scholarly journals Food and Trophic Relationships of Four Mullet Fish (Mugilidae) in the Shatt Al-Arab River, Iraq

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Abdul-Razak M Mohamed ◽  
Abdullah N. Abood
Keyword(s):  
Food Item ◽  
Feeding Activity ◽  
Food Composition ◽  
Trophic Relationships ◽  
Relative Importance ◽  
Fish Eggs ◽  
Direct Competition ◽  
Competition For Food ◽  
Index Of Relative Importance ◽  
Monthly Variations

Food composition and feeding relationships of four mullet species, Planliza abu, P. subviridis, P. klunzingeri and Osteomugil speigleri from the Shatt Al-Arab River, Iraq, were assessed during 2016-2017.Fish were captured by gill nets, cast net and electro-fishing. The index of relative importance (IRI%) of food item was determined by combined the frequency of occurrence and points methods. Monthly variations in feeding activity and intensity of all species were observed. All species were herbivorous and P. abu and  P. klunzingeri were considered non-specialized feeders, while P. subviridis and O. speigleri were low specialist feeders. P. abu fed mainly on diatoms (38.6%), high plants (21.7%), algae (15.9%), detritus (15.3%), fish eggs (6.9%) and zooplankton (1.6%).The diet of P. subviridis constituted from diatoms (42.2%), high plants (20.9%), detritus (17.7%), algae (15.9%), zooplankton (2.0%) and fish eggs (1.8%). P. klunzingeri fed mainly on diatoms (35.5%), high plants (29.3%), detritus (16.4%), algae (13.4%), fish eggs (4.1%) and zooplankton (2.4%). O. speigleri were consumed mainly diatoms (52.0%), detritus (17.8%), algae (16.6%), high plants (10.7%), zooplankton (2.5%) and fish eggs (2.4%).Similarity dendrogram among fish species based on their diet showed high significant overlaps among the mullet species. It means that these species might be in direct competition for food in the Shatt Al-Arab River.

scholarly journals Aspectos da alimentação natural de Larimus breviceps Cuvier, 1830, proveniente do litoral norte da Paraíba, Brasil

2020 ◽  
Vol 1 (52) ◽  
pp. 185
Author(s):  
Andreza Da Silva Nascimento ◽  
Jonas De Assis Almeida Ramos
Keyword(s):  
Feeding Habits ◽  
Food Composition ◽  
Marine Debris ◽  
Northern Coast ◽  
Relative Importance ◽  
Synthetic Material ◽  
Fish Feeding ◽  
Food Items ◽  
Index Of Relative Importance ◽  
Social Importance

<p>The knowledge of natural fish feeding is important to understand the species feeding habits and how they interact with the environment. In addition to that, this kind of research can provide relevant data to improve the capture of these animals, considering their economy and social importance. This study aimed to analyze the food composition of Larimus breviceps specimens from the northern coast of Cabedelo city, evaluating the importance of each food item for their diet. The specimens came from the local artisanal fisheries. In laboratory, the individuals were identified, measured and dissected to remove the stomachs content and then examined. Three different analyzes were performed, percentage by frequency of occurrence, by number and by weight, then the index of relative importance (IRI%) was computed. In total, 30 stomachs were analyzed, 15 distinct food items were identified, the most representative prey were fish fragments, Copepoda, Gammaridae, Decapoda (shrimp), algal fragments and synthetic material. Given the results, the diet of this species becomes more diversified as young individuals reach the adults size, and ingest marine debris which indicates an anthropogenic impact.</p>

Reproduction, diet and habitat use of leopard sharks, Triakis semifasciata (Girard), in Humboldt Bay, California, USA

2005 ◽  
Vol 56 (8) ◽  
pp. 1089 ◽  
Author(s):  
David A. Ebert ◽  
Thomas B. Ebert
Keyword(s):  
Habitat Use ◽  
Sexual Segregation ◽  
Minor Importance ◽  
Nursery Ground ◽  
Relative Importance ◽  
Fish Eggs ◽  
Index Of Relative Importance ◽  
Diet Analyses ◽  
Triakis Semifasciata ◽  
Leopard Sharks

