scholarly journals Trophic relationships among fourteen native and non-native fish species in the Shatt Al-Arab River, Iraq

2021 ◽  
Vol 11 (1) ◽  
pp. 190-202
Author(s):  
Abdul-Razak Mahmood Mohamed ◽  
Abdullah N Abood
Keyword(s):  
Fish Species ◽  
Native Species ◽  
Diet Breadth ◽  
Trophic Niche ◽  
Trophic Relationships ◽  
Dietary Analysis ◽  
Oreochromis Aureus ◽  
Food Items ◽  
Invading Species ◽  
High Degree

The present study objectified to evaluate the trophic relationships among 14 fish species (10 natives and 4 non-natives) in the Shatt Al-Arab River, considering the trophic niche breadth and the diet overlaps of the species. The food items in the stomach of each species are determined by adopting the index of relative importance (IRI). The dietary analysis revealed a total of 12 types of major food items consumed (which represent >10% IRI). Two species (Oreochromis aureus and Cptodon zillii) were herbivores consumed mostly macrophytes, algae and diatoms. Four species (Planiliza abu, P. klunzengeri, P. subviridis and Osteomugil speigleri) were herbivores mainly fed on diatoms, macrophytes, detritus and algae. Three species (Carasobarbus luteus, Carassius auratus and Cyprinus carpio) were omnivores mostly consumed macrophytes, detritus, diatoms and algae. Two species (Tenualosa illisha and Nematalosa nasus) were filter feeders fed largely on zooplankton, algae, detritus and macrophytes. Three species (Acanthopagrus arabicus, Johnius belangerii and J. dussumeiri) were carnivores mainly preyed on shrimps, crabs and fish. Levin’s index diet breadth analyses divided the studied fish species into three categories; two species with high specialization, five species with low specialization, and seven species with generalization feeders. The dietary composition of fish species exhibited 62 diet overlaps as indicated by the Jaccard index, eight of them high, 36 moderate and 18 low overlaps. Only J. dussumeiri and J. belangerii have no diet overlap with other species. Overall, the study demonstrates that most trophic overlaps between species were moderate, but high degree overlap was between the native species (C. luteus) and invading species (C. auratus) and therefore strengthen earlier conclusions regarding interspecific competition between these two species.

Trophic Interactions between Two Cichlid Species in Shatt Al-Arab River, Iraq

2021 ◽  
Vol 5 (1) ◽  
pp. 74-85
Author(s):  
Abdul-Razak Mohamed
Keyword(s):  
Feeding Activity ◽  
Trophic Niche ◽  
Trophic Relationships ◽  
Food Sources ◽  
Oreochromis Aureus ◽  
Cichlid Species ◽  
Food Items ◽  
Blue Tilapia ◽  
High Degree ◽  
Monthly Variations

The diet composition and trophic relationships of the blue tilapia, Oreochromis aureus and redbelly tilapia, Coptodon zillii were investigated in the Shatt Al-Arab river from November 2015 to October 2016. Fishes were collected by gill nets, cast net and electro-fishing. The index of relative importance (IRI%) of food items was determined by combining the frequency of occurrence and points methods. There were monthly variations in feeding activity and intensity of both species, which decreased in the colder months. Both species were classified as herbivores. The main food items of O. aureus were macrophytes (44.3%), algae (31.4%), diatoms (9.3%), aquatic insects (6.6%) and detritus (6.3%). The diet of C. zillii is composed mainly of macrophytes (60.8%), algae (23.0%), detritus (8.6%) and diatoms (6.4). The trophic niche breadth values varied between 0.217 for C. zillii and 0.360 for O. aureus. The results demonstrated a high degree of dietary overlap between O. aureus and C. zillii, as both species fed on the same food sources

scholarly journals Advancing improvement in riverine water quality caused a non-native fish species invasion and native fish fauna recovery

