Juvenile Grouper Research Articles

Effects of dietary inclusion of soybean meal and cholesterol on the growth, cholesterol status and metabolism of the giant grouper (Epinephelus lanceolatus)

The study evaluated effects of cholesterol supplementation in a diet with high soybean meal (SBM) on the growth and cholesterol metabolism of giant grouper (Epinephelus lanceolatus). All‐fish‐meal diet was used as control. The diet including SBM (replaced 50% of the fish meal protein, SBM diet) and the SBM diet supplemented with 10 g/kg cholesterol (SBM + cholesterol) were used as experimental diets. Three diets were each fed to triplicate groups of juvenile grouper (initial body weight: 12.39 ± 0.36 g) in a recirculating aquaculture system for 8 weeks. Grouper fed the control diet showed higher (p < .05) weight gain, feed intake, feed efficiency and protein efficiency ratio than the other two dietary treatments. Hepatic cholesterol concentrations and 3‐hydroxy‐3‐methylglutaryl coenzyme A reductase gene expressions were higher in fish fed the control diet than fish fed the control diet and SBM + cholesterol diet. Hepatic cholesterol 7α‐hydroxylase gene expression was higher in fish fed the SBM + cholesterol diet than that in fish fed the control diet. Results indicate that giant grouper on a diet low in cholesterol can regulate cholesterol synthesis, suggesting that the reduced dietary cholesterol intake in the fish fed diet containing SBM is sufficiently compensated by increased cholesterol synthesis.

Effects of dietary supplementation with coconut oil on the growth, fatty acid profiles and some lipid metabolism relative gene expressions of orange‐spotted grouperEpinephelus coioides

This study investigated the effects of coconut oil as a dietary supplement on the growth, lipid metabolism and related gene expressions of juvenile orange‐spotted grouper Epinephelus coioides. Coconut oil at concentrations of 0, 10, 30 and 50 g/kg was used to replace dietary lipids in a basal diet containing 150 g/kg lipids. The four experimental diets were, respectively, fed to triplicate groups of juvenile groupers (initial weight: 8.53 ± 0.13 g) in a recirculating system for 8 weeks. Fish fed the diet containing 50 g/kg coconut oil exhibited lower (p < .05) weight gain than did fish fed the diet containing 30 g/kg coconut oil; however, no significant differences in weight gain were observed between fish fed diets containing 0 and 10 g/kg coconut oil. Hepatic carnitine palmitoyltransferase‐1, fatty acid synthase, fatty acid elongase, fatty acid desaturase and peroxisome proliferator‐activated receptor gamma gene expressions were all the highest in fish fed the diet containing 10 g/kg coconut oil. Fish fed the coconut oil‐free basal diet demonstrated upregulated gene expression of neuropeptide Y. The results suggest that dietary supplementation with 10 g/kg coconut oil exerted beneficial effects on lipid metabolism by E. coioides.

Evaluation of the thermal tolerances of different strains of rainbow trout Oncorhynchus mykiss by measuring the effective time required for loss of equilibrium at an approximate upper lethal temperature

The thermal tolerance phenotypes of different strains of rainbow trout Oncorhynchus mykiss was investigated in this study. The time at which a fish, acclimated to 17 °C, was no longer able to maintain its equilibrium after reaching the test temperature of 28 °C was recorded as its effective time (ET) in the zone of thermal resistance and used as a parameter of its thermal tolerance. The ET was compared among two strains of rainbow trout, thermally selected and Nikko, and two types of their hybrid progenies (thermally selected male × normal female and thermally selected female × normal male), using 14–15 individuals of each group in tests. Individuals of the thermally selected strain with smaller bodies had a longer ET than those with lager bodies. Five groups of F2 juveniles produced from a full-sibling cross of F1 progenies (Nikko strain females × thermally selected strain males), each containing 40 or 41 individuals, had an ET of 39.3–46.4 min, which was not significantly correlated with body size. Although its ET was influenced by body size, the thermally selected strain showed good thermal tolerance at all body sizes. Moreover, the coefficient of variation of ET was 32–39%, suggesting there was a wide diversity of ET values. Because samples subjected to ET experiments can recover and survive, ET is a promising, convenient indicator to use when examining thermal tolerance phenotypes of large numbers of individuals, which can subsequently provide live individuals with inherited thermal tolerance for use in selective breeding.

