Stages Of Gonadal Development Research Articles

A Shuttling Protein Kank1 Plays Important Role in the Sex Determination in Yellow Drum

Sex is one of the most important scientific topics, and the existence of sex dimorphism is a conserved feature in vertebrate taxa. The research on sex-determining genes and sex chromosome evolution is a hot topic in biology. The majority of sex-determining genes expressed in somatic cells, and reciprocal interactions between germ cells and somatic cells, are important for gonadal differentiation. However, the knowledge of how signals are transmitted between somatic cells and germ cells remains unclear. In this study, we confirmed the 36 dph was a sex determination critical stage in yellow drum through transcriptome analysis at the early development stages. We further found that Kank1 participated in the germ cells’ motility process in yellow drum through KEGG pathway analysis together with protein-protein interaction network. With the dual-luciferase reporter assay, we detected that Kank1 increased the transcription of dmrt1_Luc gene in CHO cells and 293T cells. Additionally, we observed that Kank1 was not only expressed in the cytoplasm but also in the nucleus in CHO cells through a fluorescence microscope. These results suggest that Kank1 acts as a shuttling protein as in humans and may play a difunctional role at the early gonad development stage in yellow drum, and it not only participated in the germ cells’ motility but also increased the expression of dmrt1 in yellow drum.

Water flow velocity influence the gonad maturation, glucose and energy levels of mud crab, Scylla olivacea

Environmental factors affect the biological functions of aquaculture species both in the wild and in captivity. Therefore, optimization of the husbandry conditions under captivity can improve the production performance of an aquaculture species. In this study, the effect of water velocity on the glucose concentration, energy level of different body parts (i.e., hepatopancreas, gonad, muscle, and feces), and gonadal maturation of the Mud crab Scylla olivacea was evaluated. Immature crab samples of both sexes were collected from the Setiu Wetland and reared for 60 days in different water velocities (0, 20, 40, and 60 cm/s). The results of this study suggested that rearing the mud crab in 20 cm/s and 0 cm/s elicited the least stress as revealed by the glucose concentration of male and female crabs respectively when compared to other flow velocities. The trend of energy reserved in the hepatopancreas, and feces of both sexes however showed a significant decrease with the increasing flow velocity. A similar trend was also observed in the muscles of male S. olivacea. The energy in the muscle and gonad of the female mud crab on the other hand was higher in 20 cm/s and declining thereafter (with least recorded in 0 cm/s). This study also noticed that the 20 cm/s flow velocity advanced the stages of gonadal development (i.e., stages 3 and 4 for males and females respectively) of the crabs better than other flow velocities. It was therefore concluded that the 20 cm/s flow velocity is optimum to induce gonadal maturation and lessen the stress encountered by S. olivacea in captivity.

Evaluation of the reproductive cycle and gonadal development in the climbing perch, Anabas testudineus (Bloch, 1792) in captivity

The climbing perch Anabas testudineus, the most demanded indigenous fish species of India, were used for the evaluation of reproductive strategy and gonadal development at first maturation under the controlled laboratory condition. In both sexes, four distinct gonadal developmental stages namely preparatory, pre-spawning, spawning, and post-spawning were identified based on the gonadosomatic index (GSI), hepatosomatic index (HSI), gonadal morphology, and the levels of serum sex hormones. The spawning stage was identified from July and August and the fecundity ranged from 6500–11000 eggs. The GSI exhibited a significant increase from preparatory to pre-spawning and spawning stages, and maintained high until August. The HSI was maintained the same during preparatory, pre-spawning, and spawning stages while increased in post-spawning stage in both sexes. Serum estrogen and testosterone levels increased significantly during pre-spawning, and spawning stages in both sexes. Fecundity showed a positive correlation with the length, weight, and ovary weight. Histological sections showed that male A. testudineus were group-synchronous spawners. Both sexes showed discrete reproductive cycles characterized by distinct changes in gonadal size, sex hormones and gonadal indices. This study will bridge the gap of insufficient knowledge to support the best practices suitable for the A. testudineus culture and survival under captivity.

