Stages Of Sexual Maturation Research Articles

Macroscopic evolution of the Pomadasys jubelini testis from the Ivorian continental shelf

Undernourishment linked to a lack of animal protein is rife in Africa. Fish consumption appears to be the solution to this problem. However, fish products are becoming increasingly scarce due to the depletion of fish farming resources in maritime and continental waters. Hence the need to intensify fish farming. This requires mastery of the reproduction of the fish to be domesticated. After dissecting the fish, their sex and stage of sexual maturity were determined. An anatomical study showed that the Pomadasys jubelini testis consists of 2 lobes and presents 5 stages of sexual maturity. They become spermiant at stage 4, making stage 4 males ideal broodstock for fish farming.

Utility of First-Morning-Voided Urinary Total Luteinizing Hormone in Detecting the Onset of Central Puberty

Introduction: Early morning basal serum luteinizing hormone (S-LH) ≥0.3 IU/L is a specific marker for the onset of central puberty. In this study, we aimed to investigate the sensitivity and specificity of the first-morning-voided (FMV) total urinary LH (U-LH) to replace this marker. Methods: We re-analyzed our previously published data set of 297 children (145 boys and 152 girls, aged 5–15 years, across Tanner stages 1 through 5) using receiver operating characteristic (ROC) analysis and determined cutoff values for FMV total U-LH in predicting early morning S-LH concentration at or above 0.3 IU/L. We also determined S-LH and serum follicle-stimulating hormone (S-FSH) concentrations in girls at different stages of sexual maturation. Results: ROC analysis showed that FMV total U-LH levels of 0.60 and 0.63 IU/L in girls and boys, respectively, predicted early morning S-LH levels of 0.3 IU/L or higher with 97.4% sensitivity and 90.6% specificity. Higher cutoff levels for U-LH (0.78 IU/L for boys and 0.79 IU/L for girls) yielded 94.7% specificity at the expense of a relatively lower level of sensitivity (94.1%). The areas under the curve were 0.98 in boys and 0.99 in girls, respectively. Additionally, the increase in FMV total U-LH (or S-LH) levels identified the activation of central pubertal development at the mean age of 10.3 (10.3) in boys and 10.5 (10.6) in girls. The S-FSH concentrations of the six biochemically prepubertal girls with thelarche, ranging between 2.3 and 2.7 IU/L, were significantly higher than those measured in biochemically and clinically prepubertal girls of the same 10–12-year-old age group and significantly lower than those measured in both biochemically and clinically pubertal girls (p = 0.039 and p = 0.018, respectively). Conclusions: A FMV total U-LH concentration of 0.6 IU/L or above reliably reflects pubertal morning S-LH levels and is effective in detecting the onset of central puberty, which occurs at similar ages in both sexes. Concurrent S-FSH or noninvasive FMV U-FSH determinations may be useful in the differential diagnosis of isolated thelarche.

Reproductive biology of the rock oyster Striostrea prismatica in two populations of the Mexican Central Pacific

ABSTRACT The oyster Striostrea prismatica is a fishery-relevant species in the eastern tropical Pacific, particularly in the Mexican Central Pacific (MCP), and little is known about its reproductive cycle. Therefore, our study analysed gametogenesis, sex ratio, sexual maturity stages, shell height at first maturity, and condition index during 2014 and 2015 in El Tizate and La Victoria in the MCP. The sex ratio was significantly biased towards males at both sites, presumably due to ontogeny or fishing pressure. The highest condition index was observed between April and May in both years, while lower values were observed from September to December. The reproductive cycle in both sites was annual, with maturity and spawning from June to August and the degradation phase in August. The condition index showed a negative correlation with temperature and chlorophyll a in both sites: as a result, the period of maximum maturity and spawning coincided with the closure of the fishery in Mexico (June-August). Females had more significant shell height at first maturity than males at both sites, possibly associated with fishing pressure. The information from this study is a significant contribution, but it is necessary to extend the studies to populations further south and further north.