Identification of potential biomarkers for soybean meal-induced enteritis in juvenile pearl gentian grouper, Epinephelus lanceolatus♂ × Epinephelus fuscoguttatus♀

This study identifies the potential biomarkers of soybean meal-induced enteritis in juvenile pearl gentian grouper using ultra-performance liquid chromatography-mass spectrometry (UPLC-MS). There were 480 female juvenile grouper randomly assigned to two groups (n = 4), including the fish meal (FM) group (control) and 20% soybean meal (SBM20) group, which were fed by two iso‑nitrogenous (50% crude protein) and isolipidic (10% crude lipid) diets for 10 weeks. The diets and distal intestinal (DI) content samples of FM and SBM20 groups were collected for metabonomics analysis. The data generated from the UPLC-MS was analysed using principal components analysis (PCA) and partial least-squares discriminant analysis (PLS-DA). The PLS-DA model with satisfactory explanatory and predictive ability can discriminate the SBM20 from the FM group. The area under the curve (AUC) was calculated as the cumulative ability to distinguish between dietary patterns. Results showed that 20% SBM substitution level induced distal intestinal physiological injury and enteritis of juvenile grouper, which can be reflected by hematoxylin and eosin staining and transmission electron microscope analysis. In diets, a total of 171 metabolites in positive mode and 104 metabolites in negative mode in SBM20 group were significantly distinguished from the FM group. In DI contents, a total of 395 metabolites in positive mode and 219 metabolites in negative mode in SBM20 group were significantly distinguished from the FM group. Between diets and DI contents, there are only 9 co-contained differential metabolites in positive mode and 4 co-contained differential metabolites in negative mode. The 17 most influential metabolites in DI contents were identified as the potential biomarkers in positive and negative modes via the metabonomics UPLC-MS profiles. In DI contents, compared with the FM group, the intestines of 5-methylbenzimidazole, Glycitin, Byakangelicol, Genistin, Malonylglycitin, Genistein 4’-O-glucuronide, Glycitein, 3,4-dihydroxyphenylacetic acid, Daidzein, FMNH2, Soyasaponin I, olmelin, Genistein, Ginsenoside Ro, 4-Phenolsulfonic acid, and Baicalin in the SBM20 group were significantly increased (p < .01); however, the intensity of amfonelic acid in SBM20 group decreased significantly (p < .01) (AUC > 0.9). The present study identified a broad array of DI content metabolites that differed between FM and SBM dietary patterns that could provide some valuable reference for further management of fish intestine health issues.

Effect of different commercial feeds on growth and reproductive performance of Guppy, &lt;em&gt;Poecilia reticulata&lt;/em&gt; Peters

A 15 week feeding trial was conducted to investigate the effects of three commercial feeds; Prima diet, Galaxy diet and Prawn diet on the growth performance and reproductive performance of Guppy, Poecilia reticulata. Triplicate groups of guppy juveniles (mean initial weight of 0.07 + 0.03g) were stocked in 9 indoor glass aquaria (30 x 22 x 8.5cm), at a density of 20 fish tank-1 at a sex ratio of 1:1. Fish were fed ad-libitum 5 times daily using respective diet and growth performance (Total length, weight, %SGR, FCR) and reproductive performance (Gonadosomatic index (GSI), Time taken for first spawning, total number of larvae, and spawning interval) were evaluated. Feed consumption (10.80-12.58 % Bwt/day) was not differed among treatments. The highest growth performance of fish in terms of final mean body weight (0.83+ 0.46g), total length (4.63 + 0.41cm), and specific growth rate (SGR 2.34 + 0.03)) was observed in the fish fed Prawn diet compared to fish fed on other two feeds. Total body weight and GSI were found to be significantly higher in females compared to males in all treatments. Fish fed on Prawn diet recorded the significantly highest mean number of larvae per tank (33.67 + 7.51). However, total length of larvae showed no significant difference among three treatments. In the present study significant highest growth and reproductive performance (in terms of number of larvae tank-1) of guppy was observed in fish fed on Prawn diet. Therefore, for guppy broodstock rearing in indoor aquaria Prawn diet could be recommended as the best feed out of three commercial diets tested herein.

