Fish Feeding

Growth affects the performance of structure, so the pattern of growth must influence the role of a structure and an organism. Because animal performance is linked to morphological specialization, ontogenetic change in size may influence an organism's biological role. High bite force generation is presumably selected for in durophagous taxa. Therefore, these animals provide an excellent study system for investigating biomechanical consequences of growth on performance. An ontogenetic series of 27 cownose rays (Rhinoptera bonasus) were dissected in order to develop a biomechanical model of the feeding mechanism, which was then compared with bite forces measured from live rays. Mechanical advantage of the feeding apparatus was generally conserved throughout ontogeny, while an increase in the mass and cross-sectional area of the jaw adductors resulted in allometric gains in bite force generation. Of primary importance to forceful biting in this taxon is the use of a fibrocartilaginous tendon associated with the insertion of the primary jaw adductor division. This tendon may serve to redirect muscle forces anteriorly, transmitting them within the plane of biting. Measured bite forces obtained through electrostimulation of the jaw adductors in live rays were higher than predicted, possibly due to differences in specific tension of actual batoid muscle and that used in the model. Mass-specific bite forces in these rays are the highest recorded for elasmobranchs. Cownose rays exemplify a species that, through allometric growth of bite performance and morphological novelties, have expanded their ecological performance over ontogeny.

The aim of the present study was to evaluate the effects of dietary vitamin E, nanoselenium (nanoSe), and their combination on growth and acute stress responses in rainbow trout previously subjected to chronic stress. The fish were divided into five groups according to stocking density and diet: Normal (20 kg m −3 ; basal diet), Dense (80 kg m −3 ; basal diet), Vit E (80 kg m −3 ; 500 mg kg −1 vitamin E-supplemented diet), NanoSe (80 kg m −3 ; 1 mg kg −1 nanoSe-supplemented diet), and Combination (80 kg m −3 ; 500 mg kg −1 vitamin E and 1 mg kg −1 nanoSe-supplemented diet). The fish in each group were weighed after 60 days. The best growth under high density condition was observed in fish fed on vitamin E-supplemented diets (Vit E and Combination groups). Following high stocking rearing, fish were subjected to an acute confinement stress by decreasing water volume in the tanks (200 kg fish m −3) for 45 min and sampled at 0, 2, 4, 8 and 24 h post-stress to evaluate the fish performance to additional stressors. The levels of serum cortisol, glucose, lactate, alanine aminotransferase, as-partate transaminase, and alkaline phosphatase were significantly higher in the Dense group at most of time points after initiation of acute stress. The results showed that rainbow trout can reach adaptation to chronic stress conditions, resulting in intensified stress responses to an acute stressor. The data also showed that vitamin E-supplemented diets can exert positive effects on the welfare of chronically stressed rainbow trout subjected to an additional acute stressor.

The importance of aquaculture sector is increasingly enhanced due to decrease in natural fish stocks, increasing nutritional requirements and qualified protein need. In parallel with the rise, and becoming an important value, of aquaculturesector, significant developments have occurred in fish feed production as well. It is a fact that the most important cost elements within aquaculture are feeds and usage costs of the feeds and these are effective as much as 70% in production. Substantial and great developments are observed for fish feed production industry and thus raw material, additives, feed machine manufacturers and suppliers recently. With this study, it was detected that there were 28 fish feed production plants in to 8 mounts, that generally extruder feed production technology was used and that majority of production systems were imported. It was recorded that fish feed production plants produced 355.387 tons of feed as from 2013. It was observed that 85% of feed production was regionally in Aegean Region and concordantly, supplier companies were centered in this region.This study can be recommended in terms of being an important source for academic and private sector employees studying and working in fish feed production and fish feeding subjects.

El paiche o paichi (Arapaima aff. gigas, Arapaimidae) es el pez con escamas más grande de la cuenca del Amazonas. Su introducción y posterior expansión a Bolivia se produjo por el río Madre de Dios alrededor de los años setenta, desde proximidades de la localidad peruana de Puerto Maldonado. Se desconoce su dieta en ambientes de Bolivia y su efecto sobre las comunidades acuáticas por lo que el objetivo de esta investigación fue determinar su dieta en un lago del río Madre de Dios (Lago El Mentiroso), durante el periodo de aguas bajas (julio/2012). Se colectaron 238 estómagos de ejemplares con una longitud estándar promedio de 109.9 ± 29.9 cm. Los ítems presentes en cada estómago fueron pesados, contados, fotografiados e identificados hasta el nivel taxonómico más bajo posible. Para describir la dieta se usaron los índices de Frecuencia de Ocurrencia (% FO), Frecuencia Numérica (% N), Frecuencia Gravimétrica (% G) y el Índice de Importancia Relativa Presa Específico (% PSIRI). Adicionalmente se realizó un análisis comparativo de la dieta en base al tamaño de los individuos separados cada 20 cm y según su sexo. De los 238 estómagos, sólo 166 presentaron contenido estomacal. 94 de estos ejemplares fueron hembras y 62 machos. La mayor parte de los ejemplares estudiados pertenecieron a las clases de tamaño comprendida entre 81-100 y 101-120 cm (83 y 44 individuos, respectivamente). Se encontró que la dieta se compone principalmente de peces (%FO=84.3; % G=53; % N=37.3), materia vegetal (% FO=89.2; % G=7) e invertebrados (%FO=21,7; % G=1; %N=10.1). El ítem peces fue el único que fue categorizado como primario (% PSIRI=45.2%). Dentro de los peces el orden más importante tanto en frecuencia (22.3 %), número (37.3) y peso (53 %) fue Characiformes. Las familias más importantes dentro de este taxón fueron Characidae y Curimatidae. Los órdenes de invertebrados más importantes fueron Coleóptera, Hemíptera y Decápoda. No se observaron diferencias significativas entre la composición de la dieta de las diferentes clases de tamaño y sexos a nivel de ítems generales. Sin embargo, a nivel específico solo las clases de tamaño 81-100 y 101-120 presentaron una dieta similar. El Nivel Trófico (NT) calculado y la longitud del intestino del paiche sugieren que es una especie omnívora más que estrictamente piscívora como sugiere la literatura.

