Gonad Weight Research Articles

English

The study was done to examine some aspects of the reproductive biology of Nile tilapia (Oreochromis niloticus) in Tekeze Reservoir a newly man made hydropower reservoir. A total number of 1826 specimens of Nile Tilapia (O. niloticus) were collected from the reservoir from July 2015 to June 2016. Size at first maturity, sex ratio, gonado-somatic index (GSI), breeding season and fecundity were studied. The overall sex-ratio female: Male (F: M) was 1.6:1 which is deviated from the expected 1:1 sex ratio (χ2 = 10.13; p<0.05). Length at first maturity was 14 and 15 cm for females and males respectively. The breeding period of females extended from January to September. Two annual breeding seasons were noticed. A minor breeding season which extended from January to March and a major breeding season from July to September and monthly Condition Factor (CF) (mean ± SD) value of O. niloticus in the reservoir ranged from 1.73±0.03 in July to 2.05±0.02 in November for males and 1.61±0.02 in July to 1.99±0.05 in April for females. Fecundity ranged between 399 to 2129 g. Fecundity correlated well with total weight (r = 0.086), total length (r = 0.77) and ovary weight (r = 0.72) than with gonadal weight (r = 0.86). Nile tilapia at Tekeze Reservoir showed isometric growth pattern (b=2.92), indicating that the reservoir was favorable for the fish growth. For proper management of the fish species in the reservoir, it is better for the fishermen not to capture the fish during the breeding season of the year in the reservoir. Key words: Reproductive biology, Oreochromis niloticus, Gonado-somatic index, fecundity. &nbsp

Biological Analysis of Blue Swimmer Crab (Portunus pelagicus) from Collectors in Lamongan, Tuban, Pasuruan, and Rembang, Java, Indonesia

Blue swimmer crab ( Portunus pelagicus ) can increase the country’s incomes due to its high demand of export. This study aims to determine biological analysis on the population of blue swimmer crab in Lamongan, Tuban, Pasuruan, and Rembang. The sampling location was based on the fishing area and the method used survey method from collectors in each location. The blue swimmer crab’s biological characteristics which observed are the correlation on wide of carapace and blue swimmer crab weight, sex ratio, and gonad maturity level. The results showed the correlation between the wide and weight of carapace in Lamongan (male: 113.80-122.99 mm and 87.98-121.60 g then female: 108.21-117.27 mm and 71.80-99.74 g), Tuban (male: 113.26-117.74 mm and 89.63-102.76 g g then female: 114.36 mm and 106.51 g), Pasuruan (male: 87.66-94.43 mm and 39.68-49.90 g then female: 101.94-110.89 mm and 66.98-82.89 g), and Rembang (male: 120.30-126.69 mm and 93.53-118.43 g then female: 125.30-132.13 mm and 134.42-157.47 g); sex ratio (male: female) in Lamongan (1.4: 1), Tuban (1: 1.5), Pasuruan (2.8: 1), and Rembang (1: 1.46); and also gonad maturity level in Lamongan (dominant male at level III was 30.29%, female at level II and III was 30.40%), Tuban (dominant male at level II was 41.93%, female at level III was 33.33%), Pasuruan (dominant male at level III was 25.79%, female at level III was 48.10%), and Rembang (dominant male at level II was 32.35%, female at level II was 33.33%). These results indicate that the total of Portunus pelagicus which was being caught had fulfilled the standards rules by No.1/PERMEN-KP/2015. However, it requires continuous direct monitoring and counseling to maintain the stock of blue swimmer crab resources. Keywords: Blue swimmer crab ( Portunus pelagicus ), gonad maturity level, sex ratio, wide and weight.

Perinatal exposures to phthalates and phthalate mixtures result in sex-specific effects on body weight, organ weights and intracisternal A-particle (IAP) DNA methylation in weanling mice.

