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Showing 16 results for Feeding
Mehdi Naderi Jolodar , Gholamreza Salarvand , Asghar Abdoli , Hasan Fazli , Maesomeh Eshaqi Nimvaryy,
Volume 1, Issue 3 (12-2013)
Abstract
This study aimed to identify the food items of Rutilus frisii kutum and the feeding intensity for this species was performed in the southern coast of the Caspian Sea.Sampling was carried out at 6 times from late March 2012 until late May 2013 in the distribution areas of kutum (less than 60 meter depths in the southern coast of the Caspian Sea) and 193 fish were studied for the contents of the digestive tract. The average total length and total weight of samples which were 36.9 ± 8.5 cm and 562.9±353.2 g, respectively. The results of this study showed that kutum are generally fed from Cerastorderma sp. and Balanus sp. as the presence frequency of Balanus sp. was more than Cerastorderma sp., but the amount of its consumption was less than Cerastorderma sp. In order of importance after the Bivalvia, Gastropoda, Crabs, Fish eggs, Filamentous algae were present in kutum GI. The feedingintensity and food strategy of this species are exposed to alter in term of gender, sampling periods and longitudinal length groups. Thus, the feedingintensity in males was more than females and the length groups in smaller than 30 cm was more than in higher length groups of 30 cm (P<0.05). Also the feeding intensity was shown in the different sampling periods as the reproductionperiods was drastically decreased with reducing temperature and in late winter. (P<0.05). At the recent survey, the results are indicated that the influence of adaptation and behavioral mechanisms, physiological and ecological, such as Bivalvia has a pivotal role for feeding of kutum, but the diversity amount on food consumption and feeding from Bivalvia were less than last years. If this species was surveyed in the southern coast of the Caspian Sea, it was appeared that this species was mostly fed on Cerastorderma sp., while it is recently demon strated the above prey was general food for kutum. It seems that releasing of fingerling kutum was mostly carried out by artificial propagation and its stock increasing was caused to decreasing frequency this food.
Rezvanolah Kazemi, Farzaneh Noori, Ali Bani, Eebrahim Hossein Najdegerami, Mohammadali Yazdani Sadati,
Volume 3, Issue 2 (9-2015)
Abstract
Reduction of quality and quantity of wild and farm Persian sturgeon in early life cycle is the most important problems in this endemic and economical species. The purpose of this study was to increase the production efficiency of Acipenser persicus in the first feeding stage to fingerling stage using effect reaction between photoperiod and light intensity. This study was conducted with 13 treatments including 4 photoperiod (24L:00D, 16L:08D, 12L:12D and 08L:16D), 3 light intensity (100, 250 and 450 lux) and one control with three repetition in each treatment (each repeated include 1800 larvae with initial weight and length 41.66 mg and 19.64 mm, respectably) during 60 days. During the experimental period, individual body length and weight were taken at the first and 60th day after the first feeding. All of the fish were fed on live food in the same amount. Biological measurements, including final weight, final length, weight gain (WG), specific growth rate (SGR), condition factor (CF), body weight increase (BWI (and Survival rate (SR), were analyzed. The result indicated that except for survival rate, growth factors were subject to the mutual effect of photoperiod and light intensity, although the final weight and length were affected more by the photoperiod. The growth factors of fish that were in 12L:12D photoperiod with an intensity of 100 lux and 08L:16D photoperiod with an intensity of 250lux were significantly better than others photoperiod and light intensity treatments.
