Introduction of alien parasitic nematodes to the wild fish species might result in a severe threat to native species biodiversity including native fish species and native parasitic fauna. In the present study, the invasive Asian nematode, Camallanus cotti (NEMATODA: Camallanidae), has been reported for the first time in Giant Danio (Devario aequipinnatus) in the Cauvery river systems of Southern part of Western Ghats, India. The occurrence of this parasite in both aquarium-cultured fish as well as from the natural aquatic bodies dwelling fish is evident of the introduction of the alien organisms due to insufficient prophylactic measures during the transmission of non-native hosts between countries and also the spread of them by the anthropogenic introduction to natural systems.

During 2000-2002 a study on nematodes of 665 fish specimens from Khouzestan province were carried out by set net and electro fishing. Fishes were collected from 3 stations in Hoor- Al- Azim, Hoor- shadegan and Karoon river.There were Aspius vorax (44 specimens), Barbus grypus (75 specimens), B. luteus (175 specimens), B. sharpeyi (94 specimens), B. pectoralis (8 specimens), B. esocinus (9 specimens), Liza abu (130 specimens), Cyprinion macrostomum (14 specimens), Cyprinus carpio (44 specimens) and Silurus triostegus (22 specimens). From 665 fishes 21% were infected by different parasitic worms collected PARASITES: Rhabdochona denudata, Rh. fortunatowi, Rhabdochona sp., Proleptinae gen. Cucullanus sp., Pseudocapillaria tomentosa, Philometra karunensis, Philometra sp., Anisakis sp.,Contracaecum sp. Rhabdochona fortunatowi is the first report in, B. pectoralis, B. luteus, B. grypus, S. triostegus and Cyprinion macrostomum of Khouzestan province area.

In order to identify plant-parasitic nematodes of eastern forests in Guilan province, soil and root samples were collected and the extracted nematodes were studied based on morphological and morphometric characters.Twenty eight species of plant parasitic nematodes were identified. A population of the genusHoplotylus was recovered and identified as H. femina.The identification was also verified by partial sequencing of the large subunit ribosomal DNA (rDNA). In addition, two populations of the genusMalenchus were also recovered and based on morphological and morphometric characteristics were identified asM. solovjovae and M. acarayensis. The two speciesHoplotylus femina and Malenchus solovjovae are new records for Iran.

In the present study, helminth PARASITES of 78 specimens of two sturgeons namely Acipenser persicus (N= 43) and A. stellatus (N= 35) from the south coast of the Caspian Sea were considered.Four parasite species were found including: Cucullanus sphaerocephalus (NEMATODA), Skrjabinopsolus semiarmatus (Digenea), Leptorhynchoides plagicephalus (Acanthocephala), Eustrongylides excises (Larval NEMATODA). Dominant species in A. persicus and A. stellatus are C. sphaerocephalus and S. semiarmatus, respectively. Shannon diversity index in A. persicus is significantly higher than A. stellatus. There are no significant differences between the prevalences, abundances and mean intensities of PARASITES in the males and females or different age groups. The results revealed that distribution of PARASITES in different microhabitats within gut is not related to intraspecific competitive exclusion.

After studying of the plant parasitic nematodes, collected from different plants and regions of Iran, seven species belong to Paratylenchus, including P. arculatus, P. colinus, P. conicephalus, P. neoprojectus, P. similis, P. straeleni and P. veruculatus were identified. Among them, P. colinus, P. neoprojectus and P. veruculatus are new records for Iranian nematode fauna that full description of them and also that of P. straeleni were given. These species were collected and identified from different hosts and localities as follows: P. colinus from the rhizosphere of apple trees in Divandareh, Kurdistan province, P. neoprojectus from both shade-trees in Tabriz and apricot seedlings in Sanandej, and P. veruculatus from sugarcane fields of Khuzestan province. Furthermore, a dichotomous key for identification of Iranian species of this genus was presented.

