Average Fecundity Research Articles

Optimizing goldfish hatchery of the oranda variety Carassius auratus to improve cultivation performance at BSD fish farm

The business of cultivating ornamental fish is quite popular because its sales are profitable for cultivators. Ornamental fish also have attractive colors; therefore, many people are interested in this commodity. One ornamental fish commodity that is in great demand is the oranda goldfish Carassius auratus, which has a variety of colors, unique movements, and body shapes. The annual increase in market demand for oranda goldfish reaches 95,000 fish annually, and each year, there is an increase in the production of 3,000 fish of around 3% each year. This study was carried out in an effort to explore technical information on goldfish cultivation so that the information obtained can be disseminated widely and used as a reference source for the community so that it will add value to the benefit of improving sustainable welfare. The results of the study show that the technique of spawning oranda goldfish can be performed naturally using a substrate in the form of a water hyacinth. The average fecundity produced by one female parent oranda goldfish was 6429 eggs, with a presentation hatching rate of 74% and a presentation survival rate of 64%.

Fecundity of <i>Sepioteuthis lessoniana</i> (Cephalopoda:Loliginidae), in the Gulf of Mannar Marine BiosphereReserve

Sepioteuthis lessoniana is one of the commercially important species, showing genetic differences among its lineages B (Gulf of Mannar) and C (Palk Bay). This study estimated the average fecundity of S. lessoniana from lineages B at 1,043 oocytes, ranging from 308 oocytes in a female, 18.0 cm dorsal mantle length (DML), (11.8 g ovary weight), to 2,563 oocytes in a female, 34.9 cm DML (70.4 g ovaryweight). Larger females exhibited higher fecundity, which increased with DML according to the equation Fecundity=0.2266*DML2.5802. The fecundity-ovary weight relationship followed the equation: Fecundity=21.379+33.131*ovary weight. These findings contribute to our understanding of S. lessoniana stocks from lineage B and their management.

Reproductive Biology of the Invasive Blue Crab Callinectes sapidus in the Thermaikos Gulf (Northwest Aegean Sea, Eastern Mediterranean): Identifying Key Information for an Effective Population Management Policy

The reproductive biology of the invasive blue crab Callinectes sapidus was studied in the Thermaikos Gulf (Northwest Aegean Sea, Eastern Mediterranean). In the two-year survey, 5698 (2897♂/2801♀) crabs were caught with the use of fyke nets. Total sex ratio (♂/♀) reached equality (1.03:1). The female blue crab exhibited a protracted reproductive period. Mature and ovigerous females exhibit short migratory movements from estuarine and inshore waters, where the population mostly congregates (0–3 m), and move to slightly deeper waters (1–3 m) up to 9 m for spawning. A total of 340 ovigerous females were caught. Their number varied both spatially and temporally; they were observed for a 7-month period (April to October) with a clear peak in July–August and at a 3 m depth gradient corresponding to ≈60% of the total number of ovigerous females caught in both years. Size at first sexual maturity (CW50) was estimated at 113.1 mm CW. Average fecundity was ≈790,000 eggs. Experimental trawling showed that inshore waters (<1 m) in the estuaries serve as nursery areas for juveniles. Defining the spatiotemporal and bathymetrical distribution of ovigerous females in any invaded coastal habitat could be considered key information for the implementation of a management policy for the species.

Biology, morphometric and integrative taxonomy of litchi fruit borer, Conopomorpha sinensis Bradley, 1986: A major pest of litchi (Litchi chinensis Sonn.)

Abstract Conopomorpha sinensis (Lepidoptera: Gracillariidae), commonly known as the litchi fruit borer, is a devastating pest of litchi, leading to substantial economic losses in fruit production. The present study was incepted to supplement updated information on biology, morphometrics, integrative taxonomy, and phylogenetic analysis of C. sinensis. The duration of developmental stages such as egg, larval, pre-pupal, pupal, male and female adult lasts for 3.45 ± 1.13, 11.10 ± 2.52, 2.05 ± 0.51, 5.85 ± 0.88, 5.55 ± 1.00, and 9.00 ± 1.12 days, respectively. The average fecundity was 33.10 ± 6.84 eggs/female. The head capsule width for five larval instars was 0.11 ± 0.01, 0.18 ± 0.02, 0.34 ± 0.01, 0.58 ± 0.04, and 0.64 ± 0.06 mm, respectively. Phylogenetic analysis revealed distinct species-groups formed by C. sinensis with other fruit borer species considered (C. cramerella, C. litchiella Bradley, and Thaumatotibia batrachopa (Meyrick)). Understanding the life cycle of C. sinensis and its correct identification is crucial for targeted pest control strategies. Traditional and molecular taxonomy assist in rapid and accurate species identification and understanding of the evolutionary relationships among Conopomorpha species.