Developmental exposure to phthalates has been implicated as a risk for obesity; however, epidemiological studies have yielded conflicting results and mechanisms are poorly understood. An additional layer of complexity in epidemiological studies is that humans are exposed to mixtures of many different phthalates. Here, we utilize an established mouse model of perinatal exposure to investigate the effects of three phthalates, diethylhexyl phthalate (DEHP), diisononyl phthalate (DINP) and dibutyl phthalate (DBP), on body weight and organ weights in weanling mice. In addition to individual phthalate exposures, we employed two mixture exposures: DEHP+DINP and DEHP+DINP+DBP. Phthalates were administered through phytoestrogen-free chow at the following exposure levels: 25 mg DEHP/kg chow, 25 mg DBP/kg chow and 75 mg DINP/kg chow. The viable yellow agouti (A vy ) mouse strain, along with measurement of tail DNA methylation, was used as a biosensor to examine effects of phthalates and phthalate mixtures on the DNA methylome. We found that female and male mice perinatally exposed to DINP alone had increased body weights at postnatal day 21 (PND21), and that exposure to mixtures did not exaggerate these effects. Females exposed to DINP and DEHP+DINP had increased relative liver weights at PND21, and females exposed to a mixture of DEHP+DINP+DBP had increased relative gonadal fat weight. Phthalate-exposed A vy /a offspring exhibited altered coat color distributions and altered DNA methylation at intracisternal A-particles (IAPs), repetitive elements in the mouse genome. These findings provide evidence that developmental exposures to phthalates influence body weight and organ weight changes in early life, and are associated with altered DNA methylation at IAPs.

Does prenatal alcohol exposure cause a metabolic syndrome? (Non-)evidence from a mouse model of fetal alcohol spectrum disorder.

Although prenatal alcohol exposure (PAE) reduces offspring growth, it may increase obesity risk at adolescence. Animal models of PAE display glucose intolerance and increased adiposity, suggesting that PAE causes metabolic reprogramming. We tested this hypothesis in a mouse model of binge PAE, wherein pregnant C57Bl/6J females received 3 g/kg alcohol (ETOH) daily from gestational day 12.5 to 17.5; maltodextrin (MD) and medium chain triglycerides (MCT) served as isocaloric nutritional controls, and sham (H2O) treatment controlled for gavage stress. Our comprehensive assessment quantified body composition, energy expenditure, glucose tolerance, and cardiovascular function in offspring at age 17 weeks. Although ETOH pups were initially lighter than all other groups, they did not have a unique obesogenic phenotype. Instead, a similar obesogenic phenotype emerged in all three caloric groups (MCT, MD, ETOH), such that caloric groups had greater post-weaning weight gain (both sexes), reduced gonadal fat weight (males), and reduced glucose clearance (males) compared against H2O offspring. PAE did not affect body composition, respiratory exchange ratio, metabolic adaption to high-fat or low-fat diet, eating behavior, and blood pressure, and ETOH values did not differ from those obtained from isocaloric controls. Exposure to a higher alcohol dose (4.5 g/kg) or a high-fat (60%) diet did not exacerbate differences in body composition or glucose tolerance. “PAE-specific” effects on postnatal growth, glucose tolerance, adiposity, or hypertension only emerged when PAE offspring were compared just against H2O controls, or against MD controls. We conclude that prior reports of obesity and glucose intolerance in adult PAE offspring reflect the contribution of added gestational calories, and not alcohol’s pharmacologic action. Results suggest that the increased adiposity risk in FASD is not caused by metabolic reprogramming, and instead originates from behavioral, medication, and/or dietary practices. This study highlights the importance of appropriate dietary controls in nutritional studies of PAE.

