Feeding Behaviour of Tank Goby, Glossogobius giuris (Hamilton) and Its Rearing Feasibility in Upper Assam

2020 ◽  
Vol 7 (1) ◽  
pp. 61-68
Author(s):  
Monjeet Sonowal ◽  
Nipen Nayak ◽  
S P Biswas
Keyword(s):  
Feeding Behaviour ◽  
Natural Habitat ◽  
Food Preferences ◽  
Trophic Levels ◽  
Small Fish ◽  
Fish Feed ◽  
Commercial Fish ◽  
Wide Range ◽  
Glossogobius Giuris ◽  
Animal Diet

Feeding behaviour and rearing feasibility of a multipurpose wild goby fish, Glossogobius giuris in backyard ponds has been discussed. The fish shows inclination towards animal diet with wide range of food preferences at various trophic levels. Specimens collected from natural habitat and also from rearing pond indicate its preference towards small sized fishes. The fish is a voracious feeder and exhibit somewhat aggressive behaviour when kept in fasting mode for a period of 12 to 24 hour. Further, the fish prefers mostly in live food, be it small fish, earthworm or mosquito larvae but exhibit little interest towards homemade and commercial fish feed.

scholarly journals Assessment of Fungal Contamination in Fish Feed from the Lake Victoria Basin, Uganda

Toxins ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 233 ◽  
Author(s):  
Victoria Tibenda Namulawa ◽  
Samuel Mutiga ◽  
Fred Musimbi ◽  
Sundy Akello ◽  
Fredrick Ngángá ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Lake Victoria ◽  
Enzyme Linked Immunosorbent Assay ◽  
Fungal Colonization ◽  
Fish Feed ◽  
Lake Victoria Basin ◽  
Commercial Fish ◽  
Mycotoxin Contamination ◽  
Wide Range ◽  
Feed Samples

The emergence of commercial fish farming has stimulated the establishment of fish feed factories in Uganda. However, no information is available on the safety of the feed, mainly due to lack of mycotoxin testing facilities and weak regulatory systems. A study was carried out to examine fungal colonization and mycotoxin contamination in fish feed samples (n = 147) of different types collected from nine fish farms (n = 81) and seven fish feed factories (n = 66) in the Lake Victoria Basin (LVB). Fungi were isolated in potato dextrose agar, grouped into morphotypes and representative isolates from each morphotype were identified based on the internal transcribed spacer (ITS) region of ribosomal DNA sequences. Aflatoxin B1 (AFB1) and total fumonisin (combinations of B1, B2 and B3; hereinafter named fumonisin) levels in feed samples were determined by enzyme-linked immunosorbent assay (ELISA). A wide range of fungi, including toxigenic Aspergillus flavus and Fusarium verticillioides, were isolated from the fish feed samples. AFB1 was detected in 48% of the factory samples and in 63% of the farm samples, with toxin levels <40 and >400 µg/kg, respectively. Similarly, 31% of the factory samples and 29% of the farm samples had fumonisin contamination ranging between 0.1 and 4.06 mg/kg. Pellets and powder had higher mycotoxin contamination compared to other commercially available fish feed types. This study shows AFB1 as a potential fish feed safety issue in the LVB and suggests a need for more research on mycotoxin residues in fish fillets.

Relationship between morphometrics and trophic levels in deep-sea fishes

2020 ◽  
Vol 637 ◽  
pp. 225-235 ◽  
Author(s):  
MA Ladds ◽  
MH Pinkerton ◽  
E Jones ◽  
LM Durante ◽  
MR Dunn
Keyword(s):  
Stable Isotopes ◽  
Trophic Level ◽  
Deep Sea ◽  
Strong Relationship ◽  
Ecosystem Model ◽  
Trophic Levels ◽  
Fish Size ◽  
Wide Range ◽  
Gape Size ◽  
Morphological Variables

