Diet Composition and Seasonal Fluctuations in the Feeding Habit of Snow Barbel (Schizothorax plagiostomus) in River Indus, Pakistan

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

Role of green innovation and sustainable supply chain management in firm internationalization

Purpose: Purpose of this study is to explore the nature of relationship between internationalization of firms, sustainability of their supply chains, and the extent of their green innovations. Understanding of the relationship between these constructs is important because of the ever increasing sustainability awareness of consumers in the leading economies of the world. This awareness is now compelling importers of goods from cheap-labor countries to ensure that their suppliers comply with sustainability regulations. This compliance becomes very challenging because of the lack of control on second-tier and third-tier suppliers in a supply chain. First-tier suppliers in this case may drive this effort but need to be motivated enough to do so. In case of environmental sustainability, green innovation (GI) may provide a gradual, and thus more affordable and practical, move toward more eco-friendly ways. As far as the motivation to commit to sustainability and GI is concerned, internationalization and export business expansion may act as one of the most effective motivators for these suppliers. However, the nature of relationship between these three constructs, i.e. internationalization of firms, sustainability of their supply chains and the extent of their GI requires a better understanding. Design/methodology/approach: The work uses a novel data set collected from 146 medium and large textile firms operating in Pakistan. The partial least square-structural equation modeling approach is used for data analysis. Findings: All three constructs of internationalization, GI and sustainable supply chain management (SSCM) are significantly associated and thus complement each other. Originality/value: This work uses a novel agency theory perspective to analyze the relationship between internationalization, GI and SSCM. In that sense, the findings indicate that internationalization could be one of the incentives that can be used by the principals to deal with agents’ goal conflict and information asymmetry

Assessment of fish oil to check the stability and meat quality of some commercially available tin packed fish in Islamabad, Pakistan

Fish contains all the essential nutrients which is important for human health so it is important to analyse all the nutrients present in tin packed fish meat. Keeping in view its importance present study is conducted on the assessment of fish oil to check the stability and quality of fish meat by proximate analysis of commercially available tin packed fish. Four tin packed fish species i.e., Sardine (Sardinella longiceps), Red salmon (Oncorhynchus nerka), Pink salmon (Oncorhynchus gorbuscha) and Skipjack tuna (Katsuwonus pelamis) were collected from different supermarkets of Islamabad, Pakistan. Proximate analysis viz., crude protein, crude fat, moisture and ash contents of the fish meat has been done to evaluate the meat quality. The antioxidant activity in oil was also analysed by FRAP assay. The result indicated that maximum percentage of moisture i.e., 78.61% present in Skipjack Tuna meat, Pink Salmon contain highest percentage of crude protein i.e., 70.00%, Red Salmon contain highest percentage of crude fat i.e., 30.00% while Sardine and Skipjack Tuna contains highest percentage of ash contents i.e., 8.00% and the total antioxidant capacity (uM) is higher in oil of Red Salmon (24.35%) followed by Sardines (14.78%), Skipjack Tuna (9.86%) and Pink Salmon (9.48%). It was concluded that the fish meat after thermal processing contains suitable percentage of crude protein, crude fats, and moisture and ash contents

Histomorphological changes in gonads of Clupisoma naziri during spring and summer season

Present study was conducted to analyse the effect of breeding and non-breeding seasons on histomorphological changes in gonads of Clupisoma naziri. In Khyber Pakhtunkhwa and northern Punjab, Pakistan, 43 mature fish of both sexes were gathered from the Indus River and its tributaries. In the non-breeding season (spring), both testis and ovaries went through a preparatory phase, with thick tunica albuginea and fast spermatogenesis in testes and the formation of cortical alveoli or yolk vesicles in the cortex of the cytoplasm in ovaries. The testicular lobules were loaded with spermatozoa and some spermatogenic cells during breeding season (summer), while the ovaries were filled with mature ovarian follicles. The breeding season is marked by spermatozoa leaking freely from testes and ovaries brimming with completely mature eggs. The gonadosomatic (GSI) results are consistent with the histomorphological results of gonads, as their values peak during breeding season and drop during non-breeding season. C. naziri breeds once a year during the summer season, according to the current study, and this information will aid aqua breeders in the culturing of this commercially significant catfish in Pakistan

