Spidle. 1993. Colonization, ecology, and population structure of the "quagga" mussel (Bivalvia: Dreissenidaej in the lower Great Lakes. Can. ). Fish. Aquat. Sci. 59: 2305-231 4.An invasive dreissenid mussel given the working name of "quagga" has a present (spring 1993) distribution in the Laurentian Great Lakes from the western basin of Lake Erie to Quebec City. In Lake Erie, quaggas were collected as early as 1989 and now are most common in the eastern basin. In Lakes Erie and Ontario, proportions of quaggas increased with depth and decreasing water temperature. In the eastern basin of Lake Erie, quaggas outnumbered zebra mussel (Dreissena pdymoapkaj by 1 4 to 1 in deeper waters (>29 mj. In Lake Ontario, quaggas were observed at depths as great as 130 rn, and both quagga and zebra mussel were found to survive at depths (>50 rn) where temperatures rarely exceed 5°C. Quaggas were sparse or absent along inland waterways and lakes of New York State. Mean shell size of quagga mussel was larger than that of zebra mussel at sites in the Niagara River, Lake Ontario, and the St. Lawrence River. The largest quaggas (38 mm) were observed in the St. Lawrence River at Cape Vincent.&I ne moule envahissante des groupe des dreissenides, appeiee provisoirement (( quagga a occupe 2i B'heure actuel le ( rintemps 4993) les Grands Lacs depuis le bassin de I'ouest du lac Erie jusqu'h la ville de Qukbec. Dans le lac gi e, des,quaggas ont ete preievees des 1989 et eiles sont maintenant trps courantes dans le bassin de I'est. Dans les lacs Erie et Ontario, la prsporfion de quagga a augment6 avec la profondeur et la baisse de la temperature. Dans [e bassin de I'est du lac Erie, les quaggas sont plus nombreuses que les msesles mebr6es (Baeissena polymorphaj, la proportion sP6tablissant 14 pour 4 en eau profonde (> 29 rn), Dans le lac Ontario, des quaggas ont 6t6 observkes A des prsfondeurs atteignant 130 m; les quaggas et les rs~oules z6brees peuvent suwivre 2i des prsfondeurs (> 50 rn) ob la temperature &passe r?rement 5°C. Les quaggas etaient rares s u absentes le long des vsies navigables de I'intkrieur et dans les lacs de I'Etat de New York. La taille rnoyenne de la coquille des quaggas 6tait supkriekare A celle des rnokales zebrkes sur certains sites du Niagara, du lac Ontario, et du fleuve Saint Laurent.Les quaggas les plus grosses (38 mm) ont et6 observkes dans le fleuve Saint-Laurent au niveau de cap Vincent.

Zebra mussels ( Dreissena polymorpha) from throughout the Shannon River drainage area in Ireland were tested for the anthropozoonotic waterborne parasites Cryptosporidium parvum, Giardia lamblia, Encephalitozoon intestinalis, E. hellem, and Enterocytozoon bieneusi, by the multiplexed combined direct immunofluorescent antibody and fluorescent in situ hybridization method, and PCR. Parasite transmission stages were found at 75% of sites, with the highest mean concentration of 16, nine, and eight C. parvum oocysts, G. lamblia cysts, and Encephalitozoon intestinalis spores/mussel, respectively. On average eight Enterocytozoon bieneusi spores/mussel were recovered at any selected site. Approximately 80% of all parasites were viable and thus capable of initiating human infection. The Shannon River is polluted with serious emerging human waterborne pathogens including C. parvum, against which no therapy exists. Zebra mussels can recover and concentrate environmentally derived pathogens and can be used for the sanitary assessment of water quality.

The filarial nematode Dirofilaria repens is currently considered to be one of the most extensively spreading human and animal parasites in Europe. In Ukraine, reporting cases of dirofilariasis has been mandatory since 1975, and the disease was included in the national surveillance system for notifiable diseases. Up until December 31st 2012, a total of 1533 cases have been registered, with 1465 cases occurring within the previous 16 years. Most of the cases of dirofilariasis were registered in 6 regions: Kyiv, and the Donetsk, Zaporizhzhya, Dnipropetrovsk, Kherson and Chernihiv oblasts. In the years 1997-2002 the highest incidence rate was noted in the Kherson oblast in the south of the country (9.79 per 100 000 people), and the lowest in western Ukraine (0.07-1.68 per 100 000 people). D. repens infections were registered in all oblasts. Parasitic lesions were most often located in the head, the subconjunctival tissue and around the eyes. D. repens lesions were also found in the limbs, torso, male sexual organs, and female mammary glands. Dirofilariasis was diagnosed in persons aged from 11 months to 90 years old, most often among people between 21-40 years of age. Most patients had only one parasitic skin lesion; the majority of isolated nematodes were female. The results of our analysis point to a constant increase in D. repens dirofilariasis incidence in humans in Ukraine. Despite educational efforts, infections have become more frequent and the territory in which the disease occurs has enlarged to encompass the whole of Ukraine. Nevertheless, the Ukrainian sanitary-epidemiological services managed to achieve some measure of success, e.g. by creating a registration system for D. repens infections and establishing proper diagnostics for the disease.

Spermiogenesis and the ultrastructural characters of the spermatozoon of Mesocestoides lineatus are described by means of transmission electron microscopy, including cytochemical analysis for glycogen. Materials were obtained from a golden hamster (Mesocricetus auratus) after experimental infection with tetrathyridia metacestodes obtained from naturally infected lizards (Anolis carolinensis) from Louisiana. Spermiogenesis in M. lineatus is characterized by the orthogonal growth of a free flagellum, a flagellar rotation, and a proximodistal fusion. The zone of differentiation contains 2 centrioles associated with striated rootlets and a reduced intercentriolar body. The mature spermatozoon of M. lineatus lacks a mitochondrion, and it is characterized by the presence of (1) a single, spiraled, crested body 150 nm thick; (2) a single axoneme of the 9+'1' pattern of trepaxonematan Platyhelminthes; (3) a parallel and reduced row of submembranous cortical microtubules; (4) a spiraled cordon of glycogen granules; and (5) a spiraled nucleus encircling the axoneme.

The capacity of synanthropic flies belonging to the families Calliphoridae, Sarcophagidae, and Muscidae to serve as mechanical vectors of Cryptosporidium and Giardia among livestock and wildlife in a multispecies agricultural complex in northwest Georgia (USA) was studied using fluorescent in situ hybridization (FISH) and immunofluorescent antibody (IFA) techniques. Flies from all three families were carrying viable Cryptosporidium oocysts and Giardia cysts internally and externally, and deposited them on trap surfaces. Furthermore, the contaminated flies and trap surfaces occurred in association with each of the four domestic animal units (beef, dairy, equine, and sheep), and in wildlife areas dominated by deer (Odocoileus virginianus) and Canada Geese (Branta canadensis). Cryptosporidium was isolated from 55.56% of the fly samples, whereas Giardia was isolated from only 7.94%. The highest numbers of Cryptosporidium were associated with cattle and wildlife areas, while Giardia occurred in greatest numbers in the sheep area. Cryptosporidium was isolated comparably from exoskeletal elutants and fly homogenates, but Giardia was isolated primarily from homogenates, indicating primarily internal transport in the latter. Surfaces visited by the flies (i.e., traps) became contaminated by both Cryptosporidium (18.89%) and Giardia (1.11%). In conclusion, these flies can serve as mechanical vectors of both Cryptosporidium and Giardia in all of these settings, and undoubtedly play a role in movement of these pathogens among the various host species.