Average Egg Size Research Articles

Carry-Over Effects of Broodstock Conditioning on the Salinity Tolerance of Embryos of the New Zealand Geoduck (Panopea zelandica)

The New Zealand geoduck (Panopea zelandica) has seen considerable interest from the NZ aquaculture industry. A major bottleneck in culturing P. zelandica is early life stages mortality (e.g., embryo). Therefore, in this study, we investigated the embryonic performance and their transition to the first feeding larval stage (D-veliger) under different salinities (26, 30, 32, and 35 ppt) of four different offspring groups generated from broodstock being fed different ratios (25 : 75, 50 : 50, 60 : 40, and 75 : 25) of the haptophyte Tisochrysis lutea (formerly Isochrysis galbana) (ISO) and the diatom Chaetoceros muelleri (CM) during gametogenesis. Broodstock within all diet ratio treatments successfully conditioned, producing viable embryos. Average egg size ranged between 75 and 80 µm and was not affected by the diet ratios of the broodstock. Survival 48 hr postfertilization, D-veliger larvae yield, and incidence of abnormalities depended on both the embryo rearing salinity and broodstock feeding ratios. The combined salinity of 32−35 ppt and a feeding ratio of 50 : 50 and 60 : 40 (ISO:CM) had the highest survival of embryos (56.0%–77.5%), highest production of D-veliger larvae (>65%), and lowest incidence of abnormalities within D-Veliger (<47%). The size of the larvae decreased with decreasing salinities, with the largest found at 35 ppt (101.22 ± 0.49 µm in shell length). Embryos and larvae did not survive at salinity 26 ppt. These results suggest that diet during gametogenesis can play a role on the offspring ability to cope with environmental stressors at least during the critical first few days after fertilization. These findings provide important information on transgenerational effects due to broodstock diet, especially during the early life stages.

Effect of rearing density on female investment in reproduction and melanotic encapsulation response in the sand cricket (Gryllus firmus) (Orthoptera: Gryllidae)

Abstract The density-dependent prophylaxis hypothesis posits that because pathogens are expected to be transmitted among conspecifics in crowded conditions, individuals living in such conditions should minimize their chance of infection and maximize survival by elevating their baseline immunity. Further, if individuals developing in crowded conditions indeed allocate more resources to immunity then resource allocation to other life-history traits, such as reproduction, should decline. We tested these hypotheses by rearing sand crickets (Gryllus firmus) at either low or high density in the laboratory and quantified immune function (melanotic encapsulation response) and reproductive investment (ovary mass, egg size) at adulthood. The results did not support the density-dependent prophylaxis hypothesis, but we did find that rearing density significantly affected investment in two reproductive traits, with average ovary mass and egg size both being larger in low-density crickets. We discuss possible explanations for the lack of a trade-off between immunity and reproduction in our study.

Standard- and large-sized eggs of Trichuris trichiura in the feces of schoolchildren in the Yangon Region, Myanmar: Morphological and molecular analyses.

Standard- and large-sized eggs of Trichuris trichiura were found in the feces of schoolchildren in Yangon, Myanmar during epidemiological surveys and mass deworming with albendazole in 2017-2019. The standard-sized eggs were identified as those of T. trichiura, but it was necessary to exclude the possibility of the large-sized eggs belonging to Trichuris vulpis, a dog whipworm. We conducted morphological and molecular studies to determine the species of the 2 types of Trichuris eggs. Individual eggs of both sizes were isolated from Kato-Katz fecal smears (n=20) and mechanically destroyed using a 23G injection needle. Nuclear DNA was extracted, and the 18S rRNA region was sequenced in 15 standard-sized eggs and 15 large-sized eggs. The average size of standard-sized eggs (T. trichiura) was 55.2×26.1 μm (range: 51.7-57.6×21.3-28.0 μm; n=97), whereas the size of large-sized eggs was 69.3×32.0 μm (range: 65.1-76.4×30.1-34.5 μm; n=20), slightly smaller than the known size of T. vulpis. Regarding standard-sized eggs, the 18S rRNA nucleotide sequences exhibited 100% homology with T. trichiura deposited in GenBank and 88.6-90.5% homology with T. vulpis. Regarding large-sized eggs, the nucleotide sequences showed 99.8-100% homology with T. trichiura in GenBank and 89.6-90.7% homology with T. vulpis. Both standard- and large-sized eggs of Trichuris spp. found in Myanmar schoolchildren during 2017-2019 were morphologically and molecularly confirmed to belong to T. trichiura. The conversion of eggs from smaller to large sizes might be due to anthelmintic treatments with albendazole.

