Search results for "ACANTHOCEPHALA"

Segregation of three corynosoma spp. (acanthocephala) in paratenic hosts?

1998

Parasite assemblages of crucian carp (Carassius carassius) – is depauperate composition explained by lack of parasite exchange, extreme environmental…

2005

Recent studies on parasite communities have considered the factors which contribute to variability in parasite infections among populations of one host species. This paper examined parasite assemblages of crucian carp (Carassius carassius) in a natural set-up of two distinctive environments inhabited by the same host species and differing in respect to composition of other fish species: ponds, where extreme conditions prevent other fish species from occurring and lakes, where crucian carp coexist with other fish species. Our aim was to evaluate the significance of parasite exchange, environmental conditions and host suitability for the depauperate parasite assemblages observed in pond cruci…

Proximate factors affecting the larval life history of Acanthocephalus lucii (Acanthocephala).

2007

The growth and eventual size of larval helminths in their intermediate hosts presumably has a variety of fitness consequences. Therefore, elucidating the proximate factors affecting parasite development within intermediate hosts should provide insight into the evolution of parasite life histories. An experimental infection that resulted in heavy intensities of an acanthocephalan (Acanthocephalus lucii) in its isopod intermediate host (Asellus aquaticus) permitted the examination of parasite developmental responses to variable levels of resource availability and intraspecific competition. Isopods were infected by exposure to egg-containing fish feces, and larval infrapopulations were monitor…

Variation and covariation in infectivity, virulence and immunodepression in the host-parasite association Gammarus pulex-Pomphorhynchus laevis.

2009

Parasites often manipulate host immunity for their own benefit, either by exacerbating or suppressing the immune response and this may directly affect the expression of parasite virulence. However, genetic variation in immunodepression, which is a prerequisite to its evolution, and the relationship between immunodepression and virulence, have rarely been studied. Here, we investigated the variation among sibships of the acanthocephalan parasite, Pomphorhynchus laevis , in infecting and in immunodepressing its amphipod host, Gammarus pulex . We also assessed the covariation between infectivity, parasite-induced immune depression and host mortality (parasite virulence). We found that infecti…

Intestinal helminth fauna of striped dolphins (Stenella coeruleoalba) in the western Mediterranean: No effects of host body length, age and sex

2014

The intestine of 52 (28 males and 24 females) striped dolphins (Stenella coeruleoalba) from western Mediterranean waters was examined for helminths. Animals were found stranded along the Spanish coasts during the morbillivirus epizootic in 1990. In accordance with observations from other pelagic tetrapods, including cetaceans from other geographical regions, the intestinal helminth community was depauperate. Four helminth species were found: three tetrabothriid cestodes, Tetrabothrius forsteri (prevalence: 96.2%; mean intensity [95% CI]: 47.4 [34.4–68.2]), Trigonocotyle globicephalae (9.6%; 1.8 [1.0–2.2]), and Strobilocephalus triangularis (23.1%; 5.3 [2.9–10.2]), and immature individuals o…

Carotenoid-based colour of acanthocephalan cystacanths plays no role in host manipulation.

2009

Manipulation by parasites is a catchy concept that has been applied to a large range of phenotypic alterations brought about by parasites in their hosts. It has, for instance, been suggested that the carotenoid-based colour of acanthocephalan cystacanths is adaptive through increasing the conspicuousness of infected intermediate hosts and, hence, their vulnerability to appropriate final hosts such as fish predators. We revisited the evidence in favour of adaptive coloration of acanthocephalan parasites in relation to increased trophic transmission using the crustacean amphipodGammarus pulexand two species of acanthocephalans,Pomphorhynchus laevisandPolymorphus minutus. Both species show car…

Parasite-induced alteration of plastic response to predation threat: increased refuge use but lower food intake in Gammarus pulex infected with the a…

2014

6 pages; International audience; Larvae of many trophically-transmitted parasites alter the behaviour of their intermediate host in ways that increase their probability of transmission to the next host in their life cycle. Before reaching a stage that is infective to the next host, parasite larvae may develop through several larval stages in the intermediate host that are not infective to the definitive host. Early predation at these stages results in parasite death, and it has recently been shown that non-infective larvae of some helminths decrease such risk by enhancing the anti-predator defences of the host, including decreased activity and increased sheltering. However, these behavioura…

Parasites in Stranded Cetaceans of Patagonia

2008

There is an increasing interest in parasites of marine mammals of Argentina. Here, we examined several poorly known cetaceans, i.e., 2 spectacled porpoises and 1 Burmeister's porpoise (Phocoenidae), and 1 Gray's beaked whale and 1 Cuvier's beaked whale (Ziphidae); we also updated the parasite information for 1 sperm whale (Physeteridae). These hosts strand only occasionally. We found Anisakis simplex s.l. in 2 spectacled porpoises and the Burmeister's porpoise, and recorded its distribution among the stomach chambers. Anisakis physeteris infected the sperm whale; Corynosoma cetaceum occurred in the duodenal ampulla of the Burmeister's porpoise; Corynosoma australe was found in the posterior…

Is metal accumulation in Pomphorhynchus laevis dependent on parasite sex or infrapopulation size?

2010

SUMMARYConcentrations of the elements As, Cd, Co, Cu, Fe, Mn, Mo, Ni, Pb, Sn, V, Zn were analysed by inductively coupled plasma mass spectrometry (ICP-MS) in the acanthocephalan Pomphorhynchus laevis and its fish host Barbus barbus. A total of 27 barbels were collected from the Danube River in autumn 2006 close to the town Kozloduy (685 river kilometer) on the Bulgarian river bank. Fish were divided into 3 groups. According to their P. laevis infrapopulation size hosts were considered as heavily infected (>100 worms per fish) and lightly infected (<20 worms per fish). The third group was used to compare heavy metal concentrations between male and female P. laevis. The 5 elements As, C…

Breizacanthus aznari sp. n. (Acanthocephala: Arhythmacanthidae) from the banded cusk-eel Raneya brasiliensis (Ophidiiformes: Ophidiidae) from the Pat…

2012

Breizacanthus aznari sp. n. is described from the banded cusk-eel Raneya brasiliensis (Kaup) (Ophidiiformes: Ophidiidae) from the Patagonian coast in Argentina. Breizacanthus Golvan, 1969 is currently composed of five species (including the new species) and is characterised by the absence of trunk spines, a short cylindrical proboscis with two types of hooks and lemnisci longer than the proboscis receptacle. Breizacanthus aznari is clearly distinguished from B. chabaudi Golvan, 1969 by having 12 longitudinal rows of hooks on the proboscis, instead of 16-18. The new species resembles B. golvani Gaevskaya et Shukhgalter, 1984, B. irenae Golvan, 1969, and B. ligur Paggi, Orecchia et Della Seta…