Length–Weight Relationship and Sexual Maturity Stages of Bluefish: Pomatomus saltatrix (L, 1766) in Tripoli Coast, Libya

Pomatomus saltatrix (L, 1766) is an important commercial fish in several countries, and that suffer from overfishing problems. In this study, 50 individuals of P. saltatrix were conducted during the fall, (October-November, 2022), on the Tripoli coast. Their total lengths and total weights were measured. The sex of the fish was determined, and the stages of sexual maturity were identified. The results showed that their lengths ranged 23.5-35cm, total weights 139-408g. The relationship between length and weight was negatively allometric, the number of males was higher than that of females, and all stages of sexual maturity were present.

Fluoxetine and Sertraline Inhibit Height Growth and Growth Hormone Signaling During Puberty.

The aim of this study was to examine the effect of fluoxetine and sertraline on height growth and insulin-like growth factor-1 (IGF-1) during puberty. In this 6-month cohort study, electronic medical records were used to identify 8- to 15-year-old participants, within 1 month of starting fluoxetine (n = 39) or sertraline (n = 27), and sexual maturation stages 2 to 4 were confirmed. Conditions that interfere with height growth led to exclusion. Participants underwent anthropometric assessments and phlebotomy. Healthy, unmedicated children (n = 36) also provided anthropometric data. After the baseline height Z-score, sex, Tanner stage, daily selective serotonin reuptake inhibitor (SSRI) dose, and time were accounted for, the interaction effect of dose by time was inversely associated with height Z-score in SSRI-treated participants (β = -0.18; 95% confidence interval [CI]: -0.35, -0.02). Sertraline and fluoxetine did not differ in their effect on height growth. Compared with being unmedicated, SSRI treatment was associated with a smaller growth in height (time × dose 2-way interaction effect β = -1.30; 95% CI: -2.52, -0.09). The interaction effect of dose by time was significant for body mass index Z-score (β = 0.35; 95% CI: 0.06, 0.64) but not weight Z-score (β = 0.24; 95% CI: -0.01, 0.49). Body mass index Z-score increased more with sertraline compared with fluoxetine (time × dose × SSRI type 3-way interaction effect P < 0.05). SSRI dose was inversely associated with IGF-1 (β = -63.5; 95% CI: -112.2, -14.7) but not insulin growth factor binding protein-3 concentration (β = -207.3; 95% CI: -536.2, 121.5). Fluoxetine and sertraline reduce height gain and IGF-1 concentration, in a dose-dependent manner. Longer-term studies are necessary.

Current trend of sexual maturity, teeth eruption, and bone fusion in the present female population, relative to documented age and development of prediction model for age of females.

Understanding sexual maturity and bone fusion is crucial in forensic investigations and legal contexts. This study investigates the contemporary trend of sexual maturity and bone fusion in females, comparing the observed age-related characteristics with documented ages. Such analyses contribute to the accuracy of age estimation methods used in medico-legal scenarios. A comprehensive study was conducted involving a diverse sample of females, and their sexual maturity and bone fusion were assessed relative to documented ages. The research utilized a cross-sectional design, collecting data through interviews, medical examinations, and radiographic imaging. Ethical approval was obtained, and participants provided informed consent. Variables included documented age, age of menarche, stages of sexual maturity, dentition, and bone fusion. Validation of model performance was conducted. Among 70 cases studied, the mean age of menarche was 10.48 years (range: 7-12 years). Maternal reports indicated menarche onset between 12-17 years. Tanner's Staging 5 for pubic hair and fully developed breasts occurred at 14 years. Permanent teeth increased with age, with 28 or more teeth present at age 14 or above. Fusion of the distal end of the Radius and Ulna with the parent bone was positive from 15 years onwards. The regression model predicted age accurately (97.99% fit). The results highlight the early onset of sexual maturation, consistent teeth eruption, and bone fusion patterns in females. The observed correlations offer valuable insights for medicolegal practitioners and forensic experts.

The influence of physiological and functional characteristics of the body of girls aged 17-18 years on playing sports