The present study investigates the potential of the supplementation of the seaweed Ulva lactuca, as a dietary
additive ingredient in fish feed, to improve the Nile tilapia (Oreochromis niloticus) growth performance, feed
utilization and carcass composition. The experiment was conducted in the Deroua fish farming facilities (Beni
Mellal, Morocco), on male Nile tilapia of a mean weight of 50 ± 1g. Three experimental diets composed of 32% of dietary protein were prepared using dried algae meal ingredient incorporated at levels of 0% (control), 5% and 10% of fish feed. By the end of the experiment, fish growth parameters, feed utilization, somatic indexes and carcass composition were evaluated. Fish fed on 5% seaweed diet tended to have higher growth performance than those fed to the control and 10% seaweed diet (p>0.05). Feed utilization by fish seemed not to be affected by seaweed meal rates change (p>0.05). The viscerosomatic (VSI), hepatosomatic (HSI) and gonadosomatic (GSI) indexes showed no significant difference between diets. Crude protein and crude lipid contents in the fish carcass
were not statistically significant (p>0.05), whereas significant differences (p<0.05) in ash content was observed between treatments. In addition, Ulva lactuca meal can be included as supplement ingredient in the diet without impairing growth performance, feed utilization and body composition of Nile Tilapia. Get more articles at: http://www.innspub.net/volume-7-number-3-september-2015-ijaar/

ÖZET Akuakültür üretim miktarının hızla artması, yem katkılarının ekonomikliği, alternatif yem katkıları, yem katkılarının sürdürülebilir temini konularını gündemde tutmaktadır. Balık yeminde temel hayvansal protein kaynağı olan balık unu temininin zaman içerisinde süreksizliği, alternatif hayvansal protein kaynaklarının arayışını hızlandırmıştır. Son yıllarda, evsel ve endüstriyel organik atıkların zirai alanlarda gübre olarak kullanımı amacıyla toprak solucanlarından yararlanılmaktadır. Bu üretimde son ürün olarak ortaya çıkan toprak solucanı önemli bir hayvansal protein kaynağıdır. Esansiyel amino asit bakımından önemli olan solucan ununun balık yetiştiriciliğinde kullanımı kayda değerdir. Ülkemiz akuakültürünün 2015 yılı itibarıyla toplam yetiştiricilik miktarının 240.334 ton'a ulaşması, balık yeminin önemli bir bileşeni olan hayvansal protein kaynağına olan artan ihtiyacı ortaya koymaktadır. Amaç solucan ununun balık yetiştiricilik performansına etkisinin araştırılması gerekliliği dikkat çekmektedir. Solucan ve unlarının evcil hayvanların yemlerinde kullanımının yanında son zamanlarda balık yemlerinde de kullanımına ilişkin çalışmalar hızla artmaktadır. Bu derlemede, solucan ve solucandan elde edilen unun önemi, balık yemlerinde kullanılabilirliği konusunda yapılan araştırmalar irdelenmiştir. Solucan unu kullanımıyla yetiştiricilik miktarındaki sürdürülebilir artışın sağlanması için bazı çözüm önerileri sunulmuştur. Anahtar sözcükler: Akuakültür, solucan unu, Eisenia fetida, balık unu, sürdürülebilir ABSTRACT Use of Worm meal as Animal Protein Source in Fish Feed: Aquaculture keeps topics of rapid increase in manufacturing amount, economy of feed additives, alternative feed additives, and sustainable supply of feed additives on the agenda. Discontinuity in supply of fish meal being fundamental animal protein source in fish-feed accelerated pursuit for alternative animal protein sources. Earthworms are preferred for the use of domestic and industrial organic wastes as fertilizer in agricultural areas in recent years. Earthworm is a significant animal protein source which emerges as final product in this manufacturing. The use of worm meal, which has a significant value in terms of essential amino acid in aquaculture. Total aquaculture production of Turkey in 2015 reached up to 240.334 ton which reveal the increasing need towards animal protein source being a significant component of fish-feed. The aim is to attract attention to the need of researching the effect of worm meal on aquaculture performance. In addition to the use of worms and worm meal in domestic animal feed, research on the use of them in fish-feed also increases rapidly. In this review, importance of the worm and worm meal, and researches conducted with usage potential in fish-feed were discussed. Some resolution advisories for sustainable growth in the amount of aquaculture were presented via worm meal in fish-feed.