Some Aspects of Reproductive Biology of the Mudskipper Apocryptes Bato From the Coast of Chitagong

Some aspects of reproductive biology of the mudskipper Apocryptes bato (Hamilton 1822) from the coastal waters of Chittagong, Bangladesh was conducted. Disproportionate occurrence of male and female (1.20 : 1) was observed in the number of two sexes. A prolonged spawning season was found from June to early October with a single peak. The aspects in the ovary indicate one complete spawning of females in a single spawning season. The fecundity was found to vary from 7453 - 31195 with an average of 17590 ± 6867. Significant coefficient of correlation between the diameters of the eggs of corresponding anterior, middle and posterior regions of the right and left ovaries indicated the simultaneous release of eggs from both the ovaries. A much closer relationship of fecundity and the significant ‘t’ values indicated fecundity increases with the increase of total length, standard length, body weight and gonad weight.
 Asiat. Soc. Bangladesh, Sci. 44(1): 91-99, June 2018

Ulva lactuca biofilter from a land-based integrated multi trophic aquaculture (IMTA) system as a sole food source for the tropical sea urchin Tripneustes gratilla elatensis

The performance of Tripneustes gratilla elatensis using IMTA-produced Ulva lactuca as the sole food source, in comparison to Gracilaria conferta and formulated diets, was evaluated in a long term (251-day) experiment in a land based facility in the tropical Gulf of Aqaba. T. gratilla elatensis fed IMTA-produced U. lactuca exhibited significantly (P < 0.01) better performance in terms of somatic growth, SGR, gonad yield, colour and survival, compared to sea urchins fed G. conferta and formulated diets. These differences can be attributed mainly to the high consumption rate and digestibility of the protein rich Ulva compared to the other diets. IMTA-produced Ulva as a sole feed was found to be a suitable diet for both somatic and gonadal growth. T. gratilla elatensis was shown as able to reach a commercial test size (~60 mm) in 5–6 months. T. gratilla elatensis grew (from spawning) in 400 days to 44.44 ± 2.01, 61.80 ± 3.69, and 73.28 ± 1.46 mm test diameter with average Specific Growth Rate (SGR) of 0.21 ± 0.02, 0.35 ± 0.05, and 0.42 ± 0.03% d−1 for formulated diet, G. conferta and U. lactuca diets, respectively. Gonad weights were 9.14 ± 2.3, 8.5 ± 2.7 g, and 24.6 ± 7.4 g. and Gonado-Somatic Index (GSI) reached 14.4 ± 2.01, 13.1 ± 5.0, and 13.7 ± 4.56 for formulated diet, G. conferta and U. lactuca diets, respectively, at the end of the experiment. No specific seasonality was observed with regard to gonad development, growth and GSI dynamics. Gonad growth and spawning events occurred throughout the year. T. gratilla elatensis fed IMTA-produced Ulva exhibited 90–100% commercially acceptable gonad colour, while the formulated diet (10% Ulva inclusion) showed poorer results of 30–60% acceptable colour and the G. conferta diet ca. 80%. In addition to enhancing sea urchin performance, U. lactuca as a biofilter in the IMTA considerably improved the system's sustainability and waste management.

Geographic Variation in the Reproductive Ecology of the Panamic Grunt in the Southeastern Gulf of California

AbstractBiological parameters pertaining to the reproductive ecology of the Panamic Grunt Pomadasys panamensis were investigated in 788 individuals sampled from the southeastern Gulf of California between November 2009 and October 2010. Length frequency distributions and mean TLs differed between sampling areas, with organisms from the coastal population exhibiting two clear modes that included most of the organisms (mostly adults; mean TL = 25.7 cm), while the open‐sea population appeared to consist of several cohorts (mean TL = 19.5 cm). Significant differences were recorded in spawning activity, gonadosomatic index (GSI), gonad weight, and size at maturity between fish from the coastal area and specimens from the open sea. The highest gonad weights and GSI values were recorded in the coastal zone during spring, coinciding with a peak in the number of mature females. In the open sea, the mature individuals were reproductively inactive throughout most of the yearlong study period, as individuals in late maturity stages represented a small portion of the sample. Female TL at 50% maturity (i.e., L50) was significantly lower in the coastal zone than in the open sea. The results suggest a differential use of available habitats by Panamic Grunts and highlight a need to consider temporal and geographic differences in reproductive ecology when formulating an adequate management program for this species.

Trans-life cycle acclimation to experimental ocean acidification affects gastric pH homeostasis and larval recruitment in the sea star Asterias rubens.