Variations in the Reproductive Strategies of Different Charadrius alexandrinus Populations in Xinjiang, China.

Due to the influence of bio-geographical and environmental factors, as well as anthropogenic landscape features, organisms show different reproductive strategies among different populations. There is a lack of detailed information on the reproductive biology of Kentish plover Charadrius alexandrinus in arid lands in Central Asia. In this study, we summarized the characteristics of the reproductive biology of three geographically distinct plover populations in Aibi Lake in northwestern Xinjiang, Taitema Lake in southern Xinjiang and artificial reservoirs around Urumqi City in northern Xinjiang, based on 440 eggs from 158 nests observed and analyzed from April to July of 2019 and 2020. We found that there was no significant difference in clutch size among the three populations. However, the egg size of the Taitema Lake population was significantly larger than those of the other two populations, whilst the egg volume and clutch volume of the artificial reservoirs' populations were significantly larger than that of Aibi Lake. With the postponement of laying dates, the northern and northwestern populations showed the characteristics of a small clutch size and a relatively small egg size, respectively, and a decrease in reproductive output. The heavier female plovers in Taitema Lake laid eggs earlier, and there was a significantly positive correlation between female body mass and clutch size and egg size. The tarsometatarsus length of the female plovers was significantly positively correlated with the reproductive output in all three populations. The model selection results show that female body size and ambient temperature restrict the egg size and reproductive output of Kentish plovers, which is consistent with the upper limit hypothesis of the maternal condition and maternal constraint. Our data support the hypothesis that Kentish plovers show distinct flexibility in their breeding strategies to cope with the harsh natural environment in the arid lands of Xinjiang, China. The results of a relatively high average clutch size and average egg size imply that the saline wetlands of Western China are important breeding habitats for Kentish plovers.

Comparative use efficiency of the same type feed additives in the diet of replacement stock and laying hens of the parent herd

The use of two similar feed additives Sorbitox and Probitox in the diet of replacement stock and subsequently in the diet of laying hens, at a dose of 0.50 kg/t of feed allowed to increase the poultry survival rate at 18 weeks of age by 1.4% with the addition of Sorbitox and 6.4% - with Probitox, the group uniformity by 5.3 and 7.3%, respectively, in comparison with the control group. At the same time, the culling of birds in the experimental groups decreased due to endoenteritis and necrotic enteritidis, and the antibody titer to Gumboro disease increased in the blood. During the productive period of laying hens, the difference in the antibody titer was significantly higher, as was the livestock survival rate. The tested feed additives contributed to a better development of ovogenesis organs. As a result, the egg productivity of chickens with Sorbitox was higher than the control group by 6.5%, with Probitox – by 11.6%. The study of the egg incubation qualities showed that the young stock hatching rate from an average egg size in the group with Sorbitox was 6.9% higher than the control group, with Probitox – by 11.0%, and the hatchability of eggs was 1.1 and 1.6% higher than in the average one. In laying hens at the beginning and at the end of egg laying, the number of infertile small eggs decreased in the group with Sorbitox by 0.60%, with Probitox - by 1.0%, large eggs – by 1.23 and 2.45%, respectively. The chicken hatching rate from small and large eggs in poultry of the experimental groups exceeded the control by 2.9-5.9% at the beginning of egg laying, by 10.0-14.8% at its completion at the age of 56 weeks. The addition of Sorbitox in the diet of replacement stock allowed to reduce feed costs for growing one head of service pullet by 6.9%, with Probitox – by 12.6%, to increase the production profitability by 5.5 and 7.8%, and in laying hens of experimental groups, feed costs decreased by 4.4 and 10.0%, profitability increased by 2.0 and 5.3%, respectively.