Assessment of Lethal, Sublethal, Transgenerational, and Biochemical Effects of Isaria fumosorosea on Mythimna separata.

Mythimna separata is a destructive polyphagous pest of field crops. Insecticides are generally applied for its control which not only negatively affect natural enemies and the environment and cause resistance in the insect pests. There is a need for the friendly method which is safe for the environment and life. Currently, entomopathogenic fungi are being used as biological control agents for different insects. The influence of Isaria fumosorosea on survival, life table parameters, and enzymatic activities of M. separata were assessed. On the seventh day post-treatment, the highest concentration 3 × 108 spores/mL-1 caused the 92.5% larval mortality. The effect of LC15 and LC50 of I. fumosorosea were recorded on parental generation (F0) and first filial generation (F1) of M. separata. The life table parameters of F1 showed a decreasing trend in the intrinsic rate (r), net reproductive rate (Ro), mean generational time (T), total larval duration, and fecundity ratio in treated groups. In LC15 and LC50, groups the average fecundity ratio was 319.2 and 191.18 eggs/female, respectively. The activities of detoxifying enzymes were concentration-dependent and highest activities were recorded on the third day. I. fumosorosea negatively affected the growth parameters of M. separata and can be included in M. separata management program.

Multi-omics analysis reveal the fall armyworm Spodoptera frugiperda tolerate high temperature by mediating chitin-related genes

Climate change facilitates the rapid invasion of agricultural pests, threatening global food security. The fall armyworm Spodoptera frugiperda is a highly polyphagous migratory pest tolerant to high temperatures, allowing its proliferation in harsh thermal environments. We aimed to demonstrate mechanisms of its high-temperature tolerance, particularly transcriptional and metabolic regulation, which are poorly understood. To achieve the aim, we examined the impact and mechanism of heat events on S. frugiperda by using multiple approaches: ecological measurements, transcriptomics, metabolomics, RNAi, and CRISPR/Cas9 technology. We observed that several physiological indices (larval survival rate, larval period, pupation rate, pupal weight, eclosion rate, and average fecundity) decreased as the temperature increased, with the 32 °C treatment displaying a significant difference from the control group at 26 °C. Significantly upregulated expression of genes encoding endochitinase and chitin deacetylase was observed in the chitin-binding, extracellular region, and carbohydrate metabolic process GO terms of hemolymph, fat body, and brain, exhibiting a tissue-specific pattern. Significantly enriched pathways (e.g., cutin, suberin, and wax biosynthesis; oxidative phosphorylation and cofactor biosynthesis; diverse amino acid biosynthesis and degradation; carbon metabolism; and energy metabolism), all of which are essential for S. frugiperda larvae to tolerate temperature, were found in metabolites that were expressed differently. Successful RNA interference targeting of the three chitin-related genes reduced gene expression levels and larval survival rate. Knockout of the endochitinase gene by using the CRISPR/Cas9 system significantly reduced the relative gene expression and increased sensitivity to high-temperature exposure. On the basis of our findings, theoretical foundations for understanding the high-temperature tolerance of S. frugiperda populations and latent genetic control strategies were established.