Mr Hadi Raeisi, Dr Ehsan Kamrani, Dr Rahman Patimar, Dr Iman Sourinejad,
Volume 3, Issue 3 (12-2015)
Abstract
The present study aimed at investigating the diet of white cheek shark, Carcharhinus. dussumieri, in order to determine its feeding preferences in Hormozgan waters, Persian Gulf. Overall, stomach contents of 360 shark were sampled including female (n=169) and male (n=191). The content of 360 white cheek sharks including 169 female and 191 male, which were caught using trawl and gill net during 18 months from December 2013 to May 2015, were examined. Diet of Whitecheek shark, with the length range of 41-98 and weight range of 500-5100 gr., was described using the numeric, frequency, weight methods and the index of relative importance index (IRI). Two hundred fifty two stomachs contained food items and small teleost fish were found in the majority of full stomachs. Results indicated that C. dussumieri fed on a wide variety of teleost species, primarily Engraulidae, Synodontidae, Nemipteridae with occasional crustacean and cephalopod prey. There was a significant difference in diets of males and females shark samples. The average prey content in the stomach was 1.59±0.84 and 1.51±0.81 for male and female, respectively. In addition, trophic level was calculated 4.4. A shift in diets of maturing, immature and mature males and females deemed to be an evidence that C. dussumieri experiences an ontogenetic feeding diet shift.
Elham Mohammadzadeh, Dr Mehran Javaheri Baboli, Mr Mohammad Velayatzadeh,
Volume 4, Issue 1 (6-2016)
Abstract
This study aimed to determine the feeding habits and diet of Alburnusmossulensis in the Abgarmeh River in Saleh Abad, Ilam Province, in different seasons of 1386-1387.Sampleincludes fifty five A. mossulensis which were caught using Cast net (mouth diameter: 3mm; mesh size: 20mm) and Scoop net (mesh size: 2mm) from 4 stations. The length range of fishes in the sample was 4.70-14.50 cm. In this study obtained the digestive of A.mossulensis were Odonata (138), Diptera (165), Hemiptera (91), Amphipoda (75), Trichoptera (35), Ephemeroptera (95), Coleoptera (62), Oligochaeta (89), Plecoptera (34) and Hirudinea (50) respectively. The highest and lowest abundance of food in the digestive tract were of the Diptera (19.78%) and the Plecoptera (4.07%), respectively. According to the frequency of food groups in the river and the results of digestive tract of fish, it was determined that this fish has tendency to Coleoptera (0.029) and Trichoptera (0.023) and the lowest desire to Amphipoda (-0.053). Average relative length of the intestine (1.095±0.81g) and fullness index of A.mossulensis (946.68±76.97) were higher in spring than those observed in other seasons. Also, the mean condition factor index was higher in winter (795.06±24.99) than that of other seasons. After investigating the gastrointestinal tract it was found that of the 55 cases studied the that all the fish were full stomach. According to the results, A. mossulensis in the Abgarmeh River from Ilam province is a gobbler and omnivorous species who has greatest tendency to Coleoptera and Trichopteraand as its food and the least desire to Amphipoda. This species also has extremely high nutritional.
Mr Gholamali Bandani, Mr Mohammad Larijani, Dr Keyvan Abbasi, Dr Farhad Keymaram, Mr Ahmad Reza Jabaleh,
Volume 5, Issue 3 (12-2017)
Abstract
Common carp ( C. carpio) is remarkable commercially in the southern Caspian Sea, especially in the southeastern coast. Its biology in natural environments has been less studied despite the commercial importance and value of this species. In this study, a total of 328 specimens were sampled and analyzed during the sampling period. The minimum and maximum length for females and males were 63 mm and 99 mm, 656 mm and 563 mm, respectively. The species included 11 age groups on the basis of biometric data and the autopsy. Analysis of fish feeding strategies and percentage of empty digestive tract in different seasons was conducted using the Costello (1990) graphical method. Out of the 328 fish which were examined, 235 empty stomachs and 66 stomachs containing food were observed. The Stomach emptiness percentage was variable between 69.72 to 75 % in which the maximum and minimum was reported for winter and spring, respectively. Feeding indexes including: probability percentage (Fi), frequency percentage (Ai) and dominance index (Ip) were examined in the digestive tract during different seasons. In all seasons, the highest digestive content was related to molluscs. The annelids presented the second highest content in the fish stomach in spring and plants indicated the highest content in fall and winter. The most reason for changing in the priorities of the food items during the period of study is the abundance of available food sources. In fact, C. carpio is an opportunistic and flexible feeder based on abundance and accessibility of foods.