Cyp17a effected by endocrine disruptors and its function in gonadal development of Hyriopsis cumingii

Estrogens and androgens that coexist in the aquatic environment could potentially affect shellfish, however, endocrine disrupting effects of them in shellfish are significant. As an important aquaculture shellfish in China, Hyriopsis cumingii has remarkable economic benefits. In this study, the effects of endocrine disrupting chemicals on the steroid synthase Hc-Cyp17a in the male and female gonads of the H. cumingii were assessed by exposing juvenile mussels to cultured waters containing 17β-Estradiol (E2) and 17α-Methyltestosterone (MT) for 28 days. At the same time, the E2 content in the four stages of gonadal development, the expression changes of Hc-Cyp17a in gonadal development and its localization in the mature gonad were measured to explore the relationship between genes and hormones. The results showed that both E2 and MT at 50 ng/L and 200 ng/L could affect the transcription level of Hc-Cyp17a, which was inhibited initially and promoted in post-development. E2 content was positively correlated with gonadal development stage, which was in mussel. By tracing the expression of Hc-Cyp17a, difference was found during different developmental periods. The expression level in ovary was higher than that in testis during gonadal development of 1/ 2/ 3-year-old mussels and showed an increasing trend with age. Furthermore, the expression levels in 6 tissues of mature individuals were measured and it showed that there was a significant difference between male and female in the gonads (p < 0.01). In situ hybridization, it suggested that Hc-Cyp17a was significantly signaled in the follicular wall and oocyte of female and in the follicular membrane of testis, respectively. These results could play a vital role in assessing and understanding the effects of aquatic environment on the endocrine system of H. cumingii.

Time-Course Transcriptional and Chromatin Accessibility Profiling Reveals Genes Associated With Asymmetrical Gonadal Development in Chicken Embryos.

In birds, male gonads form on both sides whereas most females develop asymmetric gonads. Multiple early lines of evidence suggested that the right gonad fails to develop into a functional ovary, mainly due to differential expression of PITX2 in the gonadal epithelium. Despite some advances in recent years, the molecular mechanisms underlying asymmetric gonadal development remain unclear. Here, using bulk analysis of whole gonads, we established a relatively detailed profile of four representative stages of chicken gonadal development at the transcriptional and chromatin levels. We revealed that many candidate genes were significantly enriched in morphogenesis, meiosis and subcellular structure formation, which may be responsible for asymmetric gonadal development. Further chromatin accessibility analysis suggested that the transcriptional activities of the candidate genes might be regulated by nearby open chromatin regions, which may act as transcription factor (TF) binding sites and potential cis-regulatory elements. We found that LHX9 was a promising TF that bound to the left-biased peaks of many cell cycle-related genes. In summary, this study provides distinctive insights into the potential molecular basis underlying the asymmetric development of chicken gonads.

Maximum gonad investment of the sexes of the broadcast-spawning sea cucumber Holothuria (Halodeima) inornata (Echinodermata: Holothuroidea)

AbstractAn organism's maximum gonad investment (MGI) typically indicates its reproductive season and is often measured by the peak of the gonadosomatic index. Since external sexual dimorphism is often not evident, intrinsic sex differences remain unstudied. We analysed the reproductive seasonality of each sex of the broadcast-spawning sea cucumber Holothuria (Halodeima) inornata in two populations (Caleta de Campos, Michoacán ‘CC’ and Puerto Madero, Chiapas ‘PM’) in the southern coast of the Mexican Pacific by examining: intensity and duration of MGI, frequency of each gonadal developmental stage (GDS) through time, sexual asymmetry in GSI, sexual asymmetry in GDS, and adult sex ratio. We observed a trade-off between the intensity (%) and duration (months) of each sex's MGI: as intensity decreases, duration increases and conversely. The frequency of ripe and spawning stages was consistently higher in females than males. Sexual asymmetry in GSI was slightly female-biased in the PM population, but male-biased in the CC population. Sexual asymmetry in GDS showed a more recurrent sexual equality at PM than at CC. The adult sex ratio of each population did not differ significantly from unity, but showed a near-significant trend for male bias in the CC. Although H. inornata exhibited different MGI responses between males and females and more markedly in CC than in PM, it also showed a synchronized relation between its mass investment (GSI) and physiological investment (GDS), possibly reflecting an optimum reproductive strategy. Lastly, changes in GSI were not underpinned by changes in local temperature, but rather by regional temperature.

