Natural diet of the tiger prawns Penaeus esculentus and P. semisulcatus

1987 ◽  
Vol 38 (1) ◽  
pp. 169 ◽  
Author(s):  
TJ Wassenberg ◽  
BJ Hill

Foregut contents of 702 P. esculentus and 426 P. semisulcatus collected from seagrass and offshore habitats in the Gulf of Carpentaria, Torres Strait and Moreton Bay between December 1983 and March 1984 were analysed, and the numerical composition and frequency of occurrence of food items in the diet were compared statistically. Periodicity in feeding was examined in adult prawns collected in hourly 20-min trawls overnight. Gut contents from these prawns were weighed and corrected for size by an empirically derived relationship V = 0.00931l2.818 between gut volume (V, �l) and carapace length (I, mm). The guts of both species were partially filled with food throughout the night. Bivalves, gastropods, ophiuroids, crustaceans and polychaetes were the most abundant food items of both species. Dietary composition overlapped for both species caught in the same trawl, but significant differences (P<0.05) were found in average numbers of pariicuiar items. No significani differences (P > 0.05) in numerical composition or frequency of occurrence of dietary items were found between the sexes of either species. Bivalves, gastropods and crustaceans were the most common items in juvenile and adult P. semisulcatus. Bivalves and gastropods were the most common food items in juvenile and adult P. esculentus. Bivalves were more common in adult than in juvenile P. esculentus. Ophiuroids were found more frequently with larger size of P. esculentus but were constant in all sizes of P. semisulcatus. The only meiofauna found in either species in significant numbers were harpacticoid copepods and these were found mainly in prawns from seagrass beds. P. esculentus and P. semisulcatus appear to eat similar taxa of benthic fauna. Quantitative differences between the diets of both species of prawns captured in the same trawl suggest that they are selective in their diet. Strong regional differences in diet were probably due to differences in the availability of prey.

1990 ◽  
Vol 41 (2) ◽  
pp. 301 ◽  
Author(s):  
TJ Wassenberg

The natural diet of juveniles of Penaeus esculentus Haswell (mean size 13.0 � 3.3 mm CL) collected from a seagrass (Zostera capricorni Aschers.) bed in Moreton Bay over 18 months was studied. There was a marked seasonal change in the occurrence of Z. capricorni seeds in their diet. These seeds made up to 1370 of the ash-free dry weight of the prawns' diet in November but disappeared completely from the diet between June and September. When seeds were not available, juvenile P. esculentus ate filamentous algae. Prawns less than 8 mm CL were not found with seeds in their foregut. There was no indication that prawns feed on seeds because of a shortage of other food items such as crustaceans or gastropods. Prawns studied in the laboratory removed seeds from the spathes and selected mature seeds. The seeds (each about 0.75 mg dry weight) had an energy content of 15.36 kJ g-1 dry weight. Seeds were found at densities of 456 m-2 in the seagrass beds. This study and other studies indicate that many species of juvenile penaeids incorporate vegetable material into their diet.


1979 ◽  
Vol 30 (3) ◽  
pp. 387 ◽  
Author(s):  
MJ Conacher ◽  
WJR Lanzing ◽  
AWD Larkum

The fanbellied leatherjacket, M. chinensis, was found to ingest fresh seagrass as a major part of its diet. Other important food items were gammarid amphipods, carid shrimps and several species of epiphytic algae. All food items were of seagrass bed origin. Microscopic examination of gut contents suggested that seagrass and algae did not appear to be digested by the fish, but 14C-labelling of the plants showed that significant amounts of the labile carbon compounds were removed and assimilated during digestion. The fanbellied leatherjacket was found to feed in the seagrass beds during the day, probably relying on eyesight for detecting food. Variations in tide height did not seem to affect their feeding pattern. The amounts of seagrass, algae, amphipods and shrimps removed by M. chinensis in Quibray Bay were calculated and compared with the availability of each of these foods. Grazing by M. chinensis had little effect on seagrass and algae production rates and standing crops, but probably had a significant influence on carid shrimp and amphipod populations.


