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Johan A.J. Verreth

Bio: Johan A.J. Verreth is an academic researcher from Wageningen University and Research Centre. The author has contributed to research in topics: Clarias gariepinus & Catfish. The author has an hindex of 51, co-authored 251 publications receiving 8768 citations.


Papers
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Journal ArticleDOI
TL;DR: This review aims to summarize the most recent developments within RAS that have contributed to the environmental sustainability of the European aquaculture sector and identifies the key research priorities that will contribute to the future reduction of the ecological impact of RAS.

699 citations

Journal ArticleDOI
TL;DR: This study confirms the contribution of IEL (mainly T-like cells) and basophils in the enteritis process and shows a clear involvement of up- and down-regulated cytokine genes in both the onset and recovery of the SBM-induced enteritis in the hindgut of carp.

288 citations

Journal ArticleDOI
TL;DR: Analyzing nutrient conversions, which are taking place in integrated intensive aquaculture systems, finds that fish culture alone retains 20–50% feed nitrogen and 15–65% feed phosphorous and the combination of fish culture with phototrophic conversion increases nutrient retention of feed N and feed P by up to 53%.

259 citations

Journal ArticleDOI
TL;DR: In this article, the main mechanisms and parameters affecting the design and performance of trickling filters in aquaculture are discussed, including the relationship between nitrification rates and easily accessible process parameters, like bulk phase concentration of TAN, O2, organic matter (COD), nitrite, temperature, HCO3−, pH and hydraulic loading of the trickling filter.

220 citations

Journal ArticleDOI
TL;DR: It is found that eels swim 4–6 times more efficiently than non-eel-like fish, removing a central objection to Schmidt's theory by showing that their energy reserves are, in principle, sufficient for the migration.
Abstract: One of the mysteries of the animal kingdom is the long-distance migration (5000-6000 km) of the European eel Anguilla anguilla L. from the coasts of Europe to its spawning grounds in the Sargasso Sea. The only evidence for the location of the spawning site of the European eel in the Sargasso Sea is the discovery by Johannes Schmidt at the beginning of the previous century of the smallest eel larvae (leptocephali) near the Sargasso Sea. For years it has been questioned whether the fasting eels have sufficient energy reserves to cover this enormous distance. We have tested Schmidt's theory by placing eels in swim tunnels in the laboratory and allowing them to make a simulated migration of 5500 km. We find that eels swim 4-6 times more efficiently than non-eel-like fish. Our findings are an important advance in this field because they remove a central objection to Schmidt's theory by showing that their energy reserves are, in principle, sufficient for the migration. Conclusive proof of the Sargasso Sea theory is likely to come from satellite tracking technology.

208 citations


Cited by
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Journal ArticleDOI

7,335 citations

Journal Article
TL;DR: In this article, the authors present a document, redatto, voted and pubblicato by the Ipcc -Comitato intergovernativo sui cambiamenti climatici - illustra la sintesi delle ricerche svolte su questo tema rilevante.
Abstract: Cause, conseguenze e strategie di mitigazione Proponiamo il primo di una serie di articoli in cui affronteremo l’attuale problema dei mutamenti climatici. Presentiamo il documento redatto, votato e pubblicato dall’Ipcc - Comitato intergovernativo sui cambiamenti climatici - che illustra la sintesi delle ricerche svolte su questo tema rilevante.

4,187 citations

Journal ArticleDOI
TL;DR: This document reviews various plant feedstuis, which currently are or potentially may be incorporated into aquafeeds to support the sustainable production of various ¢sh species in aquaculture and strategies and techniques to optimize the nutritional composition and limit potentially adverse eiects of bioactive compounds are described.
Abstract: Continued growth and intensi¢cation of aquaculture production depends upon the development of sustainable protein sources to replace ¢sh meal in aquafeeds. This document reviews various plant feedstuis, which currently are or potentially may be incorporated into aquafeeds to support the sustainable production of various ¢sh species in aquaculture. The plant feedstuis considered include oilseeds, legumes and cereal grains, which traditionally have been used as protein or energy concentrates as well as novel products developed through various processing technologies. The nutritional composition of these various feedstuis are considered along with the presence of any bioactive compounds that may positively or negatively aiect the target organism. Lipid composition of these feedstuis is not speci¢cally considered although it is recognized that incorporating lipid supplements in aquafeeds to achieve proper fatty acid pro¢les to meet the metabolic requirements of ¢sh and maximize human health bene¢ts are important aspects. Speci¢c strategies and techniques to optimize the nutritional composition of plant feedstuis and limit potentially adverse eiects of bioactive compounds are also described. Such information will provide a foundation for developing strategic research plans for increasing the use of plant feedstuis in aquaculture to reduce dependence of animal feedstuis and thereby enhance the sustainability of aquaculture.

1,910 citations

Book
29 May 2006
TL;DR: Reynolds as discussed by the authors provides basic information on composition, morphology and physiology of the main phyletic groups represented in marine and freshwater systems and reviews recent advances in community ecology, developing an appreciation of assembly processes, co-existence and competition, disturbance and diversity.
Abstract: Communities of microscopic plant life, or phytoplankton, dominate the Earth's aquatic ecosystems. This important new book by Colin Reynolds covers the adaptations, physiology and population dynamics of phytoplankton communities in lakes and rivers and oceans. It provides basic information on composition, morphology and physiology of the main phyletic groups represented in marine and freshwater systems and in addition reviews recent advances in community ecology, developing an appreciation of assembly processes, co-existence and competition, disturbance and diversity. Although focussed on one group of organisms, the book develops many concepts relevant to ecology in the broadest sense, and as such will appeal to graduate students and researchers in ecology, limnology and oceanography.

1,856 citations

Journal ArticleDOI
TL;DR: Meta-analysis is used to ask whether different types of behaviours were more repeatable than others, and if repeatability estimates depended on taxa, sex, age, field versus laboratory, the number of measures and the interval between measures.

1,671 citations