Assessment of Biological Characteristics of Red Spider Mite (Tetranychus urticae) Koch on Brinjal

Red spider mite, Tetranychus urticae Koch passed through five stages viz., egg, larva, protonymph, deutonymph and adult with three short resting stages known as quiescent stages which termed as nymphochrysalis, deutochrysalis and teleiochrysalis. The incubation period of egg was 3.28 ± 1.10 days with 0.13 ± 0.01 mm diameter in size. The average length and breadth of larva, nymphochrysalis, protonymph, deutochrysalis, deutonymphs, teleiochrysalis, adult male and adult female stage were 0.14 ± 0.01 and 0.10 ± 0.01; 0.19 ± 0.01 and 0.12 ± 0.01; 0.20 ± 0.01 and 0.12 ± 0.01; 0.24 ± 0.02 and 0.13 ± 0.01, 0.29 ± 0.02 and 15 ± 0.02, 0.35 ± 0.03 and 0.18 ± 0.01, 0.43 ± 0.04 and 0.19 ± 0.01; and 0.47 ± 0.02 and 0.22 ± 0.01 mm, respectively. The mean duration of male and female larva, nymphochrysalis, protonymph, deutochrysalis, deutonymphs, teleiochrysalis and adult was 2.07 ± 0.73 and 2.36 ± 0.22, 0.58 ± 0.32 and 0.68 ± 0.22, 2.23 ± 0.35 and 2.92 ± 0.81, 0.70 ± 0.35 and 0.76 ± 0.39, 2.12 ± 0.44 and 2.56 ± 0.51, 0.77 ± 0.19 and 0.87 ± 0.37 and 7.12 ± 0.93 and 11.08 ± 0.86 days, respectively. Female of T. urticae occupied 2.48 ± 0.96, 5.32 ± 0.99 and 2.35 ± 0.84 days as pre-oviposition, oviposition and post-oviposition period, respectively. Total life period of male and female was 19.14 ± 2.06 and 23.85 ± 1.65 days, respectively. The average fecundity and hatching percentage were 47.60 ± 6.13 days and 91.11 ± 4.14 per cent, respectively with 1 : 2.50 sex ratio.

Fitness and Survival of the Fall Armyworm, Spodoptera Frugiperda (Lepidoptera: Noctuidae) on Maize in West Java, Indonesia

An important pest of maize is a new invasive species called Spodoptera frugiperda, also known as the fall armyworm (FAW), causing a considerable economic impact in Indonesia since 2019. This insect has a large host range, a quick generation time at the right temperature, a high rate of reproduction, and a high dispersal capacity. In population ecology and pest management, fitness and survival are crucial. This research was aimed to determine some biological aspects and demographic statistics of three FAW populations (lowland, midland, and highland) in a laboratory setting with 25 ± 2 °C, 75 ± 5% relative humidity, and a 12:12 (L:D) hour photoperiod. Findings indicated no variation in the length of the FAW life stage or its reproductive capacity. Nonetheless, notable variations were noted in the average fecundity of females, with FAW of the highland population laying the most eggs (1242.1 eggs). FAW had the shortest mean generation time (T), the highest intrinsic rate of increase (rm), the finite rate of increase (λ), and the highest net reproductive rate (R0) of the highland population. Overall FAW collected from highland, midland, and lowland can adapt well when brought to a laboratory with a constant temperature at 25 ± 2 °C without detriment to the parameters of the life table. The knowledge gained from this study is crucial for managing FAW because it improves comprehension of its life cycle and adaptability to various altitudes, enabling us to take appropriate action to stop its spread.

Trait-Fitness Associations via Fecundity and Competition in a Two-Million-Year-Long Fossil Record.

AbstractThe evolution of phenotypic traits is usually studied on generational timescales or across species on million-year timescales. We bridge this conceptual gap by using high-density sampling of a species lineage, Microporella agonistes (Bryozoa, Cheilostomatida), over 2 million years of its evolutionary history, to ask whether trait-fitness associations are consistent with evolutionary trait models often applied to phenotypic time series. We use average fecundity and competitive outcome as two different fitness components, where competitive outcome is a proxy for partial survival. Examining three quantitative traits in multivariate analyses, we present evidence that some traits experienced substantial selective pressures, in part controlled by past environments. A complex interplay of resource competition with an altering set of competitors and past temperatures has contributed to the changing patterns of phenotypes within the focal species. A comparison with congeneric species living in the same regional community suggests that size traits are more temporally variable and less constrained than shape traits. Our analyses also show that while controls on phenotypes are complex and varied in time, ecological and evolutionary processes that unfold on shorter timescales are not inconsistent with macroevolutionary patterns observed on longer timescales.