2008 ◽  
Vol 6 (4) ◽  
pp. 637-644 ◽  
Author(s):  
André Luiz da Costa Castro ◽  
Aline de Farias Diniz ◽  
Ieda Zaparolli Martins ◽  
Ana Lúcia Vendel ◽  
Tacyana Pereira Ribeiro de Oliveira ◽  
...  

This paper presents the results of the first analysis of the natural diet of Hippocampus reidi, one of the most sought after seahorse species in the international aquarium trade. Its main goals were to investigate food items and prey categories consumed by the species, and to discuss feeding strategy and inter and intra-individual components of niche breadth. Data were gathered from October 2005 to September 2006 at the Mamanguape estuary, State of Paraíba, NE Brazil. Food items from seahorses anaesthetized with clove oil were obtained by using a modified version of the flushing method, and were counted and identified to the lowest possible taxonomic level. Specimens were marked and had their height, sex, life and reproductive stage recorded, and then returned to the same place where they were found for the further assessment of anaesthetization/gut flushing on seahorses. Food items were analyzed using frequency of occurrence, relative abundance, index of preponderance and prey-specific abundance using the points method. The graphic method of Amundsen et al. (1996) was used to interpret the feeding strategy and contribution to niche breadth. Nematodes and crustaceans were the most important items found, the latter item usually being the most commonly found in the gut contents of syngnathids. No significant differences in diet composition were found between reproductive stages, however, a higher proportion of large items were consumed by the larger seahorses. The feeding strategy and niche breadth analysis suggests that H. reidi has a generalist feeding strategy, with high variation between phenotypes. Our results suggest that the anaesthetization-flushing technique has the potential to be a useful tool in seahorse research.


Author(s):  
Artūras Skabeikis ◽  
Jūratė Lesutienė

AbstractFeeding activity and diet composition of round goby were investigated in the south-eastern Baltic Sea, the Lithuanian coastal waters during May-October 2012 in order to determine main feeding objects and seasonal periods when native fauna could be most affected by predation of this highly invasive species. In total, prey represented by 18 taxa was found in the gut contents of dissected fish. Feeding activity of round goby varied depending on the body size, sex and stage of the reproduction period. The gut contents of < 50 mm specimens were dominated by zooplanktonic and meiobenthic organisms, whereas larger individuals (50–99 mm) shifted to amphipods and mollusks. Individuals of the intermediate 100-200 mm length had a variable diet, changing depending on the season; in spring they mostly preyed on Macoma balthica, in summer − on polychaetes, while in autumn the contribution of Mytilus trossulus and fish considerably increased in their diet. Diet composition of individuals ≥ 200 mm was relatively constant in the course of the study with substantial preference to M. balthica. These findings imply that benthic fauna, particularly a newly settled generation of epibenthic mollusks in autumn is under strong predatory pressure of the round goby.


1973 ◽  
Vol 21 (3) ◽  
pp. 391 ◽  
Author(s):  
BJ Coman

Stomach contents were examined for 1229 foxes collected in Victoria during 1968-70. Of these, 967 stomachs contained measurable quantities of food. The fox appears to have a very wide dietary range but is predominantly carnivorous. The main food items encountered were rabbits, sheep carrion, and mice. Lesser amounts of native mammals, birds, cold-blooded vertebrates, invertebrates, and plant material were encountered. For many foods, particularly insects, the intake was markedly seasonal. Regional differences in diet were also apparent. Much of the variation in intake of particular foods over time and between regions was explicable in terms of changing availabilities of these foods.


