The Satellite DNA Catalogues of Two Serrasalmidae (Teleostei, Characiformes): Conservation of General satDNA Features over 30 Million Years.

Satellite DNAs (satDNAs) are tandemly repeated sequences that are usually located on the heterochromatin, and the entire collection of satDNAs within a genome is called satellitome. Primarily, these sequences are not under selective pressure and evolve by concerted evolution, resulting in elevated rates of divergence between the satDNA profiles of reproductive isolated species/populations. Here, we characterized two additional satellitomes of Characiformes fish ( and ) that diverged approximately 30 million years ago, while still retaining conserved karyotype features.

Male reproductive system of the freshwater prawn Macrobrachium brasiliense (Decapoda: Palaemonidae): Notes on spermatophore formation and sperm count.

Studies on the morphology of the reproductive system are essential for understanding the reproduction processes of species or even within genera or families. The present study aimed to describe the functional morphology of the male reproductive system, spermatophore formation, and sperm count of Macrobrachium brasiliense. The anatomy of the reproductive system consists of a pair of testes from which the vasa deferentia (VD) starts, extending to the fifth pair of pereopods.

Low microbiome diversity in threatened amphibians from two biodiversity hotspots.

Microbial diversity positively influences community resilience of the host microbiome. However, extinction risk factors such as habitat specialization, narrow environmental tolerances, and exposure to anthropogenic disturbance may homogenize host-associated microbial communities critical for stress responses including disease defense. In a dataset containing 43 threatened and 90 non-threatened amphibian species across two biodiversity hotspots (Brazil's Atlantic Forest and Madagascar), we found that threatened host species carried lower skin bacterial diversity, after accounting for key environmental and host factors.

Establishing a model fish for the Neotropical region: The case of the yellowtail tetra in advanced biotechnology.

The use of model organisms is important for basic and applied sciences. Several laboratory species of fishes are used to develop advanced technologies, such as the zebrafish (), the medaka (), and loach species ( spp). However, the application of these exotic species in the Neotropical region is limited due to differences in environmental conditions and phylogenetic distances.

Effects of stress-associated odor on ventilation rate and feeding performance in Nile tilapia.

In this study, we described immediate/acute reactions to stress-related chemical cues (SC - Stress Cue) in fish. Specifically, we evaluated the effects of SC on ventilation rate (VR) and feeding behavior in Nile tilapia (), a highly relevant species for world aquaculture, therefore, to understand the diversity of stressful contexts and stress responses in this species have important practical applications (stress reduction). Stress cue was obtained from conspecifics exposed to a handling stressor.

The association of modified QuEChERS and DLLME to offer high analytical detectability to assess residual depletion profile of erythromycin in fish.

An analytical method for the determination of erythromycin A (ERY) residues in fish fillet was developed, optimized, and validated employing a modified QuEChERS procedure associated to DLLME technique as a preconcentration step. The obtained LOD and the LOQ were 0.1 µg kg and 1 µg kg, respectively.

Genome-wide association study of host resistance to the ectoparasite Ichthyophthirius multifiliis in the Amazon fish Colossoma macropomum.

Background: Tambaqui, Colossoma macropomum, is the most important native fish species farmed in South America, particularly in Brazil, where its production is limited in the southern and southeastern regions due to disease outbreaks caused by the parasite Ichthyophthirius multifiliis. Therefore, genome level analysis to understand the genetic architecture of the host resistance against I. multifiliis is fundamental to improve this trait in tambaqui.

Cannabidiol improves Nile tilapia cichlid fish welfare.

Cannabidiol (CBD) is a substance derived from Cannabis sativa, widely studied in medicine for controlling neural diseases in humans. Besides the positive effects on humans, it also presents anxiolytic proprieties and decreases aggressiveness and stress in mammals. Therefore, CBD has the potential to increase welfare in reared animals, as it seems to reduce negative states commonly experienced in artificial environments.

Dietary Supplementation of a Commercial Prebiotic, Probiotic and Their Combination Affected Growth Performance and Transient Intestinal Microbiota of Red Drum ( L.).