Fish breeding is a promising branch of farming, so the creation of tools for automation of this area is quite relevant. Feeding on fish farms is the main component of the successful functioning of such businesses. However, this process requires an in-depth preparation, as each species of fish has a different food culture, as well as various behaviours during nutrition. Moreover, in the method of feeding fish, farmers must take into account the age, size of the fish, and other characteristics. This paper contains information on the creation of a Preference testing by images processing is considered as the most effective tool that can be used to determine the sensory behaviour of an animal, which can record the eating behaviour of fish and determine the degree of their hunger, and, finally, to feed them. Moreover, small fish are shyer, which provokes their malnutrition. A smart feeding system can solve the issue of uniform the distribution of food for all fishes.

The aim of this study are to investigate metabolic oxygen consumption rate, energy content and growth performance of Hybrid tilapia (Oreochromis sp) with mealworm (Tenebrio molitor) and artificial food. Two separate feeding trial were conducted in 28 days, the feeding trial was divided into 14 days for each feeding trial using 60 hybrid tilapia (Oreochromis sp). Metabolic oxygen consumption rate and ammonia excretion were calculated and digestibility of the two diets were conducted. For Metabolic oxygen consumption rate and ammonia excretion were significantly higher in fish fed with artificial food. In term of digestibility, protein and lipid showed significant effect  (p<0.005) while glycogen was insignificant ( p> 0.005)  The general evaluation showed that mealworm (Tenebrio molitor) have the potential to replace or to supplement fish meal. Through the result, hybrid tilapia fed with mealworm showed good results in survival and overall growth performances throughout 14 days of feeding trial

The Mekong River supports a rich diversity of fish species and seasonally inundated riparian forest habitats, including those in the Siphandone Wetlands in Khong District, Champasak
Province, southern Laos and adjacent areas in Stung Treng and Kratie Provinces in northeastern Cambodia. However, there has been little systematic research done regarding the relationships between fishes and seasonally flooded forests in the Mekong River Basin. This paper confirms that terrestrial plants are important food sources for some important fish species, by means of a study of fish stomach contents conducted at Ban Hang Khone, a rural fishing village situated on an island in the Mekong River just below the Khone Falls. A total of 1,617 fish specimens belonging to at least 73 species, 52 genera and 20 families were examined. At least 35 species of forest fruits, 13 species of fresh leaves, and 3 species of flowers were found in fish stomachs along with bark, roots and a wide variety of other fish foods. Species in the family Pangasiidae were found to be the most important consumers of fruits and other fresh vascular plant material. Hypsibarbus spp., Tor tambroides, Leptobarbus hoeveni (Cyprinidae), Osphronemus exodon (Ospronemidae) and other fishes also consume considerable amounts of plant matter. Villagers mentioned 73 plant species believed to be consumed by fishes, including 9 suitable for baiting hooks for catching fish. The importance of seasonally inundated forests to the aquatic ecosystem of the Mekong River is considered, including the possible role of fishes as plant seed dispersers and predators. Flooded forests along the Mekong River are threatened by hydrological changes caused by the constructionof large dams both up and down river.

The effects of dietary calcium chloride (CaCl 2) concentration on the growth, survival, moulting and body composition of Astacus leptodactylus were studied. Diets were prepared using supplementation of 0 (control), 30, 60 and 120 g kg À1 calcium chloride commercial trout larvae diet containing 50% protein and 12% lipid. Astacus leptodacty-lus larvae with an average total length of 22.0 AE 0.05 mm (TL) and weight of 0.53 AE 0.01 g obtained from eighteen ovigerous females collected from Seydisehir Sugla Dam lake in Konya, Turkey, were stocked in 0.2-m 2 aquariums at a rate of 50 crayfish m À2 and reared for 90 days. The experiments included four treatments (diets) with three replicates each. Calcium chloride exerted positive effects on growth, moulting frequency, feed efficiency and survival of narrow-clawed crayfish. Crayfish fed with 60 g calcium kg À1 calcium chloride-supplemented diet exhibited the highest weight gain and specific growth rate (SGR) but the lowest survival rate (63.3%) (P < 0.05). There were no significant differences (P > 0.05) in mean moisture (803.5 g kg À1) and protein content (177.0 g kg À1) in crayfish tail meat. However, lipid values were between 3.8 and 11.6 g kg À1 and significantly different among the diets (P < 0.05). Diet with 60 g kg À1 calcium chloride is recommended for the best growth of freshwater crayfish.

The chapter summarizes current knowledge on fish biology in Lake Kinneret. Nineteen native fish species belonging to six families populate the lake. Three of these species are endemic to the lake and four other species are endemic to the Jordan Valley system. Eight alien species are found in the lake. Four of them are breeding in nature, three can’t breed but are regularly stocked, and one is a hitchhiker that can’t breed. Growth rate equations and weight-length relationships are presented for the dominant cyprinids (Mirogrex terraesanctae, Hypophthalmichthys molitrix, Cyprinus carpio, Barbus longiceps, Capoeta damascina, Carasobarbus canis), cichlids (Oreochromis aureus, Sarotherodon galilaeus, Tilapia zillii, Tristramella simonis), grey mullets (Liza ramada, Mugil cephalus), and catfish (Clarias gariepinus).    The long-term changes in fish community composition in the lake were associated with introduction and invasion of fishes; changes in fishing intensity; modifications of the littoral, and changes of the lake ecological regime. Temporal dynamics, spatial distribution, total abundance and biomass of fish in the lake were studied based on long-term hydroacoustic monitoring. The size structure and abundance of fish in the pelagic zone of the lake display explicit seasonal changes associated with fish spawning migrations and winter-spring recruitment of the dominant bleak M. terraesanctae. Water level fluctuations beyond natural have modified the littoral habitats, which are of specific importance during different life stages of fish. Water level has an immense impact on fish reproduction, survival, recruitment, population dynamics, and eventually determines the catches of commercially important species.
See also chapter: "Fisheries Management"

