Helminths and helminth communities of Carassius gibelio (Bloch, 1782) from the Panicheri Reservoir, Aegean Water Basin, Bulgaria

Ecologoparasitological research was done based on the helminths and helminth communities of the Prussian carp (Carassius gibelio (Bloch, 1782)) from the freshwater ecosystem of the Panicheri Reservoir, Aegean Water Basin, Bulgaria. As a result of the examined nine specimens of the Prussian carp, two species of helminths were found: Ligula intestinalis (Linnaeus, 1758), larvae and Pomphorhynchus laevis (Müller, 1776). The dominant structure of the helminth communities was determined. The Panicheri Reservoir is a new habitat in Bulgaria of P. laevis and L. intestinalis from C. gibelio. C. gibelio is a new host record for L. intestinalis in Bulgaria. The two helminth species are core species for the helminth communities of the examined species of the freshwater fish. P. laevis was distinguished with higher prevalence and mean intensity (P%=33.34; MI=1.34) than L. intestinalis (P%=22.23; MI=1.0). The circulatory pathways of the helminth flow were traced.

Changes in land use affect anuran helminths in the South Brazilian grasslands

Degradation and habitat loss of natural grasslands in Southern Brazil has a negative impact on native organisms, potentially including the composition of anuran helminth communities. Here, we characterized the richness, abundance, taxonomic composition, prevalence and intensity of helminth infection in four anuran species. Host anurans were collected in 34 ponds (19 in native grasslands with livestock and 15 in agricultural cultivation) from the highland grasslands in the Brazilian states of Santa Catarina and Paraná. Our results showed a significant difference between native grasslands with livestock and agricultural cultivation regarding the structure of helminth communities for the hosts Aplastodiscus perviridis and Pseudis cardosoi. We also found a greater prevalence and intensity of infection in anurans in areas of agricultural cultivation than in native grasslands with livestock. We found that the environmental descriptors (local and landscape) seem to explain most of the differences in anuran parasitism recorded between native grasslands with livestock and agricultural areas. Thus, we emphasized that the loss of grassy habitat due to conversion to agricultural cultivation can alter helminth communities in anurans, with further work needed to understand the mechanisms involved.

Gastrointestinal helminth fauna and helminth communities of bleak (Alburnus alburnus, L. 1758) from lower section of Danube River

The present study presents the results from examinations of bleak’s endohelminth species and structure of helminth communities from the Bulgarian part of the Lower Danube River. In 2015 and 2016, on a seasonal manner, 91 specimens of Alburnus alburnus (Linnaeus, 1758) (bleak) were examined with standard techniques for parasites. Five species of parasites: Nicolla skrjabini (Ivanitzky, 1928), Ligula intestinalis (Linnaeus, 1758), Acanthocephalus lucii (Müller, 1776), Pomphorhynchus laevis (Müller, 1776) and Contracoecum microcephalum (Stossich, 1890), larvae were identified. The analysis of the dominant structure of the found parasite species is presented to the component and infracommunities levels. All parasite species were accidental for the parasitic communities of examined fish with the exception of P. laevis and N. skrjabini. P. laevis was a core parasite species and N. skrjabini was a component parasite species for the helminth communities of bleak. The parasite communities of A. alburnus were discussed and compared with previous research data on parasite communities of bleak from River Danube in Bulgaria. New data for helminths and helminth communities of A. alburnus from Danube River (biotope Vetren) and their seasonal occurrence are presented.

Communities of Helminth Parasites in Sciaenid Fish From the Alvarado Coast, Veracruz, Mexico, Southern Gulf of Mexico

A helminthological examination was performed on 114 specimens of sciaenids that were captured on the Alvarado coast, Veracruz, Mexico, between August 2004 and July 2006. Bairdiella chrysoura (n = 15); Cynoscion arenarius (n = 31); Menticirrhus americanus (n = 16); Menticirrhus littoralis (n = 33) and Umbrina coroides (n = 19). 26 parasites were identified at the species, 12 genus and 5 family levels, as follows: 21 digeneans (14 adults and 7 metacercariae), 9 monogeneans, 7 nematodes (4 adults and 3 larvae), 2 cestodes (larvae), and 4 acanthocephalans (adults). Digeneans and monogeneans were the most abundant. Helminths with the highest prevalence in all five communities were Pseudorhamnocercoides stichospinus and Tetraphyllidae. The species with highest mean intensity were Diplomonorchis leiostomi and Tetraphyllidae, and Hysterothylacium sp., were registered in the five communities. Significant correlations between the host total length and species richness, U. coroides (r = 0.54), and total length and abundance, M. americanus (r = 0.63), were found. The highest similarity was recorded among communities of M. americanus and M. littoralis. The infracommunities and component communities in species richness and diversity, in all cases, were within ranges observed in most marine fish helminth communities.