A total of 312 female leopard sharks (Triakis semifasciata) was sampled in Humboldt Bay, California, USA, an important nursery ground for this species, during the spring month of May from 1983 to 1984 and 1985. Sexual segregation is strong as only three males were observed in the study area. Females ranged in size from 120 to 154 cm total length, and all examined were determined to be mature. Overall, 130 out of 153 females examined in early May contained term embryos. The number of embryos per female ranged from 1 to 37 with larger females tending to possess more embryos. Of the 159 individuals examined in late May, no females were found carrying embryos and most were ovulating. Diet analyses revealed that, overall, fish eggs (Atherinopsis californiensis) at 48.0%, had the highest percentage Index of Relative Importance (%IRI), followed by the cancrid crabs, Cancer antennarius (29.8%) and C. magister (11.6%). All other prey were of relatively minor importance, cumulatively representing 10.6% of the overall diet. Adults shift their diet after parturition: early May sharks fed almost exclusively on fish eggs, while crabs were more important in those examined in late May.

scholarly journals Diet Composition and Feeding Strategy of Nemipterus japonicus Bloch, 1791 from Tha-baw-seik, Myanmar

Bionatura ◽  
2019 ◽  
Vol 4 (3) ◽  
pp. 901-907
Author(s):  
Thet Htwe Aung
Keyword(s):  
Diet Composition ◽  
Food Item ◽  
Feeding Strategy ◽  
Stomach Content Analysis ◽  
Food Composition ◽  
Feeding Strategies ◽  
Relative Importance ◽  
Food Items ◽  
Importance Index ◽  
Nemipterus Japonicus

Food composition of Nemipterus japonicus was studied by analyzing about 600 specimens from Tha-baw-seik (Lat. 14° 05' and long. 98° 05' E), Myanmar during October 2016 to September 2017. Based on the stomach content analysis, the relative importance index (IRI value) was calculated, and the predator feeding strategies were conducted during the study period. This study showed that N. japonicus is a generally demersal carnivore, and its trophic spectrum was composed of 23 food items. Among them, algae had not been described as a food item for N. Japonicus in the other previous studies. Crustaceans were the most dominant diet in the guts in term of the IRI value. Also, fish items were commonly the most dominant food followed by prawn, crab, and Acetes spp in all length groups but sex variation had no significant food changes with their IRI value.

Trophic Interactions between Two Cichlid Species in Shatt Al-Arab River, Iraq

2021 ◽  
Vol 5 (1) ◽  
pp. 74-85
Author(s):  
Abdul-Razak Mohamed
Keyword(s):  
Feeding Activity ◽  
Trophic Niche ◽  
Trophic Relationships ◽  
Food Sources ◽  
Oreochromis Aureus ◽  
Cichlid Species ◽  
Food Items ◽  
Blue Tilapia ◽  
High Degree ◽  
Monthly Variations

The diet composition and trophic relationships of the blue tilapia, Oreochromis aureus and redbelly tilapia, Coptodon zillii were investigated in the Shatt Al-Arab river from November 2015 to October 2016. Fishes were collected by gill nets, cast net and electro-fishing. The index of relative importance (IRI%) of food items was determined by combining the frequency of occurrence and points methods. There were monthly variations in feeding activity and intensity of both species, which decreased in the colder months. Both species were classified as herbivores. The main food items of O. aureus were macrophytes (44.3%), algae (31.4%), diatoms (9.3%), aquatic insects (6.6%) and detritus (6.3%). The diet of C. zillii is composed mainly of macrophytes (60.8%), algae (23.0%), detritus (8.6%) and diatoms (6.4). The trophic niche breadth values varied between 0.217 for C. zillii and 0.360 for O. aureus. The results demonstrated a high degree of dietary overlap between O. aureus and C. zillii, as both species fed on the same food sources

scholarly journals Variations of Salminus hilarii diet (Ostariophysi, Characidae): seasonal and ontogenetic effects

2015 ◽  
Vol 75 (3) ◽  
pp. 574-580
Author(s):  
GA Villares Junior ◽  
R Goitein
Keyword(s):  
Prey Size ◽  
Pearson Correlation ◽  
Feeding Activity ◽  
Stomach Contents ◽  
Food Composition ◽  
Spearman Correlation ◽  
Statistical Comparison ◽  
Significant Difference ◽  
Ontogenetic Effects ◽  
Size And Morphology

