Batch or trickle: understanding the multiple spawning strategy of southern calamary, Sepioteuthis australis (Mollusca : Cephalopoda)

2008 ◽  
Vol 59 (11) ◽  
pp. 987 ◽  
Author(s):  
Matthew R. Kuipers ◽  
Gretta T. Pecl ◽  
Natalie A. Moltschaniwskyj
Keyword(s):  
Egg Production ◽  
Reproductive Effort ◽  
Developmental Stages ◽  
Spawning Season ◽  
The Other ◽  
Lifetime Fecundity ◽  
Multiple Spawning ◽  
Maturation Stages ◽  
Oocyte Stage ◽  
Batch Spawning

Many cephalopods are ‘multiple spawners’; however, we know little about the timing and dynamics of egg production. This has implications for the allocation of energy to reproduction, lifetime fecundity and subsequent recruitment. The current study aimed to determine if Sepioteuthis australis (Quoy and Gaimard, 1832), which spawns multiple times, produces mature oocytes for deposition in a continuous trickle or in larger discrete batches. Throughout a spawning season, developmental stages were assigned to the ovaries of each female by combining macroscopic and histological analyses of the oocytes. Half of the females (46%) showed a significant peak in oocytes at one of the maturation stages, indicating that females were developing eggs in batches. It was hypothesised that the remaining females were also batch spawning, given that the oviduct weights of the remaining females (54%) were high and the other measured biological characteristics were similar to those of the females showing a peak in oocyte stage. Average batch fecundity declined over the 3-month spawning season, but total egg numbers in the ovary increased, suggesting that females might have deposited small batches more often during December. As reproduction requires large allocations of energy, understanding how females distribute reproductive effort throughout their lives is crucial to understanding the behaviour of populations, individuals and their offspring.

Multiple spawning and the dynamics of fish populations: inferences from an individual-based simulation model

1998 ◽  
Vol 55 (10) ◽  
pp. 2244-2254 ◽  
Author(s):  
Susan K Lowerre-Barbieri ◽  
James M Lowerre ◽  
Luiz R Barbieri
Keyword(s):  
Simulation Model ◽  
Egg Production ◽  
Adult Population ◽  
Individual Variability ◽  
Spawning Season ◽  
Average Life Span ◽  
Multiple Spawning ◽  
Individual Based Simulation ◽  
First Maturity ◽  
Size At Age

We used an individual-based Monte Carlo simulation model to assess how aspects associated with multiple spawning (within a spawning season) affected survivorship, lifetime fecundity, cohort egg production, and yield-per-recruit of a highly exploited species. To make our model more realistic, we included and tested the effects of individual variability in growth and a seasonal growth pattern. Birth months influenced when fish first matured and became vulnerable to the fishery. There was a sixfold increase in mature fish at the beginning of their first spawning season associated with having been born early versus late the previous season. Early born fish had a lower average life-span than later born fish. Although early born fish had lower survivorship they produced the most eggs because of an early size at first maturity, low fishing mortality in the first year, and their larger size at age. These results suggest multiple spawning can have important implications for recruitment and adult population dynamics.

Golden Shiner Egg Production during a Spawning Season

2010 ◽  
Vol 72 (3) ◽  
pp. 272-277 ◽  
Author(s):  
Troy Clemment ◽  
Nathan Stone
Keyword(s):  
Egg Production ◽  
Spawning Season ◽  
Golden Shiner

The extracellular electrical current pattern and its variability in vitellogenic Drosophila follicles

1986 ◽  
Vol 81 (1) ◽  
pp. 189-206 ◽  
Author(s):  
J. Bohrmann ◽  
A. Dorn ◽  
K. Sander ◽  
H. Gutzeit
Keyword(s):  
Juvenile Hormone ◽  
Current Density ◽  
Developmental Stages ◽  
Electrical Current ◽  
Posterior Pole ◽  
The Other ◽  
Follicular Epithelium ◽  
Nurse Cells ◽  
Vibrating Probe ◽  
Current Pattern

We determined the extracellular electrical current pattern around Drosophila follicles at different developmental stages (7–14) with a vibrating probe. At most stages a characteristic pattern can be recognized: current leaves near the oocyte end of the follicle and enters at the nurse cells. Only at late vitellogenic stages was an inward-directed current located at the posterior pole of many follicles. Most striking was the observed heterogeneity both in current pattern and in current density between follicles of the same stage. Different media (changed osmolarity or pH, addition of cytoskeletal inhibitors or juvenile hormone) were tested for their effects on extrafollicular currents. The current density was consistently influenced by the osmolarity of the medium but not by the other parameters tested. Denuded nurse cells (follicular epithelium locally stripped off) show current influx, while an accidentally denuded oocyte produced no current. Our results show that individual follicles may be electrophysiologically different, though their uniform differentiation during vitellogenesis does not reflect such heterogeneity.