Breeding ecology of the laughing dove (Streptopelia senegalensis) in the Taif City, Kingdom of Saudi Arabia.

The Laughing Dove (Streptopelia senegalensis) is a columbid bird commonly found throughout most of Africa, the Middle East, Central Asia, India and Australia. Its preferred habitat includes scrubland, agricultural lands, and human settlements. Despite this species' extensive breeding range, very little information is available regarding its breeding ecology. The main objective of this study was to investigate the breeding features of the Laughing Dove in Taif City, Saudi Arabia between March and May 2018 and December 2018 and May 2019. The results indicate that this species constructs its nests at a mean height of 2.74 ± 0.1 m from the ground. The average number of nesting materials used for building a Laughing Dove nest was 109.3 ± 11.25. This study recorded that this species starts breeding in the middle of February. A clutch of two eggs comprised 72% of all the nests, with a mean of 1.75 ± 0.06 eggs per clutch. The average egg size was 25.27 ± 0.43 mm x 20.25 ± 0.19 mm, with an average egg volume of 5.01 ± 0.13 cm3. In total, 39.5% of the eggs hatched, and 64.7% of hatchlings reached the fledgling stage, resulting in an overall breeding success of 25.6%. This study suggested that nest desertion and predation were the major factors contributing to nest failure.

Effect of Giving Turmeric Rhizome and Teak Leaves Combination on Egg Quality and Productivity of Laying Hens

This research was conducted to study the effect of feeding additives in the form of a combination of turmeric rhizome (Curcuma longa) and teak leaf (Tectona grandis) on egg quality and productivity of laying hens. The method used in this research is an experimental method with a completely Randomized Design (CRD). The study used one control group (P0) and three treatment groups. The treatment group was given feed additives in drinking water in the form of a combination of turmeric rhizome and teak leaves at intervals of once a day (P1), once every two days (P2), and once every four days (P3). The study was conducted on light-type laying hens aged about 72 weeks for 28 days. The data was obtained in the form of size and weight of eggs and egg production. Data on the size and weight of eggs were obtained by measuring the circumference and weight of the eggs, while data on egg productivity was obtained by calculating the number of chicken eggs produced each day. Data analysis with One Way Anova using SPSS 23 program. The results showed that egg quality was not significantly different but the provision of feed additives at intervals of once a day resulted in the highest average egg size and egg production.

Spider mite predator Feltiella acarisuga (Vallot, 1827) (Diptera: Cecidomyiidae) in greenhouse strawberry cultivation in Antalya Province: recognition, population dynamics and parasitization by Aphanogmus sp.

Feltiella acarisuga (Vallot, 1827) (Diptera: Cecidomyiidae) is an effective and common beneficial species that feeds on many species of Tetranychid mites. Although it has been detected in Turkey, there are few studies on this predatory species. In this study, weekly leaf samples were taken to represent the growing area in the soilless strawberry greenhouse of Akdeniz University in 2020 and 2021. In leaf examinations, it was determined that F. acarisuga had an average egg size of 0.21 mm, young and mature larva of 0.26-1.51 mm, and a cocoon size of 2.01 mm. The average body length of male and female individuals was measured as 0.89 mm and 1.11 mm, respectively. It was determined that F. acarisuga can feed on all biological stages of Tetranychus urticae Koch, 1836 (Acari: Tetranychidae), as eggs, larvae, nymphs and adults were seen in the greenhouse in all seasons. Feltiella acarisuga is the most common natural enemy of T. urticae , with a maximum average of 0.38 larvae + cocoons/leaf in the greenhouse in the first year and 0.62 larvae + cocoons/leaf in the second year. In this study, a new species was detected, Aphanogmus sp., which was determined to be the parasitoid of F. acarisuga and different from its known congeners. The parasitization rate of F. acarisuga was found to be between 0 and 51.5%.

