The frequency of muscle protein polymorphism in Menidia menidia (Atherinidae) along the Atlantic coast

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Differenzierung roher und geräucherter Aale durch Protein- und DNA-Analyse

Raw or smoked eel was analysed by isoelectric focusing of sarcoplasmic proteins. For raw fish specific protein patterns were obtained for A. anguilla/A. rostrata, A. japonica and A. australis, but in case of smoked fish differentiation was only possible between Atlantic and Pacific species. Differentiation of raw or smoked eel was possible by PCR-SSCP, but patterns of ssDNA showed some intra-specific variability depending on the type of amplicon.

Improved utilization and increased availability of fishery products as an effective control of aggravated animal protein deficiency - induced malnutrition in Nigeria

The estimated potential of Nigerian fish resources is 1,830,994 tonnes(t) whereas the demand based on per capita consumption of 12.0kg and a population of 88.5 million is 1.085 million tonnes. Supply is presently less than 500,000 tons. The gap between demand and supply have to be met through improved utilization and increased availability of fish and fishery products. The role of fish in nutrition is recognized, since it supplies a good balance of protein, vitamins and minerals and a relatively low caloric content. This paper appraises the consumption and utilisation pattern of fish in Nigeria, the spoilage of fish and prevention of losses as a means of increasing the availability of fish for human consumption and consequent control of aggravated animal protein deficiency - induced malnutrition. The paper further highlights the point that without increased landings, increased supply of fish can be achieved through reduction of postharvest loss of what is presently caught. The use of newly designed smoke - drying equipment to achieve such goal is highlighted. The paper also emphasises the need to put into human food chain those non-conventional fishery resources and by-catch of shrimp and demersal trawl fishes by conversion into high value protein products like fish cakes, fish pies and salted dried cakes

The effects of supplemental feeds containing different protein: Energy ratios on the growth and survival of Tilapia nilotica (Oreochromis niloticus) in brackishwater ponds

A research was conducted in thirty approximately 100 sq.m earthern ponds of the Brackishwater Aquaculture Centre (BAC), College of Fisheries, University of the Philippines, Leganes Iloilo from November 7, 1982 to March 7, 1983 to evaluate the effects of nine supplemental feeds containing different protein: energy ratios on the growth and survival of Tilapia nilotica in brackishwater ponds. Nine supplemental feeds formulated were with protein levels of 20%, 25%, and 30% each at three energy levels of 3,000 kcals; 3,500 kcals; and 4,000 kcals. There was a control treatment with no feeding so that mean weight gain growth rate, feed conversion rate, and survival were determined. Fish fingerlings were acclimated from 0-29 ppt. salinity before the experiment and 20% of fish in each treatment were sampled after every 30 days. Growth rates were significantly different and increased with increasing energy level at the 30% protein feeds but decreased at high energy levels in the 20% and 25% protein feeds. Feed conversion was significantly different due to interaction between protein and energy levels in the feeds, and was better at the 30:3,500 kcals feeds having a feed conversion of 1.55 g. Survival was not significantly different

Protein and amino acid requirements of warm-water fishes: a tool to efficient and low-cost fish feed production in Nigeria

Numerous investigations have utilized various semi-purified and purified diets to estimate the protein and amino acid requirements of several temperate fishes. The vast literature on the protein and amino acid requirements of fishes has continued to omit that of the tropical warm water species. The net effect is that fish feed formulation in Nigeria have relied on the requirement for temperate species. This paper attempts to review the state of knowledge on the protein amino acid requirements of fishes with emphasis on the warm water species, the methods of protein and amino acid requirement determinations and the influence of various factors on nutritional requirement studies. Finally evidence are presented with specific examples on how requirements of warm water fishes are different from the temperate species and used this to justify why fish feed formulation in Nigeria are far from being efficient

Fischartbestimmung von Caviar durch Protein- und DNA-Analyse

Deutscher Caviar, made from roe of lumpfish or capelin, gives species specific patterns in protein electrophoresis. The same techniques can be used to differentiate caviar from salmon and trout. The differentiation of sturgeon caviar (beluga, osietra, sevruga) is possible by isoelectric focusing, but not by SDS-PAGE. PCR-based methods of DNA-analysis for identification of the origin of sturgeon caviar are under development.

Botanical insecticides prescription for fish pest control and infestation free protein yield

The dry powders of four local species namely Piper guineense Schum and Thonn, Aframomum melegueta Schum, Zingiber officinale Rose; Capsicum annum Miller at three concentrations of 15g, 20g and 25g.kg were evaluated for their insecticidal effects against the larval of the dried fish weevil Demestes maculates Degeer. All the four species showed some effectiveness with P. guineense given a 100% mortality at the end of 72 hours at the three concentrations. The other species though gave less mortality were able to slow down the rate of development of the larvae to the adult size

Haematological response of Heterobranchus longifilis fed varying dietary protein levels

Hematological effects of feeding varying dietary crude proteins levels to one hundred and fifty (150) H.longifilis fingerlings was examined on biweekly basis. The fingerlings of mean weights 1.26g plus or minus 0.24g were stocked in eight hapa nets (1mx1m) at 15 fingerlings per hapa. Four experimental diets with crude protein; 35%, 40%, 45% and 50% coded diet 1-4 respectively were fed to the fish for 8 weeks. The blood sample was taken and examined for packed cell volume (PCV) total protein (TP) Hemoglobin (Hb), Serum album, Erythrocyte count (RBC), while blood cell (WBC) mean corpuscle volume (MCV) and mean corpuscle hemoglobin, concentration (MCHC). There was an increase in the values of the hematological indices studied with increase in protein inclusion levels. A higher positive correlation with no significant difference (P greater than or equal to 0.05) exists between the treatments RBC, WBC, Hb and TP. The best RBC (2.10x10 super(6) count/l). WBC (7.65x10 super(4) count/l), PCV (35.4%) and Hb (5.79mg/l) were presented in fingerlings fed 40% crude protein followed by 45% crude protein. The dietary crude protein of 40% is recommended for H. longifilis for sound and healthy condition

