Puzzling parrotfishes: Radiocarbon age validation and updated longevity estimates for western Atlantic species in support of sustainable fisheries management.

For management efforts to succeed in Caribbean fisheries, local fishers must support and be willing to comply with fishing regulations. This is more likely when fishers are included in a stock assessment process that utilizes robust scientific evidence, collected in collaboration with fishers, to evaluate the health of fish stocks. Caribbean parrotfishes are important contributors to coral reef ecosystem health while also contributing to local fisheries. Scientifically robust stock assessments require regional species-specific information on age-based key life history parameters, derived from fish age estimates. Evaluation of the accuracy of age estimation methods for fish species is a critical initial step in managing species for long-term sustainable harvest. The current study resulted from a collaborative research program between fish biologists and local fishers investigating age, growth, and reproductive biology of the seven parrotfish species landed in U.S. Caribbean fisheries; specifically, we validated age estimation for stoplight parrotfish Sparisoma viride and queen parrotfish Scarus vetula. This is the first study to directly validate age estimation for any parrotfish species through analysis of Δ14C from eye lens cores. Our age estimation validation results show that enumeration of opaque zones from thin sections of sagittal otoliths for a Sparisoma and a Scarus species provides accurate age estimates. The oldest stoplight parrotfish and queen parrotfish in the Δ14C age estimation validation series were 14 y and 16 y; while the oldest stoplight parrotfish and queen parrotfish we aged to-date using the Δ14C validated age estimation method were 20 y and 21 y, respectively. Fish longevity (maximum age attained/life span) is a key life history parameter used for estimation of natural mortality, survivorship, and lifetime reproductive output. Past reviews on parrotfishes from the Pacific and Atlantic concluded that most Caribbean/western Atlantic parrotfish species are relatively short-lived with estimated maximum ages ranging from 3-9 y. However, information from our collaborative research in the U.S. Caribbean combined with recently published age estimates for Brazilian parrotfish species indicate that many western Atlantic parrotfishes are relatively long-lived with several species attaining maximum ages in excess of 20 y.

Correlations of dynamic changes in lipid and protein of salted large yellow croaker during storage.

Protein and lipid are two major components that undergo significant changes during processing of aquatic products. This study focused on the protein oxidation, protein conformational states, lipid oxidation and lipid molecule profiling of salted large yellow croaker during storage, and their correlations were investigated. The degree of oxidation of protein and lipid was time-dependent, leading to an increase in carbonyl content and surface hydrophobicity, a decrease in sulfhydryl groups, and an increase in conjugated diene, peroxide value and thiobarbituric acid reactive substances value. Oxidation caused protein structure denaturation and aggregation during storage. Lipid composition and content changed dynamically, with polyunsaturated phosphatidylcholine (PC) was preferentially oxidized compared to polyunsaturated triacylglycerol. Correlation analysis showed that the degradation of polyunsaturated key differential lipids (PC 18:2_20:5, PC 16:0_22:6, PC 16:0_20:5, etc.) was closely related to the oxidation of protein and lipid. The changes in protein conformation and the peroxidation of polyunsaturated lipids mutually promote each other's oxidation process.

PREVALENCE OF OPECOELID TREMATODES (TREMATODA: DIGENEA: OPECOELIDAE) IN THE WOOLLY SCULPIN CLINOCOTTUS ANALIS FROM THE PACIFIC COAST OF THE BAJA CALIFORNIA PENINSULA.

Prevalence values for 3 digenean species of the family Opecoelidae were calculated during a half-year period from 20 individuals per month of the fish species Clinocottus analis, collected from an intertidal environment of Baja California, Mexico. Trematode species recovered were Opecoelus adsphaericus, Opecoelus cameroni, and Opecoelus pacificus. Of these, only O. adsphaericus was present throughout the study, whereas O. pacificus and O. cameroni were recorded for 1 or 2 mo, respectively, exhibiting relatively low prevalence values. The decrease in prevalence of O. adsphaericus coincides with the appearance of O. pacificus and O. cameroni; these last 2 species were found only in the largest hosts, and their presence represents new records for Mexican marine fauna.

Population dynamics and spatial structure of the grey rockcod (Lepidonotothen squamifrons) in the vicinity of Heard Island and the McDonald Islands.

