While single factor diet studies appear to be of simple design, the space constraints in aquaculture caused by the need to filter the aqueous media often c reate constraints on the implementation of the experimental design. A number of papers have been published in which the experimental design and subsequent analysis is incorrect. This paper reviews the principles of experimental design as it related to single factor diet evaluation studies in aquaculture. By adhering tosimple design principles to ensure that experimental units are independent, the data generated by future experiments will be of high quality and results more robust.

diet evaluation --- blocked-design --- experimental design --- statistics

The Sundarban forest, located in the southwest of Bangladesh, is one of the largestcontinuous blocks of mangrove forests in the world. This mangrove forest ecosystem in Bangladesh isnow in captious position. Negative natural and anthropogenic impacts and overexploitation of naturalresources have caused severe damage to the ecosystem. Growing human population with fewalternative livelihood opportunities poses a serious threat to the mangrove forest. The rapidlyexpanding shrimp farming industry is a significant threat to the mangrove forests of Bangladesh. Dueto illegal cutting, encroachment of forest areas and illegal poaching of wildlife, the mangrove forest islosing biodiversity in an alarming rate. This forest ecosystem also has become vulnerable to pollution,which may have changed the ecosystem's biogeochemistry. Further threats arise from global climatechange, especially sea level rise. This study seeks to identify the root causes of deterioration of theSundarban mangrove forest in Bangladesh. It also recommends the application of sustainablemanagement strategies covering needs for an advanced silvicultural system, improvement of scientificresearch as well as conservation measures.

Sundarban --- Mangroves --- Bangladesh --- deterioration --- sustainable management

It is the central objective of the Water Framework Directive of the EC to achieve “good status”for all bodies of water, both surface and ground waters, but with the exception of heavily modified andartificial bodies. For the latter ones, the central objective is defined as "good environmental potential". Inessence, environmental goals by 2015 include: 1) for surface water bodies: achieving good ecologicalstatus and good chemical state, or good ecological potential and good chemical status for heavilymodified water and artificial bodies; 2) for underground water bodies: achieving good chemical statusand good quantitative status; 3) protected areas: environmental objectives under specific legislation; 4)keeping the surface water and ground water away of deterioration status. In this context, our studyhighlights aspects of water resource management of the Crasna catchment, sub-catchment of SomeșTisa, to ensure compliance with the contents of the EU Framework Directive 2000/60/EC, in the year2008, and prospects achieving the objectives set, by processing synthetic data created by the SomeșTisa Water Directorate, through monitoring quality and quantity of surface resources. Structuralfunctionalpeculiarities of Crasna on the flow velocity, the nature of substrate, flow and water levelvariations, the influence of the structure and the functioning of plant and animal populations, which inturn determine the physical-chemical properties of water, are analysed. Deteriorating environmentalconditions, especially following acute pollution of aquatic organisms, is producing shocks, which areaffecting parts of or all trophic structures, so the result is a decrease in aquatic ecosystems’ diversity,critical for populational survival.

aquatic ecosystem --- quality status --- ichthyofauna --- evaluation

Benthos is the most important ingredient of natural food of fish in carp ponds. Its chemicalcomposition and profile of fatty acids has not been studied up to now. The aim of this research was todetermine these parameters for the benthic organisms that carp feeds on, which are a source of fattyacids and cholesterol, as well as amino acid composition and fatty acid profile of these organisms.Benthos was sampled from 2 ponds with Ekman-Birge sediment sampler in July and October. Benthosfrom the bottom of drained ponds was also collected after the harvest. The content of basic nutrients wasdetermined in the benthos samples using AOAC procedures. Amino acids and fatty acids profiles werealso determined. It has been found that benthos in carp ponds contains a high amount of protein and it isrich in the essential amino acids. The limiting amino acids in benthic protein are the sulphur amino acids:cystine and methionine as well as tyrosine. The fat content of the benthos is at intermediate level with ahigh content of essential unsaturated fatty acids.

benthos --- carp ponds --- fatty acids --- amino acids

The present paper summarizes the Pricopian theory of sexuality, discussed in the context offishes’ sex determination. On a logical approach and considering the most recent genetic evidencesreported from studies on bacteria, invertebrates, fish, frogs, reptiles, birds, mammals and even humans,one may allready abandon the chromosomal concept of the sex determination (such as the dosage of Zchromosomes). The sex-determining locus is not a true locus, but an agglomeration of loci very seldomseparated by genetic recombination. Moreover, the W chromosome in ZZ-ZW systems and the Y in XXXYsystems are not empty at all, but still carry information

theories --- hypotheses --- sex determination --- sex chromosomes