A practical evaluation of machine learning for classification of ultrasound images of ovarian development in channel catfish (Ictalurus punctatus)

Machine learning is a powerful tool to improve efficiency of industrial processes, but it has not yet been well utilized in aquacultural and hatchery applications. The goal of the present study was to evaluate the feasibility of using a broad array of machine learning approaches (testing of >200 vectorization and model combinations, reporting on 20) to classify ultrasound images spanning annual ovarian development (i.e., from undeveloped to mature) of channel catfish (Ictalurus punctatus). The specific objectives were to: 1) establish dataset preprocessing to standardize image features; 2) develop and train image classification models with deep learning methods; 3) develop and train models with traditional machine learning methods; 4) compare performance of deep learning and traditional methods on two classification problems (2-class and 5-class), and 5) propose insights to deploy models in practical aquaculture applications for research and hatchery use. A total of 931 ultrasound images of catfish ovaries were used to train and evaluate models for a 2-class problem (as a ‘yes’ or ‘no’ answer) to support hormone-injection decisions for spawning management in hatcheries, and a 5-class problem for classifying gonadal development stages for research. By using feature extraction, cropping, dimension reduction, and histogram normalization, a preprocessing method was created to standardize images to develop traditional (i.e., vector input), and deep learning convolutional neural network (CNN) (i.e., image input) approaches. Traditional machine learning models with image classification achieved 100% median accuracy on the 2-class problem (with the models RN-50 and RN-152), and 96% median accuracy for the 5-class problem (with VGG-19 image vectorization). The deep learning approach for the 2-class problem had a median accuracy of >98% for 15models. The 5-class deep learning models produced a steady increase in median accuracy with training net size, achievable through expansion of the dataset. These models can be developed further, but traditional models (using CNN architectures to simply calculate image vectors) outperformed the deep learning approach. These models can be directly applicable to aquaculture in hatcheries and reproductive biology research, in addition to a wide variety of other image-based applications.

The female-biased expression, transcriptional regulation and knock-down effect of insulin-like growth factor binding protein 7 in Chinese tongue sole, Cynoglossus semilaevis

Insulin-like growth factor binding protein 7 (igfbp7) is a member of the insulin-like growth factor binding protein (IGFBP) superfamily, which is involved in the regulation of insulin-like growth factor (IGF) and insulin signal transduction. Recently, igfbp7 was found to be female-biased expressed in the gonad of Chinese tongue sole (Cynoglossus semilaevis), a marine flatfish exhibited female-biased sexual dimorphism. This study aimed to explore the roles of igfbp7 in the growth and sex differentiation of C. semilaevis. Firstly, C. semilaevis igfbp7 was cloned, and the coding sequence (CDS) was 666 bp encoding 221 amino acids. The phylogenetic and structural analyses revealed that C. semilaevis igfbp7 was clustered with Atlantic halibut (Hippoglossu shippoglossus), sailfin molly (Poecilia latipinna), and so on. The subsequent temporal and spatial expression analyses showed that igfbp7 was mainly expressed in female gonad. During the different gonad developmental stages, the expression of igfbp7 displayed the highest level at 6-month. Methylome data showed that female igfbp7 exhibited lower methylation levels than male and pseudomale across the whole gene region in the gonad. Dual-luciferase experiment revealed that C. semilaevis igfbp7 promoter exhibited strong transcription activity. In addition, pituitary-specific positive transcription factor 1 (POU1F1) and steroid hormone-testosterone significantly enhanced the transcriptional activity of the igfbp7 promoter. In vitro transfection experiment revealed the activation of igfbp7 on the nuclear factor kappa B (NF-κB) signaling pathway. Finally, the activation of insulin-like growth factor 1 receptor (igf1r), serine/threonine kinase 1 (akt) and heat shock 60 protein 1 (hspd1) was observed in C. semilaevis ovary cells transfected by igfbp7 small interfering RNA (siRNA). These results provided causal clues for igfbp7 in growth regulation by influencing igf1r, akt and NF-κB signal.

Use of quantitative real-time PCR to select reference genes in the testis and ovary of Apostichopus japonicus during the breeding period

Gonads play a critical role in the reproduction of sea cucumbers, and their development is regulated by a large number of genes. To date, the ideal reference genes (RGs) for studying sea cucumber gonadal development have not been reported. In this study, we selected ten RGs and conducted quantitative real-time PCR analysis to identify the most stable among Apostichopus japonicus gonads at four different stages of gonadal development. We used ∆Cq, GeNorm, NormFinder, BestKeeper, and RefFinder to evaluate the stability of candidate genes. EF1β and Grb2 together were the preferred combination of stable RGs among all of the gonad samples and for the ovaries alone. UBQ combined with RPS4 was the best combination of stable RGs in the testes. This study aimed to provide a basis for analysis of differences in gene expression related to gonadal development in sea cucumbers, and the results provide valuable information for further studies of the molecular mechanisms involved in sea cucumber gonadal development.