Serum liver enzyme profile in Timor deer (Cervus timorensis) with fascioliasis in Indonesia.

Timor deer (Cervus timorensis) at Surabaya zoo, Indonesia, that were found to be naturally infected with Fasciola, showed elevated level of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP). Of a total of 75 deer examined, 12 (25%) of the 47 adult deer and 8 (29%) of the 28 juvenile deer were found to be infected with fascioliasis, as evidenced by the shedding of the parasite eggs. The level of ALT, AST and ALP were significantly elevated (p<0.05) in all the infected deer. Only Fasciolainfected deer showed elevated serum liver enzyme. Deer with elevated enzyme level show a trend that positively correspond with higher Egg per gram of feces (EPG). The average size of the parasite eggs at 169.0±11.1 × 96.0±3.5μm, correspond well with that of Fasciola gigantica. No other trematode eggs were observed besides that of F. gigantica. There was no significant difference in the enzyme profile between the two sexes in both the infected and the uninfected group. This is the first report of the elevation of serum liver enzyme in Timor deer that is associated with not only fascioliasis and also correspond positively with the EPG.

Breeding Biology of the Lald (Fulica atra L.) at the Water Treatment Facilities of the Kharkov City.

Introduction.The anthropization of ecosystems is an important factor for the evolution of species and adaptation processes. Fulica atra L. is a fairly abundant species of wetlands in Ukraine. The adaptation of the coot to anthropogenic territories occurs during the winter period in cities, later birds remain in these areas for nesting.Purpose.To assess the current state of the coot population at water treatment facilities and Lake Novy Liman, which are the parts of the territory of the city of Kharkov. Studies of nesting biology of Fulica atra on Lake Novy Liman and silt sites of treatment facilities make it possible to assess the current state of the population of the species in the water bodies of Kharkov, as well as important for completeness assessments of the distribution of birds in wetlands.Methods. The studies were carried out in 2020-2021 during expedition trips to Lake Novy Liman and biological treatment facilities No 2 in Kharkov.Results.The nesting biology of the coot (Fulica atra L.) was investigated at the silt sites of water treatment facilities of the biological treatment complex No 2 in Kharkov and Lake Novy Liman in April-June 2020-2021. The reproduction biology of 73 pairs of coot was studied. To set the nesting density, a map with the coordinates of the nests has been created. The first eggs in clutches were found on average on April 16±1,4 at an average daily temperature of +5 ± 1,73 ̊Сat night and +20 ± 0,89 ̊Сduring the day in 2020 and on April 18±1,9 at +14,9 ± 3,08 ̊Сduring the day and +5 ± 2,76 ̊Сat night in 2021. Average clutch size 7,1 ± 1,13 eggs. First chicks: May 8-10. Average egg size (n = 223): 53,37 ± 2,56 x 37,05 ±1,45 mm. Vertebrates and birds of prey have been identified that can affect the breeding success of the coot.Originality.For the first time, a study of the breeding biology of the coot was carried out on the territory of treatment facilities and their surroundings.Conclusion.Wastewater treatment plants are an important place in the city of Kharkov, where birds undergo the process of adaptation to the anthropogenic landscape.Key words: coot, nestingbiology, egg laying, sewage treatment plants, Novy Lyman lake.

Common carp maturation and fecundity and reproduction optimization in Uzbekistan

Reproductive biology of cultured common carp in Uzbekistan was studied. The ages, total lengths of the samples studied ranged 1-5 years, 5.0 - 87.0 cm in standard length. In spring, 1-year-old fish (8.0-25.0) cm had gonads at stage I; 2-years-old females (18.0 – 33.0 cm) had gonads at stage I (23 %) and II (77 %); 3-years-old females (25.6–47.1 cm) had ovaries at stage II (43 %) and III-IV (57 %); all 4-year-old and 5-year-old females were mature. Females mature when they reached 32 cm in standard length. Absolute fecundity varied 131–1830 thousand eggs, relative fecundity was 190.5–344.0 eggs/g of gutted fish body, real fecundity was 200.0–1300.0 thousand eggs. Average individual ripe egg size varied 1.32–1.52 mm. Positive correlation between maturation, absolute fecundity and growth was determined. For broodstock forming optimization, additional (to body size) fish characteristic should be entered to selection; fish growth could be recommended as such measure. Annual artificial selection of fishes with standard length at different ages (at least SL1 – 13 cm; SL2 - 25 cm; SL3 – 32 cm) would form broodstock which mature at 3-years-old age with real fecundity 800 – 1300 thousand eggs.