Monitoring and Occurrence Prediction of the Migration Population of Helicoverpa armigera (Hübner) Based on Adult Semiochemical Attractants

Helicoverpa armigera (Hübner) is a destructive agricultural pest. Facultative migration usually causes regional catastrophes; therefore, developing a simple and easy new technology for the monitoring and early warning of immigrant populations is urgent. Between 2021 and 2023, we conducted a population-monitoring study on H. armigera immigrants in Xundian County, Yunnan Province, where the migration pathway for pests from southeast Asia extends to southwest China. Based on the differences in the reproductive organ development parameters of H. armigera at different ages, we established an adult age discrimination model. The monitoring results of field populations with semiochemical attractants and sex pheromones between 2021 and 2023 showed that the daily average age of the adult population of H. armigera fluctuated above 6 days, and the trapping dynamics with semiochemical attractants and sex pheromones were the same. Both trapping methods yielded H. armigera males of different ages and had identical age structures, indicating that the H. armigera population primarily migrated from other regions. The trajectory analysis showed that the H. armigera population that migrated to Xundian between May and September was primarily from South Kunming, and after October, it was primarily the southward-migrating population north of Qujing City, Yunnan Province. Based on the relationship between the daily average fecundity and the age of H. armigera, a dynamic prediction model for the fecundity of the immigrant population was established. In this study, the prediction models and methods based on semiochemical attractants could potentially be used in the surveillance and population alerting of H. armigera.

Effect of temperature on the development, reproduction and survival of Tetramoera schistaceana (Lepidoptera: Tortricidae)

Tetramoera schistaceana Snellen is an important stem borer of sugarcane, which causes severe damage to sugarcane in China. Temperature is a key factor affecting its development and reproduction. Development duration, reproduction and survival rate of T. schistaceana were determined at five different temperatures (20, 23, 26, 29 and 32 °C) in this study. Results showed that temperature had significant effects on the development duration, survival rate and reproduction of T. schistaceana. The development rate of T. schistaceana for each stage increased linearly with increasing temperatures between 20 and 32 °C. Egg hatching rate, larval pupation rate and pupal eclosion rate were the highest between 23 and 26 °C. The lower thermal threshold (T0) for egg, larva, pupa, pre-adult and whole generation were 9.98, 9.80, 9.47, 9.50 and 8.87 °C, respectively and the thermal constant (K) for the development of the respective life cycle stages of were 89.29 for eggs, 400.00 for larvae, 151.52 for pupae, 625.00 for pre-adult and 666.67DD for whole generation, respectively. The average fecundity per female was also the highest between 23 and 26 °C. Therefore the optimum temperature range for the development and reproduction of T. schistaceana was between 23 and 26 °C.

Insights into ovarian maturation and reproductive traits of the deep-water penaeid shrimp Metapenaeopsis andamanensis (Wood-Mason in Wood-Mason and Alcock, 1891) from southwestern India

The present study delves into the reproductive characteristics of Metapenaeopsis andamanensis, a commercially significant deep-water shrimp collected from Sakthikulangara, off Kollam, India (8°56′60.78″ N/76°32′34.27″ E) during September 2019 to May 2022. Despite its economic importance, the reproductive traits of this species remain elusive. This research comprehensively examines macroscopic and microscopic features associated with gonadal maturity stages, including determination of size at first maturity (CL50), gonadosomatic index, and fecundity of M. andamanensis. Male-to-female sex ratio was noted as 1:1.03 using chi-square analysis. The smallest mature individuals were observed at 12 mm and 16 mm carapace length for males and females, respectively. Macroscopic observation categorized females into five groups based on gonadal coloration, while microscopic examination identified seven stages using histological characteristics. Notably, the absence of cortical crypts in the periphery of oocyte cytoplasm, a characteristic feature of the genus Metapenaeopsis, was observed in this species. Males were classified into two categories based on macroscopic and microscopic observation. The gonadosomatic index ranged from 4.25 to 10.13 for mature female individuals, exhibiting a significant increase until stage IV. Continuous spawning was observed, with a peak in May and November. The size at first maturity for females and males was determined as carapace length (CL) 23.05 mm and 17.53 mm, respectively. The average absolute fecundity was calculated as 53,889 with an average relative fecundity of 9934 oocytes. This investigation contributes valuable insights into the reproductive traits of the deep-water penaeid shrimp M. andamanensis, facilitating the development of effective management strategies for sustainable fisheries.