Marine food webs are structured, in part, by predator gape size. Species found in deep-sea environments may have evolved such that they can consume prey of a wide range of sizes, to maximise resource intake in a low-productivity ecosystem. Estimates of gape size are central to some types of ecosystem model that determine which prey are available to predators, but cannot always be measured directly. Deep-sea species are hypothesized to have larger gape sizes than shallower-water species relative to their body size and, because of pronounced adaptive foraging behaviour, show only a weak relationship between gape size and trophic level. Here we present new data describing selective morphological measurements and gape sizes of 134 osteichthyan and chondrichthyan species from the deep sea (200-1300 m) off New Zealand. We describe how gape size (height, width and area) varied with factors including fish size, taxonomy (class and order within a class) and trophic level estimated from stable isotopes. For deep-sea species, there was a strong relationship between gape size and fish size, better predicted by body mass than total length, which varied by taxonomic group. Results show that predictions of gape size can be made from commonly measured morphological variables. No relationship between gape size and trophic level was found, likely a reflection of using trophic level estimates from stable isotopes as opposed to the commonly used estimates from FishBase. These results support the hypothesis that deep-sea fish are generalists within their environment, including suspected scavenging, even at the highest trophic levels.

Evaluation and Avoidance of False Alarm by Controlling Rhine Water with Continuously Working Biotests

1994 ◽  
Vol 29 (3) ◽  
pp. 207-209 ◽  
Author(s):  
H. Puzicha
Keyword(s):  
Warning System ◽  
Point Sources ◽  
Trophic Levels ◽  
River Rhine ◽  
Wide Range ◽  
River Test ◽  
Continuous Working ◽  
Range Of Variation ◽  
Contaminant Load ◽  
Rhine Water

Effluents from point sources (industries, communities) and diffuse inputs introduce pollutants into the water of the river Rhine and cause a basic contaminant load. The aim is to establish a biological warning system to detect increased toxicity in addition to the already existing chemical-physical monitoring system. To cover a wide range of biocides, continuous working biotests at different trophic levels (bacteria, algae, mussels, water fleas, fishes) have been developed and proved. These are checked out for sensitivity against toxicants, reaction time, validity of data and practical handling under field conditions at the river. Test-specific appropriate methods are found to differentiate between the normal range of variation and true alarm signals.

scholarly journals Temporal and ontogenetic variations in feeding habits of Hollandichthys multifasciatus (Teleostei: Characidae) in coastal Atlantic rainforest streams, southern Brazil

2009 ◽  
Vol 7 (3) ◽  
pp. 415-420 ◽  
Author(s):  
Vinícius Abilhoa ◽  
Hugo Bornatowski ◽  
Gislaine Otto
Keyword(s):  
Quantitative Methods ◽  
Feeding Habits ◽  
Atlantic Rainforest ◽  
Small Fish ◽  
Fish Feed ◽  
Southern Brazil ◽  
Qualitative And Quantitative ◽  
Qualitative And Quantitative Methods ◽  
Black Water ◽  
Terrestrial Insects

Feeding habits of the characin Hollandichthys multifasciatus were investigated. Samplings were made between March 2004 and February 2005 in two black water streams of the coastal Atlantic rainforest in southern Brazil. The diet, evaluated by qualitative and quantitative methods, included aquatic and terrestrial insects, decapods, oligochaetes, plants and spiders. Large individuals feed mainly on plants, terrestrial insects, and spiders, whereas small fish feed basically on plants and oligochaetes. The species showed an omnivorous feeding habit, and its diet was composed of autochthonous (mainly oligochaetes) and allochthonous (plants and terrestrial insects) material.

scholarly journals PENGGUNAAN SLUDGE SEBAGAI PAKAN CALON INDUK IKAN NILA MERAH (Oreochromis sp.)

2003 ◽  
Vol 5 (2) ◽  
pp. 11
Author(s):  
Rustidja Rustidja
Keyword(s):  
Growth Rate ◽  
Survival Rate ◽  
Specific Growth ◽  
Control Group ◽  
Fish Feed ◽  
Commercial Fish ◽  
Gonadal Maturation ◽  
Randomized Design ◽  
Completely Randomized Design ◽  
Maturation Index