Mr Yonus Golalipour, Dr Hosein Khara, Dr Mahmod Mohseni,
Volume 5, Issue 3 (12-2017)
Abstract
In a feeding trial, the effects of four levels of lipid (10, 15, 20 and 25%) and raw energy (including 18.8, 19.9, 21.4 and 22.5 kJ) with the same protein (45%) were evaluated to determine the appropriate level of lipid and dietary energy on growth performance and carcass composition of Siberian sturgeon (A. bearii). A total of 120 fish (15.6 ± 0.33 g) were randomly assigned to 12 fiberglass tanks of 500 liter (n=10 per tank) and fed manually 3 times per day for 12 weeks with ad libitum feeding. Results of growth trend at the end of the period showed that the fish fed with lipid content of 10 to 15 percent obtained significantly more weight gain (WG) and specific growth rate (SGR) than the fish fed with diet containing 20 and 25 percent of lipid. However the feed conversion ratio of fish fed with lipid content of 10 to 15 percent was significantly lower than other treatments. Analysis of fish carcasses indicated the significant differences in the composition of lipid, protein and ash. According to the results of present study, increasing of the lipid levels in diet of Siberian sturgeon (A. bearii) up to 15% can cause an improvement in growth rate, diet efficiency and carcass composition.
Mr Eslam Mehdizadeh, Dr Mehdi Safaie, Dr Soheila Ebrahimi,
Volume 5, Issue 3 (12-2017)
Abstract
Feeding habits of bamboo shark ( C. arabicum) were studied monthly in Persian Gulf (Bandar Abbas area) during the period from November 2015 to April 2016. A total sample of 180 specimens (including 102 males and 78 females) ranging from 37/2 to 73/4 mm total length, were caught in Persian Gulf waters (Bandar Abbas up to Qeshm island) using trawl and bottom gill nets. The contents of the stomachs consisted of mainly large quantities of fish (47%), crustaceans (31%), mixed materials (unidentifiable matter) (19%) and molluscs (3%). Based on the major food contents observed in different seasons, fish item was the most dominant in March (63 %) and the crustaceans items and Mollusca were the most dominant ones in January (45 %) and November (8%), respectively. There was no significant difference in terms of the diet composition in both sexes, but significant differences were observed in the preference for food items in different size groups. The Stomach emptiness index (CV) index varied significantly in both sexes that was ranged between 3/3- 23/3% and 3/8 - 11/8 % for male and female, respectively. Additionally the results showed that the maximum and minimum of Gastrosomatic index (GaSI) observed in March and April 2016, respectively.
Dr Ali Arshadi, Dr Javad Mirdarharijani,
Volume 5, Issue 4 (3-2018)
Abstract
Snow trout (S. zarudnyi) is a commercial, ecological and biological valuable species which is native to the southeastern Iran (Sistan). In this study, 41 samples of Snow trout were caught by gill net from Chah nimeh reservoirs, Sistan and Baluchestan Province, and their biological characteristic were investigated. The results showed that the average weight and length of fish were 121.70±57.07g and 22.35± 3.49cm, respectively. The sexual ratio in Snow trout was 1:1.16 (male: female), and the gonadosomatic Index (GSI) of female was 1.08±0.74%. Moreover, the maximum and minimum percentage of GSI was reported in March (1.75%) and May (0.84%), respectively. The changes in the percentage of GSI indicated that the sexual maturity and breeding season of this fish happened in March. The average relative and absolute fecundity recorded was 33140 ± 1905.65 egg/kg and 26964±1001/97 eggs, respectively. The condition factor (CF) was 1.01±0.12 %, and the maximum and minimum amount of CF was reported in March and May, 1.30% and 0.76%, respectively. The relative gut length (RLG), as the ratio of intestine length to body length was 1.73±0.30. Consequently, considering the amount of RLG which was more than one, Snow trout categorized as omnivorous with herbivorous tendency. The average of feeding intensity (IF) was 180.64±108.99%, and the maximum and minimum of IF was found in May and February, 480.54 and 43.02%, respectively. Finally, the relationship between the length and weight for the species was recorded as W=0.0058L3.177 with r=0.98. The b-value as coefficient of WLR indicates that the growth of Snow trout is isometric.