About the fertility of pink salmon Iturup Island

The purpose of the work is to present data for the last 15 years and analyze the fecundity of pink salmon at the present stage of its natural and hatchery reproduction on the island Iturup.The research material was based on the results of biological analysis of pink salmon breeders running to spawn in the basins of Prostor and Kurilsky bays (Iturup Island, Sakhalin region) in July-September 2008–2022. Methods used: standard methods of biological analysis, descriptive statistics methods.Results: it was established that over the past 15 years there has been a trend towards a decrease in the weight of female pink salmon. The value of absolute fecundity during this period varied from 289 to 3568 oocytes, and on average, with one exception, ranged from 1277 to 1640 oocytes. Fecundity was positively but weakly correlated with the length and weight of females within each of the annual samples, and the reliability of this relationship was achieved due to the volume of the samples. The relationship between the fecundity and weight was stronger than that between the fecundity and the length of fish. Average fecundity values were closely correlated with the average weight of females, and, therefore, as in the case of fish weight, in the period from 2008 to 2022 there was a trend toward a decrease in average fecundity values.Practical significance: we studied the fertility of female pink salmon from the only large commercial stock in Russia, formed through natural and hatchery reproduction.

Effects of Synthetic Hormones on Fertilization, Fecundity, Hatching and Gonado-Somatic Index of Giant Snakehead (Channa Marulius) in Captivity

The effects of a crude protein (40% CP) diet on the spawning performance of giant Snakehead (Channa marulius) broodstock were assessed in this study through a three-week feeding trial. Mature C. marulius brood stock (N = 36) was taken from the brooders pond and stocked into nine small experimental breeding ponds, each measuring 4mx2mx1.5m (LxWxD). Following acclimatization, all male and female C. marulius broodstock with an average weight of 1.5–2.5 kg BW and a length of 70 cm were removed from the small breeding ponds. The current study's objective was to induce breeding in C. marulius by injecting synthetic hormones intramuscularly and monitoring fertilization, fecundity, hatching, and gonado-somatic index. Using a completely randomized design (CRD), nine fishponds were split into three treatments (T1, T2, and T3) during the study period, each with three replicates. In addition to evaluating the effects of artificially applied hormones, Conceptal® (T1), Suprefact® (T2), and Ovaprim® (T3), this study aimed to comprehend the reproductive biology of C. marulius. The hormones were injected into the test fish at the following proportion (0.3ml, 0.4ml and 0.5ml to male and 0.8ml, 0.9ml and 1.0ml to female’s ml/kg body weight) and then released into the earthen ponds for large scale production of seed. Two-way analysis of variance (ANOVA) was used. The results showed no successful spawning on Conceptal®. The gonado-somatic index (GSI) estimates for the study period showed that Suprefact had the highest average GSI values for both males and females (3.32±1.62% and 1.67±0.18%, respectively), followed by Ovaprim (1.13±0.56 and 1.22±0.68, respectively). Absolute fecundity was also estimated. The result showed that fish stimulated with suprefact (T2) obtained the highest average fecundity (3079.3±100.7%), fertilization rate (96.33±1.20%), hatching rate (94.67±2.40%), and survival rate (95.75±1.51%), then in ovaprim fecundity rate (1669.3±836.5%), fertilization rate (58.00±29.02), hatching rate (61.27±30.65), survival rate (64.67±32.34%), respectively. In conclusion, the use of Suprefact® and Ovaprim® can optimise the results of C. marulius breeding induction in small experimental breeding ponds, ensuring higher-quality eggs and a greater number of normal larvae.