AbstractThis study described the variations seasonal and ontogenetic of Salminus hilarii diet. Samples were collected in the Sorocaba River, São Paulo, Brazil, one of the few rivers where individuals of the species still occur in a higher frequency. The preys consumed were analyzed by Importance Alimentary Index (AIi). To determine similarities between year seasons, the AIi data were analyzed by the Morisita-Horn index and reduced in cluster analysis, along with a statistical comparison made by one-way ANOSIM test (5%). The feeding activity was analyzed according to the stomach repletion index and compared among the year seasons using non parametric variance analysis Kruskal-Wallis test (5%). Comparison of prey consumed between immature and adult individuals was made by Spearman correlation (5%). A Pearson correlation (5%) was applied between the standard length of the fish and prey consumed, as well as between the mouth and prey heights. The analyzes of stomach contents showed that the diet of this species was exclusively piscivorous, with significant difference of prey consumption during the period, the same happening among adult and immature individuals. It was observed that these fishes use to swallow their prey whole and that significant correlations between size of predator and prey size can be observed. There is also correlation between the mouth height and the maximum prey depth. Salminus hilarii feeds on the available prey, and the species food composition and feeding activity depends on prey`s abundance, their size and morphology, as do the water temperatures.

scholarly journals Spatial and seasonal changes in the diet of Oligosarcus hepsetus (Characiformes, Characidae) in a Brazilian Reservoir

2005 ◽  
Vol 65 (1) ◽  
pp. 1-8 ◽  
Author(s):  
F. G Araújo ◽  
C. C Andrade ◽  
R. N Santos ◽  
A. F. G. N Santos ◽  
L. N Santos
Keyword(s):  
Seasonal Changes ◽  
Prey Capture ◽  
Gut Contents ◽  
Relative Importance ◽  
Food Items ◽  
Dietary Shifts ◽  
Index Of Relative Importance ◽  
Almost All ◽  
Previous Autumn ◽  
Very High

We assessed spatial and seasonal changes in the diet of Oligosarcus hepsetus in order to describe the strategy developed by this species that allows their very high abundance in Lajes reservoir, Rio de Janeiro, Brazil. Fish samplings were carried out using gill nets, deployed during ca. 12 and 24 hours, between April 2001 and May 2002. A total of 289 individuals were examined, of which 97 showed gut contents. We used the index of relative importance (IRI) to compare probable dietary shifts, and the frequency of occurrence (% OC) to analyze possible ontogenetic influences on feeding. O. hepsetus showed carnivorous habits, feeding preferably on fish and insects, the latter of which occurred in 71.0% of the guts presenting contents. O. hepsetus consumed different items along the three reservoir zones: insects (61.0% IRI) and Cichla monoculus (38.9% IRI) in the lower zone; Lepidoptera (57.0% IRI) in the middle zone; and C. monoculus (77.0% IRI) in the upper zone. Food items changed seasonally with C. monoculus predominating in autumn 2001, and Hymenoptera and Lepidoptera in the winter. In spring almost all food was Lepidoptera (99.8% IRI), while in the summer Hemiptera dominated in the diet. In autumn 2002 Hemiptera (97.0% IRI) was dominant, in significant contrast with the previous autumn. Individuals smaller than 190 mm SL fed heavily on insects, while fishes predominated in the diet of individuals larger than 190 mm SL. Shifts in prey-capture ability among length classes suggest decreasing intraspecific competition. A higher food plasticity seems to be the strategy employed by this opportunist species, which used food resources available in the reservoir.

scholarly journals Bio-Ecological Traits of Western Tubenose Goby Proterorhinus semilunaris (Heckel, 1837): A Key to Understand Its Invasion Success

Water ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1247 ◽  
Author(s):  
Gülşah Saç
Keyword(s):  
Standard Length ◽  
Natural Habitat ◽  
Invasion Success ◽  
Biological Traits ◽  
Relative Importance ◽  
Ecological Traits ◽  
Tubenose Goby ◽  
Significant Difference ◽  
Index Of Relative Importance ◽  
Proterorhinus Semilunaris