Effect of three forms of manganese on growth performance, antioxidant capacity, and intestinal morphology of juvenile hybrid grouper ( Epinephelus fuscoguttatus ♀× E. lanceolatu ♂)

Effect of three forms of manganese on growth performance, antioxidant capacity, and intestinal morphology of juvenile hybrid grouper ( <i>Epinephelus fuscoguttatus</i> ♀× <i>E. lanceolatu</i> ♂)

Социально-демографическая характеристика личности несовершеннолетних жертв преступлений (региональное исследование)

The research examined the social and demographic characteristics of juvenile victims in Irkutsk Region and Krasnoyarsk Territory in 2008–2017 based on data provided by the Information Center of the Main Directorate of the Ministry of Internal Affairs. The paper defined the place of social and demographic characteristics in the personality structure of a vic-tim and substantiated the importance of their re-search within victim studies. The author identified the analogous trends in the victimization of juve-niles in the regions under review. The gender and age distribution of juvenile victims changed in a similar way as well. Considering the socialization, the psychological and physiological maturation of children, the study presented the age groups of ju-veniles that could serve as a basis for changes in primary statistical reports.

Digestive coordination of the gastric function in Atlantic salmon Salmo salar juveniles

Artificial diets have been reported to produce suboptimal pH values in the stomach of salmonid species. Therefore, it is interesting to investigate the gastric function of different species fed commercial diets. In the present work, two groups of Atlantic salmon juveniles were either fasted or fed with a commercial diet. The gastric and duodenal pH values were measured over a 25 h post-prandial period and, dry matter, moisture and protease activity in the gastric chyme of the fed group were also determined. In the fed group, the gastric pH dropped to 3.5, and duodenal pH increased from 7.0 to 7.5 at the 4th h post-feeding, whereas fasted fish showed no significant changes in the gastric pH or duodenal pH. Fed animals showed: i) two discrete events of evacuation, before the 2nd hand after the 8th h of digestion, ii) a change in the moisture of the gastric chyme from less than 10% in the diet to 60% at the 2nd h post-feeding, and iii) a maximal gastric proteases activity of 600 U mL -1 at the 2nd h followed by a nearly constant of value of ~300 U mL -1 . It can be concluded that the juveniles of the Atlantic salmon can suitably acidify a commercial diet to a value generally accepted as optimal for gastric proteases of fish, and to retain about 2/3 of the ingested diet under such conditions and at a nearly constant protease activity until the 8th h of digestion. Normal 0 21 false false false ES-CL X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:Tabla normal; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:Calibri,sans-serif; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-fareast-language:EN-US;}

Outbreak of viral haemorrhagic septicaemia (VHS) in lumpfish (Cyclopterus lumpus) in Iceland caused by VHS virus genotype IV.

A novel viral haemorrhagic septicaemia virus (VHSV) of genotype IV was isolated from wild lumpfish (Cyclopterus lumpus), brought to a land‐based farm in Iceland, to serve as broodfish. Two groups of lumpfish juveniles, kept in tanks in the same facility, got infected. The virus isolated was identified as VHSV by ELISA and real‐time RT‐PCR. Phylogenetic analysis, based on the glycoprotein (G) gene sequences, may indicate a novel subgroup of VHSV genotype IV. In controlled laboratory exposure studies with this new isolate, there was 3% survival in the I.P. injection challenged group while there was 90% survival in the immersion group. VHSV was not re‐isolated from fish challenged by immersion. In a cohabitation trial, lumpfish infected I.P. (shedders) were placed in tanks with naïve lumpfish as well as naïve Atlantic salmon (Salmo salar L.). 10% of the lumpfish shedders and 43%–50% of the cohabiting lumpfish survived after 4 weeks. 80%–92% of the Atlantic salmon survived, but no viral RNA was detected by real‐time RT‐PCR nor VHSV was isolated from Atlantic salmon. This is the first isolation of a notifiable virus in Iceland and the first report of VHSV of genotype IV in European waters.