Achieving competitive results in women’s sports for athletes aged 17-18 requires structuring training processes around their physiological characteristics. This article analyzes recent scientific data on the impact of sexual dimorphism in girls aged 17-18 on sports participation and training. Relevant scientific works from the past five years were collected and analyzed. At this age, girls undergo the final stage of sexual maturation. The effectiveness of sports activities varies individually, influenced by the ovarian-menstrual cycle, hormonal background, and symptoms in each cycle phase. Physical activity declines during the menstrual, ovulatory, and premenstrual phases, while postmenstrual and postovulatory phases are more favorable for sports participation. Performance indicators depend on sexual dimorphism: female athletes show unique features in central nervous system activity, high psycho-emotional excitability, and earlier development of somatic and physical qualities compared to males. The skeletal structure in 17-18-year-old female athletes is smaller and shorter, with a wider pelvis and more developed shoulder girdle. These findings can be used by sports schools, rehabilitation specialists, coaches, and sports physicians to adapt and structure training processes, taking into account the physiological characteristics of 17-18-year-old female athletes, aiming for highly competitive results. Keywords: Sexual Dimorphism, Hormonal Changes, Women’s Sports, Physical Culture, Sports Performance.

Progranulin and Vaspin as Potential Novel Markers in the Etiology of Type 1 Diabetes in Children.

Background and Objectives: Diabetes is a significant health problem, prompting the search for new therapeutic strategies. Recently, researchers have focused on identifying novel markers for the progression of this condition. It is well established that adipokines, such as progranulin and vaspin, play crucial roles in regulating lipid and carbohydrate metabolism. Materials and Methods: This single-center cross-sectional study aimed to assess serum progranulin and vaspin levels in 80 children diagnosed with type 1 diabetes (T1D) and to examine their correlation with body mass index (BMI), glycated hemoglobin, and lipid profile. The cohort included 40 children newly diagnosed with diabetes, 40 children with long-term diabetes (20 well-controlled and 20 poorly controlled), and 14 non-diabetic children as a control group. Progranulin and vaspin levels were determined using a sandwich enzyme-linked immunosorbent assay. Results: There were no significant differences in the progranulin and vaspin concentrations in the studied groups (p = 0.246 and p = 0.095, respectively). No statistically significant differences were noted in the levels of both adipokines among boys and girls within the T1D, well-controlled T1D, and poorly controlled T1D groups. We did not find any differences in the progranulin and vaspin levels among all children with T1D and healthy controls when divided based on BMI percentiles. A negative correlation was observed between progranulin concentration and the age of children in the T1D, well-controlled T1D, and healthy groups. Furthermore, progranulin correlated negatively with BMI among children with T1D. In contrast, vaspin concentration correlated positively with age among healthy children. Conclusions: Our study provides novel insights into the status of progranulin and vaspin among pediatric participants with varying levels of type 1 diabetes control. However, further research involving larger patient cohorts and different stages of sexual maturation is warranted.

Dietary supplementation with ginseng extract enhances testicular function, semen preservation, and fertility rate of mature and aging Thai native roosters

The decrease in fertility in aging roosters is related to the reduced quality of ejaculated sperm. This study aimed to investigate the effect of dietary supplementation with ginseng extract at various concentrations (0–150 mg/kg) on testicular function, semen preservation, and fertility at different stages of sexual maturity (mature and aging roosters) in Thai native roosters. Pradu Hang Dum roosters at 32 (mature; n = 24) and 75 (aging; n = 24) weeks of age were fed diets with non-supplemented or supplemented ginseng extracts (50, 100, and 150 mg/kg) until the end of the experiment. In experiment 1, fresh semen samples were examined for the quality parameters of semen volume, sperm concentration, sperm motility, sperm viability, lipid peroxidation, and enzymatic activities. In experiment 2, semen was preserved at 5 °C for up to 48 h, and the semen quality and fertility potential were determined. In experiment 3, testicular function and testosterone concentrations were evaluated. The results showed that ginseng extract supplementation in the diets of both mature and aging roosters at 50 and 100 mg/kg improved fresh semen quality (P < 0.05). A decrease in malondialdehyde levels in fresh semen was observed with increasing enzyme activities. In mature roosters, the progressive motility of cold-stored semen and fertility rates were higher in the G50 and G100 groups compared to the control and G150 groups after 24 h of storage (P < 0.05). In aging roosters, the highest significant differences in progressive motility, viability, and fertility rates were observed in the G50 and G100 groups at all storage times (P < 0.01). These improvements might be attributed to good testicular function in spermatogenesis, as revealed by the results of histological examination and testosterone concentrations. However, higher doses of ginseng extract supplementation negatively affected sperm quality. In summary, the recommended dose of ginseng extract supplementation in diets is 50 mg/kg. Fertility results indicated that insemination with semen preserved for 24 h was satisfactory in both mature and aging roosters.