The grey rockcod, Lepidonotothen squamifrons is an important prey species for seals, penguins and Patagonian toothfish (Dissostichus eleginoides) in the Southern Ocean. Across the Kerguelen Plateau, the species was fished to commercial extinction (ca. 152 000 tonnes between 1971 and 1978) prior to the declaration of the French Exclusive Economic Zone in 1979 and the Australian Fishing Zone in 1981. In this study we estimate; age, growth, maturity, sex ratio, body condition (weight-at-length), and population density of grey rockcod using data from 19 trawl surveys from 1990 to 2014. There appeared to be three distinct geographical populations, with differences in biological parameters within each population. This study has identified separate metapopulations within the southern region of the Kerguelen Plateau and we recommend that management should take into account the different characteristics of these populations, and that this meta-population structure may be a factor in why this species required several decades to show signs of recovery.

The effects of intensive trapping on invasive round goby densities.

The round goby (Neogobius melanostomus) is an invasive benthic fish first introduced to the Laurentian Great Lakes in 1990 that has negatively impacted native fishes through increased competition for food and habitat, aggressive interactions, and egg predation. While complete eradication of the round goby is currently not possible, intensive trapping in designated areas during spawning seasons could potentially protect critical native fish spawning habitats. Baited minnow traps were spaced 10 meters apart in shallow water along a 100-meter stretch of shoreline within the Duluth-Superior Harbor during the round goby breeding period (June to October) with captured round gobies removed from interior traps (N = 10) every 48 hours. These traps were bracketed by two pairs of reference traps deployed weekly for 48 hours, from which round gobies were also tagged and released. The number of round gobies captured in the interior traps declined by 67% compared to reference traps over the course of the study, with extended periods of no captures. The tagged round gobies showed high site affinity, with 82.8% of tagged fish recaptured at the previous release site. The results indicate that even at open water sites, which allow natural migration of round gobies into the area, extensive trapping could reduce local population numbers.

Phylogenetic position of Ancyrocephalus (sensu lato) curtus Achmerov, 1952 (Monopisthocotylea, Dactylogyridae), a parasite of fish Perccottus glenii Dybowski, 1877(Gobiiformes: Odontobutidae).

The genus Ancyrocephalus sensu lato is a large assemblage of species of dactylogyrid monopisthocotyleans without clear taxonomic boundaries. Despite an urgent need for revision, only three representatives of this taxon have been molecularly characterised so far. We found specimens of Ancyrocephalus curtus, a previously non-genotyped species, in gills of Perccottus glenii caught in the River Syumnyur, Amur Basin, Russia. The aim of this study was to assess the phylogenetic position of this parasite using partial sequences of 28S rRNA gene. In the phylogenetic tree, A. curtus appeared as a sister taxon to the dactylogyrine genus Gobioecetes. The new molecular evidence supports the hypothesis about the non-monophyletic status of Ancyrocephalus sensu lato.

Caribbean red snapper fishing performance indicators in Brazilian amazon shelf: Is it the beginning of the end of a fishing system?

Red snapper fishing (Lutjanus purpureus) is an important fishing activity for the Brazilian economy due to its export. The scarcity of up-to-date information on this system's ecology, economy, and social characteristics contributes to inefficient management. We analyze whether the commercial snapper fishery on the Amazon continental shelf is socioecologically sustainable. For this, an assessment tool was used that can be applied to fishing systems with little data, the Fisheries Performance Indicators (FPI). The results showed that the critical points of this activity are mainly related to the Ecological indicator (2.3) and the Economic indicator (2.8). The best indicator was the Community (3.8). The problems that put at risk the permanence of the activity and its maintenance are: (i) fishing for juveniles; (ii) illegal vessels; (iii) lack of collaboration of the fishing sector with science, and (iv) unreliability of data supplied. All the points mentioned make the snapper fishery on the north coast of Brazil socio-ecologically unsustainable in the long term.

Figure-ground segmentation based on motion in the archerfish.

Figure-ground segmentation is a fundamental process in visual perception that involves separating visual stimuli into distinct meaningful objects and their surrounding context, thus allowing the brain to interpret and understand complex visual scenes. Mammals exhibit varying figure-ground segmentation capabilities, ranging from primates that can perform well on figure-ground segmentation tasks to rodents that perform poorly. To explore figure-ground segmentation capabilities in teleost fish, we studied how the archerfish, an expert visual hunter, performs figure-ground segmentation. We trained archerfish to discriminate foreground objects from the background, where the figures were defined by motion as well as by discontinuities in intensity and texture. Specifically, the figures were defined by grating, naturalistic texture, and random noise moving in counterphase with the background. The archerfish performed the task well and could distinguish between all three types of figures and grounds. Their performance was comparable to that of primates and outperformed rodents. These findings suggest the existence of a complex visual process in the archerfish visual system that enables the delineation of figures as distinct from backgrounds, and provide insights into object recognition in this animal.

