Ergasilus (von Nordmann, 1832) (Ergasilidae) is a species-rich group of parasitic copepods with a wide distribution in freshwater, marine and brackish environments. Up to now, 9 species of Ergasilus are known from cichlid fishes in Africa. In this study, 5 species, including 3 new, were collected from the gills of 12 cichlid species (11 genera: Bathybates, Ctenochromis, Eretmodus, Gnathochromis, Lamprologus, Neolamprologus, Ophthalmotilapia, Perissodus, Simochromis, Spathodus and Tanganicodus) of the northeastern shore of Lake Tanganyika in Burundi, namely E. macrodactylus (Sars, 1909), E. megacheir (Sars, 1909), E. caparti n. sp., E. parasarsi n. sp. and E. parvus n. sp. All species found were identified and described on the basis of adult female specimens using an integrative taxonomy approach mixing morphological characterization and molecular analyses of 2 ribosomal DNA markers (partial 18S and 28S rDNA sequences). An identification key for Ergasilus species from Lake Tanganyika is included. This study provides the first molecular data for Ergasilus species in Africa. The phylogenetic analyses suggest that the Ergasilus species parasitizing Lake Tanganyikan cichlids form a well-supported clade within the Ergasilidae. However, their phylogenetic relationships with other congeners still remain unclear due to a lack of molecular data for this diverse genus.

• Klíčová slova
• Africa, Tanganyika, cichlids, diversity, parasitic crustaceans,
• MeSH
• cichlidy * genetika   parazitologie   MeSH
• Copepoda * genetika   MeSH
• druhová specificita MeSH
• fylogeneze MeSH
• jezera MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Tanzanie MeSH

Little phylogeographic structure is presumed for highly mobile species in pelagic zones. Lake Tanganyika is a unique ecosystem with a speciose and largely endemic fauna famous for its remarkable evolutionary history. In bathybatine cichlid fishes, the pattern of lake-wide population differentiation differs among species. We assessed the congruence between the phylogeographic structure of bathybatine cichlids and their parasitic flatworm Cichlidogyrus casuarinus to test the magnifying glass hypothesis. Additionally, we evaluated the use of a PoolSeq approach to study intraspecific variation in dactylogyrid monogeneans. The lake-wide population structure of C. casuarinus ex Hemibates stenosoma was assessed based on a portion of the cox1 gene combined with morphological characterisation. Additionally, intraspecific mitogenomic variation among 80 parasite samples from one spatially constrained metapopulation was assessed using shotgun NGS. While no clear geographic genetic structure was detected in parasites, both geographic and host-related phenotypic variation was apparent. The incongruence with the genetic north-south gradient observed in H. stenosoma may be explained by the broad host range of this flatworm including eupelagic bathybatine host species that form panmictic populations across the lake. In addition, we present the first parasite mitogenome from Lake Tanganyika and propose a methodological framework for studying the intraspecific mitogenomic variation of dactylogyrid monogeneans.

• Klíčová slova
• Bathybatini, Cichlidogyrus, PoolSeq, cox1, monogenea,
• Publikační typ
• časopisecké články MeSH

BACKGROUND: Lake Tanganyika is considered a biodiversity hotspot with exceptional species richness and level of endemism. Given the global importance of the lake in the field of evolutionary biology, the understudied status of its parasite fauna is surprising with a single digenean species reported to date. Although the most famous group within the lake's fish fauna are cichlids, the pelagic zone is occupied mainly by endemic species of clupeids (Actinopterygii: Clupeidae) and lates perches (Actinopterygii: Latidae, Lates Cuvier), which are an important commercial source for local fisheries. In this study, we focused on the lake's four lates perches and targeted their thus far unexplored endoparasitic digenean fauna. METHODS: A total of 85 lates perches from four localities in Lake Tanganyika were examined. Cryptogonimid digeneans were studied by means of morphological and molecular characterisation. Partial sequences of the nuclear 28S rRNA gene and the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene were sequenced for a representative subset of the specimens recovered. Phylogenetic analyses were conducted at the family level under Bayesian inference. RESULTS: Our integrative approach revealed the presence of six species within the family Cryptogonimidae Ward, 1917. Three out of the four species of Lates were found to be infected with at least one cryptogonimid species. Two out of the three reported genera are new to science. Low interspecific but high intraspecific phenotypic and genetic diversity was found among Neocladocystis spp. Phylogenetic inference based on partial 28S rDNA sequences revealed a sister group relationship for two of the newly erected genera and their close relatedness to the widely distributed genus Acanthostomum Looss, 1899. CONCLUSIONS: The present study provides the first comprehensive characterisation of the digenean diversity in a fish family from Lake Tanganyika which will serve as a baseline for future explorations of the lake's digenean fauna. Our study highlights the importance of employing an integrative approach for revealing the diversity in this unique host-parasite system.