Dual-purpose production of eggs and meat\u2014part 2: hens of crosses between layer and meat breeds show moderate laying performance but choose feed with less protein than a layer hybrid, indicating the potential to reduce protein in diets

The use of modern chicken genotypes with high egg or meat performance results in the ethically unacceptable practice of culling day-old male layer chicks because of their inefficient fattening performance. Dual-purpose genotypes with a balanced performance profile for eggs and meat are one option to avoid this practice. In this study, the performance of four crosses of a layer breed (White Rock or New Hampshire) and the meat breed Bresse Gauloise, purebred Bresse Gauloise and the layer hybrid Lohmann Sandy was compared under organic husbandry conditions. Part 2 focuses on the laying performance of the hens until the age of 72 weeks and their feed choices when offered energy-rich and protein-rich feed mixtures. Feed consumption was generally high (133–143 g day−1), but the crosses consumed less protein feed than Lohmann Sandy, indicating a potential to reduce the proportion of high-protein components. Bresse Gauloise × White Rock showed severe plumage loss due to feather pecking, which was most likely caused by their low consumption of protein feed. Apparently, free-choice feeding did not agree with this genotype. Average laying performance of the crosses was 68–73% total eggs per average hen, which can be considered moderate. Average egg weights and egg size distribution were comparable with Lohmann Sandy, while slaughter performance of the senior hens was comparable with purebred Bresse Gauloise. Based on these findings, egg production with dual-purpose laying hens can be an ethically desirable alternative to high-performance genotypes, but will require further research on optimal feeding strategies and animal behaviour.Trial registered on July 7, 2017 (reference number V 241-26532/2017)

Effects of manganese and Bacillus subtilis on the reproductive performance, egg quality, antioxidant capacity, and gut microbiota of breeding geese during laying period

This experiment was conducted to investigate the effects of manganese (Mn) and Bacillus subtilis (BS) on the production performance, egg quality, antioxidant capacity, and gut microbiota of breeding geese during laying period. A total of 120 forty-six-week-old breeding geese (Wulong) were randomly assigned to 1 of 6 treatment diets formulated to supply 10, 20, and 30 mg/kg Mn with 5 × 109 CFU/kg or 2.5 × 109 CFU/kg BS for a 10-wk trial. Results showed that dietary supplementation with 20 and 30 mg/kg Mn could decrease the daily feed intake (DFI) of geese. Moreover, 30 mg/kg Mn significantly increased the laying rate. Besides, although Mn addition had no obvious effect on egg quality, 5 × 109 CFU/kg BS was found to elevate the hatching egg hatching rate and eggshell thickness. For the serum hormones, 30 mg/kg Mn promoted estradiol secretion, while 5 × 109 CFU/kg BS increased the level of follicle-stimulating hormone. Furthermore, 20 and 30 mg/kg Mn and 5 × 109 CFU/kg BS significantly enhanced the total antioxidant capacity by increasing the activity of total superoxide dismutases or decreasing the content of malondialdehyde. Dietary supplementation with 5 × 109 CFU/kg BS also increased the intestinal villus height and upregulated the abundance of Fusobacteria, Fusobacteriaceae, Fusobacterium, and Faecalibacterium in cecal content. In addition, 20 and 30 mg/kg Mn elevated the levels of Bacteroidetes, Bacteroidaceae, Bacteroides, and Ruminococcaceae but decreased Streptococcaceae. Importantly, an interaction effect was observed between Mn and BS on the DFI, egg mass, average egg size, and the abundance of Bacteroides as well as Faecalibacterium. In conclusion, dietary inclusion of Mn and BS could improve the production performance, egg quality, antioxidant capacity, intestinal structure, as well as gut microbiota. Supplementation of 30 mg/kg Mn and 5.0 × 109 CFU/kg BS provided the optimal effect.