The genus Helicotylenchus with about 250 described species is one the largest genera in order Tylenchida or infraorder Tylenchomorpha. In order to identify the species of Helicotylenchus, over 500 soil and root samples collected from rhizosphere of different plants and localities of Iran, during 2009-2010. Soil samples were collected and its nematodes extracted, killed and processed to glycerin. Then the nematodes examined by light microscope, equipped with drawing tube and digital camera. In this study, in addition to 15 species of 26 previously reported species of the genus Helicotylenchus, a number of other known species were isolated and identified. Among the identified species, due to morphological and morphometric similarities, H. indicus, H. insignis, H. falcatus and H. egyptiensis are discussed in two groups. The ventral tail projection in the first three species usually is shorter than two body annuls width, and in H. egyptiensis is as long as two body annuls width or longer. The morphometric characters of the first three species are very similar and for this reason H. insignis and some other species were synonymized with H. indicus by several authors. However the shape of stylet knobs is different among these species. Stylet knobs are sloping backward in H. indicus, but indented forward in H. insignis. H. egyptiensis has a usually pointed tail tip. H. insignis and H. falcatus, as new records for Iranian nematode fauna are described. Also the descriptions of H. indicus and H. egyptiensis which has already been reported form Iran, presented in more details.

In order to study taxonomy of the genus Mesocriconema in Iran, 250 soil and root samples were collected from different field crops, orchards, forests and pastures in Iran, during 2004-2005 years. The nematode specimens were extracted from the soil by using the centrifugal-flotation technique and were processed to glycerin by modified Se inhorst method. The extracted nematodes were mounted in permanent slides. In this study nine species of this genus, M. ornatum, M. curvatum, M. dherdei, M. antipolitanum, M. solivagum, M. sphaerocephalum, M. pseudosolivagum,M. rusticum and M. xenoplax were identified. M. dherdei, M. pseudosolivagum and M. rusticum are new records for Iran. The first two species were isolated from soil samples around the root of ash tree in Garedagh forest (Kaleibar) and the latter species was isolated from soil samples collected from rhizospheres of grass in Saee park (Tehran). A key for identification of species of the genus Mesocriconema in Iran is also provided.

A high number of PARASITES are able to infect fish and some of them can be transmitted to human too. Human or fish-eating mammals can be the main host of these PARASITES. Today, more than 40 species of fish borne PARASITES have been identified causing disease in human. These PARASITES can be classified as protozoa, trematode, cestoda, NEMATODA and acanthocephala. Infection in humans usually occurs following the consumption of the larvae-infected meat. The possibility and the rate of infection has a direct relationship with different criteria including the fish consumption rate, level of hygiene, feeding habits, and methods of cooking or processing. In this article, having discussed the fish-borne PARASITES, the reports of zoonotic PARASITES from fish in Iran have been discussed.

Introduction: Wild birds have important pacts in distribution of PARASITES and other infectious disease.Their study has importance in ecology of PARASITES study. Wild and migratory birds may act as reservoir for zoonotic disease and monitoring of their disease has medically importance.Methods: For study of intestinal PARASITES of birds in Khuzestan province, this study was conducted on 46 dead birds found in the area. Specimens were stained by Carmen dye and were morphologically identified by diagnostic keys.Results: Herons (Egretta spp.) was heavily infected. They had highest prevalence of infection and were host of most variety of PARASITES. In parasitologic point of view Trematoda, mainly Priosoma sp (Family Echinostomidae) was most prevalent parasite. Cestoda like Taufiqia, Laritenia and diorchis were found in 4 and 5 carcasses of 10 cestod-infected birds respectively. Infection to NEMATODA was seen less. In 9 cacesses which was infected with NEMATODA, 2 were infected with Anisakis sp. and in 4 cases immature larva were seen.Conclusion: This study may show table of helminthic PARASITES in wild birds of Khuzestan, in which Herons (Egretta spp.) seems to be more important. This is the first report of Taufiqia iranica which is parasite of necrophagous birds in Himantopus himantopus.

In order to identify the nematodes (order: Tylenchida) in wheat fields, 54 soil, root and ear samples were collected from different localities of Isfahan province. The nematodes were extracted by centrifugal flotation technique. Then they were fixed according to the De grisse method. Investigation of specimens revealed 17 species belonging to 12genera of order Tylenchida. Thegenera Geocenamus, Helicotylenchus and Pratylenchus have been most frequently observed nematodes, respectively.Two species Seinura demani and Tylenchorhynchus teeni are first species records for Iran. Because of importance and lack description, morphological and morphometrical information and drawing for each species with description of Heterodera filipjevi are discussed.