Philometrid nematodes parasitic in fishes

Species of philometrid nematodes (Philometridae) represent the largest and most important group of Dracunculoidea parasitizing fishes. This diverse group has a world-wide distribution and many species are known as parasites of freshwater, brackish-water and marine fishes, including those of economic importance, in which they attack various organs and body cavities, such as musculature, subcutaneous tissues, mouth tissues, oculo-orbits, fins, gill-covers, swimbladder, body cavity, gill arteries and, in marine fishes, most frequently ovaries. Numerous species are highly pathogenic, often causing serious diseases or even death to their fish hosts. The significance of recognizing these parasites increases with the recent development of aquaculture in many countries and with transcontinental transfers of fish. A prerequisite for developing effective control measures in fish culture is the exact identification of these parasites as well as the knowledge of their complicated host – parasite – environment relationships. To date, the fauna of these parasites is insufficiently known and their species identification is often problematic. Due to a considerable sexual dimorphism, many earlier described species are hitherto known only by their large-sized and often red-coloured females. However, only during the last 15 years, detailed morphological studies of minute males with the use of scanning electron microscopy has shown a considerable species diversity of these parasites, so that the number of species increased for more than 100% since 2006. So far, no monograph dealing specifically with these nematodes has been published, so that everybody interested in this important group of fish parasites is reliant on species descriptions scattered in many, sometimes hardly accessible journals. Therefore, this book is meant to provide basic data on nematodes of the family Philometridae, enabling their species determination based on present knowledge. It provides keys to identifications, diagnoses of higher taxa and descriptions and illustrations of all species. It also gives data on their hosts, localization in the host, distribution and, if existing, on their life cycles and ecology. Altogether 221 species belonging to 18 genera are dealt with in this way. The book includes a few brief general chapters. The host-parasite list is also provided. This book is intended for parasitologists, biologists, veterinarians, workers in fisheries and university students, as well as for ichthyologists, museum curators and those engaged in nature conservation.