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Amerikaanse onderzoekers, waaronder mark Lilies, verbonden aan de Auburn University in Alabama, hebben onderzoek gedaan naar de sterfte onder de meervallen (de Channel Catfish, Ictalurus) in de nog jonge meervalkwekerijen in het zuidoosten van de USA. Het gaat om een nieuwe stam van de Aeromonas hydrophila.

Het kweken van meervallen als tweede tak. De vroegere Noordzeevis en runt daarnaast een melkveehouderijbedrijfser Wouter Sterk promoot deze kweekvis en runt daarnaast een melkveehouderijbedrijf

Utah Conservation Data Center Species fact sheet and distribution map on the black bullhead, Ameiurus melas.

Utah Conservation Data Center Species fact sheet and distribution map on the channel catfish, Ictalurus punctatus.

Utah Conservation Data Center Species fact sheet and distribution map on the channel catfish, Ictalurus punctatus.

Utah Conservation Data Center Species fact sheet and distribution map on the black bullhead, Ameiurus melas.

Een voordracht over de volgende roofvissen: snoek, snoekbaars, meerval, rivierbaars, paling

Op basis van representatieve gegevens, afkomstig van 6 fulltime meervalkwekers, is een kwaliteitskostenanalyse gemaakt voor de intensieve meervalteelt in Nederland.

Beweringen over de vraatzucht van de meerval en de toename van het aantal in Nederland worden van kanttekeningen voorzien en zonodig naar fabeltjesland verwezen

The absence of adequate techniques for rearing fish larvae constitutes a bottleneck for sustainable aquacultural growth. Important constraints are the tiny size of the larvae, the dependance on live food organisms and the developmental stage of the fish larvae. The development of dependable rearing techniques requires knowledge of the critical aspects in nutrition in relation to the development of the digestive and metabolic system. In the present study, this relation between fish nutrition and development was investigated using the African catfish Clarias gariepinus (Burchell) as research model. The study was subdivided into three phases, dealing respectively with husbandry conditions, developmental aspects and with the lipid metabolism. During the first phase, in a comparative study with different dry diets, the dependance of African catfish larvae on live food organisms (e.g., Artemia ) was demonstrated. A technique to estimate quantitative food rations was developed and used to elucidate the quantitative relations between food ration, water temperature and growth. African catfish larvae can be successfully weaned to a dry diet without growth loss provided that they receive live food organisms during the first four days of exogenous feeding. Durint the second phase of the project, the morpho-functional development of the digestive system and the activities of metabolic enzymes were investigated. The results indicated that at the onset of exogenous feeding, African catfish larvae can eat, digest, absorb and metabolize the absorbed nutrients. The changes in feeding habits were correlated with the development of stomach functions. Together with this functional development of the stomach, several other ontogenetic changes in the larval physiology occurr. This combined change of ontogenetic events occurs at a body size of approximately 10-20mg. Therefore this size is suggested as a marker for the end of the larval period in C. gariepinus . The different studies on the

Report on a catfish microhatchery in Ho Chi Minh City (Vietnam). This small-scale family business produces 70 million hybrid catfish hatchlings per year using a minimum of resources

Fish husbandry can contribute substantially to the production of animal protein for human nutrition, especially in tropical countries. To determine the suitability of C. lazera for aquaculture, the propagation and production ,management as well as the growth physiology of this fish were studied.The planned production of Clarias fingerlings can be realized through artificial reproduction, including hypophysation followed by stripping of the females and dissection of the testes of the males to fertilize the eggs. Methods for successful incubation of the eggs and subsequent rearing of the fry to fingerlings are reported.In growing the fingerlings to marketable size good results were obtained both in extensive pond-farming as well as in high density culture in tanks. Under conditions that prevail in African subsistence fish farming. the Clarias outyield tilapia by more than 250%. Under optimal conditions in tanks they grow more than 200 g in 5 months from birth, while the feed conversion rate (feed/ gain) stays well below unity. The efficient feed conversion is explained by modest maintenance requirements as compared with the maximum feed uptake and feed utilization capacity. The effects of body weight, temperature and feeding level on the growth and feed utilization of C. lazera were studied and discussed. On this basis a feeding guide for the intensive culture of the African catfish was established.

In the early '70 it was tried to identify new fish species for aquaculture in Africa. Amongst the most promising candidates was the African catfish. Clariasgariepinus (Burchell 1822). It is an omnivorous fish. which means a wide feeding spectrum. The fish is a partial air breather, so the oxygen concentration in the water is no strongly limiting factor, which facilitates high density culture.To provide the basis for a production programme of any species the various phases of its culture process must be elaborated. First of all methods for reproduction have to be established to ensure a reliable supply of fingerlings. Secondly raising of fingerlings to fish of marketable size is a field of major importance.An important question in fattening of fish is what to feed how much. The amount and the composition of the fish diet have a pronounced effect on growth rate and feed conversion. The conversion process of feed nutrients into fish biomass is influenced by a number of biotic and a-biotic factors like for instance body weight, maturity, water temperature and water quality. Many experiments are required to perform dose-respond relationships for the amount of feed and the weight gain at different temperatures, different weight classes and various diet compositions. To reduce these efforts developing a growth model may be helpful.In this study an explanatory growth model is developed to gain knowledge about the influence of various factors on the growth process. The quantitative equations of the model describe the processes at the underlying levels of growth, the intermediate metabolism and biochemistry. These equations reflect our understanding and knowledge of the relationship in the real system.To carry out the simulation the state variable approach is used. All rates of change between small time lags are calculated from the conditions of the system at time of start and if necessary from data in the past. The state of the system can be calculated by semi-parallel integ

Gegevens over de eigenschappen van de Afrikaanse meerval (Clarias gariepinus) als consumptievis en over de afzetmogelijkheden die er vermoedelijk zullen zijn voor dit produkt

Two unidentified game wardens inspect canisters of fish guts at the scene where Bryant Baumgartner, fish dealer at Waterville, confronted three game wardens who had come to investigate alleged handling of more bullheads than the law allows and killed all three with successive shots of his 12 gauge automatic shotgun. Baumgartner then shot himself dead. The murdered game wardens are A. Melvin Holt of Worthington, D. M. Brady of Windom and Marcus Whipple of Kasota. See P89870-P89873.