Ovarian development of Xiphopenaeus kroyeri (Crustacea: Penaeidae) from Espírito Santo, southeastern Brazil.

This study aimed to describe and characterize the stages of gonadal development of females of Xiphopenaeus kroyeri caught by artisanal fishers in Espírito Santo state, southeastern region of Brazil. All females (n= 1,831) were subjected to macroscopic and microscopic morphological analysis (n= 333) of the ovaries. From the morphology, coloration and degree of turgidity of the fresh ovary, macroscopic analysis determined five stages of gonadal development. The macroscopic analysis showed difficulties in differentiating the immature and spawning stages due to the similarity between the colors of the ovaries, which confirms the need to perform the macroscopic and histological analysis simultaneously for fisheries management studies. Microscopic observations allowed us to analyze the following six stages of cell development: oogonia, previtellogenic oocytes, primary vitellogenic oocytes, secondary vitellogenic oocytes, mature oocytes and atretic oocytes. From this, five stages of gonadal development were defined, i.e., immature, early development, advanced development, mature and spawned. The presence of peripheral bodies was not observed in this species. These results help to clarify and better understand the reproductive and population aspects of the Atlantic Seabob, which are fundamental for the establishment of management and conservation measures of this resource.

Seasonal variation in population structure and sexual maturity of Sylviocarcinus pictus (Decapoda: Trichodactylidae) in a Neotropical intermittent river

Sylviocarcinus pictus is a South American freshwater crab recently recorded for the first time in the Caatinga biome. Our objective was to characterize the population and reproductive biology of S. pictus from the semi-arid northeastern region of Brazil and verify the influence of seasonal environmental changes in this population. The crabs were collected from a stretch of Guaribas River, PI, Brazil, every month between October 2013 and September 2014. The crabs were identified, sexed and the carapace width (CW) was measured. Physiological sexual maturity was determined based on the gonadal development stage. A total of 178 crabs were obtained (111 males and 67 females), with a sex ratio biased towards males 1.66:1. The number of crabs collected was higher in the months of drought. Males and females reach physiological sexual maturity with 36.80 and 34.20 mm of CW, respectively. The occurrence of individuals with developed or developing gonads throughout the study indicates that these crabs reproduce continuously during the year, although recruitment was higher in February and May. Our results indicate that this population uses a reproductive strategy to optimize its reproductive fitness in an intermittent environment.

Histological and Histochemical Dynamism of Oogenesis in the Cinnamon River Prawn Macrobrachium acanthurus (Caridea: Palaemonidae) Induced by Eyestalk Ablation

Macrobrachium acanthurus is a caridean prawn native to Brazil, and studying techniques to assist in its cultivation is important due to economic interest in it. Eyestalk ablation is commonly used to promote ovarian development and maturation of captive crustaceans, but it can have possible consequences on fertility and brood quality. Histological and histochemical dynamism of oogenesis was analyzed under control (non-ablated females) and unilateral eyestalk ablated females. Females with ovaries in the spent stage of gonadal development were divided into two treatments: unilaterally ablated and non-ablated. A second experiment with the same treatments was conducted using females with mature gonads. Histological and histochemical analyses of the ovaries indicated that the ablation did not affect oogenesis based on ovarian structure, oocyte size, histochemical properties, and atretic oocytes. Ovarian maturation was not accelerated by ablation, either. Survival, nuptial molting, and spawning were also unaffected. From an applied point of view, unilateral eyestalk ablation is not needed in M. acanthurus farming because it does not improve reproductive performance.