Comprehensive analysis of histophysiology, transcriptome and metabolome tolerance mechanisms in black porgy (Acanthopagrus schlegelii) under low temperature stress.

Low temperature stress has adverse effects on fish growth and reproduction, causing huge economic losses to the aquaculture industry. Especially, black porgy (Acanthopagrus schlegelii) farming industry in north of Yangtze River has been severely affected by low temperature for a long time. To explore the tolerance mechanism of black porgy to low temperature stress, the experiment was designed. The liver and gill tissues of black porgy were taken from the water temperature point of 15 °C (control group named as CG), 3.8 °C (cold sensitive group named as CS) and 2.8 °C (cold tolerant group named as CT) with a cooling rate of 3 °C/d from 15 °C for histophysiology, transcriptomics and metabolomics analysis. After cold stress, the histological results showed that the nucleus of the black porgy liver tissue appeared swelling, the cell arrangement was disordered; meanwhile the gill lamellae were twisted and broken, the epidermis was detached and aneurysm appeared. In addition, the expression of antioxidant, glucose metabolism and immune-related enzymes in the liver and gill of black porgy also changed significantly after low temperature stress. By analyzing the transcriptome and metabolome dates of black porgy liver, 3474 differentially expressed genes (DEGs) and 689 differentially expressed metabolites (DEMs) involved in low temperature stress were identified, respectively. The results of the transcriptome and metabolome combined analysis showed that individuals in the CS group mainly supplied energy to the body through lipid metabolism and amino acid metabolism, and meanwhile the apoptosis pathway was activated. While, individuals in the CT group mainly through glucose metabolism and steroid hormone biosynthesis to supply energy for the body. The validation results of qPCR on eight functional genes further demonstrated the reliability of RNA-Seq data. In summary, the results provide molecular information about adaptation to climate change and genetic selection of black porgy.

High NaCl Concentrations in Water Are Associated with Developmental Abnormalities and Altered Gene Expression in Zebrafish.

Salt is frequently introduced in ecosystems, where it acts as a pollutant. This study examined how changes in salinity affect the survival and development of zebrafish from the two-cell to the blastocyst stage and from the blastocyst to the larval stage. Control zebrafish embryos were cultured in E3 medium containing 5 mM Sodium Chloride (NaCl), 0.17 mM Potassium Chloride (KCL), 0.33 mM Calcium Chloride (CaCl2), and 0.33 mM Magnesium Sulfade (MgSO4). Experiments were conducted using increasing concentrations of each individual salt at 5×, 10×, 50×, and 100× the concentration found in E3 medium. KCL, CaCl2, and MgSO4 did not result in lethal abnormalities and did not affect early embryo growth at any of the concentrations tested. Concentrations of 50× and 100× NaCl caused embryonic death in both stages of development. Concentrations of 5× and 10× NaCl resulted in uninflated swim bladders in 12% and 65% of larvae, compared to 4.2% of controls, and caused 1654 and 2628 genes to be differentially expressed in blastocysts, respectively. The ATM signaling pathway was affected, and the Sonic Hedgehog pathway genes Shh and Ptc1 implicated in swim bladder development were downregulated. Our findings suggest that increased NaCl concentrations may alter gene expression and cause developmental abnormalities in animals found in affected ecosystems.

Differences in diacylglycerol acyltransferases expression patterns and regulation cause distinct hepatic triglyceride deposition in fish.

Triglyceride (TAG) deposition in the liver is associated with metabolic disorders. In lower vertebrate, the propensity to accumulate hepatic TAG varies widely among fish species. Diacylglycerol acyltransferases (DGAT1 and DGAT2) are major enzymes for TAG synthesis. Here we show that large yellow croaker (Larimichthys crocea) has significantly higher hepatic TAG level than that in rainbow trout (Oncorhynchus mykiss) fed with same diet. Hepatic expression of DGATs genes in croaker is markedly higher compared with trout under physiological condition. Meanwhile, DGAT1 and DGAT2 in both croaker and trout are required for TAG synthesis and lipid droplet formation in vitro. Furthermore, oleic acid treatment increases DGAT1 expression in croaker hepatocytes rather than in trout and has no significant difference in DGAT2 expression in two fish species. Finally, effects of various transcription factors on croaker and trout DGAT1 promoter are studied. We find that DGAT1 is a target gene of the transcription factor CREBH in croaker rather than in trout. Overall, hepatic expression and transcriptional regulation of DGATs display significant species differences between croaker and trout with distinct hepatic triglyceride deposition, which bring new perspectives on the use of fish models for studying hepatic TAG deposition.