Experimental simulation of near-future ocean acidification (OA) has been demonstrated to affect growth and development of echinoderm larval stages through energy allocation towards ion and pH compensatory processes. To date, it remains largely unknown how major pH regulatory systems and their energetics are affected by trans-generational exposure to near-future acidification levels. Here, we used the common sea star Asterias rubens in a reciprocal transplant experiment comprising different combinations of OA scenarios, to study trans-generational plasticity using morphological and physiological endpoints. Acclimation of adults to pHT 7.2 (pCO2 3500μatm) led to reductions in feeding rates, gonad weight and fecundity. No effects were evident at moderate acidification levels (pHT 7.4; pCO2 2000μatm). Parental pre-acclimation to pHT 7.2 for 85days reduced developmental rates even when larvae were raised under moderate and high pH conditions, whereas pre-acclimation to pHT 7.4 did not alter offspring performance. Microelectrode measurements and pharmacological inhibitor studies carried out on larval stages demonstrated that maintenance of alkaline gastric pH represents a substantial energy sink under acidified conditions that may contribute up to 30% to the total energy budget. Parental pre-acclimation to acidification levels that are beyond the pH that is encountered by this population in its natural habitat (eg, pHT 7.2) negatively affected larval size and development, potentially through reduced energy transfer. Maintenance of alkaline gastric pH and reductions in maternal energy reserves probably constitute the main factors for a reduced juvenile recruitment of this marine keystone species under simulated OA.

Parental exposure to heavy fuel oil induces developmental toxicity in offspring of the sea urchin Strongylocentrotus intermedius

The present study investigated the toxic effects of parental (maternal/paternal) exposure to heavy fuel oil (HFO) on the adult reproductive state, gamete quality and development of the offspring of the sea urchin Strongylocentrotus intermedius. Adult sea urchins were exposed to effluents from HFO-oiled gravel columns for 7 days to simulate an oil-contaminated gravel shore, and then gametes of adult sea urchins were used to produce embryos to determine developmental toxicity. For adult sea urchins, no significant difference in the somatic size and weight was found between the various oil loadings tested, while the gonad weight and gonad index were significantly decreased at higher oil loadings. The spawning ability of adults and fecundity of females significantly decreased. For gametes, no effect was observed on the egg size and fertilization success in any of the groups. However, a significant increase in the percentage of anomalies in the offspring was observed and then quantified by an integrative toxicity index (ITI) at 24 and 48 h post fertilization. The offspring from exposed parents showed higher ITI values with more malformed embryos. The results confirmed that parental exposure to HFO can cause adverse effects on the offspring and consequently affect the recruitment and population maintenance of sea urchins.

Fecundity of Morocco Dentex Dentex maroccanus Valenciennes, 1830 Distributed in Izmir Bay (Central Aegean Sea of Turkey)

In this study, the reproductive properties of the Dentex maroccanus species distributed in the Aegean Sea were determined. A total of 439 fish were collected during the period from December 2012 to March 2014 from the commercial fishers who seasonally hunt in the Foça-Mordoğan region (İzmir, Turkey) were examined. After the measurement of the total lengths and body and gonad weights of the fish samples in the laboratory, their sexes were identified, which revealed that 140 of the samples were male, 206 of the samples were female and 93 of the sample were undeterminated. The female:male ratio was 1.5:1. The 5-point maturity phase discrimination method developed by Holden and Raitt for maturity stages in 1974 was macroscopically examined for female and male fish specimens. A total of 16 ovaries, which were determined to be at the 3rd and 4th stages of maturity according to the method, were used to determine fecundity. The gonadosomatic index values that were calculated based on the seasons revealed that the reproductive period of the species was summer (2.87) and autumn (2.10). The first maturation length for the species was 13.4 cm. Estimates of total fecundity varied between 74252 and 201187 eggs (mean: 123263±44586). There was an exponential relationship between fecundity and total length as F = 10.643L3.111. The diameter of the mature eggs ranged from 0.49 mm to 0.67 mm (mean: 0.59±0.06 mm).

