Investigations on saprolegniosis. II. Study on the process of penetrations showing evidence of a proteolytic enzyme and histopathological aspects [Translation from: Riv.ital.Piscicolt.Ittiopatol. 11(4), 109-117, 1976]

The study of enzymatic activity is of great importance in the immunology of fungi. Indeed, knowledge of biological activity of antigenic structures is important for the elucidation of host-parasite relations as well as in the search for a taxonomic factor permitting differential diagnoses. The authors used Saprolegnia cultures to analyse soluble antigenic fractions arising from the mycelium of cultures of 4 species of Saprolegnia, which are found most frequently in the parasitic state on fish: S. parasitica, S. ferax, S. delica, S. diclina. The authors conclude that in the study of saprolegniasis, the enzymatic approach affords new elements for the examination of the etiology of fungi as well as an element of gravity concerning the biochemical modifications necessary to the change of saprophytism to parasitism.

Coastal States and Distant-water Fishing Nation Relations: An Economist's Perspective

The widespread implementation of Extended Fisheries Jurisdiction (EFJ) has confronted coastal states with several resource management problems. One of these consists of the economic relations, if any, that the coastal state should establish with distant-water fishing nations (DWFN's) seeking access to the coastal state's 200-mile zone. Several of the other papers presented here deal with specific aspects of the issue. This paper, on the other hand, will concern itself with the question of the analytical framework to be used by economists in studying this issue. It will offer some suggestions with respect to possible components of the framework. In doing so, the paper will restrict itself to the coastal state's perspective of EFJ and the management issues arising therefrom. It goes without saying, of course, that an enlightened coastal state will attempt to acquaint itself with the DWFN view of the world.

The four seam trawl nets operated off Cochin: an analysis of the design aspects: the integration of the various parts of trawl

A study has been made of 22 different designs of four seam trawls operated at Cochin for shrimp trawling. Formulae for the relations between the different parts of the nets have been derived.

The potential for further proliferation of water hyacinth in Lakes Victoria, Kyoga and Kwania and some urgent aspects for research

Shore environments of Lakes Victoria and Kyoga with potential for the establishment and proliferation of water hyacinth were identified. They are characterised by: (i) shelter from violent off-shore and along-the-shore wind and wave action (ii) flat or gentle slope under relatively shallow water, and (iii) a muddy bottom rich in organic matter. Such environments are strongly associated with emergent macrophytes of papyrus, Vossia sp and, at times Typha sp where Pistia stratiotes, species of ceratophyllum, myriophylum and nymphaea also occur. In Lake Kyoga association with Vossia sp facilitated establishment of water hyacinth even along wind-swept shores and promoted extension of mats of the two machrophytes into the open lake. Urgent research on water hyacinth is proposed in the areas of nutrient relations, weed biology and on its impact on the biodiversity resource, with particular emphasis on the fishery component. Findings from the research could facilitate formulation of weed control options and alternative resource management strategies. A regional approach to address the water hyacinth menace is highly recommended.