The aim of study was to know the effect of sludge in the ration on the gonadal growth of Oreochromis sp. broodstock. Experimental design used in this experiment was completely Randomized Design. The broodstocks were fed with the ration containing 0-40% of sludge, or with a commercial fish feed as a control.The results were not significantly differences between the treatment in all parameters. The sludge in ration ranging from 0 to 40% resulted the level of gonadal maturation of 4, 6, 7, dan 9. The value of Gonadal Maturation Index on 0,96 to 3,98 % and the control group on 1,75 %. The specific growth rate of broodstock fed with the ration ranged from 1,1 to 1,62 Bw/day and that of the development of gonadal control group was 1,97. The survival rate were variated between 14,29 to 100% and that of the development of gonadal control group is 71,43%. The ration containing 40% sludge is the most suitable feed for maturation in Oreochromis.

scholarly journals Type of organic fertilizer rather than organic amendment per se increases abundance of soil biota

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11204
Author(s):  
Maria Viketoft ◽  
Laura G.A. Riggi ◽  
Riccardo Bommarco ◽  
Sara Hallin ◽  
Astrid R. Taylor
Keyword(s):  
Organic Matter ◽  
Organic Amendments ◽  
Trophic Levels ◽  
Soil Biota ◽  
Organic Fertilizers ◽  
Nitrogen Fertilizers ◽  
Mineral Fertilizers ◽  
Soil Organisms ◽  
Wide Range

Addition of organic amendments is a commonly used practice to offset potential loss of soil organic matter from agricultural soils. The aim of the present study was to examine how long-term addition of organic matter affects the abundance of different soil biota across trophic levels and the role that the quality of the organic amendments plays. Here we used a 17-year-old fertilization experiment to investigate soil biota responses to four different organic fertilizers, compared with two mineral nitrogen fertilizers and no fertilization, where the organic fertilizers had similar carbon content but varied in their carbon to nitrogen ratios. We collected soil samples and measured a wide range of organisms belonging to different functional groups and trophic levels of the soil food web. Long-term addition of organic and mineral fertilizers had beneficial effects on the abundances of most soil organisms compared with unfertilized soil, but the responses differed between soil biota. The organic fertilizers generally enhanced bacteria and earthworms. Fungi and nematodes responded positively to certain mineral and organic fertilizers, indicating that multiple factors influenced by the fertilization may affect these heterogeneous groups. Springtails and mites were less affected by fertilization than the other groups, as they were present at relatively high abundances even in the unfertilized treatment. However, soil pH had a great influence on springtail abundance. In summary, the specific fertilizer was more important in determining the numerical and compositional responses of soil biota than whether it was mineral or organic. Overall, biennial organic amendments emerge as insufficient, by themselves, to promote soil organisms in the long run, and would need to be added annually or combined with other practices affecting soil quality, such as no or reduced tillage and other crop rotations, to have a beneficial effect.

Kinematics and efficiency of steady swimming in adult axolotls (Ambystoma mexicanum)

1997 ◽  
Vol 200 (13) ◽  
pp. 1863-1871 ◽  
Author(s):  
K D'Août ◽  
P Aerts
Keyword(s):  
Swimming Speed ◽  
High Speed ◽  
Natural Habitat ◽  
Total Body Length ◽  
Ambystoma Mexicanum ◽  
The Body ◽  
Entire Body ◽  
Amplitude Profile ◽  
Wide Range ◽  
Tail Tip

The kinematics of steady swimming at a wide range of velocities was analysed using high-speed video recordings (500 frames s-1) of eight individuals of Ambystoma mexicanum swimming through a tunnel containing stationary water. Animals in the observed size range (0.135&shy;0.238 m total body length) prefer to swim at similar absolute speeds, irrespective of their body size. The swimming mechanism is of the anguilliform type. The measured kinematic variables &shy; the speed, length, frequency and amplitude (along the entire body) of the propulsive wave &shy; are more similar to those of anguilliform swimming fish than to those of tadpoles, in spite of common morphological features with the latter, such as limbs, external gills and a tapering tail. The swimming speed for a given animal size correlates linearly with the tailbeat frequency (r2=0.71), whereas the wavelength and tail-tip amplitude do not correlate with this variable. The shape of the amplitude profile along the body, however, is very variable between the different swimming bouts, even at similar speeds. It is suggested that, for a given frequency, the amplitude profile along the body is adjusted in a variable way to yield the resulting swimming speed rather than maintaining a fixed-amplitude profile. The swimming efficiency was estimated by calculating two kinematic variables (the stride length and the propeller efficiency) and by applying two hydrodynamic theories, the elongated-body theory and an extension of this theory accounting for the slope at the tail tip. The latter theory was found to be the most appropriate for the axolotl's swimming mode and yields a hydromechanical efficiency of 0.75&plusmn;0.04 (mean &plusmn; s.d.), indicating that Ambystoma mexicanum swims less efficiently than do anuran tadpoles and most fishes. This can be understood given its natural habitat in vegetation at the bottom of lakes, which would favour manoeuvrability and fast escape.