Dr Zeid Ahmadi, Dr Reza Akrami, Mr Mehdi Kharkan Ghamsari,
Volume 6, Issue 3 (3-2019)
Abstract
Growth, hematological parameters and water quality for great sturgeon (Huso huso), were determined at three different stocking densities and three feeding rates. Stocking density were 1, 1.5 and 2 kg m-2 and feeding rates were 1, 2, and 3% body weight day-1. Sturgeon were offered to 18 tanks and 3×3 experimental design was used with two replicates per treatment. Initial average body weights of the fish were 25 ± 1.5g and were hand-fed a pelleted commercial feed (44 % protein, 20% fat, and 7% ash) twice daily throughout the experiment period. After about 7 weeks of feeding, optimal feeding rate and growth performance was observed in 1 kg m-2 and 3% of body weight day-1 and there were significant difference interaction in stocking density and feeding rate between treatments (P<0.05). The results demonstrated that hematological parameters were not significantly different in all groups (P>0.05). No mortality was abserved during the experiment. Water quality including ammonia (NH3) and dissolved oxygen (DO) showed significant differences (P<0.05) among the treatments affected by different densites and feeding rates, while temperature and pH showed no significant difference (P>0.05). Results show that the optimum feeding rate and stocking density for fishes weighing 25 to 155 would appear at a feeding rate at 3% body weight day-1 with the stocking density 1 kg m-2.
Mehdi Naderi Jolodar, Seed Abdolla Hashemian, Abolghassem Roohi Kolahgar, Mohammad Ali Afraei Bandpei, Hassan Fazli, Ali Mokarammi,
Volume 7, Issue 3 (10-2019)
Abstract
The sampling of fishes and Macrobenthic were performed in Goharbaran Mazandaran province by selecting four stations at a depth of 5 meters and four stations at a depth of 10 meters a monthly basis from May 2013 to April 2014 and fish samples of coastal blade caught were used. During the study, a total of 565902 Macrobenthic invertebrates isolates belonging to 22 species of 9 families. Oligochaeta worms were identified at the level of the class and Polychaeta worms including 5 genera and species were. Crustacea with 16 species had the highest number of species than other species. Among the 6 species of fish, Rutilus kutum and Liza aurata were 73.05% and 24.67% of the total catch, respectively.The present study showed that Bivalvia, especially Cerastorderma, have a high relative importance for Rutilus kutum and the importance of Gastropoda, Crabs, Fish eggs, Filamentous alge was rare for this species. Also the most feeding of Cyprinus carpio, Liza auratus, and Liza saliens species were from Detrite. After Detrite, the most important food items for Cyprinus carpio were Bivalvia, Abra ovata, Gastropoda, Oligochaeta, Nereis, Fish eggs, Filamentous alge. After Detrite, the most important food items for Liza auratus were Foraminifera, Porifera and Balanus and for Liza saliens were related to Gastropoda, Bivalvia and Porifera. Due to the combination of Macrobenthic invertebrates and the reduction of Bivalvia in the Goharbaran region, bait Food is not enough for the Rutilus kutum stocks. The present study showed that Bivalvia, especially Cerastorderma, have a high relative importance Rutilus kutum. The relative importance of Bivalvia in feeding carp was far more than other foods. In Ditritus, Mugillidae of fish in the present study was consistent with the results of other studies.