Stock structure of the Brazilian sardine Sardinella brasiliensis from Southwest Atlantic Ocean inferred from otolith elemental signatures

The Brazilian sardine (Sardinella brasiliensis) supports the most important pelagic fishery in the southeast-south Brazil. The first studies on the population structure of S. brasiliensis suggested the existence of two stocks taking into account distinct regional somatic growth rates and spawning areas. However, subsequent works were unable to confirm this scenario, and at present for fisheries management purposes a single stock is considered in Brazil. In order to unravel the stock structure of S. brasiliensis, ninety adult individuals (two-year-old fish) were collected between February and October 2018 in three fishing grounds within its distribution area [Rio de Janeiro (RJ), Santa Catarina (SC) and Rio Grande do Sul (RS)]. Multi-elemental signatures of whole otoliths were determined using inductively coupled plasma mass spectrometry and combined with basic biological data (somatic condition, sex and gonadal developmental stages). A generalized linear model found somatic growth rates significantly different across regions. Whole otolith chemical signatures exhibited distinct regional patterns, mainly driven by differences in Ba/Ca, Cu/Ca, Li/Ca, Mg/Ca, Mn/Ca, Sr/Ca, and Zn/Ca. Combining somatic and reproductive data with multi-elemental signatures, the leave-one-out reclassification reassigned the individuals to their areas of origin with a high accuracy (100%, 93% and 87% for RJ, SC and RS, respectively). The results indicate a spatial isolation for the RJ individuals and some degree of intermixing between SC and RS. The data suggest that these fishing grounds should be considered as two stocks (RJ and SC+RS) for fisheries management purposes, although the southern stock is not necessarily homogeneous.

Microplastics and bisphenol A hamper gonadal development of whiteleg shrimp (Litopenaeus vannamei) by interfering with metabolism and disrupting hormone regulation

Gonadal development is a prerequisite for the reproductive success of an organism, and might be affected by environmental factors such as emergent pollutants. Although marine crustaceans are threatened by ubiquitous emergent pollutants such as microplastics (MPs) and bisphenol A (BPA) under realistic scenarios, studies about the impacts of these pollutants on the gonadal development of crustacean species are rare. In this study, the effects of MPs and BPA, alone or in combination, on gonadal development were investigated in whiteleg shrimp (Litopenaeus vannamei). The results obtained demonstrated that whiteleg shrimp exposed to MPs and BPA had significantly smaller gonad-somatic index (GSI) and an obvious delay in the gonad developmental stage. In addition, exposure of whiteleg shrimp to pollutants tested resulted in a reduction in the oxygen consumption rate, elevation in the ammonia excretion rate, decline in the O: N ratio, and downregulation in the expression of metabolism-related genes, indicating significant disruptions of shrimp metabolism by the pollutants. Furthermore, in addition to a few exceptions, both the in vivo contents of gonadal development-related hormones (GIH and MIH) and the expression of genes encoding regulatory hormones (GIH, MIH, and CHH) were upregulated by the exposure of whiteleg shrimp to the pollutants investigated, suggesting a significant obstruction of endocrine regulation. Moreover, MP-BPA coexposure was shown to be more toxic to whiteleg shrimp than the corresponding single exposures and significantly greater amount of BPA accumulated in the gonads (both testis and ovaries) of shrimp with the coexistence of MPs, which may be caused by the Trojan horse effect and summation of the toxic impacts on common targets. In general, the data obtained in this study demonstrated that MPs and BPA at environmentally realistic concentrations significantly inhibited the gonadal development of whiteleg shrimp probably by interfering with metabolism and disrupting endocrine regulation.

Environmental Factors and Genetic Diversity as Drivers of Early Gonadal Maturation: A Gonadosomatic Index Based Investigation on Indian Shad, Tenualosa ilisha Population of Bangladesh