scholarly journals Occurrence of Fungi and Fungal Toxins in Fish Feed during Storage

Toxins ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 171
Author(s):  
Constanze Pietsch ◽  
Georg Müller ◽  
Sulayman Mourabit ◽  
Simon Carnal ◽  
Kasun Bandara
Keyword(s):  
Relative Humidity ◽  
Ochratoxin A ◽  
Short Duration ◽  
Storage Conditions ◽  
Fish Feed ◽  
Fungal Contamination ◽  
Commercial Fish ◽  
Fungal Toxins ◽  
Fish Feeds

Periods of unfavorable storing conditions can lead to changes in the quality of fish feeds, as well as the development of relevant mycotoxins. In the present study, a commercial fish feed was stored under defined conditions for four weeks. The main findings indicate that even storing fish feeds under unsuitable conditions for a short duration leads to a deterioration in quality. Mycotoxin and fungal contamination were subsequently analyzed. These investigations confirmed that different storage conditions can influence the presence of fungi and mycotoxins on fish feed. Notably, ochratoxin A (OTA) was found in samples after warm (25 °C) and humid (>60% relative humidity) treatment. This confirms the importance of this compound as a typical contaminant of fish feed and reveals how fast this mycotoxin can be formed in fish feed during storage.

scholarly journals New handbook for standardised measurement of plant functional traits worldwide

2013 ◽  
Vol 61 (3) ◽  
pp. 167 ◽  
Author(s):  
N. Pérez-Harguindeguy ◽  
S. Díaz ◽  
E. Garnier ◽  
S. Lavorel ◽  
H. Poorter ◽  
...  
Keyword(s):  
Functional Traits ◽  
Environmental Changes ◽  
Plant Traits ◽  
Leaf Traits ◽  
Plant Functional Traits ◽  
Trophic Levels ◽  
Evolutionary Patterns ◽  
Ecosystem Properties ◽  
Species Invasions ◽  
Wide Range

Plant functional traits are the features (morphological, physiological, phenological) that represent ecological strategies and determine how plants respond to environmental factors, affect other trophic levels and influence ecosystem properties. Variation in plant functional traits, and trait syndromes, has proven useful for tackling many important ecological questions at a range of scales, giving rise to a demand for standardised ways to measure ecologically meaningful plant traits. This line of research has been among the most fruitful avenues for understanding ecological and evolutionary patterns and processes. It also has the potential both to build a predictive set of local, regional and global relationships between plants and environment and to quantify a wide range of natural and human-driven processes, including changes in biodiversity, the impacts of species invasions, alterations in biogeochemical processes and vegetation–atmosphere interactions. The importance of these topics dictates the urgent need for more and better data, and increases the value of standardised protocols for quantifying trait variation of different species, in particular for traits with power to predict plant- and ecosystem-level processes, and for traits that can be measured relatively easily. Updated and expanded from the widely used previous version, this handbook retains the focus on clearly presented, widely applicable, step-by-step recipes, with a minimum of text on theory, and not only includes updated methods for the traits previously covered, but also introduces many new protocols for further traits. This new handbook has a better balance between whole-plant traits, leaf traits, root and stem traits and regenerative traits, and puts particular emphasis on traits important for predicting species’ effects on key ecosystem properties. We hope this new handbook becomes a standard companion in local and global efforts to learn about the responses and impacts of different plant species with respect to environmental changes in the present, past and future.

Sign in / Sign up

Export Citation Format

Share Document