A Study of Age, Sex Ratio, Gonado-Somatic Index, Fecundity, and Breeding Season, of Nile Tilapia (Oreochromis niloticus Linnaeus, 1758) from Khashm El-Girba Reservoir and Atbara River, Eastern Sudan

This study aims to investigate some reproductive aspects of Nile tilapia, Oreochromis niloticus in the Khashm El-Girba reservoir and Atbara River, eastern Sudan. The study was conducted during December 2015 to November 2016. Samples were collected bi-monthly basis from three localities, namely; Um Aswad (Atbara River), El-Remila, and El-Monaba (Khashm El-Girba reservoir), using beach seine nets of 1.2 cm 4.0 cm and 7.0 cm stretched mesh. A total of 1595 O. niloticus specimens were collected from all sampling sites. The age of O. niloticus was estimated using five anterior vertebrae of fish body; The results indicate that the age ranged between 0+ to 4+ years. Most of the collected fish specimens were of age 1+, with females most dominant at this age. Sex ratio was 1:1(M: F). Gonado-somatic index (GSI) of females of O. niloticus ranged between 1.965 – 2.620, and from 0.434 – 0.439 for males. Two periods of increase of GSI were observed reflecting two breeding seasons of this species. Used gravimetric method to estimate the average fecundity of O. niloticus ranged between 481 eggs in Um Aswad sampling site, and 638 in El-Remila site. The fecundity of O. niloticus has a high correlation with gonadal weight (r=0.82708) but a low correlation with standard length (r=0.47612) and total weight (r=0.50874). The results of this investigation on O. niloticus indicate that the age of the fish ranged from 0+ to 4+ years, with a sex ratio of 1:1. The Gonado-somatic Index (GSI) indicated two spawning seasons, and fecundity was found to be strongly correlated with gonad weight, and moderately correlated with total length and standard length. This results can be used formulate management policies and procedures for protecting and conserving the fisheries resources and to regulate and improve the catches of the most important commercial fish species in that region.

Effects of miR-306 Perturbation on Life Parameters in the English Grain Aphid, Sitobion avenae (Homoptera: Aphididae).

MicroRNAs (miRNA) play a vital role in insects' growth and development and have significant potential value in pest control. Previously, we identified miR-306 from small RNA libraries within the English grain aphid, Sitobion avenae, a devasting insect pest for wheat. miR-306 not only involves in wing morphogenesis, but also is critically important for aphid survival. Its specific impacts on the life history traits, however, remain unclear. Here, we evaluate the impact of miR-306 perturbation on S. avenae populations using a two-sex life table approach. This comprehensive analysis revealed that miR-306 perturbation significantly prolongs the developmental stages (9.64% and 8.20%) and adult longevity of S. avenae, while decreasing pre-adult survival rate (41.45% and 38.74%) and slightly reducing average fecundity (5.80% and 13.05%). Overall, miR-306 perturbation negatively affects the life table parameters of the aphid population. The population prediction models show a significant decline in the aphid population 60 days post interference, compared to the control groups (98.14% and 97.76%). Our findings highlight the detrimental effects of miR-306 perturbation on S. avenae population growth and suggest potential candidate genes for the development of RNAi-based biopesticides targeted specifically at this pest species.

Temporal declines in fecundity: A study of southern Gulf of St. Lawrence Atlantic herring (Clupea harengus) and implications for potential reproductive output.

Individuals must reproduce to survive and thrive from generation to generation. In fish, the fecundity of individuals and estimates of total reproductive output are critical for evaluating reproductive success and understanding population dynamics. Estimating fecundity is an onerous task; therefore, many populations lack contemporary estimates of fecundity and size-fecundity relationships. However, reproductive dynamics are not static in time; therefore, it is important to develop contemporary fecundity estimates to better inform conservation and management action. To highlight the importance of contemporary fecundity estimates, we examined the fecundity of southern Gulf of St. Lawrence (sGSL) spring and fall spawning Atlantic herring in 2022, developed size-fecundity models, and compared these to historical fecundity estimates and models. Our results suggest that the average fecundity of sGSL spring and fall herring has undergone a substantial temporal decline of approximately 47% and 58%, respectively, since the 1970s and 1980s. The size-fecundity relationships for fall spawning herring have shifted, with fish of a given size exhibiting lower fecundity in 2022 compared to the 1970s. Alternatively, the size-fecundity relationships for spring spawning herring have remained relatively static. Furthermore, simulations highlighted a substantial reduction in potential reproductive output in 2022 compared to 1970 of approximately 32% and 68% for spring and fall spawners, respectively, based on a fixed number of mature females, which may have negative implications for stock rebuilding. Overall, our study provides support for periodic estimates of fecundity in fish populations to better understand temporal changes in reproductive and population dynamics.