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Łukasz Głowacki ◽  
Andrzej Kruk ◽  
Tadeusz Penczak
Keyword(s):  
Water Quality ◽  
Fish Species ◽  
Native Species ◽  
Interference Competition ◽  
Fish Fauna ◽  
Species Traits ◽  
Native Fish ◽  
Biological Degradation ◽  
Species Invasion ◽  
Prussian Carp

AbstractThe knowledge of biotic and abiotic drivers that put non-native invasive fishes at a disadvantage to native ones is necessary for suppressing invasions, but the knowledge is scarce, particularly when abiotic changes are fast. In this study, we increased this knowledge by an analysis of the biomass of most harmful Prussian carp Carassius gibelio in a river reviving from biological degradation. The species' invasion followed by the invasion's reversal occurred over only two decades and were documented by frequent monitoring of fish biomass and water quality. An initial moderate improvement in water quality was an environmental filter that enabled Prussian carp’s invasion but prevented the expansion of other species. A later substantial improvement stimulated native species’ colonization of the river, and made one rheophil, ide Leuciscus idus, a significant Prussian carp’s replacer. The redundancy analysis (RDA) of the dependence of changes in the biomass of fish species on water quality factors indicated that Prussian carp and ide responded in a significantly opposite way to changes in water quality in the river over the study period. However, the dependence of Prussian carp biomass on ide biomass, as indicated by regression analysis and analysis of species traits, suggests that the ecomorphological similarity of both species might have produced interference competition that contributed to Prussian carp’s decline.

Nodulation and performance of exotic and native legumes in Australian soils

2003 ◽  
Vol 51 (5) ◽  
pp. 543 ◽  
Author(s):  
María A. Pérez-Fernández ◽  
Byron B. Lamont
Keyword(s):  
Native Species ◽  
Treated Soil ◽  
Retama Sphaerocarpa ◽  
Australian Species ◽  
And Performance ◽  
Natural Stands ◽  
High Degree ◽  
Western Australian ◽  
Cytisus Balansae ◽  
New Habitats

Six Spanish legumes, Cytisus balansae, C. multiflorus, C. scoparius, C. striatus, Genista hystrix and Retama sphaerocarpa, were able to form effective nodules when grown in six south-western Australian soils. Soils and nodules were collected from beneath natural stands of six native Australian legumes, Jacksonia floribunda, Gompholobium tomentosum, Bossiaea aquifolium, Daviesia horrida, Gastrolobium spinosum and Templetonia retusa. Four combinations of soils and bacterial treatments were used as the soil treatments: sterile soil (S), sterile inoculated soils (SI), non-treated soil (N) and non-treated inoculated soils (NI). Seedlings of the Australian species were inoculated with rhizobia cultured from nodules of the same species, while seedlings of the Spanish species were inoculated with cultures from each of the Australian species. All Australian rhizobia infected all the Spanish species, suggesting a high degree of 'promiscuity' among the bacteria and plant species. The results from comparing six Spanish and six Australian species according to their biomass and total nitrogen in the presence (NI) or absence (S) of rhizobia showed that all species benefitted from nodulation (1.02–12.94 times), with R.�sphaerocarpa and C. striatus benefiting more than the native species. Inoculation (SI and NI) was just as effective as, or more effective than the non-treated soil (i.e. non-sterile) in inducing nodules. Nodules formed on the Spanish legumes were just as efficient at fixing N2 as were those formed on the Australian legumes. Inoculation was less effective than non-treated soil at increasing biomass but just as effective as the soil at increasing nitrogen content. Promiscuity in the legume–bacteria symbiosis should increase the ability of legumes to spread into new habitats throughout the world.

scholarly journals Freshwater temperature in the state of Rio Grande do Sul, Southern Brazil, and its implication for fish culture