Abnormalities in shape and size of Eurytemora affinis (Copepoda, Calanoida) and its eggs under different environmental conditions

Abstract In this study we examined the morphological anomalies of 2023 ovigerous females of the copepod Eurytemora affinis from laboratory and field samples. Field copepod collections were collected from 10 sites in Europe and North America. Laboratory cultured copepods were reared at 6 experimental conditions during several generations. The observation under the microscope of the ovigerous females’ bodies revealed the presence of a ‘Tumor Like Anomaly’ (TLA) on a few individuals, which were manifested on the urosome. The occurrence of TLA was only noticed on copepods from the field samples. This result shows that under controlled laboratory conditions, E. affinis do not manifest any abnormal morphology, even when temperature and salinity conditions are stressful, which also demonstrates the high plasticity of this copepod species and its capacity to live at a wide range of environmental parameters. In this study, we also confirmed that E. affinis is capable of producing eggs with a wide range of sizes, ranging from very small and abnormal eggs of 75.79 μm only, to very large eggs, reaching a maximal diameter of 128.71 μm. The observed large eggs are abnormal compared to the average size of the other eggs produced within the same clutch. Other abnormalities on eggs, such as deformed eggs or eggs infested by fungi, are only observed from field samples at a few sampling sites. In the Seine estuary, several abnormalities in eggs and adult females were observed during February 2010. The critical period for E. affinis’ development is sampling site-specific and needs to be accurately studied in the future to better explain the causes of the abnormalities described in this work, and their effects at population level.

Effects of adoption of freshwater residency on life‐history ecology of terapontid grunters

Abstract While fish reproduction has played a critical role in development of life‐history theory, the collective effects of a marine‐to‐freshwater invasion on a clade's reproductive ecology have rarely been explored in a phylogenetic context. We analysed and compared a range of quantitative and qualitative components of reproductive ecology in the Australasian terapontid fishes, a family distributed widely across marine, estuarine and freshwater habitats in the Indo‐Pacific region. We specifically tested hypotheses that life‐history strategies such as larger egg sizes and reduced fecundities are a key characteristic of freshwater species in comparison with their close marine relatives, and also fit a range of currently available evolutionary models describing the processes of ecomorphological and macrohabitat‐related diversification. Using recently developed phylogenetic comparative methods, differences in several quantitative reproductive traits were evident between marine and freshwater species, with reductions in average fecundity and increases in average egg size specifically characterising freshwater species. Evolutionary modelling of major trait axes, as well as specific traits across the family, highlighted significant increases in rates of evolutionary diversification across both freshwater lineages and within freshwater subclades. Modelling also supported the evolution of distinctive morpho‐ecotype optima between marine and freshwater species over simpler models of random‐walk evolution or single morphological optima. Review of life‐history behaviour identified environmental stimuli related to photoperiod, temperature, and lunar‐tidal cycles (and possibly combinations thereof) as playing an important role in stimulating spawning behaviour in most marine–euryhaline species. While some of these variables (temperature and photoperiod) continue to play an important role in some freshwater species, flow regime, particularly streamflow increases, appear more important in stimulating spawning responses, underlining the role of flow regime emerging as a master variable shaping evolutionary trajectories in freshwater clades. In this review and meta‐analysis, we document that adaptation to an entirely freshwater existence has catalysed significant, and in several cases, relatively rapid adaptive evolution to very different life‐history strategies within freshwater species. The invasion of freshwaters has had profound impacts on the trajectory of terapontid life‐history evolution, driving significant changes in a range of traits relating to fecundity, egg size, spawning stimuli, and spawning substratum. Collective results suggest a distinct adaptive landscape difference between marine and freshwaters. Terapontids can provide a useful model for assessing the consistency of these outcomes with other freshwater‐invading groups.