2017 ◽  
Vol 67 (3-4) ◽  
pp. 287-300 ◽  
Author(s):  
María I. Deserti ◽  
Karina S. Esquius ◽  
Alicia H. Escalante ◽  
Fabián H. Acuña

Hydra is a genus of common, sessile, solitary freshwater cnidarians, which are defined as carnivorous and efficient predators. The purpose of this study was to obtain information on the feeding habits and diet of Hydra vulgaris collected from its natural habitat in Nahuel Rucá Lake (Buenos Aires Province, Argentina). We found three categories of food items in the coelenteron: algae, fungi, and small invertebrates. Algae dominated the diet in terms of abundance and frequency of occurrence, but their volumetric contribution was almost negligible, as was their possible nutritional value. Invertebrate prey captured, using active predation, represented the major volumetric contribution, with four different taxa found. The detection of phytoplankton in the gastral cavities reveals the input of some organisms present in the surrounding waters in addition to the invertebrates. This information is novel, since studies on the natural diet of Hydra are very scarce.


2018 ◽  
Vol 46 (1) ◽  
pp. 8
Author(s):  
Muhammad Qayash Khan ◽  
Muhammad Zubair Anjum ◽  
Shamim Akhter ◽  
Irfan Khattak ◽  
Abid Ali

Background:Schizothorax plagiostomus is widely distributed in river Indus and is most important food fish in Pakistan. The feeding habit of fish is directly related to the size of fish, its metabolic rate and environmental temperature. The accurate description of fish diet and feeding habit is a very important aspect in fisheries management for the purpose of species conservation, breeding and culture. The present work was aimed to investigate the specie abundance, the diet composition and seasonal variations in the feeding habit of Snow barbell Schizothorax plagiostomus.Materials, Methods & Results: A total of 1799 fish specimens were caught at the confluence of six tributaries along river Indus at Indus Kohistan, northeastern Pakistan. The fish were collected by 5-panels of gill net during first week of each month. The site specific Catch Per Unit Effort (CPUE) and season specific CPUE of fish fauna were assessed. For the gut content analysis 240 samples (99 male and 141 females) of S. plagiostomus were selected on monthly basis. Frequency of occurrence method and volumetric method were applied to record the different food items in the gut of S. plagiostomus. The physico-chemical parameters, NO3 concentration and dissolved Co2 of water from different localities of river Indus were recorded month wise by Hach sensION 156 meter, Horiba LAQUA Nitrate Meter and EA80 meter respectively. Significant difference was observed in water temperature during the four seasons. Except alkalinity no other water parameter showed significant variation across different localities. The results showed that highest Mean CPUE was observed for Darel Stream (0.55) and lowest for Jalkot stream (0.26). Peak abundance of fish was recorded in the month of November with a mean catch of 44.50, mean CPUE of 0.74 and mean Kruskal-Wallis rank value of 63.25. Spirogyra and Ulothrix occurred as maximum food items in the gut of S. plagiostomus during summer while their minimum amount occurred during autumn. According to the ranking index spirogyra and ulothrix ranked higher with significant difference in comparison to other food items. The results showed that S. plagiostomus is phytophagous in its feeding habit, which consumed mainly algae attached to stones and pebbles during the whole year. However, the presence of some secondary items such as animal matter, detritus, sand and mud might be due to the distinct availabilities of food along the seasons. The highest feeding activity of S. plagiostomus was recorded during summer while the lowest one occurred during autumn, spring and winter. Discussion: Catch per unit effort (CPUE) is an indirect measure of the abundance of a target species. It is used as an index of stock abundance in fisheries and conservation biology. During the study low fish fauna was found in River Indus as reported previously. Majority of the fish occurred in snow fed river tributaries in the study area as these tributaries are comparatively less turbulent. Previous studies have also recorded that Schizothoracine generally prefer clean waters. The present findings of gut contents analysis showed clearly that S. plagiostomus is a phytophagous fish which scrap and consumed spirogyra and ulothrix attached to stones and pebbles. Earlier it was reported that mouth of S. plagiostomusis is inferior, wide, with deep lower jaw having keratinized cutting edge and the lower lip is folded and expanded with numerous papillae making it best suited for scrapping algae attached to stones and pebbles. The highest feeding activity was observed during warmer months as compared to cold months. S. plagiostomus spawn twice in a year in autumn and in spring. The highest feeding activity of S. plagiostomus seems to be link with a reflex of recovery strategy due to physiological process of gonadal development.