Feed conversion, protein efficiency, digestibility and growth performance of Oreochromis niloticus fed Delonix regia seed meal

Oreochromis niloticus fingerlings (mean weight 5.27~c0.29g) were fed raw and boiled Delonix regia seed meals following standard procedures. The weight gain, specific growth rate (SGR), feed conversion ratio (FCR), protein efficiency ratio (PER), net protein utilization (NPU) were determined as growth indices. Diet formulated with seed boiled for 80 minutes showed significantly (P<0.05) high values for the growth indices. Carcass nutrients composition were significantly (P<0.05) higher than in the control (raw) diet. Delonix regia seed meal when boiled has high potential of being utilized efficiently by O.niloticus. The implications of the respective index in fish metabolism are discussed

Differenzierung von Pangasius (Pangasius hypophthalmus) und Asiatischem Rotflossenwels (Hemibagrus wyckioides) durch Protein- und DNA-Analyse

In the last years farmed Pangasius (Tra-Pangasius, Pangasius hypophthalmus) from Vietnam has reached a considerable market share, whereas aquaculture of Asian Redtail Catfish (Hemibagrus wyckioides) is in its infancy. Recently it has been detected by food control authorities in Hamburg, that Pangasius fillets have been mislabelled and sold as fillets produced from Asian Redtail catfish. The necessity to improve the analytical methods for differentiation of Pangasius and Redtail Catfish prompted us to evaluate the suitability of isoelectric focusing (IEF) and DNA-analysis for identification of the two species. IEF of water soluble proteins was found to be a fast, reliable and economical method for differentiation of raw fillets of Pangasius and Redtail Catfish, as long as reference material is available. PCR-based DNA analysis was performed as follows: (i) amplification of a 464 bp segment of the cytochrome b gene; (ii) sequencing of the PCR product; (iii) comparison of the sequence with entries in GenBank using BLAST. The sequences of both species differed considerably, allowing the unequivocal differentiation between P. hypophthalmus and H. wyckioides. Kurzfassung Pangasius (Schlankwels, Tra-Pangasius, Pangasius hypophthalmus) hat sich innerhalb weniger Jahre zu einem bedeutenden Zuchtfisch entwickelt, während die Aquakultur des Asiatischen Rotflossenwelses (Hemibagrus wyckioides) in Vietnam noch in einem relativ kleinen Maßstab stattfindet. Kürzlich wurde von der Lebensmittelüberwachung in Hamburg nachgewiesen, dass im Handel erhältliche Filets mit der Deklaration „Rotflossenwels“ aus Pangasius hergestellt worden waren. Vor diesem Hintergrund wurden zwei Methoden auf ihre Eignung zur Differenzierung von Pangasius und Rotflossenwels geprüft. Es zeigte sich, dass sowohl die isoelektrische Fokussierung (IEF) wasserlöslicher Proteine als auch die PCR-basierte DNA-Analyse zur Unterscheidung beider Arten gut geeignet ist. Die IEF stellt eine schnelle und kostengünstige Untersuchungsmethode dar, die allerdings Referenzmaterial benötigt. Mit Hilfe der PCR (Polymerase-Kettenreaktion) wurde ein Abschnitt des Cytochrom b-Gens vervielfältigt und sequenziert. Die Sequenzen von P. hypophthalmus und H. wyckioides wiesen beträchtliche Unterschiede auf. Es wird diskutiert, wie sich durch Vergleich dieser Sequenzen mit Einträgen in Gendatenbanken unbekannte Proben beider Arten sicher zuordnen lassen.

Identifizierung der Welsart in Filetware durch Protein- und DNA-Analyse

Zusammenfassung Zur Identifizierung der folgenden vier Welsarten bzw. zwei Hybriden (Clarias gariepinus, Pangasius hypophthalmus, Pseudoplatystoma spp., Silurus glanis, Claresse® und Melander®) wurden die isolektrische Fokussierung (IEF) der wasserlöslichen Muskelproteine und die Polymerase-Kettenreaktion (PCR) zur Vervielfältigung und Sequenzierung eines Abschnittes aus dem Cytochrom b – Gen eingesetzt. Die IEF ergab artspezifische Proteinmuster mit hitzestabilen Proteinbanden im anodalen Gelbereich. Der afrikanische Wels (C. gariepinus) und das Hybriderzeugnis Melander® wiesen das gleiche Proteinmuster auf. Mittels DNA-Analyse ließen sich die Welsarten anhand ihrer Cytochrom b Gensequenzen eindeutig identifizieren. Auch hier zeigte der Welshybrid Melander® ein identisches Ergebnis wie der afrikanische Wels. Die Schwierigkeiten der Identifizierung von Tigerwelsen südamerikanischer Herkunft aus der Gattung Pseudoplatystoma werden diskutiert. Abstract Isoelectric focusing (IEF) of water soluble proteins and PCR-based DNA- analysis were used to differentiate between four catfish species (Clarias gariepinus, Pangasius hypophthalmus, Pseudoplatystoma spp., Silurus glanis) and two hybrids Claresse® and Melander®. Specific protein patterns have been obtained for all species and Claresse®, but in case of Melander® the identical pattern was observed as for the African catfish Clarias gariepinus. By sequencing the PCR products and application of BLAST, authenticity of the different catfish samples was confirmed. The cytochrome b gene sequences of Melander® and African catfish were identical. The difficulties of identifying catfishes of the genus Pseudoplatystoma are discussed.