Macrourids are among the most abundant and diverse demersal fishes in all deep oceans, including the Southwestern Brazilian continental slope. Although not targeted by Brazilian fisheries, they suffer impact similar than the target species, being among the most discarded fishes by deep bottom trawling.
Trophic Ecology: Data from research surveys and commercial fishing were used to analyze the trophic ecology of four species inhabiting the upper slope of southern Brazil: Coelorinchus marinii, Malacocephalus occidentalis, M. laevis and Lucigadus ori. For the two abundant ones, ontogenetic changes, seasonal variations, intra- and interspecific dietary overlap, parasite fauna and aspects of functional morphology are also described. C.marinii had an extremely diverse diet, preying infauna, epifauna, plankton, necton and carcasses.
M.occidentalis fed on larger and nektonic prey, but also included crabs and carcasses in the diet. Both species showed ontogenetic shifts and seasonal variations in diet composition, both leading to changes in intra- and interspecific diet overlap patterns. Species showed quite distinct feeding anatomy and proportions of body with mouth size, reflecting on feeding strategies. There was little interspecific food overlap. In most cases when the diet was more similar there was a spatial segregation. The coexistence of these species appears to be facilitated by the development of different functional morphologies and feeding strategies. A considerable portion of the diet of these species is due to the consumption of carcasses of pelagic and mesopelagic organisms, and even insects, bypassing the benthic trophic web. Conservative (minimum) estimates of the mean weight
of carcasses in diet ranged from 3 to 20%, increasing with the size of the predators and towards deeper waters. C.marinii showed a lower consumption of carcasses and a high proportion of mesopelagic fishes and cephalopods, however, the analysis of the feeding morphology and prey size leads to believe that most of these two groups of prey were consumed as carcasses. This source of food bypass the detritus food chains and connect the concentrations of macrourids to fluctuations in the abundance of epi and mesopelagic organisms and to oceanographic processes that increase their concentration and mortality (e.g. mesoscale anticyclonic eddies).

Distribution, Biomass and Oceanography: Data from two seasonal bottom trawl surveys were used to provide information on distribution, abundances, densities, sizecomposition and biomass estimates for seven species: Coelorinchus marinii, Malacocephalus occidentalis, M. laevis, Lucigadus ori, Hymenocephalus billsam, Ventrifossa macropogon and V. mucocephalus. The total biomass was estimated in 5.5 and 8.3 kt respectively in winter-spring and summer-autumn. C.marinii and M.occidentalis comprised 98% of the biomass. For these two abundant species, surface maps were made with spawning areas, feeding index, sex and immature/mature ratios, and were related to
oceanographic processes, providing insights on strategies and important processes regulating distribution and abundance patterns. Both species showed a marked seasonal variation in the extent and location of spawning areas. Most C.marinii females were mature (90%), suggesting an early maturation during pelagic phase and acquiring demersal habit just prior the onset of maturation, while M.occidentalis showed few matures females and settle to bottom well before maturity. Temperature rather than depth seems to be the main factor regulating the batimetric distribution of both species. We describe three processes responsible for distribution and abundance patterns found in these species. Different patterns of spatial segregation were found in both species, related with depth, sex and maturity. It is suggested that areas with high biomass Macrouridae (scavengers) are induced by zones of occurrence semi-permanent mesoscale processes (e.g. eddies). These processes increase productivity and enable large biomass of short-lived organisms found in the upper layers, and also increase the concentration, mortality and availability of carcasses, favoring scavenger predators. These processes may be responsible for inconsistencies in biomass of megafauna and macrofauna found in some studies, where biomass of megafauna was of the same order of magnitude or larger than macrofauna, contradicting the Eltonian principle. It is suggested that future studies attempt to relate mesoscale processes with the biomass of potential short-lived prey in surface waters and higher biomass of scavengers. This work highlights the importance of the study of ocean dynamics, combining biological and oceanographic observations, trying to understand the role of mesoscale physical processes on the distribution and abundance patterns of species.

The diets of five deep sea fish: Argentina sphyraena, Glossanodon leioglossus, Chlorophthalmus agassizi, Hoplostethus mediterraneus and Capros
aper from the Aegean Sea were examined in the specimens caught as bycatch and discarded by commercial trawl fisheries during 2003 spring. Stomach
contents were analyzed to determine their diet composition, which indicates that the trophic status of these species can be assigned primarily to the carnivore
guild. Two major prey groups were found in the diet composition of all five predators: Crustaceans (like copepods and isopods), and Chaetognathans (Sagitta
spp.).

Garlic (Allium sativum) is one of the earliest known
medicinal plants and has been used to improve growth and
resistance of a number of livestock and fish. The present study
was carried out to evaluate the effects of dietary supplemented
by dried garlic (A. sativum) lobes (DGL) on growth
performance, feed utilization, chemical composition of the
whole fish body, and physiological parameters of monosex
Nile tilapia, Oreochromis niloticus fingerlings for 60 days.
Fish with average body weight (17.14 ± 0.35) were randomly
distributed into four treatments (0, 1, 2, 3% DGL / kg
diet).Results revealed that 1% DGL was the best treatments,
which gave the highest significantly (P ≤ 0.05) values in
growth performance, feed utilization, chemical composition of
the whole fish body and hematological and biochemical
parameters among all treatments. So, it is recommended that
the inclusion of 1% DGL / kg diet as feed additives of all male
monosex O. niloticus are more useful for improving their
growth performance, feed utilization, chemical composition of
the whole fish body and physiological responses.