The population dynamics of metacercariae of Apatemon gracilis (Trematoda: Digenea) in three species of lake-dwelling leeches

Parasitology ◽  
1986 ◽  
Vol 93 (3) ◽  
pp. 517-530 ◽  
Author(s):  
S. M. Spelling ◽  
J. O. Young
Keyword(s):  
Population Dynamics ◽  
Relative Density ◽  
Sexual Maturity ◽  
Egg Production ◽  
Seasonal Pattern ◽  
Distinct Pattern ◽  
The Other ◽  
Mean Intensity ◽  
Density Values ◽  
Host Mortality

SUMMARYMonthly samples of the leeches Erpobdella octoculata, Glossiphonia complanata and Helobdella stagnalis were taken over a two-year period from an eutrophic, English lake to detect metacercariae of the trematode, Apatemon gracilis. In each cohort of each of the three leeches, prevalence was low in young individuals, rose to a peak in autumn/winter, and then declined until the cohort had almost died out; in E. octoculata and H. stagnalis a final brief increase occurred. Mean intensity and relative density values followed a similar seasonal pattern of change to that of prevalence in these last two species, but in G. complanata values fluctuated irregularly with no distinct pattern. The frequency distribution of the parasite in G. complanata was highly over-dispersed, but less so in the other two species. Infected E. octoculata reached sexual maturity. The parasite reduced egg production in G. complanata and H. stagnalis, but only by maximum values of 2·5 and 9% respectively. This reduction in fecundity is low compared to the subsequent high mortality, at 95% or more, of newly recruited young from as yet unidentified causes. Parasite-related host mortality was difficult to assess in young leeches, but there was some evidence for its occurrence in older leeches of E. octoculata and H. stagnalis. However, this is unlikely to play a prominent role in the control and regulation of lacustrine leech populations.

scholarly journals The effect of a lack of uncapped brood on social interactions between honey bee workers and the queen

Apidologie ◽  
2021 ◽  
Author(s):  
Sylwia Łopuch ◽  
Adam Tofilski
Keyword(s):  
Social Interactions ◽  
Honey Bee ◽  
Honey Bees ◽  
High Speed ◽  
Egg Production ◽  
Social Contexts ◽  
The Other ◽  
High Speed Camera ◽  
Time Required ◽  
Honey Bee Workers

AbstractVibro-acoustic communication is used by honey bees in many different social contexts. Our previous research showed that workers interact with their queen outside of the swarming period by means of wing-beating behaviour. Therefore, the aim of this study was to verify the hypothesis that the wing-beating behaviour of workers attending the queen stimulates her to lay eggs. The behaviour of workers and the queen was recorded using a high-speed camera, at first in the presence of uncapped brood in the nest and then without one. None of the queens performed wing-beating behaviour. On the other hand, the workers attending the queen demonstrated this behaviour two times per minute, on average, even in the presence of uncapped brood in the nest. After removing the combs with the uncapped brood, the incidence of wing-beating behaviour increased significantly to an average of four times per minute. Wing-beating behaviour did not differ significantly in its characteristics when uncapped brood was present or absent in the nest. During 3 days after removing the combs with the uncapped brood, there was no significant increase in the rate of egg lying by the queen. Therefore, the results presented here do not convincingly confirm that the wing-beating behaviour of workers affects the rate of queen's egg-lying. This negative result can be related to colony disturbance and longer time required by the queen to increase egg production.

scholarly journals Gene expression profiling identifies pathways involved in seeds maturation of Jatropha curcas

2019 ◽  
Author(s):  
Fatemeh Maghuly ◽  
Tamas Deak ◽  
Klemens Vierlinger ◽  
Stephan Pabinger ◽  
Hakim Tafer ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Seed Development ◽  
Jatropha Curcas ◽  
Molecular Mechanisms ◽  
Seed Quality ◽  
Developmental Stages ◽  
Seed Maturation ◽  
Nutrient Mobilization ◽  
Starting Point ◽  
Maturation Stages