• Klíčová slova
• Grandifundilamena n. g., Neocladocystis bemba n. sp., Neocladocystis biliaris n. sp., Species complex, Tanganyikatrema n. g.,
• MeSH
• Bayesova věta MeSH
• biodiverzita MeSH
• biologická evoluce MeSH
• cichlidy parazitologie   MeSH
• druhová specificita MeSH
• fylogeneze MeSH
• infekce červy třídy Trematoda epidemiologie   parazitologie   veterinární   MeSH
• jezera parazitologie   MeSH
• mitochondriální DNA genetika   MeSH
• respirační komplex IV genetika   MeSH
• ribozomální DNA MeSH
• RNA ribozomální 28S genetika   MeSH
• sekvenční analýza DNA MeSH
• sekvenční seřazení MeSH
• Trematoda anatomie a histologie   klasifikace   genetika   izolace a purifikace   MeSH
• žábry parazitologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Tanzanie epidemiologie   MeSH
• Názvy látek
• mitochondriální DNA MeSH
• respirační komplex IV MeSH
• ribozomální DNA MeSH
• RNA ribozomální 28S MeSH

BACKGROUND: Clupeid fisheries in Lake Tanganyika (East Africa) provide food for millions of people in one of the world's poorest regions. Due to climate change and overfishing, the clupeid stocks of Lake Tanganyika are declining. We investigate the population structure of the Lake Tanganyika sprat Stolothrissa tanganicae, using for the first time a genomic approach on this species. This is an important step towards knowing if the species should be managed separately or as a single stock. Population structure is important for fisheries management, yet understudied for many African freshwater species. We hypothesize that distinct stocks of S. tanganicae could be present due to the large size of the lake (isolation by distance), limnological variation (adaptive evolution), or past separation of the lake (historical subdivision). On the other hand, high mobility of the species and lack of obvious migration barriers might have resulted in a homogenous population. RESULTS: We performed a population genetic study on wild-caught S. tanganicae through a combination of mitochondrial genotyping (96 individuals) and RAD sequencing (83 individuals). Samples were collected at five locations along a north-south axis of Lake Tanganyika. The mtDNA data had low global FST and, visualised in a haplotype network, did not show phylogeographic structure. RAD sequencing yielded a panel of 3504 SNPs, with low genetic differentiation (FST = 0.0054; 95% CI: 0.0046-0.0066). PCoA, fineRADstructure and global FST suggest a near-panmictic population. Two distinct groups are apparent in these analyses (FST = 0.1338 95% CI: 0.1239,0.1445), which do not correspond to sampling locations. Autocorrelation analysis showed a slight increase in genetic difference with increasing distance. No outlier loci were detected in the RADseq data. CONCLUSION: Our results show at most very weak geographical structuring of the stock and do not provide evidence for genetic adaptation to historical or environmental differences over a north-south axis. Based on these results, we advise to manage the stock as one population, integrating one management strategy over the four riparian countries. These results are a first comprehensive study on the population structure of these important fisheries target species, and can guide fisheries management.

• Klíčová slova
• East Africa, Fish, Freshwater, Great Lakes, High-throughput sequencing, Panmixis, Population genomics, RAD sequencing, SNP, Stock management,
• MeSH
• analýza hlavních komponent MeSH
• diskriminační analýza MeSH
• fylogeografie MeSH
• genetické lokusy MeSH
• genom * MeSH
• haplotypy genetika   MeSH
• jednonukleotidový polymorfismus genetika   MeSH
• jezera * MeSH
• mitochondriální DNA genetika   MeSH
• populační genetika * MeSH
• rybářství * MeSH
• ryby genetika   MeSH
• sekvence nukleotidů MeSH
• zachování přírodních zdrojů * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Tanzanie MeSH
• Názvy látek
• mitochondriální DNA MeSH