Garlic (Allium sativum) is one of the earliest known medicinal plants and has been used to improve growth and resistance of a number of livestock and fish. The present study was carried out to evaluate the effects of dietary supplemented by dried garlic (A. sativum) lobes (DGL) on growth performance, feed utilization, chemical composition of the whole fish body, and physiological parameters of monosex Nile tilapia, Oreochromis niloticus fingerlings for 60 days. Fish with average body weight (17.14 ± 0.35) were randomly distributed into four treatments (0, 1, 2, 3% DGL / kg diet).Results revealed that 1% DGL was the best treatments, which gave the highest significantly (P ≤ 0.05) values in growth performance, feed utilization, chemical composition of the whole fish body and hematological and biochemical parameters among all treatments. So, it is recommended that the inclusion of 1% DGL / kg diet as feed additives of all male monosex O. niloticus are more useful for improving their gr...

Three trials were performed to identify feed enhancers for largemouth bass. Fish trained on dry pellets were stocked into 45 1 aquaria. Trial 1 evaluated the palatability of diets in which fish meal (FM) was replaced with 0, 20, 40, and 60% soybean meal @M-00, SM-20, SM-40 and SM-60). Feed intake declined as dietary concentration of soybean meal increased (P < 0.01). SM-60 was used as the control and basal diet in trials 2 and 3. Trial 2 tested the following mixture of substances: (1) amino acids: alanine, glycine, proline, serine, leucine, valine, histidine, and tryptophan; (2) nucleotides: inosine and inosine-5monophosphate (IMP-S); (3) betaine. Dietary concentrations of chemicals were kept in the same molar ratio as in aqueous krill (Euphasiu pnci'ca) extract. Chemical groups were tested alone or in all possible combinations. Nucleotides alone enhanced feed intake of fish by 46% compared with the control diet (P < 0.0.9, while amino acids and betaine were ineffective (P > 0.05). No additive effects among chemical groups were observed (P > 0.05). In trial 3, inosine and IMP-5' were tested alone at 1400, 2800, and 5600 mg kg-' of feed or together, each at 2800 mg kg-' of feed. A diet with 10% fish meal (FM-IO) was also evaluated. Effective dietary concentration of IMP-S seems to be about 2800 mg kg-' of feed which gave a feed intake 23% higher than the control diet (P < 0.051. Dietary IMP-5' level of 5600 mg kg-' of feed failed to further increase feed intake (P > 0.05). Inosine was not an effective feed enhancer at the dietary levels tested (P > 0.10). No significant additive effect of inosine in a diet flavored with IMP-5' at 2800 mg kg-' of feed was found (P > 0.10).

The feeding of marine predators is a popular means by which tourists and tour operators can facilitate close observation and interaction with wildlife. Shark-feeding has become the most
developed provisioning activity around the world, despite its controversial nature. Amongst other detrimental effects, the long-term aggregation of sharks can modify the natural behaviour of the animals, potentially increase their aggression toward humans, and favour inbreeding. During 949 diving surveys conducted over 44 mo, we investigated the ecology and residence patterns of 36 photoidentified adult sicklefin lemon sharks Negaprion acutidens. The group contained 20 females and 16 males. From this long-term survey, we identified 5 different behavioural groups that we described as ‘new sharks’ (7), ‘missing sharks’ (4), ‘resident sharks’ (13), ‘unpredictable sharks’ (5) and ‘ghost sharks’ (7). In spite of movements in and out of the area by some males and females, which were probably related to mating, the general trend was that residency significantly increased during the study, particularly in males, showing a risk of inbreeding due to the reduction of shark mobility. Intraand interspecific aggression was also witnessed, leading to an increased risk of potentially severe bites to humans. Our findings suggest the need for a revision of the legal framework of the provisioning activity in French Polynesia, which could include a yearly closure period to decrease shark
behavioural modifications due to long-term shark-feeding activities.

ABSTRACT Objective. To study the trophic ecology of Saccodon dariensis in the Peñoles and El Cardal streams, Guatape River mid-basin, Magdalena River Basin, Colombia. Materials and methods. To compare differences in size between individuals from the two streams in terms of hydrologic periods, oral polymorphisms or sexes, an analysis of variance was conducted (ANOVA). Volume percentages, frequency of occurrence and the food importance index (FII) were determined; a principal component analysis (PCA) and an ANOVA was carried out to determine the diet differences between streams, climatic periods, oral polymorphism, sexes and developmental states, as well as a Mann-Whitney pairwise comparison test for each food category. Results. A significant difference was found in size between individuals of the two streams with different oral polymorphism. Algae are the most important food item (FII: 91.9%), followed by Trichoptera and insect remains (FII: 4.3%), and vegetal material (FII: 1.8%). The PCA did not indicate significant differences in diet between streams, climatic periods, oral polymorphisms, sexes or developmental states, but the ANOVA and Mann-Whitney pairwise comparison test indicated differences in oral morphotype, where individuals with a straight mouth consumed more vegetal material. We also observed different proportions in consumption of different algae genera, and increased consumption of insects in ontogeny, this being higher in individuals with a straight mouth. Conclusions. The species is algaevorous. The oral morphotypes of S. dariensis may be related to a trophic polymorphism that confers different trophic habits and differential access to the items that constitute their diet.