2020 ◽  
Vol 32 ◽  
Author(s):  
Tatiane Araujo Santos ◽  
Thamires Souza Gonçalves ◽  
Patricia Silva do Nascimento ◽  
Cézar Augusto Freire Fernandes ◽  
Francisca Edna de Andrade Cunha

Abstract: Aim Identify seasonal variations in the diet of juvenile living in the estuary of the Parnaíba River Delta. Methods Food items were identified through analysis of stomach contents, and later submitted to analysis by regular methods for Frequency of Occurrence (FO), Frequency Numerical (FN), Gravimetric Frequency (FW) and Relative Importance Index (IRI). Results Juvenile diet of Elops saurus that inhabit the lagoons in the Parnaíba delta was composed in order decreasing of importance by Osteichthyes (Teleostei), Insecta and Crustacea in addition to Polychaeta and Nematoda. It was also observed a high frequency of occurrence of fragments of plastics in the diet. In the rainy season, 17 items were recorded in the diet, whereas in the dry season only 7 items were present. Relative Importance Index showed high presence of the Teleostei fish (69.93%) on diet of E. saurus during the rainy season, whereas during the dry period the insects of the families Corixidae (43.25%) and Dysticidae (39.16%). Conclusions With the study it was possible to identify that juvenile are piscivorous in the rainy season when there is a higher availability of prey in the environment and insectivores in the dry season when it reduces the supply of food, indicating feeding flexibility to environmental alterations.


2024 ◽  
Vol 84 ◽  
Author(s):  
F. M. Dutra-Vieira ◽  
M. S. Silva ◽  
G. S. Vieira ◽  
A. S. Carvalho ◽  
B. C. Schimming

Abstract The present study aimed to evaluate the diet of the free-living crab-eating fox by identifying the stomach contents of the 17 crab-eating foxes (Cerdocyon thous) roadkilled in two conservation units, both located in the Amazon rainforest. The food items were quantified by frequency of occurrence (FO) and percentage of occurrence (PO). The stomach contents were analysed for dry matter (DM), crude protein (CP), crude fibre (CF), ether extract (EE), and mineral matter (MM). Nitrogen-free extractives (NFE), metabolisable energy (ME) values, as well as the energy need for maintenance were estimated. The composition of the diet for the crab-eating fox presented 29 food items from the different taxonomic groups, with a greater diversity of items of animal origin (n=22), although the highest frequency of occurrence was gramineae (Poaceae) (41.18%). Among the items of animal origin, 21% were mammals, 18% reptiles, 10% amphibians, 9% invertebrates and 3% birds. A high content of CF (62.76%) were determined. Nitrogen-free extractive and dry matter averages were 5.91% and 141.82 kcal/100g, respectively. The average maintenance energy was 447.01 kcal/day. These findings suggesting that the crab-eating foxes have a generalist diet with an omnivorous diet in the Amazon basin, feeding on gramineae, fruits, insects, snakes, amphibians, birds and small mammals and have the same feeding habit that present in other Brazilian biomes.


2008 ◽  
Vol 68 (2) ◽  
pp. 321-328 ◽  
Author(s):  
LM. Gomiero ◽  
AG. Manzatto ◽  
FMS. Braga

The purpose of this study was to characterize the diet of the fish Brycon opalinus (Characidae) seasonally and locally, allowing for the determination of its food items and trophic relations with the aquatic and terrestrial environments. The study area encompasses three rivers (Paraibuna, Ipiranga and Grande) in the basin of the Paraibuna, southeast Brazil. Twelve monthly collections were made from January to December 2004. The degree of stomachic repletion and of accumulated visceral fat was analyzed, as was the intestinal length in each class of total length. The frequency of occurrence and the degree of food preference (DFP) of the food items of Brycon opalinus were determined by separating the vegetal and animal items, autochthonous and allochthonous, by insect order and vegetal family consumed. The frequency of occurrence of items of animal origin was found to be equivalent to that of vegetal origin, thus characterizing the omnivorism of Brycon opalinus feeding.


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