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1
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
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Feeding ecology and reproductive biology of some economically important fish species in the Tono Reservoir, Ghana

100%
Akongyuure D. N.
International Letters of Natural Sciences
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2020
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tom 78
The study of feeding ecology and reproductive biology ensures that the right management measures are applied for best output of fish stocks. Selection of good fish species for culture is also made possible through feeding and reproductive studies. Ghana over-relies on the culture of Nile tilapia and African catfish because there is no reliable scientific information on potential fish species that can be included for fish farming. The current study sought to investigate food habits and reproductive characteristics of economically important fish species in the Tono Reservoir of Northern Ghana. Monthly sampling was carried out from January, 2015 to December, 2016 (24 months). Specimens were obtained using cast net and gillnets of varying mesh sizes. Specimens were immediately transported to the laboratory in a chilled iced chest of temperature 4 ◦ C for morphometric measurements and microscopic analysis of gut content and gonads. Thirty-three (33) individual food items were identified from all the fish species. Phytoplankton was the most important diet (Index of Relative Importance, IRI = 1923) whereas zooplankton was the least important diet (IRI = 35) out of the five major categories of food items identified from all the fish species. The major peaks of gonadosomatic index (GSI) of females were noted in February – March and June – July. Over 80 % variation of fecundity was explained by the predictors (standard length, fish weight and gonad weight) for Clarias gariepinus and Auchenoglanis occidentalis. All the fish species were classified as omnivores and they spawned more than once in a year making all of them good candidates for aquaculture. Management measures should focus on regulating agricultural activities close to the reservoir and fishing activities in the reservoir for sustainable fish production and exploitation.
2

On the morphology and mitochondrial DNA barcoding of the flesh fly Sarcophaga (Liopygia) argyrostoma (Robineau-Desvoidy, 1830) (Diptera: Sarcophagidae) - An important species in forensic entomology

84%
Draber-Monko A., Malewski T., Pomorski J., Los M., Slipinski P.
Annales Zoologici
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2009
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tom 59
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nr 4
Descriptions of the developmental stages of Sarcophaga (Liopygia) argyrostoma (R.-D.) are given. Scanning electron microscope images of most of its immature stages are presented for the first time. The sequence of mitochondrial cytochrome c oxidase subunit I (COI) gene fulfilling DNA barcoding standards is presented for the first time.
3
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
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Fauna and importance of thrips [Thysanoptera] for rye and winter wheat in Poland. Part I. Fauna of Thysanoptera on rye and winter wheat in Poland

84%
Zawirska I., Walkowski W.
Journal of Plant Protection Research
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2000
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tom 40
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nr 1
On the basis of sweep netting samples and young plant and spike samples, the species composition and the incidence of thrips (Thysanoptera) on rye and winter wheat in different regions of Poland have been determined. A list of 49 Thysanoptera species found on these cereal crops and an overview of 11 species referred to "cereal thrips" have been given. The undertaken studies have showed that Haplothrips aculeatus Fab. was dominant on both rye and winter wheat crops.
4

Length-frequency compositions and weight-length relations for big-eye tuna, yellowfin tuna, and albacore [Perciformes: Scombrinae] in the Atlantic, Indian, and eastern Pacific Oceans

59%
Zhu G., Xu L., Zhou Y., Dai X.
Acta Ichthyologica et Piscatoria
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2008
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tom 38
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nr 2
157-161
Background. Bigeye tuna, Thunnus obesus (Lowe, 1839); yellowfin tuna, Thunnus albacares (Bonnaterre, 1788); and albacore, Thunnus alalunga (Bonnaterre, 1788), are very important species for world fisheries. It is crucial to the future existence of those economically important species that the best possible biological data on the species is provided to fisheries managers. Materials and Methods. The weight–length relations (WLRs) for bigeye tuna, yellowfin tuna, and albacore, collected in the Atlantic, Indian, and eastern Pacific oceans were studied using commonly accepted methodology. Results. Significant differences can be found from the fork length distributions and the WLRs of the above 3 tuna species and the relations of gilled-gutted and whole weight of bigeye and yellowfin tunas collected from the Atlantic, Indian, and Eastern Pacific Oceans. Significant differences of fork length distributions can be found for bigeye tuna, yellowfin tuna, and albacore from the three areas. The growth exponents (b) of bigeye tuna, yellowfin tuna, and albacore collected from the Atlantic, Indian, and eastern Pacific oceans register significant deviations from isometric value of 3. Conclusion. The date collected will be useful for the fisheries management of the three species studied.
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