Joint models reveal genetic architecture of pubertal stage transitions and their association with BMI in admixed Chilean population.

Early or late pubertal onset can lead to disease in adulthood, including cancer, obesity, type 2 diabetes, metabolic disorders, bone fractures, and psychopathologies. Thus, knowing the age at which puberty is attained is crucial as it can serve as a risk factor for future diseases. Pubertal development is divided into five stages of sexual maturation in boys and girls according to the standardized Tanner scale. We performed genome-wide association studies (GWAS) on the "Growth and Obesity Chilean Cohort Study" cohort composed of admixed children with mainly European and Native American ancestry. Using joint models that integrate time-to-event data with longitudinal trajectories of body mass index (BMI), we identified genetic variants associated with phenotypic transitions between pairs of Tanner stages. We identified $42$ novel significant associations, most of them in boys. The GWAS on Tanner $3\rightarrow 4$ transition in boys captured an association peak around the growth-related genes LARS2 and LIMD1 genes, the former of which causes ovarian dysfunction when mutated. The associated variants are expression and splicing Quantitative Trait Loci regulating gene expression and alternative splicing in multiple tissues. Further, higher individual Native American genetic ancestry proportions predicted a significantly earlier puberty onset in boys but not in girls. Finally, the joint models identified a longitudinal BMI parameter significantly associated with several Tanner stages' transitions, confirming the association of BMI with pubertal timing.

Feeding ontogeny and trophic ecology of the shortfin mako shark, Isurus oxyrinchus, on the west coast of Baja California Sur, Mexico

Certain shark species are considered top predators, which bestows them with important roles in the trophic dynamics of marine ecosystems. The present study describes the ecology and ontogeny feeding of the shortfin mako shark Isurus oxyrinchus along Baja California Sur, Mexico, through stomach content analysis (SCA) and stable isotope analysis (SIA). A total of 272 stomachs and 39 muscle samples of I. oxyrinchus were analyzed. The SCA indicated that I. oxyrinchus has a wide trophic spectrum, with a consumption preference for Dosidicus gigas, Prionotus albirostris, and Scomber japonicus; however, feeding differences by sexes and sexual maturity stages were evidenced. The SCA indicated that I. oxyrinchus is a specialist consumer (Bi = 0.10) occupying high trophic positions (TP: 4.7–5.2). SIA reflected isotopic signals between –17.3 ‰ and –15.7 ‰ for δ13C and 15.5 ‰ and 19.5 ‰ for δ15N, but with some differences by maturity stages in δ15N (Young-of-the-year = 16.4 ± 0.66 ‰, Juveniles = 18.1 ± 0.13 ‰, adults = 18.3 ± 0.56 ‰). The SIA suggests that this species has a wide isotopic niche (SEAC: 1.08 ‰2) and occupies high TP (3.9–6.2). In conclusion, I. oxyrinchus presents segregation by sex and maturity stages, shows ontogenetic changes in habitat use and prey selection related to the physical characteristics of the zone (bathymetry), and plays important roles in the trophic dynamics of marine ecosystems.

Isolation and Characterization of Beneficial Bacteria in the Guts of Cultured Sturgeon

Wild sturgeons have been harvested for their meat and caviar. Sturgeons have been cultivated to stop relying on wild stocks due to depletion. However, sturgeons take a long time to reach their sexual maturity stage. Probiotics have been said to be an ideal supplement to enhance the growth of culture sturgeon. Nevertheless, the study of beneficial bacteria in the guts of cultured sturgeon is very scarce. The purpose of this study is to isolate and characterize beneficial bacteria in the guts of culture sturgeon in Malaysia. In this study, isolation and characterization of beneficial bacteria was done in the guts of 3 different sturgeons which were Acipenser schrenckii (Amur sturgeon), Acipenser gueldenstaedtii (Russian sturgeon), and Acipenser baerii (Siberian sturgeon). The isolation of bacteria was done according to three section of guts which are foregut, midgut and hindgut and isolated on the tryptic soy agar (TSA), de Man Rogosa and Sharpe agar (MRS agar) and MRS agar with 2% of CaCO3. The total colony count and biochemical characterization including gram staining reaction, catalase and oxidase test were done on the selected colony. Total colony count revealed that hindgut area of all species is significantly higher (6.93 ± 1.39 log CFU/ml) compared to foregut (4.98 ± 2.32 log CFU/ml) and midgut (6.09 ± 0.64 log CFU/ml). Biochemical characterization results showed that all the isolates selected were gram positive, catalase negative and producing clear zones on MRS agar with 2% of CaCO3. The most potential candidate’s presence in the colony groups were genus Bacillus, Bifidobacterium and Lactobacillus. The results obtained showed that different species contain different types of bacteria. A study reported that host factors can affect the gastrointestinal microbiota of the fish. However, the weight of these three species has a big gap which were between 4.98kg to 10.51kg. Thus, the weight of the host is assumed to be another factor for the different distribution of the colonies. To conclude, further study needs to be conducted on the effect of the weight in the colonization of the beneficial bacteria in guts of culture sturgeon.