Crop Pests and Predators Exhibit Inconsistent Responses to Surrounding Landscape Composition

The idea that noncrop habitat enhances pest control and represents a win–win opportunity to conserve biodiversity and bolster yields has emerged as an agroecological paradigm. However, while noncrop habitat in landscapes surrounding farms sometimes benefits pest predators, natural enemy responses remain heterogeneous across studies and effects on pests are inconclusive. The observed heterogeneity in species responses to noncrop habitat may be biological in origin or could result from variation in how habitat and biocontrol are measured. Here, we use a pest-control database encompassing 132 studies and 6,759 sites worldwide to model natural enemy and pest abundances, predation rates, and crop damage as a function of landscape composition. Our results showed that although landscape composition explained significant variation within studies, pest and enemy abundances, predation rates, crop damage, and yields each exhibited different responses across studies, sometimes increasing and sometimes decreasing in landscapes with more noncrop habitat but overall showing no consistent trend. Thus, models that used landscape-composition variables to predict pest-control dynamics demonstrated little potential to explain variation across studies, though prediction did improve when comparing studies with similar crop and landscape features. Overall, our work shows that surrounding noncrop habitat does not consistently improve pest management, meaning habitat conservation may bolster production in some systems and depress yields in others. Future efforts to develop tools that inform farmers when habitat conservation truly represents a win–win would benefit from increased understanding of how landscape effects are modulated by local farm management and the biology of pests and their enemies

The interplay of landscape composition and configuration: new pathways to manage functional biodiversity and agroecosystem services across Europe

Managing agricultural landscapes to support biodiversity and ecosystem services is a key aim of a sustainable agriculture. However, how the spatial arrangement of crop fields and other habitats in landscapes impacts arthropods and their functions is poorly known. Synthesising data from 49 studies (1515 landscapes) across Europe, we examined effects of landscape composition (% habitats) and configuration (edge density) on arthropods in fields and their margins, pest control, pollination and yields. Configuration effects interacted with the proportions of crop and non‐crop habitats, and species’ dietary, dispersal and overwintering traits led to contrasting responses to landscape variables. Overall, however, in landscapes with high edge density, 70% of pollinator and 44% of natural enemy species reached highest abundances and pollination and pest control improved 1.7‐ and 1.4‐fold respectively. Arable‐dominated landscapes with high edge densities achieved high yields. This suggests that enhancing edge density in European agroecosystems can promote functional biodiversity and yield‐enhancing ecosystem services

Crop pests and predators exhibit inconsistent responses to surrounding landscape composition

The idea that noncrop habitat enhances pest control and represents a win–win opportunity to conserve biodiversity and bolster yields has emerged as an agroecological paradigm. However, while noncrop habitat in landscapes surrounding farms sometimes benefits pest predators, natural enemy responses remain heterogeneous across studies and effects on pests are inconclusive. The observed heterogeneity in species responses to noncrop habitat may be biological in origin or could result from variation in how habitat and biocontrol are measured. Here, we use a pest-control database encompassing 132 studies and 6,759 sites worldwide to model natural enemy and pest abundances, predation rates, and crop damage as a function of landscape composition. Our results showed that although landscape composition explained significant variation within studies, pest and enemy abundances, predation rates, crop damage, and yields each exhibited different responses across studies, sometimes increasing and sometimes decreasing in landscapes with more noncrop habitat but overall showing no consistent trend. Thus, models that used landscape-composition variables to predict pest-control dynamics demonstrated little potential to explain variation across studies, though prediction did improve when comparing studies with similar crop and landscape features. Overall, our work shows that surrounding noncrop habitat does not consistently improve pest management, meaning habitat conservation may bolster production in some systems and depress yields in others. Future efforts to develop tools that inform farmers when habitat conservation truly represents a win–win would benefit from increased understanding of how landscape effects are modulated by local farm management and the biology of pests and their enemies