Biology of Fall Armyworm Spodoptera frugiperda (J.E. Smith) on Maize under Laboratory Conditions

Maize is a important cereal harvests developed for food, fodder and raw material throughout the country. It is rich source of proteins, carbohydrates and vitamins. Corn production is decreasing day by day due to attack of more than 353 insect species and mites. Among insect pests, Fall armyworm, Spodoptera frugiperda is best destructive pest for corn production. The rearing of Fall armyworm, Spodoptera frugiperda was conducted under laboratory conditions in Department of Entomology, Acharya Narendra Deva University of Agriculture & Technology, Kumarganj, Ayodhya, U. P. during 2023. The complete metamorphosis (egg, larva, pupa and adult) was certified in Spodoptera frugiperda. The average fecundity was 2.59 ± 0.40 days. There were 6th instar larval of Spodoptera frugiperda and total larval period was 15-20 days. The growth period of 1st, 2nd, 3rd, 4th, 5th and 6th larval instar was 2-3, 2.5-3, 2.2-3, 2-2.5, 2.5-3, 4-6 days respectively on corn leaves. The average period of pupa was 10.33 ± 1.07 days. The female was long lived than male. The total evolved period from egg to adult was 45-47 days.

Effect of water quality parameters and climatic influences on reproductive phenology of Macrognathus pancalus in wetland ecosystem: recommending a long-term management approach and conservation policy.

The study conducted an investigation into the reproductive biology of M. pancalus and assessed the influence of water quality parameters and environmental factors on the spawning pattern within the Gajner Beel ecosystem in Bangladesh. A total of 1218 individuals of M. pancalus (46.39% males and 53.61% females) were collected monthly from the Gajner Beel during January to December 2018 using various fishing gears. The total length (TL) of each individual was measured using digital slide calipers, and the whole body weight (BW) was measured using an electronic balance. Fulton's conditions factor (KF) showed significant differences between males and females. The calculated Lm were 11.11 cm, 11.30 cm, and 11.10 cm based on maximum length, gonadosomatic index (GSI), and the logistic model. The spawning season extended from May through August, with June and July being peak months. The average total fecundity was 1495.52 ± 840.24, with a range of 370 to 4069. During peak spawning season, the average temperature and rainfall were 27°C and 370 mm, respectively. Rainfall, dissolved oxygen, total alkalinity, and pH all had a significant (p < 0.01) positive effect whereas temperature and TDS all had a significant (p > 0.01) negative effect on GSI. Annual air temperature in the study area increased by 0.053 °C/year, with a regression coefficient value (r2 = 0.1695), while annual mean rainfall decreased by 5.97mm/year (r2 = 0.076). This research will contribute to the development of conservation and management approaches of Mastacembelidae fish in relation to current climate variability in sub-tropical waters.

Impact of live food on the reproductive performance of the Batur toad, &lt;i&gt;Bufotes baturae&lt;/i&gt; (Stöck, Schmid, Steinlein et Grosse, 1999) in captivity

The work is devoted to the study of the reproductive performance of a narrow areal triploid toads (Batur toad, Bufotes baturae) reared on different live food (Turkestan and marble cockroaches). Material for the work was obtained over three breeding seasons. In the first breeding season, the number of pairs reared on the Turkestan cockroach (Shelfordella lateralis) was 7 (64%) and on the marbled cockroach (Nauphoeta cinerea) – 2 (18%). In the second and third seasons, the numbers were 8 (89%) and 11 (100%) respectively. The average fecundity of females fed on the Turkestan cockroach ranged from 3149 to 3300 eggs over three seasons, while that of females fed on the marbled cockroach ranged from 2472 to 2630 eggs. However, the juveniles from the group reared on marbled cockroach were superior in length to the prelarvae, as well as in length and weight to the post-metamorphic juveniles. Thus, there was no clear advantage in reproductive performance in animals consuming different diets. Both insect species were highly effective when fed to Baturian toads under laboratory conditions.