheca Wedl, 1861 (prevalence 86.7%, mean intensity = 15, n = 45) and Proteocephalus glanduligerus (Janicki, 1928) (prevalence 51.1%, mean intensity = 5, n = 45) were found in the intestines of the catfish. Both T. ciliotheca and P. glanduligerus are new locality records. There were statistically insignificant differences in the infection of the male and female C. gariepinu. Fish with standard length ranging from 40 cm – 54 cm (≥ 3 years) had the highest prevalence and mean intensity while those ranging from 10 cm – 24 cm (< 1 year) had the lowest prevalence and mean intensity for both cestodes. The study highlights the importance of changing feeding habits of C. gariepinus with age on the prevalence and mean intensity of the two gastrointestinal cestode parasites.


2005 ◽  
Vol 95 (3) ◽  
pp. 233-240 ◽  
Author(s):  
Norma Machado da Silva ◽  
Carina da Conceição Fantinel ◽  
Vera Lucia da Silva Valente ◽  
Vitor Hugo Valiati

Ecological parameters such as trophic niche overlap and niche breadth were computed from the frequency of all drosophilid species collected in 2001 and 2002, in the urban area of Porto Alegre city, Brazil. Independently of place, drosophilids community composition and components breeding or feeding sites, the highest frequencies of Zaprionus indianus (Gupta, 1970) were obtained during seasons with higher average temperatures, especially during summer. From a total of the 19,146 individuals of Z. indianus sampled, 80% were found in this season. The data of trophic niche breadth suggest a higher opportunism of adult flies in feeding substrate use, but the females are still selective in oviposition substrate choice. For the values of niche overlap, only for some species, did we find any correlation between these and species richness and/or number of resources, and the most of the correlation values considering breeding and feeding sites were positive. The colonization of Z. indianus in Porto Alegre could be leading to adjustments in the survival strategies of the resident species, but it is possible that many species have conditions for coexisting with the invader.


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