This study aims to contribute to the limited knowledge on the bio-ecological traits of the native Western tubenose goby, Proterorhinus semilunaris, which is considered to invade many inland waters in Europe and North America. During monthly sampling surveys from March 2012 to June 2013, the species was collected from the four stations in the Istranca River (Turkey) by electrofishing. The standard length and body weight of 310 samples varied between 1.4–6.1 cm and 0.08–7.09 g, respectively. The sex ratio of female to male was found to be 1.7:1.0, with a significant difference. The values of the exponent b in the length–weight relationship were approximately 3 for females, males, and all individuals, indicating an isometric growth. The size at first sexual maturity was 2.44 cm standard length (SL) for females and 2.29 cm SL for males. Absolute fecundity ranged from 56 to 344 eggs with a mean of 164 eggs. The food composition of the species comprised of 8 major groups: Insecta (Diptera, Ephemeroptera, Plecoptera, Odonata, Trichoptera, Coleoptera), Arachnida, Annelida, Gastropoda, Crustacea, Pisces, plant, and detritus. According to the results of modified index of relative importance (MI) and index of relative importance (IRI), insect and Diptera were the most prevalent prey for this fish. The present study has provided baseline information on the basic biological traits of the fish in its natural habitat for further understanding of this species success of invasion.

Feeding activity of ducks in relation to diel emergence of chironomids

1982 ◽  
Vol 60 (6) ◽  
pp. 1383-1387 ◽  
Author(s):  
Kjell Sjöberg ◽  
Kjell Danell
Keyword(s):  
Water Surface ◽  
Food Item ◽  
Feeding Activity ◽  
Emergent Vegetation ◽  
Cold Weather ◽  
Dabbling Ducks ◽  
Entire Surface ◽  
Diving Ducks ◽  
Insect Group

The diel emergence of chironomids, an insect group important as food item for both adult and young ducks, was studied in relation to the feeding activity and behaviour of ducks on a northern Swedish lake (66°3′ N, 23°46′ E) during 1975–1978. Emergence and swarming activity of chironomids peaked between 0800 and 1200. Emergence occurred even on windy days, but almost completely ceased during periods of rainy and cold weather. Swarming occurred mainly around 1000 on warm days with little or no wind. During such occasions, a large number of chironomids were observed over the entire surface of the lake. Dabbling ducks fed throughout a 24-h period, but peak feeding coincided with periods of chironomid emergence. Surface feeding by both dabbling and diving ducks on chironomid imagines present on the water surface and on emergent vegetation increased during these periods of chironomid emergence.

Hard prey specialists or opportunistic generalists? An examination of the diet of the cownose ray, Rhinoptera bonasus

2007 ◽  
Vol 58 (1) ◽  
pp. 135 ◽  
Author(s):  
A. B. Collins ◽  
M. R. Heupel ◽  
R. E. Hueter ◽  
P. J. Motta
Keyword(s):  
Feeding Behaviour ◽  
Stomach Contents ◽  
Relative Importance ◽  
Charlotte Harbor ◽  
Severe Damage ◽  
Important Prey ◽  
Cownose Ray ◽  
Rhinoptera Bonasus ◽  
Group Feeding ◽  
Index Of Relative Importance

Atlantic cownose rays (Rhinoptera bonasus) are benthic, suction feeders whose foraging activities have been implicated in severe damage to commercial shellfish industries. With jaws highly modified for durophagy, it has been assumed that R. bonasus are crushing specialists that feed primarily upon hard molluscan prey. Stomach contents from R. bonasus caught within Florida’s Charlotte Harbor estuary between July 2003 and July 2004 were analysed using the index of relative importance (IRI) to determine most important prey types. Prey items were identified from 38 families and fell into nine distinctive groups. The three most dominant prey groups were crustaceans (%IRI = 55.31), polychaetes (%IRI = 25.20) and bivalves (%IRI = 12.58). Shoalmates had more similar diets than non-shoalmates, suggesting group feeding. Most small or softer-bodied prey consumed were relatively intact, indicating lack of prey processing and capture through suction feeding. All larger, harder-bodied prey showed evidence of crushing (fractured and broken shells). Although R. bonasus has been characterised as a hard prey specialist, these results suggest it may behave as an opportunistic generalist, modifying feeding behaviour to consume readily available prey.

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