This work describes the ecological characteristics of the intestinal helminth communities of 50 wolves (Canis lupus L.) from Spain. The species found were classified into three groups according to prevalence, intensity and intestinal distribution. Taenia hydatigena Pallas, 1766 and Uncinaria stenocephala (Railliet, 1884) are the core species of the community. Taenia multiceps (Leske, 1780) is a secondary species. The rest of the species, Alaria alata (Goeze, 1782), Taenia serialis (Gervais, 1847), Taenia pisiformis (Bloch, 1780), Dipylidium caninum (Linnaeus, 1758), Mesocestoides sp. aff. litteratus, Toxocara canis (Werner, 1782), Toxascaris leonina (von Linstow, 1902), Ancylostoma caninum (Ercolani, 1859) and Trichuris vulpis (Froelich, 1789), behave as satellite species. The linear intestinal distribution of all helminth species was analysed. The location of most species can be considered predictable, especially for core and secondary species. The analysis of interspecific relationships between infracommunities shows that negative associations are more numerous than positive associations. The role of A. caninum in the community is compared with that of U. stenocephala.
Andrya cuniculi (Blanchard, 1891) (Cestoda: Anoplocephalidae) is redescribed from Oryctolagus cuniculus (L.) from Spain. Large ranges of variability in body length and width, testes number and position of the cirrus sac were observed. An external seminal vesicle covered with small glandular cells is present. The pattern of development of the uterus is similar to that of Andrya rhopalocephala (Riehm, 1881). The only reliable differential characters to distinguish A. cuniculi from A. rhopalocephala are the position of the uterus in gravid segments and the position of the testes in mature segments. The uterus of A. cuniculi occupies the median field and parts of the lateral fields but is restricted to the median field in A. rhopalocephala. Testes are distributed more symmetrically lateral to the female organs in A. cuniculi but are mostly antiporal in A. rhopalocephala.
Eucoleus schvalovoj Kontrimavichus, 1963 (Nematoda: Capillariidae) is redescribed. The original description of this species was brief and inadequate in thal it was based on just a few specimens removed from the Eurasian otter, Lutra lutra (Linnaeus, 1758) in the Khabarovsk region, USSR. Detailed morphological study of several specimens of E. schvalovoj from the oesophagus of L. lutra from Spain revealed new characters, above all in males, and allows for a better characterisation of this species. Since its original description £. schvalovoj has only been recorded in Spain.
Spermatological characters of the liver fluke Mediogonimus jourdanei Mas-Coma et Rocamora, 1978 were studied by means of transmission and scanning electron microscopy. Spermiogenesis begins with the formation of the differentiation zone containing two centrioles associated with striated rootlets and an intercentriolar body. These two centrioles originate two free flagella that undergo a 90° rotation before fusing with the median cytoplasmic process. Both nuclear and mitochondrial migrations toward the median cytoplasmic process occur before the proximodistal fusion of flagella. Finally, the constriction of the ring of arched membranes gives rise to the young spermatozoon. The mature sperm of M. jourdanei measures about 260 µm and presents two axonemes of different lengths with the typical pattern of the Trepaxonemata, two bundles of parallel cortical microtubules, one mitochondrion, a nucleus and granules of glycogen. An analysis of all the microphalloidean species studied to date emphasised some differences in certain characters found in Maritrema linguilla Jägerskiöld, 1908 and Ganeo tigrinum Mehra et Negi, 1928 in comparison to those in the remaining microphalloideans. The presence and variability of such ultrastructural characters according to family, superfamily or order have led several authors to propose their use in the analysis of trematode relationships and phylogeny. Therefore, apart from producing new data on the family Prosthogonimidae, the present study also compares the spermatological organization of M. jourdanei with other available ultrastructural studies focusing on the Microphalloidea.