Deformities in reared cobia, Rachycentron canadum L. and grouper, Epinephelus marginatus, in São Paulo state coast, Brazil: case report

ABSTRACT Skeletal deformities are frequent problems in cultured fish populations due mainly to unfavorable abiotic conditions, inappropriate nutrition, and genetic factors. These may cause erratic swimming, decrease of conversion rate, growth, and market value. The aim of this case report was to present the occurrence of deformities in juvenile cobia and groupers from an offshore marine farm in Ilhabela, São Paulo, Brazil. Nine cobias and seven juvenile groupers, that presented deformities, were euthanized and fixed in 10% formaldehyde. They were tagged, processed, and stained with "Alcian Blue" (AB) and "Alizarin Red-S" (ARS) for visualization of cartilage and bone tissue, respectively. After evisceration, radiographic examination was performed. The deformities observed in cobia were atrophy of the operculum, disorganization of the gill lamellae, deformity of the lower jaw, kyphosis, and scoliosis. Groupers presented lower jaw deformity and saddleback syndrome. The farm studied in this case report had poor management standards, fed commercial feed for freshwater herbivorous fish and cooked sardines, high inbreeding and absence of adequately trained professionals to manage these species. The sum of these factors must have directly influenced the appearance of these deformities. It is necessary to control this situation to minimize the incidence of malformations that have economic impacts to farmers.

Cleaner shrimp remove parasite eggs on fish cages

Benthic stages of cultured fishes' ectoparasites are a major contributor to persistent reinfections in aquaculture. These stages are resistant to chemical therapies and are costly to manage in terms of time and labour. Cleaner shrimp, unlike cleaner fishes, prey on benthic stages, suggesting they have the potential to reduce parasite reinfection pressure without having to be in direct contact with the client fish. Cleaner shrimp have never been used as biocontrols in commercial aquaculture, but offer an advantage over cleaner fishes in that they are not susceptible to the ectoparasites of their clients. We present the first investigation of a cultured cleaner shrimp, Lysmata vittata, as a biocontrol agent against the eggs of the economically important cosmo politan ectoparasite Neobenedenia girellae infecting cultured juvenile grouper, Epinephelus lanceolatus, under simulated recirculating aquaculture conditions. L. vittata removed the eggs of N. girellae entangled on the mesh of the culture cages and significantly reduced N. girellae recruitment to fish by similar to 87%. Our results demonstrate the value of cleaner shrimp in addressing ectoparasite problems and highlight the importance of investigating novel biocontrol strategies in aquaculture.

Validation of 12 species-specific, tetrasomic microsatellite loci from the Russian sturgeon, Acipenser gueldenstaedtii, for genetic broodstock management

The Russian sturgeon, Acipenser gueldenstaedtii, is a critically endangered fish species. Hatcheries are operated in several countries within its natural range to produce stocking material for release into the wild and also for aquaculture purposes (caviar and meat production). An appropriate genetic broodstock management (plan or strategy) is required to avoid negative effects, e.g., admixture and hybridization of genetically differing stocks or loss of genetic variability due to inbreeding and genetic drift. Therefore, 11 tetrasomic microsatellite loci were newly isolated from the Russian sturgeon genome and arranged together with an already known locus into four multiplex PCR sets. These microsatellites were used to characterize three groups of hatchery juveniles from Germany (aquaculture production), Turkey, and Romania (production of stocking material) as well as a group of wild-caught adults from the Danube River, Romania. Based on the variability within groups, measured by the mean number of alleles per locus and expected heterozygosity, and the differentiation between groups, measured by Nei’s GST and genetic distance D, the ability of the 12 loci to detect unwanted reductions in genetic variability within hatchery juveniles and to differentiate between groups could be demonstrated. This set of loci can also be used to identify those pairs of spawners that transmit the highest possible genetic variability to the next generation.