In the present study, the potential synergism between beneficial lactic acid bacteria () contained in a probiotic and a mixture of fermentable complex carbohydrates and autolyzed brewer's yeast (or prebiotic) were explored in red drum. Four experimental diets were formulated from practical ingredients, and the basal diet was supplemented with either probiotic, prebiotic, or both supplements. Red drum juveniles (~5.

Effects of temperature on eggs and larvae of Anisakis simplex sensu stricto and Anisakis pegreffii (Nematoda: Anisakidae) and its possible role on their geographic distributions.

Effects of temperature on development of eggs, recently hatched larvae and L3 larvae of the marine parasitic nematodes Anisakis simplex sensu stricto (s.s.) and A.

Antagonism of cysteinyl leukotriene receptors by zafirlukast modulated acute inflammatory reaction in tilapia, Oreochromis niloticus.

To identify activation pathways and effector mechanisms of innate immunity in fish has become relevant for the sanitary management of intensive fish farming. However, little is known about the blocking of cysteinyl leukotrienes receptors (CysLTRs) and their effects in teleost fish. Our study evaluated the anti-inflammatory effect of 250 and 500 μg zafirlukast (antagonist of CysLTRs)/kg b.

How has the sustainability of countries changed after COVID-19? Evidence from the pandemics' first year.

The Covid-19 crisis has caused several social-related issues; the sanitary is, perhaps, the most significant one. Lockdowns and vaccination were implemented to fight the Covid-19 virus. From a sustainability perspective, Covid-19 has been considered a meaningful crisis driver that has affected nations' economies and social and natural capitals.

Evaluation of Edwardsiella piscicida basS and basR mutants as vaccine candidates in catfish against edwardsiellosis.

Catfish farming is the largest aquaculture industry in the United States and an important economic driver in several southeastern states. Edwardsiella piscicida is a Gram-negative pathogen associated with significant losses in catfish aquaculture. Several Gram-negative bacteria use the BasS/BasR two-component system (TCS) to adapt to environmental changes and the host immune system.

Epidemiological Cutoff Values for Standard Broth Microdilution and Disk Diffusion Susceptibility Testing of Isolated from Fish.

and other closely related species cause motile aeromonad septicemia, a common fish disease. The disease affects many aquaculture sectors potentially requiring antimicrobial treatments. Therefore, researchers and laboratory diagnosticians need criteria called epidemiological cutoff values (ECVs) to determine whether a bacterial isolate has developed decreased susceptibility to an antimicrobial.

Epidemiological Cutoff Values for Standard Broth Microdilution Susceptibility Testing of Isolated from Fishes.

, the causative agent of columnaris disease in a large variety of freshwater fish, is a major problem in commercial aquaculture. A limited number of antimicrobial therapies are available to control this disease; therefore, these agents must be used judiciously. To facilitate effective monitoring for changes in susceptibility, the Clinical Laboratory Standards Institute (CLSI) has a standard broth microdilution test method specific for .

Heart inflammation and piscine orthoreovirus genotype-1 in Pacific Canada Atlantic salmon net-pen farms: 2016-2019.

Piscine orthoreovirus genotype-1 (PRV-1) is a virus commonly associated with Atlantic salmon aquaculture with global variability in prevalence and association with disease. From August 2016 to November 2019, 2,070 fish sampled at 64 Atlantic salmon net-pen farm sites during 302 sampling events from British Columbia, Canada, were screened for PRV-1 using real-time qPCR. Nearly all populations became PRV-1 positive within one year of seawater entry irrespective of location, time of stocking, or producer.

Pathology and virulence of Edwardsiella tarda, Edwardsiella piscicida, and Edwardsiella anguillarum in channel (Ictalurus punctatus), blue (Ictalurus furcatus), and channel × blue hybrid catfish.

In the mid-2010s, Edwardsiella tarda was reaffiliated into three discrete taxa (E. anguillarum, E. piscicida, and E.

Economic, social, and environmental assessment of farming Nile tilapia in net-cages in a reservoir in hot semi-arid region during an extended drought event.