The earthworm, Eudrilus eugeniae was cultured for 12 weeks and its meal utilized as a replacement for fish meal in the diet of fingerlings of the mud catfish hybrid (♂Heterobranchus longifilis X ♀Clarias gariepinus) called Heteroclarias. Two hundred and seventy adult E. eugeniae were cultured in three substrates: Soil, cellulose, or a mixture of cellulose and soil. The worms were harvested at the end of the culture period, processed by oven-drying and grounded into powdery form as earthworm meal. Cellulose substrate was the best for E. eugeniae culture with the highest weight gain and relative growth rate. The earthworm meal produced was used to replace commercial fish meal in five compounded diets at levels of 0 (control), 25, 50, 75 or 100%. The diets were fed to Heteroclarias fingerlings to evaluate the effect of earthworm meal in comparison with fish meal on the growth and nutrient utilization of the fingerlings. The feeding experiment was carried out in 40 L plastic tanks using...

Abstract An 8-week growth study was conducted
to determine the effect of ration level, energy, and
protein maintenance requirement of catfish, Heteropneustes
fossilis–Bloch, fingerling (7.90 ± 0.55
cm; 3.10 ± 0.28 g) by feeding casein–gelatin-based
purified diet (40% CP; 3.61 kcal g-1 GE) at six ration
levels 1–6% of BW/day, at 0800 and 1700 h, in
triplicate, with 20 fish per trough fitted with water
flow-through system of volume 55 L. Maximum live
weight gain, best feed conversion ratio (FCR), best
specific growth rate (SGR), and highest protein
efficiency ratio (PER) were evident for ration levels
of 4–5% body weight. However, second-degree
polynomial regression analysis for weight gain,
FCR, PER, protein, and energy retention data indicated
that the break-points occurred at 5.08, 4.18,
4.05, 4.16, and 4.17% BW/day, respectively. Significantly
(P\0.05) higher body protein content was
recorded at 4 and 5% rations. While a linear increase
in body fat content with inverse relationship in
moisture content was evident with increasing rations.
Ash content remained insignificantly (P[0.05) low
at higher rations. Protein and energy retention values
also produced significant (P\0.05) differences.
Based on the results obtained, it is recommended that
feeding in the range of 4 to 4.5% BW/day, corresponding
to 1.60–1.80 g protein and 14.46–16.27 kcal
energy g100 g-1 of the diet/day is optimum for the
growth and efficient feed utilization of H. fossilis,
while 2–3% ration levels (0.80–1.20 g protein and
7.23–10.84 kcal energy) suggest that these amounts
approximate to the maintenance requirement of this
fish.

Los análisis tróficos son una herramienta eficaz para entender las relaciones entre las especies de un ecosistema, y los patrones de alimentación aportan información valiosa para determinar los procesos de competencia, que están definidos por los recursos compartidos y por actividad alimentaria en el mismo tiempo y espacio. Los ciclos circadianos son considerados los principales sincronizadores de los ritmos biológicos en la naturaleza, de modo que el presente trabajo pretende entender los patrones diarios de alimentación de siete especies de peces óseos asociadas a fondos blandos (Selene peruviana, Lutjanus guttatus, Orthopristis chalceus, Pomadasys panamensis, Centropomus robalito, Pseudupeneus grandisquamis y Polydactylus opercularis). Los organismos provienen de la ictiofauna acompañante de la pesca de arrastre de camarón que opera en la plataforma continental de Nayarit (Pacífico mexicano) y se cuenta con información de capturas desde las 2:00 hasta las 24:00 horas, de la temporada pesquera 2005 -2006. Los individuos fueron identificados, medidos, pesados y eviscerados. Para el análisis del contenido estomacal se tomó en cuenta el grado de llenado y de digestión. El análisis de la dieta se realizó mediante la aplicación de los índices numérico (%N), gravimétrico (%P) y de frecuencia de aparición (%FA). La cronobiología alimentaria individual mostró una variación amplia en la alimentación de las especies, pero con patrones específicos y con una marcada preferencia a alimentarse en horas de luz. Las relaciones de competencia directa en tiempo y espacio fueron evidentes para L. guttatus y S. peruviana quienes comparten a los engraulidos en su dieta; al igual que O. chalceus y C. robalito los cuales compiten por los crustáceos para alimentarse. Aún cuando se observaron similitudes en la dieta con las otras especies, también fue evidente que hay un uso diferencial (tiempo y espacio) interespecífico. P Pa al la ab br ra as s c cl la av ve e: : I Ic ct ti io of fa au un na a, , c cr ro on no ob bi io ol lo og gí ía a a al li im me en nt ta ar ri ia a, , P Pa ac cí íf fi ic co o m me ex xi ic ca an no o. .