Comparative effect of advanced soy products or corn protein concentrate with porcine meal on growth, body composition, and distal intestine histology of Florida pompano, Trachinotus carolinus

The present study was designed to investigate the effects of diets containing advanced soy products (enzyme‐treated soy and fermented soy) or corn protein concentrate (CPC) in combination with porcine meal (PM) to completely replace poultry byproduct meal (PBM) on growth performance, body composition, and distal intestine histology of Florida pompano, Trachinotus carolinus. Four experimental diets were formulated to be isonitrogenous and isolipidic, to contain 400 g/kg crude protein and 80 g/kg lipid. A reference diet (PBM diet [PBMD]) contained 150 g/kg PBM and 495 g/kg soybean meal (SBM), and three test diets were formulated replacing PBM with 15 g/kg of CPC (CPC diet [CPCD]) or replacing all SBM and PBM with 535 g/kg fermented soy (fermented soybean meal diet [FSBMD]) or 451.3 g/kg enzyme‐treated soy (enzyme‐treated soybean meal diet [ESBMD]). All three test diets were supplemented with 38 g/kg of PM. Diets were fed based on a percentage of bodyweight adjusted after sampling the fish every 2 weeks to triplicate groups of Florida pompano juveniles (mean weight 8.06 ± 0.22 g). After 8 weeks of feeding, fish fed CPCD and ESBMD performed equally well in terms of final body weight, thermal growth coefficient, and percentage weight gain in comparison to fish fed PBMD. In all cases, feeding FSBMD resulted in poor feed conversion and lower feed intake compared to other treatments. Protein retention efficiency, whole‐body proximate composition, phosphorus, sulfur, potassium, magnesium, calcium, sodium, and zinc contents were not significantly influenced by the dietary treatments. The results obtained in the present histological study showed no significant differences in the thickness of serous layer, muscular layer, and submucosal layer of the intestine among treatments. Fish fed CPCD showed a significant widening of the lamina propria with an increase of cellular infiltration and higher presence of goblet cells compared to other dietary treatment. Based on these results, 451 g/kg ESBM or combination of 150 g/kg of CPC and 495 g/kg SBM supplemented with 38 g/kg PM can be utilized to develop a practical diet for juvenile Florida pompano without impacting growth, nutritive parameters, and several distal intestine health parameters.

Investigations on zinc bioavailability of different sources and dietary zinc requirement in juvenile grouperEpinephelus coioides

An experiment was implemented to study the effect of dietary zinc levels from three zinc sources on growth performance, immunity, and tissue mineral elements deposition on juvenile grouper. Based on the zinc free feeds, dietary zinc levels of 0, 10, 20, 40, 80, and 160 mg/kg were added from zinc sulphate (ZnSO4), tetrabasic zinc chloride (TBZC), and 2-hydroxy-4-(methylthio) butyrate zinc (Zn-HMB). The results of the 8-week study indicated that the weight gain rate (WGR) and specific growth rate (SGR) at level 10 mg/kg were significantly higher than the control fed and the reached a plateau until level 80 mg/kg, when the sources were ZnSO4 and Zn-HMB. WGR and SGR decreased significantly at level 160 mg/kg compared to 80 mg/kg in group TBZC. Feed coefficient (FCR) of all zinc source groups showed trend of decrease before rising. The alkaline phosphatase (AKP) in serum, catalase (CAT), total superoxide dismutase (SOD), copper-zinc superoxide dismutase (Cu-Zn SOD) in liver and zinc concentrations in whole body and vertebrae increased significantly than those in control group and then kept steadily in all treatments. Regardless of the sources, the manganic content of whole body or vertebra showed a downtrend. Based on the WGR, the dietary zinc requirements in juvenile grouper were 52.94 mg/kg from ZnSO4. The average relative bioavailability (RBV) of TBZC and Zn-HMB was 169.33% and 200.33%, respectively, compared to ZnSO4.