Asma Ahmadi, Vahid Morshedi, Shirin Hamedi,
Volume 8, Issue 4 (12-2020)
Abstract
To investigate the effect of its various aspects and the effect on growth, nutrition, and biochemical composition of body, Asian Sea bass fish with an average initial weight of 33 ± 0.9 gr were experimented in three hundred-liter polyethylene circular tanks in three repetitions. Feeding was done twice a day for up to 60 days. The results showed that growing Asian sea bass in fresh-water and seawater did not have a significant effect on growth performance indicators (except for the average final length) (P > 0.05). The mean secondary length in saltwater treatment was significantly higher (P < 0.05). Therefore, In addition, among the calculated nutritional parameters, only the food index received between treatments had a significant difference (P < 0.05) and other indicators and biochemical body compounds did not show a significant difference (P > 0.05). Cultivation of freshwater fish has a lower feed conversion ratio (0.92 ± 0.06); however, these changes were not significant. Overall, the study showed that it can withstand a wide range of different salinities for 60 days and grow well without showing any casualties.
Sarpanah , Abbasi , Sayadrahim ,
Volume 8, Issue 5 (12-2020)
Abstract
Iranian goby is an endemic fish that was described in 2015 from rivers of the Guilan province. This fish exists upstream and mid-stream of rivers and it is observed lowly in downstream and rarely in estuaries of rivers. This study has been done in 4 important rivers of Anzali Wetland (Chafrud, Khalkaee, Siahdarvishan and Pasikhan) and the main purposes were determination of diet spectrum and food preference of the fish and samples was caught using electro-shocker from spring 2016 until winter 2017. Results on 54 individuals with a total length 47-137mm showed that coefficient of vacuity, averages of relative gut length and feeding intensity, 8.5%, 0.51±0.10 and 337.3±237.6, respectively. The studied fish fed on 26 food items belong to 21 animal families of worms (Oligochaeta), Bivalvia, insects consist of orders Coleoptera, Diptera, Ephemeroptera, Trichoptera, Crustacean (Isopoda and Palaemonidae) and bony fishes (Cyprinidae, Cobitidae and Gobiidae). Chironomidae, Baetidae and Simulidae were observed in 48.1, 14.8 and 11.1% of studied stomachs and they comprised about 74.3, 7.6 and 3.2% of total counted preys and were abundant. In general, the fish is a euryphagous and mainly benthivore fish and old individuals consume on nekton such as shrimps and fish species, too.
Kamyar Javid Rahmdel , Bahram Falahatkar ,
Volume 8, Issue 5 (12-2020)
Abstract
Pikeperch (Sander lucioperca) is a species with high nutritional, ecological and commercial values which is endemic in Iran, but its natural stocks are endangered during recent years. Therefore, Iranian Fisheries Organization as the main responsible organization for preservation of aquatic natural stocks of the country planned to stock rehabilitation of this species since 1989. This program had satisfactory results and make drastic increment in pikeperch harvest value in southern parts of the Caspian Sea. The key part of restocking plan of fish including pikeperch is in-captured propagation, larviculture and production of high quality fries. Larval period is very critical and challenging stage and larviculture requests having knowledge on natural requirements of larvae and maintaining appropriate environmental and nutritional conditions. Hence, the current paper tried to evaluate principles of pikeperch larviculture and present practical manual on this field.