Substrate is a key factor for successful crayfish culture, and it can be used to increase the survival rate. The effects of substrate on the survival and growth of Astacus leptodactylus Eschscholtz, 1823 were evaluated in flow-through compartments, divided into three sections and with two different substrates, over a period of 90 days. The three treatments used in the study were: artificial ropes, small stones, and a control group that received no substrate. The survival rate was highest in the small-stones treatment group (77.3%) and was lowest in the without-substrate treatment group (41.3%), while the artificial-ropes group showed an intermediate value (65.3%). Total yield was lower in the control group, 22.46% (25.0 g) as compared to the small-stones treatment group, with 42.3% (51.3 g) and the artificial-ropes treatment with 35.51% (55.8 g). In addition, cheliped injuries were found in higher proportion in the group without cover, and the artificial ropes yielded better results compared to the small-stones and no-substrate group in regard of the growth-increase rate. RÉSUMÉ Le substrat est un facteur clé pour le succès de l'aquaculture de l'écrevisse, et il peut être utilisé pour augmenter le taux de survie. Les effets du substrat sur la survie et la croissance de Astacus leptodactylus Eschscholtz, 1823 ont été évalués dans des compartiments avec flux d'eau en continu, divisés en trois sections et avec deux substrats différents, sur une période de 90 jours. Les trois traitements utilisées dans cette étude étaient : cordes synthétiques, petits cailloux, et un groupe témoin avec aucun substrat. Le taux de survie a été le plus élevé dans le groupe avec les petits cailloux (77,3%) et le plus faible dans le groupe sans substrat (41,3%), tandis que le groupe sur cordes synthétiques a montré un taux intermédiaire (65,3%). Le rendement a été le plus bas dans le groupe témoin, 22,46% (25,0 g) par comparaison avec le groupe sur petits cailloux, avec 42,3% (51,3 g) et le groupe avec cordages artificiels 35,51% (55,8 g). De plus, des blessures sur les pinces ont été trouvées en plus grande proportion dans le groupe sans substrat, et le groupe avec les cordes synthétiques a donné de meilleurs résultats pour le taux de croissance par rapport aux groupes avec petits cailloux ou sans substrat.

This Study was carried out in the Institute of Oceanography Fish Farm which is geographically located in the historic peninsula of the Great Kwa River. This study lasted for ten weeks and was carried out in 3 hapas (A 1 , A 2 , and A 3) measuring 1.5 x 1.0 x 1.0 m 3 in earthen pond. A total of sixty (60) fingerlings of Clarias gariepinus, mean bulk weight 0.20 ± 0.02 kg (10 g for each fingerling) were collected from the University of Calabar fish farm and stocked in each of the three experimental units (20 in each unit). The fishes were fed twice daily at 3%, 8% and 12% of their body weight. Some physicochemical parameters (Dissolved oxygen, pH, Ammonia and Temperature) of the water were measured weekly with a calibrated electronic meter. Mean temperature, pH and ammonium were found not to be affected by feed application rates during the ten weeks feeding trial. However, dissolved oxygen levels increased significantly with increasing feed application rate. The food values analyzed showed varied values of their presence in the body tissue of the fish analyzed; with the mean moisture, carbohydrate and protein recording higher value in that order; followed by ash, fat and fibre. The fish samples presented a relatively higher and lower amount of proximate concentrations. Growth performance and proximate composition of Clarias gariepinus show no significant differences among different feed application rates. The results suggest that, although a feeding rate of 12% gave the highest growth performance, Clarias gariepinus should be fed at the rate of 8% body weight per day, considering feed conversion efficiency, survival rate and growth response.

Original name:
Южакова Г.Г., И.С. Островский, А. А. Симонян, Н. И. Жарикова, Г. М. Манукян. 1984. Состояние популяции севанского сига в связи со снижением его кормовой базы (1975-1983). В сб.: Лимнология горных водоемов. Изд: АН Арм. ССР, Ереван, 1984, с.349-351.

This study presents voltage control method to increase embedded generation (EG) transfer capability and to ensure distribution network voltage within statutory limits. A typical EG plant and generic 11 KV distribution network was developed. Various scenarios assessed impact of embedded generator on voltage profiles of a network with light and peak load

http://nopr.niscair.res.in/handle/123456789/9681

In this study, 173 stomach contents of prussian carp were examined and they have been caught during period of January, 2000- September, 2003 from Bafra Fish Lakes via a number of alterna-tive nets and tackles. Organisms, obtained after analysing the digestive system contents the prussian carp patterns, were examined using method of Geometric Index of Importances (GII). Some of the plant food items which are dominant in the stomach contetns of prussian Carp are Navicula, Amphora and Cymbella. Animal food items are Daphnia, Bosmina and Copepda members. Consequently, 47 food items (38 organisms were plants and 9 were animals) were found in the digestive system contents of the Prussian carp. As a result of Geometric Index of Importance, prussian carp is omnivorous.

The earthworm, Eudrilus eugeniae was cultured for 12 weeks and its meal utilized as a replacement for fish meal in the diet of fingerlings of the mud catfish hybrid (♂Heterobranchus longifilis X â™€Clarias gariepinus) called Heteroclarias. Two hundred and seventy adult E.eugeniae were cultured in three substrates: Soil, cellulose, or a mixture of cellulose and soil. The worms were harvested at the end of the culture period, processed by oven-drying and grounded into powdery form as earthworm meal. Cellulose substrate was the best for E.eugeniae culture with the highest weight gain and relative growth rate. The earthworm meal produced was used to replace commercial fish meal in five compounded diets at levels of 0 (control), 25, 50, 75 or 100%. The diets were fed to Heteroclarias fingerlings to evaluate the effect of earthworm meal in comparison with fish meal on the growth and nutrient utilization of the fingerlings. The feeding experiment was carried out in 40 L plastic tanks usi...