In recent years, attaining gonadal maturation in smaller Hilsa (Tenualosa ilisha) has become a burning issue for Hilsa fishery of Bangladesh. Causes of early maturation are not yet clearly understood. Along with environmental parameters, genetic differentiation within the population was hypothesized as the main driver, and therefore, assessing the correlation between gonadosomatic index (GSI) and environmental factors and analyzing genetic diversity were set as objectives of the present study. To address these complex issues, six diverse habitats across Bangladesh were chosen for Hilsa sample collection. For GSI, gonad was dissected from fresh fish and preserved in Bouin’s fluid for histological observation. Water quality parameters such as temperature, dissolved oxygen, pH, and salinity were also assessed. 35 fish from each habitat were used to extract and amplify DNA through the PCR technique, and genetic diversity was examined. Further, to draw a firm conclusion, the phylogenetic tree of the Hilsa population was developed by the unweighted pair-group method of arithmetic mean method based on the Cyt b gene of mitochondrial DNA. Results of GSI studies revealed that peak spawning months of T. ilisha were in October and February, where October showed the highest values in all six habitats. Histological examination showed different stages of gonadal development in different sizes and ages of Hilsa. Among all sampling sites, no statistical difference was observed for GSI value; however, smaller sized and aged Hilsa being ripped were evident in Gaglajur Haor and Kali River. Among the observed water quality parameters, temperature correlated with GSI strongly. Increased GSI was observed with temperature augmentation from downstream to upper stream, irrespective of body size and age. A perplex correlation between dissolved oxygen of observed habitats and GSI was executed. Other physico-chemical parameters viz. pH and salinity exhibited weak and moderate positive association with the GSI, respectively. Haplotype diversity of mitochondrial DNA divided the Hilsa population into three possible sub-populations, where the most distant group (Gaglajur Haor and Kali River) was subjected to early gonadal maturity. Results of this study make clear conclusions regarding the role of environmental and genetic factors on early gonadal maturations, pointing fingers at the curse of climate change and anthropogenic stressors for the migration of the Hilsa fishery of Bangladesh.

ZSWIM7 Is Associated With Human Female Meiosis and Familial Primary Ovarian Insufficiency.

BackgroundPrimary ovarian insufficiency (POI) affects 1% of women and is associated with significant medical consequences. A genetic cause for POI can be found in up to 30% of women, elucidating key roles for these genes in human ovary development.ObjectiveWe aimed to identify the genetic mechanism underlying early-onset POI in 2 sisters from a consanguineous pedigree.MethodsGenome sequencing and variant filtering using an autosomal recessive model was performed in the 2 affected sisters and their unaffected family members. Quantitative reverse transcriptase PCR (qRT-PCR) and RNA sequencing were used to study the expression of key genes at critical stages of human fetal gonad development (Carnegie Stage 22/23, 9 weeks post conception (wpc), 11 wpc, 15/16 wpc, 19/20 wpc) and in adult tissue.ResultsOnly 1 homozygous variant cosegregating with the POI phenotype was found: a single nucleotide substitution in zinc finger SWIM-type containing 7 (ZSWIM7), NM_001042697.2: c.173C > G; resulting in predicted loss-of-function p.(Ser58*). qRT-PCR demonstrated higher expression of ZSWIM7 in the 15/16 wpc ovary compared with testis, corresponding to peak meiosis in the fetal ovary. RNA sequencing of fetal gonad samples showed that ZSWIM7 has a similar temporal expression profile in the developing ovary to other homologous recombination genes.Main conclusionsDisruption of ZSWIM7 is associated with POI in humans. ZSWIM7 is likely to be important for human homologous recombination; these findings expand the range of genes associated with POI in women.

Species validation, growth, reproduction and nutritional perspective of Indian pompano, Trachinotus mookalee–A candidate species for diversification in coastal mariculture

The Indian pompano Trachinotus mookalee can be an ideal and alternative marine candidate species for aquaculture with its cultivable traits. The study aimed to understand growth, reproductive and nutritional potentials of the fish in different culture environments and also for species validation to avoid ambiguities in further research. Wild collected broodfishes have confirmed that the species is genetically and morphologically differentiated from its four closely related species of genus Trachinotus. The studied fish growth was significantly (P < 0.05) influenced by culture environments, where the maximum growth was attained in cage (684.9 ± 14.0 g), followed by pond (564 ± 13.6 g), Recirculating Aquaculture System (RAS) (471.5 ± 10 g) and the least in indoor Fibre-reinforced plastic tank (294.65 ± 10.35 g) for 12 months of culture. Growth data indicated presence of high genetic growth potential in the species, which could be improved with suitable intervention in abiotic factors. Studied reproductive sex steroid hormone concentrations varied in the fish and were matched with the different maturity stages confirmed by gonadal development stages. The sexually mature male and female fish found with elevated levels of testosterone (2.34 ± 0.25 ng/ml) and 17-β estradiol (2.56 ± 0.95 ng/ml), respectively, which indicated that sex differences has been persisting in the species and the steroid level could act as marker in assessing the maturity status of male and female fish. The gonadal developmental stages indicated that the fish became functional male and female brooders after 26 and 29 months of culture in sea cages, respectively. Nutritional contents of the fish was significantly (P < 0.05) influenced by the culture environments. Crude protein was maximum in cage reared fish (18.96 ± 0.36%), whereas fish in RAS exhibited high crude fat (6.87 ± 1.05%). Palmitic (C16:0) and glutamic acids were the maximum abundant fatty acid and amino acid, respectively in all the cultured environments. However, the content of essential polyunsaturated fatty acids (DHA and EPA) was significantly high in wild fish. Phosphorus and iron were the maximum abundant major and micro minerals, respectively in all the culture systems. With excellent traits linked with aquaculture, the species could be the most suitable candidate for species diversification in coastal mariculture. The species deserves further studies on the basis of influence of abiotic factors on different traits.

