Feeding habits shape infection levels by plerocercoids of the tapeworm Triaenophorus crassus in muscle of a sympatric pair of whitefish in an oligotrophic lake

Lake Teletskoye (West Siberia, Russia) is inhabited by a sympatric pair of whitefish, with each member of the pair being characterized by different feeding habits. Coregonus lavaretus pidschian (Gmelin, 1789) is a large ‘benthivorous’ form, while C. l. pravdinellus (Dulkeit, 1949) is a small ‘planktivorous’ form. Fish were collected from the end of August to the middle of September in 2017 and 2019–2020 in the north part of Lake Teletskoye. For the ‘benthivorous’ form the prevalence, intensity and abundance of T. crassus ranged from 22.4% to 51.9%, 1.9–2.8 and 0.4–1.3, respectively, whereas the same indices for the ‘planktivorous’ form ranged from 94.7% to 97.5%, 4.2–4.8 and 4.0–4.7, respectively. The level of prevalence of infection and abundance of T. crassus in muscle was relatively stable among studied years for both forms. The level of prevalence was higher in the years 2019 and 2020 than in 2017 for the ‘benthivorous’ form, whereas for the ‘planktivorous’ form this index did not change during the studied years. For the first time, a partial sequencing of the cox1 gene (593 bp) for T. crassus was sequenced. All 15 plerocercoids of T. crassus were represented by four haplotypes.info:eu-repo/semantics/acceptedVersio

Composition of the microbial communities in the gastrointestinal tract of perch (Perca fluviatilis L. 1758) and cestodes parasitizing the perch digestive tract

Using the approach of sequencing the V3‐V4 region of the 16S rRNA gene, we have analysed the bacterial diversity associated with the distinct compartments of the gastrointestinal tract of perch (Perca fluviatilis) and cestodes (Proteocephalus sp.) parasitizing their digestive tract. The dominant microbiota associated with cestodes (Proteocephalus sp.) was represented by bacteria from the genera Serratia, Pseudomonas and Mycoplasma. By comparing the associated microbiota of perch and cestodes, a clear difference in bacterial composition and diversity was revealed between the community from the stomach content and other parts of the gastrointestinal tract of fish. Microbiota associated with cestodes was not significantly different in comparison with microbiota of different subcompartments of perch (mucosa and content of intestine and pyloric caeca) (ADONIS, p > .05) excluding microbiota of stomach content (ADONIS, p ≤ .05). PICRUSt‐based functional assessments of the microbial communities of perch and cestodes indicated that they mainly linked in terms of metabolism and environmental information processing and could play an important role in the nutrition and health of host.info:eu-repo/semantics/acceptedVersio

Interdisciplinary Approaches in Fish Skeletal Biology (IAFSB)

Flatfish can provide a reliable model to study developmental disorders in bone tissues occurring during morphogenesis in response to nutritional imbalances. To date, most studies dealing with the effect of dietary essential fatty acids (EFA) on skeletogenesis in fish have focused their investigation on the role of docohexanoic (22:6n−3, DHA) and eicosapentaenoic (20:5n–3, EPA) acids, but only a few have focused on investigating the effects of arachidonic acid (20:4n–6, ARA) on bone during fish larval development. Bone development and composition at larval stage have been demonstrated to be highly sensitive to dietary levels of EFA, in particular the EPA and ARA acids, both precursors for highly bioactive eicosanoids presenting opposite effects on bone metabolism. Since fish are not able to synthesize EFA, they need to obtain them from the diet. However, dietary imbalances in EPA and ARA in flatfish larvae may disrupt bone formation and osteoblast differentiation in skeletal tissues, leading to the incidence of skeletal deformities, reduced mineralization and problems of bone remodelling in the cranial region associated with impaired eye migration. These anomalies in skeletal structures are one of the most important factors that affect flatfish larval quality and hamper their production. Thus, we have reviewed the current state of knowledge about the effects of dietary ARA contents on skeletogenesis in Senegalese sole (Solea senegalensis), one of the main flatfish species cultured in Europe. Their larval quality still suffers for a high incidence of skeletal anomalies induced by dietary imbalances during metamorphosis