Dietary inclusion of mealworm (Tenebrio molitor) meal as an alternative protein source in practical diets for juvenile rockfish (Sebastes schlegeli)

AbstractAn 8‐week feeding trial was designed to evaluate the potential of yellow mealworm (Tenebrio molitor) as a locally available nutrient‐rich feedstuff for juvenile rockfish (Sebastes schlegeli). Experimental diets containing elevated levels of mealworm meal (WM) supplemented with synthetic methionine were formulated to be isonitrogenous, isolipidic and isoenergetic to a WM‐free fishmeal (FM) based control diet (designated as WM0, WM8, WM16, WM24 and WM32, respectively). To determine the necessity of dietary methionine supplementation at the highest inclusion of WM, a diet was prepared to contain 32% WM without methionine supplementation (WM32‐AA). Triplicate groups of rockfish juveniles (Mean ± S.E.; 3.11 ± 0.01 g) were fed one of the experimental diets to apparent satiation twice daily for 8 weeks. Fish growth performance in terms of weight gain and specific growth rate increased with increasing dietary inclusion of WM from 0 to 16% and then tended to decrease with further increase in dietary WM levels to 32%. Protein retention (PR) values followed the same trend as growth rates with the highest values found in fish offered WM16 diet. Although fish fed WM32‐AA diet showed significantly lower growth rate and PR values compared to those fed WM16 diet, their performance was still comparable to that of the WM‐free control group. Plasma triglyceride level was negatively affected by dietary WM inclusion and the lowest values were observed in the WM32‐AA group. Whole‐body and fillet proximate and essential amino acid compositions were not altered by dietary treatment and these values were comparable to those of the WM0 group. These findings suggested that WM might prove to be a promising alternative to FM in practical diets for juvenile rockfish and could be used at an inclusion level of up to 32% without having any adverse consequences for the health and performance of the fish. Although the diet containing 32% WM seemed to support a performance similar to that of the control diet, the recommended dietary inclusion level was no more than 16% of the diet dry matter.

Serum cortisol level and survival rate of juvenile Epinephelus fuscoguttatus following exposure to different salinities.

Background and Aim:Brown-marbled grouper Epinephelus fuscoguttatus is a premium marine food fish with high demand in Asia. In fish, stress due to environmental changes such as fluctuations in the salinity can result in increased cortisol level. Stress in fish increases susceptibility to diseases ultimately resulting in death. Therefore, the aim of this study was to investigate the salinity tolerance of E. fuscoguttatus and their survival in lower salinities.Materials and Methods:In this study, grouper juveniles (92.43±standard error of the mean 0.51 mm) maintained in 31 ppt seawater were transferred into five tanks with seawater diluted to 25, 20, 15, 10, and 5 ppt. The salinity of the control group was not changed and was maintained at 31 ppt. Serum cortisol was measured using ELISA at 0, 30, 60, and 120 min after the fish were transferred to the different concentrations of salinity.Results:The survival percentage was recorded for 14 days following the transfer and the results revealed that serum cortisol of fish in a high change in salinity (15, 10, and 5 ppt) was significantly higher than the control group immediately after exposure. At the high salinity change, the cortisol levels gradually decrease at 30 min and 60 min, until no difference in cortisol concentration was observed at 120 min. No mortality was observed in fish exposed to low salinity change (25 and 20 ppt) while in higher salinity change (5 ppt), the survival percentage was 50%.Conclusion:The study revealed that the serum cortisol concentration was high initially and continues to decrease to resting cortisol level at 120 min indicating that cortisol hormone is released following acute stress as a primary response in grouper juveniles.

Maternal Effect on the Commencement of Hibernation and Body Mass of the Juvenile Edible Dormouse Glis glis in Captivity

ABSTRACT The aim of our study was to check whether maternal presence during the post-weaning period affects the onset of hibernation and weight gain under unlimited food supply in juvenile edible dormice Glis glis. We investigated four groups of siblings growing up in the presence of the mother (“with mother”; n=17) and three groups of juveniles separated from the mother after weaning (“without mother”, n = 17). We found that: (i) more juveniles started hibernation from the group “without mother” than from the group “with mother” (χ2 = 8.24, P < 0.01) at the end of study, when most dams entered hibernation, (ii) weight was not a factor which determined the decision of entering hibernation (iii) juveniles growing up “without mother” did not differ significantly from juveniles raised “with mother” in terms of mean body mass during the last weighing before hibernation (t = 0.48, P = 0.63) and maximum body mass (t = 0.11, P = 0.91), (iv) the presence of the mother may influence the process of making decisions...

