Ultrastructure of spermiogenesis and the spermatozoon in cyclophyllidean cestodes

Podeu consultar el llibre complet a: http://hdl.handle.net/2445/67430The usefulness of the ultrastructural characters of spermiogenesis and of the spermatozoon in the interpretation of relationships in the Platyhelminthes has been widely demonstrated. The present paper provides a review and an update on the ultrastructural knowledge on spermiogenesis and on the spermatozoon in cyclophyllidean cestodes. For each family of cyclophyllideans the pattern of spermiogenesis and the type of sperm cell is provided. Moreover, the most interesting characteristics of both spermiogenesis and the spermatozoon are compiled and illustrated for each family. Finally, new spermatological data on some species of the Anoplocephalidae and the Taeniidae are provided

Heavy metal accumulation by intestinal helminths of vertebrates

Podeu consultar el llibre complet a: http://hdl.handle.net/2445/32393The relevancy of parasites as potential indicators of environmental quality has been increasing over the last years, mostly due to the variety of ways in which they respond to anthropogenic pollution. The use of fish parasites as bioindicators of heavy metal pollution in aquatic ecosystems has been widely studied. However, little information concerning terrestrial habitats is presently available. In fact, in the last two decades several studies have been performed worldwide in different habitats and/or conditions (theoretically both in polluted and unpolluted terrestrial ecosystems, but mainly in aquatic ecosystems) in order to investigate heavy metal pollution using parasitological models. Different groups of vertebrates (mainly fish, mammals and birds) and several parasitological models have been tested involving acanthocephalans mostly, but also cestodes and nematodes. It is not the aim of this chapter to do a complete revision of the available data concerning this subject. Instead, we emphasize some general aspects and compile a mini-review of the work performed in this field by our research group. The results obtained until now allow confirming several parasitic models as promising bioindicator systems to evaluate environmental cadmium and mainly lead pollution in terrestrial non-urban habitats, as it was already demonstrated for aquatic ecosystems. The present knowledge also allows confirming that parasites can reveal environmental impact. Environmental parasitology is an interdisciplinary field, which needs simultaneous expertise from toxicology, environmental chemistry and parasitology. Furthermore, environmental parasitology should be taken into account in order to increase the efficiency of environmental monitoring programs

Sobre las helmintofaunas de las especies de insectívoros y roedores del delta del Ebro (NE de la Península Ibérica)

[spa] No cabe duda que ha sido sobretodo la peculiaridad de los biotopos deltaicos lo que ha propiciado el interés por el estudio de los helmintos parásitos de ciertos hospedadores del Delta del Ebro. Cabe advertir, por tanto, que la mayoría de los resultados que el presente estudio ha proporcionado parecerán lógicos tan sólo al considerar el entorno deltaico como un ecosistema especial en el marco de la Península Ibérica, en particular, y Región Paleártica, en general. La problemática ecológica que encierran los ecosistemas con condicionantes ecológicos especiales ha empezado a ser estudiada en Europa en los últimos años. Evidentemente, dados los fines muy concretos de la Memoria y la localización puntual del Delta del Ebro en Europa, sólo abordaremos aquellos aspectos de los ecosistemas especiales que puedan ayudarnos con posterioridad a comprender nuestros resultados o que definan todas aquellas particularidades que los referidos ecosistemas presentan

Sobre las helmintofaunas de la especies de los géneros Rattus Fischer, 1803 (rodentia : muridae) y Arvícola lacepede, 1799 (rodentia : arvicolidae) en el Delta del Ebro

Tesi de Llicenciatura per a la obtenció del Grau de Farmàcia. Facultat de Farmàcia. Universitat de Barcelona. Director: Carlos Feliu José . 1983

First spermatological data on the digenean genus Ityogonimus derived from the description of sperm characters of Ityogonimus ocreatus (Brachylaimidae: Ityogoniminae)

The present study describes the ultrastructural organization of the spermatozoa of the brachylaimid digenean Ityogonimus ocreatus (Ityogoniminae) by means of transmission electron microscopy (TEM). Live digeneans were collected from the digestive tract of an Iberian mole Talpa occidentalis (Eulipotyphla, Talpidae) captured accidentally during a vole pest control campaign in Priesca (Asturias, Spain). The TEM study reveals that the I. ocreatus sperm are filiform, tapered at both extremities, and have two 9+'1' trepaxonematan axonemes, external ornamentation of the plasma membrane associated with cortical microtubules, spine-like bodies, two bundles of parallel cortical microtubules and one mitochondrion overlapping the anterior part of the nucleus. The external ornamentation of the plasma membrane is located in the posterior part of the anterior region. The maximum number of parallel cortical microtubules (45) is located in the anterior part of the sperm cells. Our results are compared with the available data on the family Brachylaimidae, especially on the other Ityogoniminae studied to date (Scaphiostomum palaearcticum