Impact of semi-natural habitats on the diversity and density of carabid beetles in winter wheat

Die vorliegende Arbeit untersuchte den Einfluss der Position innerhalb eines Feldes (Feldrand bzw. -zentrum), vom Typ des angrenzenden naturnahen Habitats und von der Landschaftszusammensetzung auf die Diversität und Abundanz von Laufkäfern. Für diese Studie wurden 20 Winterweizenfelder in zehn unterschiedlichen Landschaftsausschnitten in der Schweiz ausgewählt. In jedem der zehn Landschaftsausschnitte befanden sich ein Winterweizenfeld mit angrenzender Buntbrache sowie ein Winterweizenfeld mit angrenzendem grasdominierten Feldrain. Generell wiesen die Felder höhere Aktivitätsdichten auf als die angrenzenden Buntbrachen; in den Feldrainen wurden mehr Arten nachgewiesen als in den angrenzenden Feldern. Unter den häufigsten Arten hatten Agonum muelleri und Poecilus cupreus im Zentrum der Felder höhere Aktivitätsdichten als an deren Rändern. Für Pterostichus melanarius wurden signifikante Interaktionen zwischen der Position innerhalb der Felder und der Zusammensetzung der Landschaft und zwischen angrenzendem Habitat und der Landschaftszusammensetzung gefunden. Die Abundanz von Bembidion properans nahm an den Feldrändern mit steigendem Anteil an naturnahen Habitaten in der umgebenden Landschaft zu; darüber hinaus bestand für diese Arte eine signifikante Interaktion zwischen der Position innerhalb der Felder und der Landschaftszusammensetzung. Harpalus rufipes war häufiger in Feldern mit angrenzender Buntbrache als in solchen mit angrenzedem Feldrain. Die Laufkäferarten mit den höchsten Aktivitätsdichten waren makroptere, polyphag carnivore, euryöke Offenlandarten, die signifikant häufiger in den Feldern als in den angrenzenden Buntbrachen. Die Zahl stenöker Offenlandarten war signifikant höher in den grasdominierten Feldrainen als in den angrenzenden Winterweizenfeldern waren. Unsere Resultate konnten die meisten unserer Erwartungen bestätigen. Allerdings war der positive Effekt der Buntbrachen auf die Laufkäfer nicht stärker als jener der grasdominierten Feldraine.In this work the influence of within field position, adjoining semi-natural habitat and landscape composition on the diversity and density of carabid beetles was explored. Moreover, treatment effects (SWA, grassy margins, fields adjoining SWA and fields adjoining grassy margins) on carabid assemblage similarity were studied. Twenty winter wheat fields from ten different Swiss agricultural landscapes were selected for this work, with two wheat fields (one with an adjoining SWA and one with an adjoining grassy margin) located in each landscape. Overall, activity-density was higher in fields than adjoining SWA and species richness was significantly larger in grassy margins than adjoining wheat fields. Among the most abundant species, higher densities of Agonum muelleri and Poecilus cupreus were observed in field centres compared to the edges. Pterostichus melanarius was more abundant in centre than edge positions, showed significant interactions between within-field position and landscape composition, and between adjoining habitat and landscape composition. Activity-density of Bembidion properans increased at the field edges with increasing amount of perennial habitat; in addition, a significant interaction between within-field position and landscape position was observed. Harpalus rufipes was more abundant in fields adjoining SWA than in fields adjoining grassy margins. The activity-densities of macropterous, polyphagous carnivorous and euryoecious open habitat beetles were significantly higher in fields than adjoining SWA. Species richness of stenoecious open habitat carabids was significantly higher in grassy margins compared to adjoining fields. A strong significant effect of the factor treatment and a weaker significant effect of landscape on carabid assemblages were observed. Our findings support most of our expectations but higher promotion of carabids in wheat fields by SWA compared to grassy margins could not be shown.submitted by Muhammad Zubair AnjumAbweichender Titel laut Übersetzung der Verfasserin/des VerfassersZsfassung in dt. SpracheWien, Univ. für Bodenkultur, Diss., 2009OeBB(VLID)193170