Swimming exercise to control precocious maturation in male seabass (Dicentrarchus labrax)

BackgroundMale European seabass, already predominant (~ 70%) in cultured stocks, show a high incidence (20–30%) of precocious sexual maturation under current aquaculture practices, leading to important economic losses for the industry. In view of the known modulation of reproductive development by swimming exercise in other teleost species, we aimed at investigating the effects of sustained swimming on reproductive development in seabass males during the first year of life in order to determine if swimming could potentially reduce precocious sexual maturation.MethodsPre-pubertal seabass (3.91 ± 0.22 g of body weight (BW)) were subjected to a 10 week swimming regime at their optimal swimming speed (Uopt) in an oval-shaped Brett-type flume or kept at rest during this period. Using Blazka-type swim tunnels, Uopt was determined three times during the course of the experiment: 0.66 m s− 1 at 19 ± 1 g BW, 10.2 ± 0.2 cm of standard length (SL) (week 1); 0.69 m s− 1 at 38 ± 3 g BW, 12.7 ± 0.3 cm SL (week 5), and also 0.69 m s− 1 at 77 ± 7 g BW, 15.7 ± 0.5 cm SL (week 9). Every 2 weeks, size and gonadal weight were monitored in the exercised (N = 15) and non-exercised fish (N = 15). After 10 weeks, exercised and non-exercised males were sampled to determine plasma 11-ketotestosterone levels, testicular mRNA expression levels of genes involved in steroidogenesis and gametogenesis by qPCR, as well as the relative abundance of germ cells representing the different spermatogenic stages by histological examination.ResultsOur results indicate that sustained swimming exercise at Uopt delays testicular development in male European seabass as evidenced by decreased gonado-somatic index, slower progression of testicular development and by reduced mRNA expression levels of follicle stimulating hormone receptor (fshR), 3-beta-hydroxysteroid dehydrogenase (3βhsd), 11-beta hydroxysteroid dehydrogenase (11βhsd), estrogen receptor-beta (erβ2), anti-mullerian hormone (amh), structural maintenance of chromosomes protein 1B (smc1β), inhibin beta A (inhba) and gonado-somal derived factor 1 (gsdf1) in exercised males as compared with the non-exercised males.ConclusionsSwimming exercise may represent a natural and non-invasive tool to reduce the incidence of sexually precocious males in seabass aquaculture.

Reproductive biology of lotak, Cyprinion macrostomum Heckel, 1843 (Pisces: Cyprinidae), from the Tigris River drainage

Some reproduction aspects of the doctor fish, Cyprinion macrostomum, were examined for the first time from the Tigris River drainage. A total of 316 specimens were caught from Gamasiab River in western Iran, at monthly intervals throughout the year from January to December 2013. Age, sex ratio, fecundity, oocytes diameter, gonado‑somatic (GSI), modified gonado‑somatic (MGSI) and Dobriyal (DI) indices were estimated. Regression analyses were used to find relations between fecundity and fish size (length and weight), gonad weight, and age. Sex ratio differed significantly from unity, and the percentage of males was greater than that of females. The mature females and males were longer than 108 mm and 94 mm in total length (+2 and +1 in age, respectively). The GSI ranged between 0.09-2.94% and 1.70-15.53% for males and females, respectively. Gonad indices showed spawning took place from May to August, when the water temperature was 16 to 24 °C. The average diameter of the oocytes ranged from 0.2 mm to 1.7 mm, in the spawning season. The averages of absolute and relative fecundity (relative to body weight) were 3642.51 eggs (SD ±1219.92) and of 55.04 (SD ±14.12) per gram body weight, respectively. The absolute fecundity was significantly related to body weight and ovary weight.