Congreso Peruano de Biotecnologia y Bioingeneria : libro de resumenes

Pseudoplatystoma punctifer posee un gran potencial para la acuicultura, pero la alta tasa de canibalismo existente durante su etapa temprana de vida dificulta por ahora su cultivo a gran escala. Una nutrición adecuada reduce significativamente la incidencia de canibalismo y el conocimiento de la ontogenia funcional del sistema digestivo es esencial para adaptar el protocolo de alimentación a las capacidades digestivas de esta especie y así aumentar la producción de semilla. Por tanto, el objetivo del presente estudio fue analizar la expresión de los principales genes implicados en la digestión (amilasa, tripsina, quimotripsina, pepsinógeno, fosfolipasa, lipoproteína lipasa y neuropéptido Y) durante el desarrollo larvario y juvenil temprano de P. punctifer. Los resultados mostraron que esta especie cuenta con la maquinaria enzimática necesaria para digerir el alimento exógeno antes de la primera alimentación (4 dpf). La expresión de los genes siguió el perfil común de una especie carnívora con un aumento significativo en la expresión de pepsinógeno a partir de los 10 dpf para pasar de una digestión proteica básica en el intestino (tripsina, quimotripsina) a una digestión proteica ácida más eficiente en el estómago (pepsina). Por tanto, P. punctifer está preparada para ser destetada con dietas complejas a partir de 10 dpf. Los resultados también mostraron que el cambio de dieta durante la etapa juvenil moduló la actividad enzimática a nivel transcripcional, por lo que el análisis de la expresión de los precursores enzimáticos digestivos será de utilidad en estudios nutricionales dirigidos a establecer la composición nutricional óptima para esta especie

The gut microbiota of Cystidicola farionis parasitizing the swim bladder of the nosed charr morph Salvelinus malma complex in Lake Kronotskoe (Kamchatka, Russia)

Using the approach of sequencing the V3–V4 region of the 16S rRNA gene, we have analyzed the bacterial diversity associated with the gut and “body” (other parts of nematode after dissection: cuticle, epidermis and longitudinal muscles, etc) of Cystidicola farionis parasitizing the swim bladder of different morphotypes of the nosed charr. Comparisons of the gut microbiota of nematodes with their “body” has revealed that the associated microbiota are closely related to each other. Taxonomic analysis indicated that the relative abundances of the dominant nematode-associated bacteria varied with individual fish. The common dominant microbiota of the gut and “body” of nematodes were represented by Aeromonas, Pseudomonas, Shewanella, and Yersinia, while the associated microbiota of the swim bladder of the nosed charr was dominated by Acinetobacter, Cetobacterium, Pajaroellobacter, Paracoccus, Pseudomonas, Shewanella. By comparing the associated microbiota of nematode parasitizing the different morphotypes of the nosed charr the difference in richness estimates (number of OTU’s and Chao1) were revealed between the N1g and N2 morphs.info:eu-repo/semantics/publishedVersio

Microbial community structure in a host‐parasite system: the case of Prussian carp and its parasitic crustaceans

Aims. The aim of the study was to investigate the skin microbiota of Prussian carp infested by ectoparasites from the genus Argulus and Lernaea. Methods and Results. Associated microbiota of skin of Prussian carp and ectoparasites were investigated by sequencing of the V3, V4 hypervariable regions of 16S rRNA using Illumina MiSeq sequencing platform. Conclusions. According to the Spearman rank correlation test, the increasing load of ulcerations of the skin of Prussian carp was weakly negative correlated with reduction in the abundance of the following taxa: Acrobacter, bacteria C39 (Rhodocyclaceae), Rheinheimera, Comamonadaceae, Helicobacteraceae, and Vogesella. In the present study, the microbiota of ectoparasites from genus Lernaea and Argulus were characterized for the first time. The microbiota associated with L. cyprinacea was significantly different from microbial communities of intact skin mucosa of both infested and uninfested fish and skin ulcers (ADONIS, p≤0.05). The microbiota associated with parasitic crustaceans L. cyprinacea were dominated by unclassified bacteria from Comamonadaceae, Aeromonadaceae families, and Vogesella. The dominant microbiota of A. foliaceus were represented by Flavobacterium, Corynebacterium, and unclassified Comamonadaceae. Significance and Impact of Study. Results from these studies indicate that ectoparasites have the potential to alter skin microbiota, which can play a possible role in transmission of secondary bacterial infection in fish, caused by pathogenic bacteria.info:eu-repo/semantics/acceptedVersio