Blue whales are little studied, face significant anthropogenic threats and within the Northern Indian Ocean, have a restricted range, making them an archetype for conservation needs of megafauna around the world. We studied feeding behavior of blue whales using dietary DNA metabarcoding of fecal samples. While globally blue whale populations feed predominantly on Euphausiidae, 87% of prey DNA a...

Phenotypic variation is common among conspecifics from the same population, but its causes are not always clear. Parasites may often play a role, as their ability to induce phenotypic changes in their hosts is well established, though not widely acknowledged among marine ecologists. Here, we tested for a possible role of parasites as determinants of marked colour polymorphism, as well as variat...

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 defi...

The faunas of parasitic helminths and arthropods of 87 Sherman's fox squirrels (Sciurus niger shermani) and 32 Big Cypress fox squirrels (Sciurus niger avicennia) collected from Florida (USA) over a 6-yr period (1988 to 1993) were compared. One acanthocephalan, one cestode, nine nematodes, one flea, three sucking lice, three mites, one tick, and one dipteran larva were identified. Citellinema b...

Geographic variations in the diversity and prevalence of helminth parasites of fish can provide important clues as to the relatedness of fish populations. In the present work, the stomachs of 64 conger eels, Conger conger, collected during 1999 and 2000, were examined for the presence of parasites. Four fish were infected with L3 stages of the nematode Anisakis simplex s.l. (Anisakidae), 1 with...

This study refers to the helminth fauna of the Spotted Nothura, Nothura maculosa (Temminck, 1815), on the basis of samples deposited in the Helminthological Collection of the Oswaldo Cruz Institute, and also on bibliographical data. The helminth survey of N. maculosa is represented by the digenetic trematode Brachylaemus (Centrodes) centrodes (Braun, 1901) Travassos & Kohn, 1964, by two cestode...

The metazoan parasite fauna of Hippoglossina macrops (n = 123) from northern Chile (30 degrees S) is quantitatively described for the first time, and the role of host age and sex was evaluated. Twelve parasite species were recovered, including 5 ectoparasites (2 Monogenea, 2 Copepoda and 1 Piscicolidae) and 7 endoparasites (1 Digenea, 3 Cestoda, 2 Acanthocephala, and 1 Nematoda). The copepod Ho...

In theory there should be a strong coupling between host and parasite population sizes. Here, we investigated population size and structure in 3 species of acanthocephalans, Corynosoma semerne, C. strumosum and C. magdaleni, in ringed seals (Phoca hispida) from the Bothnian Bay over a period of more than 20 years. During this period, seal numbers first decreased markedly and then increased stea...

Amphibians of 24 species were surveyed for acanthocephalans in 4 nature reserves in 2 Chinese provinces during 2004–2006. Pseudoacanthocephalus bufonis (Echinorhynchida) occurred in both nature reserves in Guangxi Province. In the Jing Xi County Provincial Nature Reserve, P. bufonis infected 36 of 62 amphibians at a mean intensity of 9.9. Less than 250 km away, at Shiwandashan National Nature R...

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 varia...