Mr Mehdi Barmar, Dr Habibollah Mohammadi, Dr Vahid Zadmajid, Mr Edris Ghaderi,
Volume 9, Issue 2 (12-2021)
Abstract
This study was conducted to survey the feeding indices of Garra rufa in Gheshlagh River, Kurdistan Province. Seasonal sampling carried out during spring, summer, autumn and winter of 2018 using electrofishing and cast net with 20 mm mesh size. For diet analysis, 40 number of Garra rufa was used. The length and weight of sampled fishes was renged of 56 to 137 cm and 2.5 to 37 g, respectively. The average of RLG index was 8.22±2.25 that specified the herbivory or prephyton feeder. The mean of gastro- somatic index, condition factor (K) and vacuity index (CV) was 11.67±5.28, 1.35±0.23 and 10 respectively. Also, according to the percentage of food groups in the environment and gastrointestinal tract of fish, it was observed that this fish is more inclined to Nitzschia, Gomphonema, Amphora, Cocconeis, Rhabdoderma and Diatoma genera for feeding, respectively and They are the most preferred food items for this fish during the sampling seasons and the genus Ocillatoria with a value of -0.8 had the lowest priority. The genera Cocconeis, Cymbella, Diatoma, Gomphonema, Melosira, Nitzschia, Synedra and Navicula as the main food, The genera Cyclotella, Pediastrum, Stephanodiscus, Cymatopleura, Gyrosigma, Gloeotrichia and Spirulina as the supplementary food and the genera Amphora, Chlorella, Cosmarium, Ocillatoria, Rhabdoderma and Scenedesmus as the incidental food of Garra rufa
Ms Mahin Raeisi, Dr Ali Sadough Niri, Dr Moslem Daliri,
Volume 9, Issue 4 (12-2021)
Abstract
The purpose of this study was to explore the feeding habits and preference prey of Sphyraena jello in Chabahar marine waters between April 2019 to March 2020. The number of 385 specimens with mean (±SD) total length and weight 64.0±3.5 cm and 925.45±12.0 g for males and 66.0±2.45 cm and 1001.35±5.2 g for females were examined. Length-weight relationships of male and female was respectively computed W=0.021L 2.752 and W=0.017L 2.823. For males, the maximum and minimum ISF% was observed in February (with 37.22%) and August (75.18%). Against, it was 18.01% and 84.75% in August and January for female. Mean (±95% CL) vicinity index (CV%) was calculated 15.90±12.79 (for male) and 7.84±2.55 (for female), which are indicated S. jello is a full-feed species. Fifteen food items were recognized which the maximum and minimum FO% were related to Clupeidae (with 25.48%) and Cuttlefish (with 1.49%). Small-pelagic fish (Sardins and Anchovis) were the most important food items (with more than 50%) of this species, totally. Considering ecological importance of S. jello, these result could provide useful information for fish biologists and stock assessment and fisheries management researchers.
Mr Madat Balouch, Dr Seraj Bita, Dr Nazanin Ghorbani Ranjbari,
Volume 12, Issue 2 (6-2024)
Abstract
Investigating the ecology of fish feeding as a part of biological studies is necessary to understand its functional role in ecosystems. In the present study, the feeding indices of Alepes djedaba (Fabricius, 1775) were investigated seasonally to identify its feeding habits. For this purpose, totally 120 fish were collected from the three areas of Ramin, Haft Tir and Tis in Makkoran coast of Oman sea from fall 2020 to summer 2021. Fishes were first biopsied and then dissected and their stomach contents were examined. The average length and weight of the fish were 28.00±4.68 cm and 311.18±12.00 g, respectively. The relative length of the intestine and the stomach fullness and emptiness index showed that this fish was carnivorous and tendency to eats relatively little food. The highest number of empty stomachs was 80% and the lowest amount of gastrosomatic index was recorded in spring, which was significantly different from winter and summer (p<0.05). The highest feeding intensity was in summer (426.52±49.35) and the lowest in spring (99.85±19.00). The value of the condition factor is more than 0.5 in all seasons and the fish has a good condition in terms of obesity. According to the results of food preference and relative importance indexes, fishes were determined as the main food item and crustaceans as the secondary food item, so that Stolephorus sp fish were more important food item than other prey. In general, this species is carnivorous and tendency to eats relatively little food. Its diet is mainly from fish, especially Stolephorus sp. and it has suitable biological conditions in the coastal waters of Makkoran.
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