0000000000588335
AUTHOR
Daniel Benesh
The natural history of Echinorhynchus bothniensis Zdzitowiecki and Valtonen, 1987 (Acanthocephala) in a high Arctic lake
The acanthocephalan Echinorhynchus bothniensis Zdzitowiecki and Valtonen, 1987 differs from most other species in the genus Echinorhynchus Zoega in Müller, 1776 by infecting mysids (order Mysida) instead of amphipods (order Amphipoda) as intermediate hosts. Here we report on the occurrence of E. bothniensis in mysids (Mysis segerstralei Audzijonytė et Väinölä) and in its fish definitive hosts in a high Arctic lake. Out of 15907 sampled mysids, 4.8% were infected with a mean intensity of 1.05 worms (range 1–5), although there was notable variation between samples taken in different years and sites. Larger mysids appear more likely to be infected. Of five fish species sampled, charr,Salvelinu…
Larval life history, transmission strategies, and the evolution of intermediate host exploitation by complex life-cycle parasites
Complex life-cycle parasites use their intermediate hosts both as an energy source and as a vessel for transmission to the next host in the life cycle. Parasites that grow rapidly to a large size may have high fitness (e.g. time spent in uninfective stages is limited), yet those that grow too aggressively may reduce host viability and their own probability of successful transmission. I examined aspects of both the growth and transmission strategy of an acanthocephalan (Acanthocephalus lucii) in its isopod intermediate host. In an experimental infection, the relative rate of larval parasite growth slowed over time, and eventually parasites seemed to reach a threshold biomass sustainable by t…
Sexual segregation of Echinorhynchus borealis von Linstow, 1901 (Acanthocephala) in the gut of burbot (Lota lota Linnaeus)
Helminths often occupy defined niches in the gut of their definitive hosts. In the dioecious acanthocephalans, adult males and females usually have similar gut distributions, but sexual site segregation has been reported in at least some species. We studied the intestinal distribution of the acanthocephalan Echinorhynchus borealis von Linstow, 1901 (syn. of E. cinctulus Porta, 1905) in its definitive host, burbot (Lota lota Linnaeus). Over 80% of female worms were found in the pyloric caeca, whereas the majority of males were in the anterior two-thirds of the intestine. This difference was relatively consistent between individual fish hosts. Worms from different parts of the gut did not dif…
The occurrence of Echinorhynchus salmonis Müller, 1784 in benthic amphipods in the Baltic Sea
Abstract: The acanthocephalan Echinorhynchus salmonis Müller, 1784 is a common parasite of salmonid fish, but it has rarely been reported from an intermediate host. Samples of benthic amphipods, Monoporeia affinis (Lindström), were taken from multiple, deep sites (usually below 70 m) in the Gulf of Bothnia over the course of more than a decade and examined for acanthocephalans. Overall, only 0.44% of 23 296 amphipods were infected, all with just a single worm. This prevalence is consistent with several previous reports of acanthocephalans in deep-water, benthic amphipods, but it appears low compared to that often reported for acanthocephalan species infecting littoral amphipods. Parasite oc…