Sperm characters of the digenean Prosorhynchus aculeatus Odhner, 1905 (Bucephalidae), a parasite of the marine fish Conger conger (Linnaeus, 1758) (Congridae)

Within the Digenea, the family Bucephalidae includes numerous species parasitizing mainly marine and freshwater fishes. This family includes five recognized subfamilies, and ultrastructural data on their sperm cells are very scarce. The existing data are restricted to the subfamily Bucephalinae. Thus, the present study is the first complete analysis of the sperm cell of a bucephalid belonging to the subfamily Prosorhynchinae. Herein, we describe the ultrastructure of the mature spermatozoon of Prosorhynchus aculeatus, a parasite of the conger eel Conger conger, assessed by means of transmission electron microscopy (TEM). The spermatozoon of P. aculeatus is a filiform cell that presents two axonemes of the 9?'1' pattern of trepaxonematan Platyhelminthes, parallel cortical microtubules, mitochondrion, nucleus, external ornamentation of the plasma membrane, spine-like bodies and a large amount of glycogen granules. According to the anterior location of the external ornamentation of the plasma membrane, P. aculeatus presents a Quilichini et al.'s type 1 spermatozoon. With respect to the posterior extremity, the sperm cell of P. aculeatus corresponds to the Quilichini et al.'s cryptogonimidean type. Our results are compared with those of the two previously studied bucephalids (Bucephalinae), Prosorhynchoides gracilescens and Pseudorhipidocotyle elopichthys

The importance of the age when evaluating mercury pollution in fishes: the case of Diplodus sargus (Pisces, Sparidae) in the NW Mediterranean

The aim of this study was to analyse the concentration of mercury (Hg) in the muscle of a common littoral, omnivorous fish such as the white seabream, Diplodus sargus, and to evaluate its relationship with the age and size of the specimens. Large, older predatory fishes have typically been the main target species for risk assessment of Hg intake in humans. The white seabream is neither a big fish nor a predator, but all sizes of NW Mediterranean specimens of this species showed high levels of Hg, with clear increases in older specimens. In addition, although the Se:Hg molar ratio was high and could reduce the impact of high concentrations of Hg in smaller fishes, it could not in the older specimens of D. sargus analysed because it decreased with age. This is not a major concern for human health because the white seabream is not a widely consumed species. However, in special situations involving toddlers, children and women of childbearing age, problems might arise if the white seabream or similar species are consumed in place of those that current recommendations advise against eating. In these cases it is very important to consider the species of fish consumed in each country and carefully assess the risk of Hg intak

Ultrastructure of the spermatozoon of Macvicaria obovata (Digenea, Opecoelidae), a parasite of Sparus aurata (Pisces, Teleostei) from the Gulf of Gabès, Mediterranean Sea

The ultrastructural organization of the spermatozoon of the digenean Macvicaria obovata (Opecoelidae) is described by transmission electron microscopy. Alive digeneans were collected from the digestive tract of Sparus aurata (Teleostei, Sparidae), caught from the Gulf of Gabès in Chebba, Tunisia (Eastern Mediterranean Sea). The male gamete of M. obovata is a filiform cell, tapered at both extremities and exhibits typical characters such as two axonemes of different lengths showing the 9+'1' trepaxonematan pattern, a nucleus, mitochondria, two bundles of parallel cortical microtubules, external ornamentation of the plasma membrane, spine-like bodies and granules of glycogen. Cortical microtubules are absent in the anterior spermatozoon extremity and appear after the disappearance of the electron-dense material. The first mitochondrion is of moniliform type and it is associated with the external ornamentation of the plasma membrane and spine-like bodies. The second mitochondrion is more posteriorly located, reaching the nuclear region. The present study provides new data on the mature male gamete of M. obovata that may be useful for the understanding of digenean relationships and phylogenetic studies

First finding of Ityogonimus lorum and I. ocreatus co-infection in the Iberian mole, Talpa occidentalis

The Ityogonimus lorum-I. ocreatus co-infection is reported for the first time in the Iberian mole Talpa occidentalis in Asturias (NW Spain). Both Ityogonimus species are stenoxenous helminths of insectivores of the genus Talpa and they have often been found parasitizing the Iberian mole and also the European mole T. europaea, but a mixed infection had not been previously reported. The present study also highlights the main differential morphometric characteristics between I. lorum and I. ocreatus such as the body length, the ventral sucker diameter, the ratio between suckers and the distance between suckers