Water reservoirs have been constructed in hot semi-arid regions, which may be used to produce fish. The present study described major features of the economic, social, and environmental characteristics of a net-cage Nile tilapia production system, stocked with 100 and 120 fish/m, implemented in a reservoir in the hot semi-arid region of Brazil during an extended drought event. The production cycle was reduced from 6-8 to 4 months because of the lack of water in the reservoir.

Longitudinal patterns in progesterone metabolites in pregnant and non-pregnant Steller sea lions (Eumetopias jubatus).

Similar to the several pinniped and a few terrestrial carnivore species, the Steller sea lion has a seasonal synchronized mating scheme enabled by a female reproductive cycle that includes embryonic diapause, delayed implantation, and pseudopregnancy (a state in which the corpus luteum produces progesterone for approximately as long as in pregnant females). Due to this, circulating systemic progesterone concentrations cannot be used to differentiate pregnant and nonpregnant females during early gestation. With the use of advanced measurement technologies such as liquid chromatography tandem mass spectrometry (LC-MS/MS) additional steroid hormones are measurable which can provide additional information on the endocrine pathways throughout gestation.

Signatures of functional bacteriome structure in a tropical direct-developing amphibian species.

Background: Host microbiomes may differ under the same environmental conditions and these differences may influence susceptibility to infection. Amphibians are ideal for comparing microbiomes in the context of disease defense because hundreds of species face infection with the skin-invading microbe Batrachochytrium dendrobatidis (Bd), and species richness of host communities, including their skin bacteria (bacteriome), may be exceptionally high. We conducted a landscape-scale Bd survey of six co-occurring amphibian species in Brazil's Atlantic Forest.

Vibrio splendidus clade associated with a disease affecting Paracentrotus lividus (Lamarck, 1816) in Sardinia (Western Mediterranean).

This work reports for the first time the so-called bald sea urchin disease of the populations of Paracentrotus lividus in Sardinia (Italy). Following the disease occurrence reported by local fishermen of about 35% on the collected specimens for commercial purpose, the phenomenon was evaluated in two areas. Animals displayed external lesions represented by loss of spines and greenish/brownish skeleton patches.

Sequencing of laser captured Z and W chromosomes of the tocantins paradoxical frog (Pseudis tocantins) provides insights on repeatome and chromosomal homology.

Pseudis tocantins is the only frog species of the hylid genus Pseudis that possesses highly heteromorphic sex chromosomes. Z and W chromosomes of Ps. tocantins differ in size, morphology, position of the nucleolar organizer region (NOR) and the amount and distribution of heterochromatin.

A genomic-based vision on the genetic diversity and key performance traits in selectively bred Arctic charr ().

Routine implementation of genomic information for guiding selection decisions is not yet common in the majority of aquaculture species. Reduced representation sequencing approaches offer a cost-effective solution for obtaining genome-wide information in species with a limited availability of genomic resources. In the current study, we implemented double-digest restriction site-associated DNA sequencing (ddRAD-seq) on an Arctic charr strain with the longest known history of selection (approximately 40 years) aiming to improve selection decisions.

Genomic selection signatures in farmed from tropical and subtropical regions in South America.

Tambaqui or cachama () is one of the most important neotropical freshwater fish used for aquaculture in South America, and its production is concentrated at low latitudes (close to the Equator, 0°), where the water temperature is warm. Therefore, understanding how selection shapes genetic variations and structure in farmed populations is of paramount importance in evolutionary biology. High-throughput sequencing to generate genome-wide data for fish species allows for elucidating the genomic basis of adaptation to local or farmed conditions and uncovering genes that control the phenotypes of interest.

Single-parentage assignments reveal negative-assortative mating in an endangered salmonid.

Understanding reproductive patterns in endangered species is critical for supporting their recovery efforts. In this study we use a combination of paired-parent and single-parent assignments to examine the reproductive patterns in an endangered population of sockeye salmon () that uses Redfish Lake in central Idaho as a spawning and nursery lake. Recovery efforts include the release of maturing adults into the lake for volitional spawning.