Paternal physical exercise demethylates the hippocampal DNA of male pups without modifying the cognitive and physical development

Maternal exercise is known to have beneficial effects in progeny development, but the influence of paternal exercise on the offspring still unclear. Since spermatogenesis is a continuous process, the father’s life experiences can reprogram epigenetic content of the sperm and somehow interfere on offspring phenotype. This study was designed to evaluate the effects of paternal physical exercise on cognitive and physical development and on hippocampal DNA methylation levels of the offspring. Adult male Wistar rats were divided into two groups: sedentary and exercised. The exercise protocol occurred before mating and consisted of treadmill running, 5 consecutive days/week for 8 weeks (20 min/day). The mothers were not trained. The following developmental parameters were examined in male offspring: body growth, physical and cognitive performance, weights of adrenal glands, gonadal fat and hindlimb muscles, BDNF expression and global DNA methylation at the hippocampus. The progeny of trained and sedentary fathers did not differ in relation to physical parameters and performance, spatial memory and BDNF expression. However, paternal exercise promoted a decrease in offspring´s relative gonadal fat weight and a lower percentage of global hippocampal DNA methylation compared to offspring of sedentary fathers. These results pointed to interference of male physical activity at the time of conception on adiposity and hippocampal epigenetic reprogramming of male offspring. The data reinforces that exercise does not harm the descendant’s development and emphasize the benefits to include the practice of physical exercise in a healthier lifestyle of the parents. Nevertheless, future studies are necessary and should investigate further the long-effects of epigenetic mechanisms in order to elucidate the father’s contribution in fetal programming.

Nonmonotonic Effects of Chronic Low-Dose Di(2-ethylhexyl) Phthalate on Gonadal Weight and Reproductive.

ABSTRACTEndocrine disruptors have been concerned in toxicology but now challenged as physiological point especially concerned with exposing dose and period. In this study the low-dose chronic administration of di(2-ethylhexyl) phthaltae (DEHP) during reproductive period was examined to evaluate the possible roles. Adult male and female CD-1 mice were exposed to DEHP with drinking water containing 133 1g/L and 1,330 /g/L DEHP in water according to OECD 433 guide line and sacrificed just after weaning. The weights of uterus and ovary were decreased by drinking of 1,330 /g/L DEHP water. There was not adverse effects on either accumulated mating rate and mating rate depend on estrus stage, pregnancy duration, and sex ration at birth. However, the accumulated rate of successful delivery and litter size were significantly high at 1,330 dg/L DEHP water. The number of epididymal sperm was significantly increased by drinking of 1,330 g/L DEHP water. In addition, the number of follicles (primary, secondary, tertiary) were more many than control at 1,330 /g/L DEHP water drunk mother. Though further studies are needed to identify what are the mechanism of DEHP in folliculogenesis and spermatogenesis. From this study we firstly report the effect of low-dose chronic administration of DEHP with drinking could change the ovarian follicle population size and spermatogenesis rate. Put together, those finding is different from previous high-dose effects and suggest the physiological role of DEHP in gonads and uterus.

Seasonal changes in the gonadal state of the oysters Crassostrea iridescens and Crassostrea corteziensis (Filibranchia: Ostreidae) in the Northwest coast of México.

The reproductive cycle in oysters has been the subject of several studies in temperate zones. However, little information is available for tropical and subtropical species. This study describes the seasonal changes in the gonadic index (GI) of two species of oysters, Crassostrea iridescens and Crassostrea corteziensis, which differ markedly in their hàbitad and time of reproduction. Both oysters were sampled at 45 days intervals in the Northwest coast of Mexico between November 1989 and October 1990. Gonadal and somatic tissue per individual were dried for three days at 90°C, weighed and recorded. The gonadic index (GI) applied in this work was calculated from: GI = Wg/ws. Were WG is the average gonadal tissue dry weight, and Ws is the average somatic tissue dry weight. Seasonal variations in the gonadal state were evident for the two species. C.iridescens exhibited only a single maximum in the year, while C. corteziensis two peaks. This situation is presumably related to the contrastable environmental conditions that prevail in the sites where each species inhabit.