Understanding the contents and gaps in sexual and reproductive health toolkits designed for adolescence and young adults: a scoping review.

Adolescence is a crucial stage of physical and sexual maturation and development and a period in which understanding sexual and reproductive health (SRH) is important. SRH interventions and toolkits provide a range of valuable resources and information to young people, educators, and members of the community on numerous topics, including contraception and puberty. The usefulness and reliability of these available toolkits have not been previously studied, thus limiting our understanding of their appropriateness and contents. Hence, this scoping review aimed to synthesize the available toolkits aimed at the SRH of adolescents and young adults to understand the contents, design, and information gaps. A systematic search was conducted of 6 medical databases and 12 gray literature sites. Sixteen toolkits published globally before May 2023 were included in our review. The majority of toolkits (n = 12) contained information related to general SRH knowledge and contraception, whereas only 3 contained information on teenage pregnancy. We found that aiming the toolkits toward educators and health care workers was a favorable design over targeting adolescents and young adults directly and that vulnerable youth-including LGBTQI+ (lesbian, gay, bisexual, transgender, queer or questioning, asexual or allied, intersex, and additional identities) and youth from humanitarian settings-were not well represented. We identified key gaps in the inclusion of information in a range of SRH topics, such as LGBTQI+ sexuality, teenage pregnancy, and safe abortion, in the currently available SRH toolkits and their lack of applicability in a global context. Furthermore, we provide recommendations for areas of improvement to encourage adolescents' agency in their SRH education.

Influence of sexual maturation on anaerobic performance of male adolescent wrestlers

This study aimed to examine the impact of sexual maturation on the anaerobic performance of male adolescent wrestlers. Methods: We included a sample of 29 freestyle and Greco-Roman wrestlers from various clubs in Barinas, Venezuela. Their physical characteristics were as follows (mean ± SD): age, 14.99 ± 1.83 years; body mass, 54.68 ± 16.80 kg; height, 161.06 ± 12.78 cm; body fat, 12.09 ± 4.11%; body mass index (BMI), 20.58 ± 3.79 kg/m2; and training experience, 3.66 ± 2.27 years. Sexual maturation was evaluated using Tanner's criteria, while anaerobic performance was assessed with the 30-second Wingate test for both lower and upper body. Results: There were moderate to strong significant correlations between maturation development and both peak power (PP) and average power (AP) — for both absolute and relative measures — for the lower and upper body. The fatigue index (%FI) for the lower body did not show any correlation with maturation development or with the pubescent and postpubescent maturation categories. Conversely, the %FI for the upper body demonstrated a significant moderate correlation with maturation development and with the postpubescent maturation category. Additionally, a strong significant correlation was observed between the pubescent maturation category and both PP and AP (absolute and relative) for the lower body. A moderate correlation was found between the postpubescent category and PP (absolute) for the upper body. PP (absolute) and AP (relative) for the upper body had a moderate correlation with the pubescent maturation category, while the postpubescent category showed a strong correlation with PP (absolute), AP (absolute), and AP (relative). Conclusion: The stages of sexual maturation significantly influence the anaerobic capacity of adolescent wrestlers, potentially affecting their training adaptations for peak performance. Future research should explore the physiological responses to training protocols tailored to specific stages of maturation.

Molecular Mechanisms of circRNA-miRNA-mRNA Interactions in the Regulation of Goose Liver Development.