Utilization of Lumpfish (Cyclopterus lumpus) Skin as a Source for Gelatine Extraction Using Acid Hydrolysis.

Lumpfish (Cyclopterus lumpus) is an underutilized marine resource that is currently only being exploited for roe. Lumpfish skin was pre-treated with alkali (0.1M NaOH) and acid (0.1M HCl) at a skin to chemical ratio of 1:10 for 24 h at 5 °C to remove non-collagenous proteins and minerals. The pre-treated skin was washed, and gelatine was extracted with 0.1M of acetic acid at three different ratios (1:5, 1:10, and 1:15), time (12,18, and 24 h), and temperature combinations (12, 28, and 24 °C). The highest total extraction yield (>40%) was obtained with combinations of extraction ratios of 1:15 and 1:10 with a longer time (24 h) and higher temperature (18-24 °C). The highest gelatine content was obtained with an extraction period of 24 h and ratio of 1:10 (>80%). SDS-PAGE analysis confirmed the presence of type-I collagen. A rheological evaluation indicated melting and gelling temperatures, gel strength, and viscosity properties comparable to existing cold-water gelatine sources.

Parental exposure to antidepressants has lasting effects on offspring? A case study with zebrafish.

Fish have common neurotransmitter pathways with humans, exhibiting a significant degree of conservation and homology. Thus, exposure to fluoxetine makes fish potentially susceptible to biochemical and physiological changes, similarly to what is observed in humans. Over the years, several studies demonstrated the potential effects of fluoxetine on different fish species and at different levels of biological organization. However, the effects of parental exposure to unexposed offspring remain largely unknown. The consequences of 15-day parental exposure to relevant concentrations of fluoxetine (100 and 1000 ng/L) were assessed on offspring using zebrafish as a model organism. Parental exposure resulted in offspring early hatching, non-inflation of the swimming bladder, increased malformation frequency, decreased heart rate and blood flow, and reduced growth. Additionally, a significant behavioral impairment was also found (reduced startle response, basal locomotor activity, and altered non-associative learning during early stages and a negative geotaxis and scototaxis, reduced thigmotaxis, and anti-social behavior at later life stages). These behavior alterations are consistent with decreased anxiety, a significant increase in the expression of the monoaminergic genes slc6a4a (sert), slc6a3 (dat), slc18a2 (vmat2), mao, tph1a, and th2, and altered levels of monoaminergic neurotransmitters. Alterations in behavior, expression of monoaminergic genes, and neurotransmitter levels persisted until offspring adulthood. Given the high conservation of neuronal pathways between fish and humans, data show the possibility of potential transgenerational and multigenerational effects of pharmaceuticals' exposure. These results reinforce the need for transgenerational and multigenerational studies in fish, under realistic scenarios, to provide realistic insights into the impact of these pharmaceuticals.

Near-Infrared Fluorescence Probe with a New Recognition Moiety for the Specific Detection of Cysteine to Study the Corresponding Physiological Processes in Cells, Zebrafish, and Arabidopsis thaliana.

Cysteine (Cys), as one of the biological thiols, is related to many physiological and pathological processes in humans and plants. Therefore, it is necessary to develop a sensitive and selective method for the detection and imaging of Cys in biological organisms. In this work, a novel near-infrared (NIR) fluorescent probe, Probe-Cys, was designed by connecting furancarbonyl, as a new recognition moiety, with Fluorophore-OH via the decomposition of IR-806. The use of the furan moiety is anticipated to produce more effective fluorescence quenching because of the electron-donating ability of the O atom. Probe-Cys has outstanding properties, such as a new recognition group, an emission wavelength in the infrared region at 710 nm, a linear range (0-100 µM), a low detection limit of 0.035 µM, good water solubility, excellent sensitivity, and selectivity without the interference of Hcy, GSH, and HS-. More importantly, Probe-Cys could achieve the detection of endogenous Cys by reacting with the stimulant 1,4-dimercaptothreitol (DTT) and the inhibitor N-ethylmaleimide (NEM) in HepG2 cells and zebrafish. Ultimately, it was successfully applied to obtain images of Arabidopsis thaliana, revealing that the content of Cys in the meristematic zone was higher than that in the elongation zone, which was the first time that the NIR fluorescence probe was used to obtain images of Cys in A. thaliana. The superior properties of the probe exhibit its great potential for use in biosystems to explore the physiological and pathological processes associated with Cys.