2008 ◽  
Vol 6 (2) ◽  
pp. 275-281 ◽  
Author(s):  
Luciano de Oliveira Garcia ◽  
Carlos Eduardo Copatti ◽  
Flávio Wachholz ◽  
Waterloo Pereira Filho ◽  
Bernardo Baldisserotto
Keyword(s):  
Water Temperature ◽  
Fish Species ◽  
Native Species ◽  
Amazon Basin ◽  
Rio Grande ◽  
The State ◽  
Tropical Species ◽  
Southern Brazil ◽  
Rio Grande Do Sul ◽  
Lower Growth

In this study we verified data of water temperatures collected by CORSAN-RS from 1996 to 2004 in several cities of the state of Rio Grande do Sul, southern Brazil, and analyzed the possibility of raising the most cultivated fish species in Brazil. The water temperature from 1996 to 2004 was 16 to 28ºC in summer, 17 to 23ºC in fall, 14 to 17ºC (down to 9ºC in the coldest months) in winter and 14 to 21ºC in spring. Native species of this state, such as silver catfish (Rhamdia quelen), traíra (Hoplias malabaricus), dorado (Salminus brasiliensis), pintado (Pimelodus maculatus), as well as carps (family Cyprinidae), are resistant to the low winter temperatures. These species have a lower growth rate in coldest months (winter/spring) but a good development in warmer months (summer/fall), reaching a satisfactory performance throughout the year. In the periods of more intense cold, mortality of some introduced species, such as surubim from Amazon Basin (Pseudoplatystoma sp.), pirapitinga (Piaractus brachypomus), pirarucu (Arapaimas gigas), pacu (Piaractus mesopotamicus), tambaqui (Colossoma macropomum) and Nile tilapia (Oreochromis niloticus) may occur. In addition, as most tropical species have a thermal range for growth and reproduction between 20 to 28ºC, some species may have poor development even in fall. Therefore, water temperature in this state should be considered in the choice of fish species to be cultivated.

Incidence of Listeria spp. in Retail Foods in the United Arab Emirates

1995 ◽  
Vol 58 (1) ◽  
pp. 102-104 ◽  
Author(s):  
VIRENDRA S. GOHIL ◽  
MOUSA A. AHMED ◽  
RON DAVIES ◽  
RICHARD K. ROBINSON
Keyword(s):  
United Arab Emirates ◽  
Dairy Products ◽  
Listeria Innocua ◽  
Processed Meats ◽  
Food Items ◽  
Fresh Vegetables ◽  
Fresh Frozen ◽  
Listeria Welshimeri ◽  
High Degree ◽  
Retail Food

A survey of 1,101 samples of retail food items in the United Arab Emirates (UAE) covering dairy products, fresh vegetables, fresh/frozen meat and poultry and a range of “ready-to-eat” meals indicated that the incidence of Listeria monocytogenes was, in general, extremely low. Only in imported frozen chicken was L. monocytogenes detectable with a high degree of frequency, but fresh chicken and semi-processed meats of local origin were also contaminated. No indication of the number of organisms present in any given sample was sought, but as all the suspect foods would have been cooked prior to consumption, risks to the consumer should have been minimal. Listeria was not found in any “ready-to-eat” meals, including those made from chicken. Although Listeria innocua and Listeria welshimeri were detected in some retail foods, these species are normally regarded as being of little consequence with respect to public health.

scholarly journals The first unified inventory of non-native fishes of the South Caucasian countries, Armenia, Azerbaijan, and Georgia

2021 ◽  
pp. 32
Author(s):  
Tatia Kuljanishvili ◽  
Levan Mumladze ◽  
Bella Japoshvili ◽  
Namig Mustafayev ◽  
Shaig Ibrahimov ◽  
...  
Keyword(s):  
Black Sea ◽  
Fish Species ◽  
Caspian Sea ◽  
Native Species ◽  
Biological Diversity ◽  
Native Fish ◽  
The Black Sea ◽  
The South ◽  
In The Wild ◽  
Native Fishes