Effects of dietary supplementation of microencapsulated Enterococcus fecalis and the extract of Camellia oleifera seed on laying performance, egg quality, serum biochemical parameters, and cecal microflora diversity in laying hens

The aim of this study was to investigate the effects of microencapsulted Enterococcus faecalis (MEF) and the extract of Camellia oleifera seed (ECOS) on laying performance, serum biochemical parameters, and cecal microflora diversity in laying hens. A total of 180 Hy-Line Brown laying hens, 26-wk-old, were randomly allocated to 6 treatments with 10 replicates and 3 hens per replicate. Dietary treatments were as follows: (A) control group, basal diet; (B) basal diet + 100mg MEF/kg diet (1 × 1010 cfu/g MEF); (C) basal diet + 300mg ECOS/kg diet; (D) basal diet + 100mg MEF/kg diet + 300mg ECOS/kg diet; (E) basal diet + 500mg ECOS/kg diet; (F) basal diet + 100mg MEF/kg diet + 500mg ECOS/kg diet. The results showed that diets supplemented with MEF and ECOS had no significant effects on laying rate, average egg size, average daily feed intake, feed conversion ratio, eggshell thickness, albumen height, and yolk color (P > 0.05), but had significant effects on egg shape index, eggshell strength, and Haugh unit (P < 0.05) during whole feeding phases. Compared to the control group, the serum IgA and IgG levels of birds in Group F significantly increased (P < 0.05). The serum total cholesterol, low-density lipoprotein cholesterol, total triglyceride, and blood urea nitrogen levels of birds in Group D and Group F significantly reduced (P < 0.05), and the high-density lipoprotein cholesterol level of birds in Group D and Group F significantly increased (P < 0.05). At the phylum level, Firmicutes decreased (P < 0.05) and Bacteroidetes increased (P < 0.05) in the birds of Group D. Ruminococcus and Bacteroides were significantly affected by dietary treatments (P < 0.05), and Bacteroides in the birds of Group D significantly increased at the genus level. Therefore, diet supplemented with MEF and ECOS can significantly improve serum biochemical parameters and increase cecal microflora diversity.

Transgenerational effects in an ecological context: Conditioning of adult sea urchins to upwelling conditions alters maternal provisioning and progeny phenotype

Transgenerational plasticity occurs when the conditions experienced by the parental generation influence the phenotype of their progeny. This may in turn affect progeny performance and physiological tolerance, providing a means by which organisms cope with rapid environmental change. We conditioned adult purple sea urchins, Strongylocentrotus purpuratus, to combined pCO2 and temperature conditions reflective of in situ conditions of their natural habitat, the benthos in kelp forests of nearshore California, and then assessed the performance of their progeny raised under different pCO2 levels. Adults were conditioned during gametogenesis to treatments that reflected static non-upwelling (~650 μatm pCO2, ~17 °C) and upwelling (~1300 μatm pCO2, ~13 °C) conditions. Following approximately 4 months of conditioning, the adults were spawned and embryos were raised under low pCO2 (~450 μatm pCO2) or high pCO2 (~1050 μatm pCO2) treatments to determine if differential maternal conditioning impacted the progeny response to a single abiotic stressor: pCO2. We examined the size, protein content, and lipid content of eggs from both sets of conditioned female urchins. Offspring were sampled at four stages of early development: hatched blastula, gastrula, prism, and echinopluteus. This resulted in four sets of offspring: (1) progeny from non-upwelling-conditioned mothers raised under low pCO2, (2) progeny from non-upwelling-conditioned mothers raised under high pCO2, (3) progeny from upwelling-conditioned mothers raised under low pCO2, and (4) progeny from upwelling-conditioned mothers raised under high pCO2. We then assessed the effects of maternal conditioning along with the effects of developmental pCO2 levels on body size of the progeny. Our results showed that differential maternal conditioning had no impact on average egg size, although non-upwelling females produced eggs that were more variable in size. Maternal conditioning did not affect protein content but did have a modest impact on egg lipid content. Developing embryos whose mothers were conditioned to simulated upwelling conditions (~1300 μatm pCO2, ~13 °C) were greater in body size, although this effect was no longer evident at the echinopluteus larval stage. Although maternal conditioning affected offspring body size, the pCO2 levels under which the embryos were raised did not. Overall, this laboratory study provides insight into how transgenerational effects may function in nature. The impacts of parental environmental history on progeny phenotype during early development have important implications regarding recruitment success and population-level effects.