The liver, a crucial metabolic organ in animals, is responsible for the synthesis, breakdown, and transport of lipids. However, the regulatory mechanisms involving both coding and noncoding RNAs that oversee the development of the goose liver remain elusive. This study aimed to fill this knowledge gap by conducting RNA-seq to profile the expression of circular RNAs (circRNAs) and microRNAs (miRNAs) during goose liver development. We analyzed circRNAs in liver samples from Sichuan white geese at three developmental stages: posthatching day 0, 10 weeks (fast growth stage), and 30 weeks (sexual maturation stage). Our findings revealed 11,079 circRNAs and 994 miRNAs, among which the differentially expressed circRNAs and miRNAs were significantly enriched in pathways such as fatty acid biosynthesis, degradation, and metabolism. Further analysis of the target genes of the differentially expressed miRNAs revealed enrichment in pathways related to fatty acid biosynthesis, metabolism, PPAR signaling, DNA replication, and the cell cycle. We also established circRNA-miRNA-mRNA regulatory networks, identifying key regulatory factors and miRNAs. In conclusion, our study offers valuable insights into the complex interplay of circRNA-miRNA-mRNA interactions during goose liver development, and illuminates the molecular pathways that regulate this vital life function.

Investigating the Incidence of Dyslipidemia among Brazilian Children and Adolescents Diagnosed with Type 1 Diabetes Mellitus: A Cross-Sectional Study.

The treatment of Type 1 Diabetes Mellitus (T1DM) has always been a challenge for health professionals in relation to glycemic control. Increased body fat has been related to a worsening of the lipid profile and increased prevalence of dyslipidemia in this population, leading to negative repercussions on the control of cardiovascular risk. We aimed to investigate the distribution of lipid levels and the presence of dyslipidemia in children and adolescents with T1DM. A cross-sectional observational study was conducted with 81 individuals of both sexes (4-19 years) diagnosed with T1DM. Anthropometric and biochemical data were collected, in addition to data on physical activity level, sexual maturation stage, and insulin administration regimen. Lipid levels were categorized as normal, borderline, and elevated, and the presence of dyslipidemia was diagnosed by the presence of one or more altered lipid parameter. We noted a prevalence of dyslipidemia in 65.4% of the participants when considering borderline lipid values. Of those, 23.5% had one altered lipid level, and 42.0% had two or more. The main altered lipid levels were total cholesterol and triglycerides, followed by non-HDL-c. The main factor associated with the worsening of lipid levels was the increase in HbA1c. Sex had a significant effect on the levels of TC, HDL-c, and ApoA-I. The results of this study reinforce the need to monitor lipid profile in children and adolescents with T1DM, as well as the importance of early intervention in treating dyslipidemia, especially in patients with poor glycemic control.

Essential and Non-Essential Elemental Composition and Health Risks in Pacific Sardine in the Northwest Pacific Ocean

Pacific sardine (Sardinops sagax) in the northwest Pacific Ocean (NPO) not only preserve the equilibrium of the NPO food chain, but also serve as a source of nutrition for humans. In order to evaluate the levels of various elements in S. sagax, we collected specimens from NWP waters and ascertained the quantities of four macronutrients, nine essential trace elements, and twelve non-essential trace elements. The factors (fatness, sex, sexual maturity, body length, body weight, and age) influencing the concentration were investigated, and the correlations of trace elements were examined. Additionally, the Estimated Daily Intake (EDI) approach and the Target Hazard Quotient (THQ) methodology were used to assess contamination levels and associated consumption risks. The results revealed that the macronutrient content (54–10,500 mg kg−1) was higher than the necessary trace elements (0–488 mg kg−1) and the non-essential trace elements (0–448 mg kg−1), and most of the elements showed positive correlation with each other. Almost all of the element concentrations were below the maximum permitted levels (MPLs) recommended by the FAO/WHO, except for As and Cd. The factors, including fatness, sexual maturity, body length, body weight, and age, showed a negative correlation with most of the trace elements. The outcomes of the stepwise regression analysis showed that sex and stage of sexual maturation were the principal biological factors influencing elemental content. The risk assessment and standard dietary intake levels indicated that the potential health issues associated with the consumption of S. sagax were negligible.

Morphochromatic spectrum through gonad development stages of the razor surgeonfish, Prionurus laticlavius (Valenciennes, 1846) (Actinopterygii: Acanthuriformes).