Promoting restoration of fish communities using artificial habitats in coastal marinas

Rapid urbanization has become an area of crucial concern in conservation, owing to urban infrastructure impacts on natural ecosystems. Urban infrastructures are often poor surrogates for natural habitats, and a diversity of eco-engineering approaches has been trialed to enhance their ecological value.Marinas are among the most common human-made infrastructures found on the shoreline, and cause substantial habitat destruction within the sheltered coastal areas previously used as nursery grounds by many fish species. The present study aimed at testing the suitability of installing artificial habitats (Biohut®) in marinas to reinforce the nursery function of the Marchica coastal lagoon, which historically hosts many species of juvenile groupers, including the endangered dusky grouper Epinephelus marginatus.Our hypothesis – that artificial habitats, by increasing habitat complexity, enhance the ecological value of a marina – was strongly supported by our results. The Biohuts hosted a high relative density of juvenile dusky and comb groupers in comparison with natural habitats. They can, therefore, be considered as a reservoir for juvenile groupers, including the endangered dusky grouper, and are suitable to reinforce the nursery function of this coastal lagoon.Subsequently, Biohuts can act as a ready-made nursery area to support the creation of small marine reserves that can reinforce the grouper population re-colonization along the coast of North Africa, which is considered to be the region from which the individuals populating the north western Mediterranean originated, and thus provide for long-term recovery of the endangered dusky grouper.

Клинико-психологические аспекты экспертной оценки уголовно-процессуальной дееспособности у несовершеннолетних обвиняемых

The article deals with issues of clinical-psychological criteria of expert evaluation of competency to stand trial (CST) in juvenile offenders. Using the material of joint forensic psychiatric-psychological evaluations of 100 male juvenile offenders the authors singled out statistically significant indices of psychic activity, which differentiated groups of juveniles with and without CST. Three blocks of parameters for the CST expert evaluation are described. The first block includes the functioning character of the main cognitive processes, the second – the adequacy of social meanings understanding and of the ability to build logical conclusions on their basis, the third – the ability of social behavior regulation. The general controlling component of the system is critical thinking. Concrete empirical indices of the parameters are presented. The authors outline perspectives of the future development of the clinical-psychological analysis of the CST.

Effect of dietary phospholipid levels on growth, lipid metabolism, and antioxidative status of juvenile hybrid snakehead (Channa argus×Channa maculata).

The study was conducted to evaluate the effect of dietary phospholipids (PLs) on growth, lipid metabolism, and antioxidative status of hybrid snakehead (Channa argus × Channa maculata). Five isonitrogenous and isolipidic diets with graded levels of PLs (8.5, 19.3, 30.7, 41.5, and 50.8gkg-1) were fed to triplicate groups of juveniles (initial body weight 12.6 ± 0.23g) for 8weeks. Results showed that dietary PL supplementation significantly improved growth of juveniles. The final body weight (FBW) and specific growth rate (SGR) significantly increased with dietary PLs increasing from 8.5 to 41.5gkg-1 (P < 0.05). Fish fed with the diet containing 8.5gkg-1 PLs showed higher feed conversion ratio (FCR) compared to the other treatments (P < 0.05). Survival rate (SR) was not affected by dietary PL levels (P > 0.05). Liver lipid contents, serum triglyceride (TG), and low-density lipoprotein cholesterol (LDL-C) contents significantly decreased with the increasing levels of dietary PLs (P < 0.05). However, serum total cholesterol (TC) and high-density lipoprotein cholesterol (HDL-C) contents and HDL-C/TC and HDL-C/LDL-C value significantly increased with increasing dietary PL levels (P < 0.05). The catalase (CAT), superoxide dismutase (SOD), and carnitine palmitoyl transferase I (CPT-1) activities in the liver significantly increased with incremental dietary PL level (P < 0.05), while the liver malondialdehyde (MDA) contents and fatty acid synthase (FAS) activity significantly reduced (P < 0.05). No significant difference was observed in the glutathione peroxidase (GPx) activity among dietary treatments (P > 0.05).These results confirmed that dietary PL supplementation has beneficial effects on growth performance and antioxidant capacity of juvenile hybrid snakehead. Dietary PLs might reduce lipid deposition in the liver of juvenile hybrid snakehead.