Contrasting latitudinal gradients of body size in helminth parasites and their hosts

AbstractAimWe examined body size scaling relationships for two developmental life stages of parasitic helminths (egg and adult) separately in relationship to latitude (i.e. Bergmann's rule), temperature and temperature seasonality. Given that helminth eggs experience environmental conditions more directly, whereas adults live inside infected host individuals, we predict stronger environmentally driven gradients of body size for eggs than for adults.LocationGlobal.Time periodPresent day.Major taxa studiedParasitic helminths.MethodsWe compiled egg size and adult body size data (both minimum and maximum) for 265 parasitic helminth species from the literature, along with species latitudinal distribution information using an extensive global helminth occurrence database. We then examined how the average helminth egg and adult body size of all helminth species present (minimum and maximum separately) scaled with latitude, temperature and temperature variability, using generalized linear models.ResultsBoth the egg size and the adult body size of helminths tended to decrease towards higher latitudes, although we found the opposite body size scaling pattern for their host species. Helminth sizes were also positively correlated with temperature and negatively, but more weakly, with temperature seasonality.Main conclusionsInstead of following the body size patterns of their hosts, helminth parasites are more similar to other ectotherms in that they follow the converse Bergmann's rule. This pattern did not differ between helminth developmental stages, suggesting that mean annual temperature and seasonality are unlikely to be related mechanistically to body size variation in this case.

Development of an artificial breeding and hatchery technique for exotic ornamental fish &lt;i&gt;Sahyadria denisonii&lt;/i&gt; (Day, 1865)

Sahyadria denisonii is one of the highly demanded exotic ornamental fish species. Development of artificial breeding technique for Sahyadria denisonii is important under local conditions. The captive breeding of this species did not occur under the environmental manipulation method used in the present study. However, breeding was successful, when Ovaprim hormone was injected at 0.5 ml per kg of body weight of the female at 9 h latency period. Average number of eggs laid was 216±33 and average egg size at maturity was 1.6±0.2 mm. Duration of development of eggs to hatchling was 36 h from time of fertilization. Feeding Artemia nauplii as an initial feed resulted a significantly higher growth (P<0.05) while micro-worm fed hatchlings exhibited significantly high survival rate. Therefore, results of this study revealed that a single dose of Ovaprim at 0.5 mL/kg of BW of females and half of that dose for males can be used for breeding of S. denisonii. Artemia nauplii, and micro-worm larval feeds can be used as the starter feeds for S .denisonii post-larvae.

Seasonal differences in egg size in three species of crabs from a tropical upwelling zone

ABSTRACTEgg size and offspring size are fundamentally important aspects of the life histories of all animals. However the impact of environmental conditions on intraspecific variation in egg size of marine invertebrates is poorly documented. Here we followed three species of intertidal crabs Xanthodius sternberghii, Petrolisthes armatus and Clibanarius albidigitus to understand how seasonal environmental variation in temperature and salinity associated with seasonal upwelling impacts egg size. Ovigerous females of both P. armatus and C. albidigitus were found year round, while X. sternberghii has a limited reproductive season, with ovigerous females found only between November and February. In all three species more than half of the variation in egg size was attributable to variation among broods from different females. Eggs collected during the dry, upwelling season were significantly larger than those collected during the wet, non-upwelling season. Multiple regression analysis showed that average egg size from each brood was significantly negatively correlated with temperature for all three species. Egg size was also negatively correlated with salinity in P. armatus when we controlled for temperature. Overall these results support the idea that changes in environmental temperature caused by seasonal upwelling play a significant role in generating seasonal differences in egg size.