Gonad development stages (GDS) are a critical tool that can be easily applied in fisheries to visually discriminate mature from immature organisms and assess their reproductive condition. This study proposes a morphochromatic scale to define gonad development stages for razor surgeonfish (Prionurus laticlavius) based on morphological and structural assessments of the gonad, histologically validated using multivariate dummy matrices modeled through multiple linear regression analyses. Gonads of 271 specimens were photographed prior to preservation to describe their shape, size, color, and turgor for morphochromatic analysis. Later, gonads were processed using standard histological methods. An oocyte growth scale was designed based on oocyte diameter and follicular wall thickness for each stage. In addition, five morphochromatic gonad development stages were histologically validated: immature, developing, spawning capable, regressing, and regenerating. Morphochromatic variations were observed in the last three stages in both sexes. Results show that gonad morphology and structure of P. laticlavius are similar to those of other acanthurids, albeit with some asymmetric and morphological differences, as well as gonad morphochromatic in both sexes. These findings confirm that maturation is species-specific. Also, although not a critical character, gonad colouration was found to play a major role in distinguishing between gonad development stages along with shape, size, vascularity (females), and folds (males). Therefore, gonad colouration should not be entirely overlooked because doing so may lead to errors in determining sexual maturity stages.

Effects of dopamine and melatonin treatment on the expression of the genes associated with artificially induced sexual maturation in Japanese eel, Anguilla japonica.

Japanese eel (Anguilla japonica) is a commercially important fish species in Asia. Understanding factors like photoperiod, temperature, and lunar cycles is crucial for successful aquaculture and managing its reproduction. Melatonin and dopamine (DA) are essential for regulating reproduction in vertebrates, including fish. This study investigated the effects of melatonin and DA on the reproductive system of mature male Japanese eels to better understand reproductive regulation in fish. To clarify the effects of these hormones on sexual maturation in eels, a critical stage in the reproductive process, sexual maturation was induced by injecting human chorionic gonadotropin, which stimulates the production of sex hormones. To check the effect of melatonin and DA on sexual maturation, DA, melatonin, and DA + domperidone were intraperitoneally injected into fish from each group (six per treatment) at a dose of 1 mg/kg body weight. The fish were then examined using quantitative RT-PCR by comparing the messenger RNA level of reproduction-related genes (gonadotropin releasing hormone 1; gnrh1, gonadotropin releasing hormone 2; gnrh2, follicle stimulating hormone; fshβ, luteinizing hormone; lhβ and DA receptor 2b; d2b), involved in the gonadotropic axis in eels, to those that received a control injection. The results indicate significant differences in the expression levels of gnrh1, gnrh2 and d2b in the brain and d2b, fshβ, lhβ in the pituitary at different stages of sexual maturation. Melatonin appears to enhance the production of sex gonadotropins, whereas DA inhibits them. These findings suggest an interaction between melatonin and DA in regulating reproduction in Japanese eels.

The Reproductive Biology of Puye (Galaxias maculatus) under Experimental Culture.

This study determines the reproductive patterns of puye (Galaxias maculatus) under culture conditions. A population of 567 wild fish was caught in the Cautín River, Chile, and held in captivity for four years. Mortality, sex ratio, gonadosomatic index (GSI), sexual maturity stages, spawning period, type and frequency of spawning, and fecundity were measured. The fish grew throughout the experimental period, with the fastest rate during the first half of the first year of life. The highest mortality occurred during the first three months of the experiment and during the spawning season. The sex ratio was almost 1:1 (female:male). First sexual maturity was reached at one year of age, with an average weight of 0.85 ± 0.01 g, total length of 4.85 ± 0.16 cm, and condition factor 0.0074. The highest GSI in both females (12.14 ± 0.74) and males (17.7 ± 2.70) was recorded in August. Nevertheless, the females spawned 3 to 10 times between September and February, with the highest reproductive peak between September and October. The number of embryos per female per day varied from 1 to 429, while the total number of embryos per female during the entire season evaluated varied from 163 to 1044. There was a high correlation (r = 0.82) between absolute fecundity and body weight. Although further studies are needed in this field, these results are basic for establishing future reproductive programs in captivity as a strategy for sustainable fisheries and aquaculture management.