An on-farm trial was conducted in seven (7) farms in Nueva Ecija, Philippines, to investigate the effect of two onsets of feeding on the growth, yield and survival of Nile tilapia. There were no significant differences on the performance data (final mean weight, daily weight gain, extrapolated gross fish yield, and survival rate) that were recorded in this study. The only statistically significant difference observed was in the total quantities of feed used in the trial. The 45-day onset in feeding produced a slightly higher mean gross value of the crop (P205,617 ha -1 ) compared with the 75-day delay (P197,063 ha -1 ) but by delaying the start of feeding, the costs were reduced such that the net value of the crop was improved (P124,242 ha -1 in 75-day vs. P106,026 ha -1 in 45-day delay).

Stomach contents of the 12 most abundant fish species in Lake Nokoué, Benin, collected between 2003 and 2005,
were analysed for temporal variations in their diet. Several species showed seasonal shifts in their diets based on
benthic prey abundance and biomass variation, which are influenced by physico-chemical environmental changes.
Five trophic guilds were identified: detritivorous, microbenthivorous, macrobenthivorous, zooplanktivorous and
piscivorous. Trophic guilds in 2003–2005, compared to 1961, showed a decrease of benthivorous species, which
illustrates the vulnerability of this group whose prey are particularly exposed to organic pollution.

The vertebrate gut tube can be divided into "front-end" and "back-end" components according to topology, function, and research tradition. The purpose of front-end feeding systems is to acquire food to be delivered to the back-end for chemical digestion and assimilation. In accomplishing this, the feeding system faces as many as five separate mechanical tasks recognized as "feeding stages:" capture/subjugation, ingestion, transport, processing, and swallowing. In general, aquatic species exploit the high density of water to manipulate food items by modulating water flow through the mouth and pharynx. In contrast, terrestrial vertebrates typically employ some form of hyolingual feeding in which movements of the tongue and hyobranchial apparatus take the place of water flow in capturing, supporting and manipulating food. The condition of the bolus, when swallowed, varies markedly among taxa. Most ectotherms process their food little, if at all, whereas mammals and birds typically reduce their food to small particles (in mammals, by oral mastication; in birds, within the "gastric mill" of the gizzard). This fundamental difference probably relates to the need of endotherms to increase gut passage rates.

Feeding is a complex behaviour comprised of satiety control, foraging, ingestion and subsequent digestion. Cichlids from the East African Great Lakes are renowned for their diverse trophic specializations, largely predicated on highly variable jaw morphologies. Thus, most research has focused on dissecting the genetic, morphological and regulatory basis of jaw and teeth development in these species. Here for the first time we explore another aspect of feeding, the regulation of appetite related genes that are expressed in the brain and control satiety in cichlid fishes. Using qPCR analysis, we first validate stably expressed reference genes in the brain of six haplochromine cichlid species at the end of larval development prior to foraging. We next evaluate the expression of 16 appetite related genes in herbivorous and carnivorous species from the parallel radiations of Lake Tanganyika, Malawi and Victoria. Interestingly, we find increased expression of two appetite-regulating genes (anorexigenic genes), cart and npy2r, in the brain of carnivorous species in all the three lakes. This supports the notion that appetite gene regulation might play a part in determining trophic niche specialization in divergent cichlid species, already prior to exposure to different diets. Our study contributes to the limited body of knowledge on the neurological circuitry that controls feeding transitions and adaptations in cichlids and other teleosts.

Dietary partitioning often accompanies the increased morphological diversity seen during adaptive radiations within aquatic systems. While such niche partitioning would be expected in older radiations, it is unclear how significant morphological divergence occurs within a shorter time period. Here we show how differential growth in key elements of the feeding mechanism can bring about pronounced functional differences among closely related species. An incredibly young adaptive radiation of three Cyprinodon species residing within hypersaline lakes in San Salvador Island, Bahamas, has recently been described. Characterized by distinct head shapes, gut content analyses revealed three discrete feeding modes in these species: basal detritivory as well as derived durophagy and lepidophagy (scale-feeding). We dissected, cleared and stained, and micro-CT scanned species to assess functionally relevant differences in craniofacial musculoskeletal elements. The widespread feeding mode previously described for cyprinodontiforms, in which the force of the bite may be secondary to the requisite dexterity needed to pick at food items, is modified within both the scale specialist and the durophagous species. While the scale specialist has greatly emphasized maxillary retraction, using it to overcome the poor mechanical advantage associated with scale-eating, the durophage has instead stabilized the maxilla. In all species the bulk of the adductor musculature is composed of AM A1. However, the combined masses of both adductor mandibulae (AM) A1 and A3 in the scale specialist were five times that of the other species, showing the importance of growth in functional divergence. The scale specialist combines plesiomorphic jaw mechanisms with both a hypertrophied AM A1 and a slightly modified maxillary anatomy (with substantial functional implications) to generate a bite that is both strong and allows a wide range of motion in the upper jaw, two attributes that normally tradeoff mechanically. Thus, a significant feeding innovation (scale-eating, rarely seen in fishes) may evolve based largely on allometric changes in ancestral structures. Alternatively, the durophage shows reduced growth with foreshortened jaws that are stabilized by an immobile maxilla. Overall, scale specialists showed the most divergent morphology, suggesting that selection for scale-biting might be stronger or act on a greater number of traits than selection for either detritivory or durophagy. The scale specialist has colonized an adaptive peak that few lineages have climbed. Thus, heterochronic changes in growth can quickly produce functionally relevant change among closely related species.