The South Caucasus (SC) region is recognized for its high biological diversity and various endemic animal taxa. The area has experienced many fish introductions over the years, but the overall information about non-native fishes in the three SC countries, Armenia, Azerbaijan, and Georgia did not exist. Although these three countries belong to the Kura River drainage, Caspian Sea basin (only the western half of Georgia drains into the Black Sea), the legislative framework for each country regarding introduction of non-native fish species and their treatment is different and poorly developed. The goal of the present study was to make an initial inventory of non-native fish species in the three SC countries, and summarize the existing knowledge as a basis for future risk assessment models and formulation of regional management policies. Here, we present a unified list of 27 non-native species recorded in the wild in Armenia, Azerbaijan, and Georgia. Among these 27 species, eight were translocated from the Black Sea basin to the Caspian Sea basin. Out of these 27 non-native fishes, 15 species have become established (three of them being considered invasive) and six fish species could not survive in the wild.

scholarly journals ‘Taking Fishers’ Knowledge to the Lab’: An Interdisciplinary Approach to Understand Fish Trophic Relationships in the Brazilian Amazon

2021 ◽  
Vol 9 ◽  
Author(s):  
Paula Evelyn Rubira Pereyra ◽  
Gustavo Hallwass ◽  
Mark Poesch ◽  
Renato Azevedo Matias Silvano
Keyword(s):  
Stable Isotopes ◽  
Food Webs ◽  
Fish Species ◽  
Trophic Interactions ◽  
Brazilian Amazon ◽  
Trophic Levels ◽  
Trophic Relationships ◽  
Ecological Knowledge ◽  
Data Limitations ◽  
Combining Data

Trophic levels can be applied to describe the ecological role of organisms in food webs and assess changes in ecosystems. Stable isotopes analysis can assist in the understanding of trophic interactions and use of food resources by aquatic organisms. The local ecological knowledge (LEK) of fishers can be an alternative to advance understanding about fish trophic interactions and to construct aquatic food webs, especially in regions lacking research capacity. The objectives of this study are: to calculate the trophic levels of six fish species important to fishing by combining data from stable isotopes analysis and fishers’ LEK in two clear water rivers (Tapajós and Tocantins) in the Brazilian Amazon; to compare the trophic levels of these fish between the two methods (stable isotopes analysis and LEK) and the two rivers; and to develop diagrams representing the trophic webs of the main fish prey and predators based on fisher’s LEK. The fish species studied were Pescada (Plagioscion squamosissimus), Tucunaré (Cichla pinima), Piranha (Serrasalmus rhombeus), Aracu (Leporinus fasciatus), Charuto (Hemiodus unimaculatus), and Jaraqui (Semaprochilodus spp.). A total of 98 interviews and 63 samples for stable isotopes analysis were carried out in both rivers. The average fish trophic levels did not differ between the stable isotopes analysis and the LEK in the Tapajós, nor in the Tocantins Rivers. The overall trophic level of the studied fish species obtained through the LEK did not differ from data obtained through the stable isotopes analysis in both rivers, except for the Aracu in the Tapajós River. The main food items consumed by the fish according to fishers’ LEK did agree with fish diets as described in the biological literature. Fishers provided useful information on fish predators and feeding habits of endangered species, such as river dolphin and river otter. Collaboration with fishers through LEK studies can be a viable approach to produce reliable data on fish trophic ecology to improve fisheries management and species conservation in tropical freshwater environments and other regions with data limitations.

scholarly journals Heterogeneity of the woody flora of swamp forests in southeastern and southern Brazil

Check List ◽  
2014 ◽  
Vol 10 (6) ◽  
pp. 1359 ◽  
Author(s):  
Bruno Coutinho Kurtz ◽  
Elisa Araujo Penna Caris ◽  
Fabio Rubio Scarano
Keyword(s):  
Native Species ◽  
Conservation Management ◽  
Southern Brazil ◽  
Hydromorphic Soils ◽  
Tolerant Species ◽  
The Future ◽  
Great Heterogeneity ◽  
Floristic Patterns ◽  
High Degree