Effects ofWithania somniferaon Reproductive System: A Systematic Review of the Available Evidence

Introduction Withania somnifera (WS) also known as ashwagandha is a well-known medicinal plant used in traditional medicine in many countries for infertility treatment. The present study was aimed at systemically reviewing therapeutic effects of WS on the reproductive system. Methods This systematic review study was designed in 2016. Required data were obtained from PubMed, Scopus, Google Scholar, Cochrane Library, Science Direct, Web of Knowledge, Web of Science, and manual search of articles, grey literature, reference checking, and expert contact. Results WS was found to improve reproductive system function by many ways. WS extract decreased infertility among male subjects, due to the enhancement in semen quality which is proposed due to the enhanced enzymatic activity in seminal plasma and decreasing oxidative stress. Also, WS extract improved luteinizing hormone and follicular stimulating hormone balance leading to folliculogenesis and increased gonadal weight, although some animal studies had concluded that WS had reversible spermicidal and infertilizing effects in male subjects. Conclusion WS was found to enhance spermatogenesis and sperm related indices in male and sexual behaviors in female. But, according to some available evidences for spermicidal features, further studies should focus on the extract preparation method and also dosage used in their study protocols.

REPRODUCTIVE BIOLOGY OF STRIPED SNAKEHEAD (Channa striata Bloch, 1973) IN BOGOR AND BEKASI, WEST JAVA

Striped snakehead is one of the potential local species, however, its production in Indonesia still comes from capture fisheries. Over exploitation had decrease the population in nature. Domestication is one of promising tool to solve the problems faced. In order to breed the domesticated species, the information of their reproduction was needed. This study aimed to describe relationship between length and weight, length and fecundity, weight – fecundity and gonad weight – fecundity of the striped snakehead from West Java. A total of 19 mature female specimens were collected from Parung (Bogor), and seven mature female specimens were collected from Babelan (Bekasi). The results showed that the determinant value (R2), the first for Parung and the second for Babelan, between weight and fecundity were 0.599 and 0.843, length-fecundity were 0.541 and 0.841; gonad weight – fecundity 1.00 and 0.846 Gonadosomatic Index (GSI) ranged from 0.67 to 9.94% and 2.03 to 8.17%. Gonad Index ranged from 6.17 – 76.73 and 18.48 – 76.77, respectively. The data indicated that growth pattern was allometric. Length and body weight has linear relationship with gonads and fecundity. Fecundity has higher correlation to the weight rather than length. Gonad weight and fecundity has a strong relationship.

SLAF-based high-density genetic map construction and QTL mapping for major economic traits in sea urchin Strongylocentrotus intermedius

Sea urchin (Strongylocentrotus intermedius) has long been a model species for developmental and evolutionary research, but only a few studies have focused on gene mapping. Here, we reported a high-density genetic map containing 4,387 polymorphism specific-length amplified fragment (SLAF) markers spanning 21 linkage groups (LG) for sea urchin. Based on this genetic map and phenotyping data for eight economic traits, 33 potentially significant QTLs were detected on ten different LGs with explanations ranging from 9.90% to 46.30%, partly including 10 QTLs for test diameter, six QTLs for body weight and eight QTLs for Aristotle’s lantern weight. Moreover, we found a QTL enrichment LG, LG15, gathering QTLs for test diameter, body weight, gonad weight, light orange-yellow color difference (≥E1) and light yellow color difference (≥E2). Among all QTLs, we genotyped four QTLs for test diameter, Aristotle’s lantern weight and body weight using High Resolution Melting (HRM) technology. Finally, we used the verified SNP marker (detected using SLAF sequencing) to explore their marker-assisted selection (MAS) breeding application potential and found that SNP-29 associated tightly with body weight and that heterozygous genotype was a dominant genotype, indicating that SNP-29 was a promising marker for MAS.

Effect of temperature on gonadal growth and maturation of Paracentrotus lividus (Lamarck, 1816)

Effect of temperature on gonadal growth and maturation of Paracentrotus lividus (Lamarck, 1816)

Reproductive biology of north-eastern Atlantic sea cucumber species: a preliminary assessment

Reproductive biology of north-eastern Atlantic sea cucumber species: a preliminary assessment