Expression of 20-hydroxyecdysone-related genes during gonadal development of Teleogryllus emma (Orthoptera: Gryllidae).

Insect gonads develop under endocrine signals. In this study, we assessed the characters of partial complementary DNAs encoding the Teleogryllus emma orthologs of 20-hydroxyecdysone (20E)-related genes (RXR, E75, HR3, Hsc70, and Hsp90) and analyzed their expression patterns in both nymph and adult crickets. 20E treatment suppressed expression of TeEcR, TeRXR, TeE75, TeHR3, TeHsc70, and TeHsp90. Temporal expression analysis demonstrated that TeERR and 20E-related genes were expressed in four stages of gonadal development from the fourth-instar nymph stage to the adult stage. The expression pattern of these genes differed in testicular and ovarian development. TeRXR, HR3, TeHsc70, and TeHsp90 were irregularly expressed in gonads of the same developmental stages, while mRNAs encoding TeERR, TeEcR, and TeE75 accumulated in higher levels in ovaries than in testes. RNA interference (RNAi) of TeEcR expression led to decrease of the expression levels of TeEcR, TeRXR, TeHR3, and TeHsc70, while it enhanced TeE75 and TeHsp90 expressions. These results demonstrate that the TeERR and 20E-related genes help regulate gonadal development, while TeEcR appears to inhibit TeE75 expression, TeE75 inhibits HR3 expression. Hsc70 indirectly regulated the expression of the primary and secondary response genes E74A, E75B, and HR3. Hsp90 regulated Usp expression with no direct regulatory relationship with EcR.

Gonadal Development of Females of the White Shrimp Penaeus schmitti (Burkenroad, 1936) Caught in Southeastern Brazil

This study describes the reproductive cell development and ovarian developmental stages, and identifies the nongerminal components of white shrimp (Penaeus schmitti) caught off the southern coast of Espírito Santo, Brazil. P. schmitti specimens were collected monthly from March 2019 to February 2020, by artisanal fishing. All shrimps were analyzed macroscopically (n = 181) and females were randomly selected monthly (n = 154) for ovarian histological analysis. The ovaries were extracted for visual analysis and then submitted to histological analysis. Macroscopic analysis determined five stages of gonadal development from the color and turgidity of the fresh ovary. Histological observations allowed us to observe five stages of gonadal development: immature, initial development, advanced development, mature and spawning. This information are fundamental for understanding the reproductive aspects of P. schmitti, as well as other penaeid shrimps, in order to promote preservation of natural stocks and provide information to assist in the development of the reproductive potential of native species in captivity.

Reproductive Phenology of Five Species of Terrestrial Frogs (Genus Eleutherodactylus) from Cuba

We studied the reproductive phenology of five endemic Eleutherodactylus species that coexist in a mountain rainforest in Cuba and estimated their sex ratios at immature and mature stages. We tested the hypothesis that in Neotropical humid sites, reproductive activity in sympatric species will vary in the time of occurrence so that there is no complete temporal overlap. We also investigated whether the length of the breeding season was associated to relative testes size as a proxy for male–male competition. We inferred reproductive phenology from seasonal variation in the number of sexually active individuals, their gonad developmental stage, and male vocal activity from January 2003 to March 2004. Our data do not support the hypothesis of temporal segregation in reproduction for this assemblage because we found a prolonged reproductive pattern in the five species, but there was decreased breeding intensity in the cooler months (November–February). This deduction is supported by a drop in the weight of the ovaries and the number of vitellogenic follicles, absence of mature females or reduction of their abundance, and disappearance of male vocal activity in the winter. We found differences in relative testes size among species, which were not related to differences in the length of the breeding season, but rather to interspecific differences in sex ratio.