Swamp forests are associated with hydromorphic soils and are naturally fragmented in their distribution. Several local phytosociological surveys on the woody flora of these forests have been conducted in southeastern and southern Brazil. We present here a comprehensive floristic list based on these surveys, including 77 families, 211 genera and 518 native species. The richest families were Myrtaceae (78 species), Fabaceae (47) and Lauraceae (38). The richest genera were Eugenia (24), Myrcia (24), Miconia (21) and Ocotea (20). The woody flora of these swamp forests has great heterogeneity, with most species occurring in one or few sites. Their flora is formed by a few flooding specialist or tolerant species, common in many sites, and many other species that come from the surrounding vegetation. Considering the high degree of deforestation in southeastern and southern Brazil, including swamp forests, the floristic patterns presented here can be useful for the future efforts of conservation, management and restoration of these forests.

scholarly journals Fish Assemblage in the Euphrates River at Al-Samawa City, Southern Iraq

2019 ◽  
Vol 32 ◽  
pp. 33-46
Author(s):  
Ammar M.S. Al-Helli ◽  
Amjad K. Resen ◽  
Atheer H. Ali
Keyword(s):  
Native Species ◽  
Ecological Factors ◽  
Abundant Species ◽  
Total Hardness ◽  
Dominance Index ◽  
Oreochromis Aureus ◽  
Euphrates River ◽  
The North ◽  
Blue Tilapia ◽  
Southern Iraq

The study was conducted in the Euphrates river in Al-Samawa city at two stations during the period from October 2016 till September 2017. The first station (north station) was Al-Majd township (45°12'49.2"E, 31°22'14.9"N), and the second station (south station) was Al-Zaier region (45°20'21.4"E, 31°18'54.4"N). Some ecological factors were monthly recorded at the stations of the current study, including water temperature, salinity, dissolved oxygen, pH, transparency, the speed of water flow, BOD5 and total hardness. All factors except total hardness have not significant differences between two stations, The hardness in the north station showed higher (844-1475) mg.l-1 than south station (655-1250) mg.l-1. Fishes were collected by gill nets, cast net, hook and line, hand net and electro-fishing. A total of 4260 fish specimens were collected which belong to 24 species and 10 families, 17 species of them were native species whereas seven of them were alien species. The most abundant species was blue tilapia Oreochromis aureus constituted 26.84% of the total caught of a north station, The value of the dominance index (D3) in north station was 62.57%, while the most abundant species in south station was Prussian carp Carassius auratus constituted 27.14% of the total caught, The value of the dominance index (D3) in the south station was 56.42%.

Biology and Management of Dogfish Sharks

2009 ◽  
Keyword(s):  
Life History ◽  
Pacific Coast ◽  
Puget Sound ◽  
Squalus Acanthias ◽  
Spiny Dogfish ◽  
Dietary Analysis ◽  
Strait Of Georgia ◽  
Food Items ◽  
Abundance Estimates ◽  
Commercial Species

Abstract.—Spiny dogfish <em>Squalus acanthias </em>have been an important commercial species on Canada’s Pacific coast for more than 130 years. In this study we show that the spiny dogfish life history results in juveniles remaining in pelagic waters for 10–15 years after birth, with lengths up to about 60 cm. Abundance estimates show that the numbers of these young dogfish, as well as some older dogfish in the pelagic waters, appear to represent a relatively large percentage of the population in these two regions. Dietary analysis shows that while euphausiids and teleosts constitute the major food items, regardless of size/age, dogfish feed on a number of species within the ecosystem. After about 15 years, there is a movement into demersal habitats where individuals eventually mature. Because dogfish are long lived, and because they are found throughout the pelagic zone and demersal habitats, it is probable that they play a key role in the Strait of Georgia and Puget Sound ecosystems.

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