Hepatic extracellular ATP/adenosine dynamics in zebrafish models of alcoholic and metabolic steatotic liver disease.

Steatotic liver disease (SLD) is a burgeoning health problem predominantly associated with excessive alcohol consumption, which causes alcohol-related liver disease (ALD), and high caloric intake, which results in metabolic dysfunction-associated SLD (MASLD). The pathogenesis of ALD and MASLD, which can progress from steatohepatitis to more severe conditions such as liver fibrosis, cirrhosis, and hepatocellular carcinoma, is complicated by several factors. Recently, extracellular ATP and adenosine (Ado), as damage-associated molecular patterns, were reported to promote inflammation and liver fibrosis, contributing to SLD pathogenesis. Here, we explored the in vivo dynamics of hepatic extracellular ATP and Ado during the progression of steatohepatitis using a genetically encoded GPCR-activation-based sensor (GRAB) in zebrafish models. We established hepatocyte-specific GRABATP and GRABAdo in zebrafish and investigated the changes in in vivo hepatic extracellular ATP and Ado levels under ALD or MASLD conditions. Disease-specific changes in hepatocyte extracellular ATP and Ado levels were observed, clearly indicating a correlation between hepatocyte extracellular ATP/Ado dynamics and disease progression. Furthermore, clodronate, a vesicular nucleotide transporter inhibitor, alleviated the MASLD phenotype by reducing the hepatic extracellular ATP and Ado content. These findings provide deep insights into extracellular ATP/Ado dynamics in disease progression, suggesting therapeutic potential for ALD and MASLD.

Rainbow Trout # 5, Brook Trout # 2, Rockfish # 5, Walley # 5 by Bonnie Murray.

Art is integrated into the Mayo Clinic environment. Since the original Mayo Clinic Building was finished in 1914, many pieces have been donated or commissioned for patients and staff to enjoy. Each issue of Mayo Clinic Proceedings features a work of art (as interpreted by the author) that is displayed in a building or on the grounds of Mayo Clinic campuses.

Effects of different curing concentrations and drying times on the microbial community structure and metabolites of dried Spanish mackerel.

Cured Spanish mackerel has a promising market owing to its nutritious nature as well as ease of transportation and preservation. However, the nutritional and flavor formation mechanism of Spanish mackerel after curing and drying is unclear. To overcome this problem, the effects of different processing conditions on the free amino acid, microbial community, and flavor of Spanish mackerel were explored. Staphylococcus and Cobetia are the main microorganisms in cured mackerel and are closely associated with the formation of their quality. Compared with fresh mackerel, cured mackerel contains increased levels of protein, fat, and chloride, contributing to its distinctive flavor. The contents of free amino acids in the BA64 group were substantially higher than those in other groups, particularly the contents of threonine, glycine, and tyrosine. These findings will contribute to the development of high-quality cured Spanish mackerel products and cured aquatic products.

Karyotypic changes and diversification time in Epinephelidae groupers (Perciformes). Implications on reproductive isolation.

Groupers (Epinephelidae and Serranidae) have attracted special attention to fish farming, and their species offer good opportunities for successful hybridizations. Cytogenetic data allow a better understanding of the role of karyotypic diversification in the acquisition of post-zygotic reproductive isolation (RI). Thus, chromosomal analyses were performed on E. striatus (Caribbean Sea), E. coioides and E. tauvina (Indo-Pacific Region), using standard procedures and mapping of six repetitive DNA classes by the in situ hybridization. The three species have 2n=48 chromosomes. The karyotypes of E. coioides and E. striatus are composed only of acrocentric chromosomes (FN=48), while E. tauvina has 8 submetacentric chromosomes (FN=56). Heterochromatin has a preferential centromeric distribution, and the microsatellite repeats are dispersed throughout the chromosomes of all species. The 18S and 5S rDNA sites are unique but show a colocalization arrangement in E. tauvina and E. striatus. The chromosomal organization suggests that the three species still maintain a significant amount of syntenic regions. The range of the karyotype divergence and the RI levels showed low, but goes turn proportionally greater in relation to the divergence time between the parental species. The slow acquisition of postzygotic RI is consistent with the high karyotype homogeneity presented by Epinephelidae family.