Abstract Background: Jatropha curcas, a tropical shrub, is a promising biofuel crop, which produces seeds with a high content of oil and protein. To better understand the development of its seeds to improve Jatropha`s agronomic performance, a two-step approach was performed: 1) generation of the entire transcriptome of six different maturation stages of J. curcas seeds using 454-Roche sequencing of a cDNA library, 2) comparison of transcriptional expression levels in six different developmental stages of seeds using a custom Agilent 8x60K oligonucleotide microarray. Results: A total of 793,875 high-quality reads were assembled into 19,841 unique full-length contigs, of which 13,705 could be annotated with Gene Ontology (GO) terms. Microarray data analysis identified 9,111 probes (out of 57,842 probes), which were differentially expressed between the six developmental stages. The expression results were validated for 70 randomly selected putative genes. Result from cluster analyses showed that transcripts related to sucrose, fatty acid, flavonoid, phenylpropanoid, lignin, hormone biosynthesis were over-represented in the early stage, while lipid storage, seed dormancy and maturation in the late stage. Generally, the expression of the most over-represented transcripts decrease in the last stage of seed maturation. Further, expression analyses of different maturation stages of J. curcas seed showed that most changes in transcript abundance occurred between the two last stages, suggesting that the timing of metabolic pathways during seed maturation in J. curcas is in late stages. The co-expression result showed a high degree of connectivity between genes that play essential role in fatty acid biosynthesis and nutrient mobilization. Furthermore, seed development and hormone pathways are significantly well connected. Conclusion: The obtained results revealed DESs regulating important pathways related to seed maturation, which could contribute to understanding the complex regulatory network during seed development. This study provides detailed information on transcription changes during J. curcas seed development and provides a starting point for a genomic survey of seed quality traits. The current results highlighted specific genes and processes relevant to the molecular mechanisms involved in Jatropha seed development, and it is anticipated that this data can be delivered to other Euphorbiaceae species of economic value.

scholarly journals Crossbred Local Chickens from East Nusa Tenggara Province Indonesia Under Semi Intensive Management System

2021 ◽  
Vol 748 (1) ◽  
pp. 012003
Author(s):  
N.G.A Mulyantini S.S ◽  
Ulrikus R Lole
Keyword(s):  
Weight Gain ◽  
Artificial Insemination ◽  
Management System ◽  
Egg Production ◽  
Abdominal Fat ◽  
Production Performance ◽  
The Other ◽  
Intensive Management ◽  
Commercial Grower ◽  
Local Chickens

Abstract The objective of this study was to compare the performance of four-breed combination under semiintensive management system. The experiment used 160 females and 40 males chickens as parents. Artificial insemination was performed to produce the experimental chicken of the four breed combinations (1. Sabu x Sabu, 2. Sabu x Semau, 3. Sabu x KUB, 4. Semau x KUB). The chickens were fed with chick starter crumb sad libitum from day old to 4 weeks of age. From 4-8 weeks of age, chickens were allowed to scavenge during the day, and also given commercial grower pellets + rice bran + corn (5:4:1). Combination of Sabu x KUBfrom 4-8 weeks of age were significantly heavier (P < 0.05) than the other combination breeds. Feed intake in the Sabu x KUB group was the lowest, and their weight gain was the highest among the others group(P < 0.05). The combination Sabu x KUB also had the highest egg production, and hatchability. However, the percentage of abdominal fat of Sabu x KUB were higher than others groups. In conclusion, combination Sabu x KUB had the best growth performance and egg production performance, but not for the percentage of abdominal fat.

scholarly journals Is maternal thyroid hormone deposition subject to a trade-off between self and egg because of iodine? An experimental study in rock pigeon

2021 ◽  
Author(s):  
Tom Sarraude ◽  
Bin-Yan Hsu ◽  
Suvi Ruuskanen ◽  
Ton Groothuis
Keyword(s):  
Egg Production ◽  
Developmental Stages ◽  
Columba Livia ◽  
Captive Population ◽  
Restricted Diet ◽  
Trade Off ◽  
Metabolic Hormones ◽  
Hormone Exposure ◽  
Maternal Thyroid ◽  
Early Developmental

Maternal hormones constitute a key signalling pathway for mothers to shape offspring phenotype and fitness. Thyroid hormones (THs; triiodothyronine, T3 and thyroxine, T4) are metabolic hormones known to play crucial roles in embryonic development and survival in all vertebrates. During early developmental stages, embryos exclusively rely on the exposure to maternal THs, and maternal hypothyroidism can cause severe embryonic maldevelopment. The TH molecule includes iodine, an element that cannot be synthesised by the organism. Therefore, TH production may become costly when environmental iodine availability is low. This may yield a trade-off for breeding females between allocating the hormones to self or to their eggs, potentially to the extent that it even influences the number of laid eggs. In this study, we investigated whether low dietary iodine may limit TH production and transfer to the eggs in a captive population of Rock pigeons (Columba livia). We provided breeding females with an iodine-restricted (I- diet) or iodine-supplemented diet (I+ diet) and measured the resulting circulating and yolk iodine and TH concentrations and the number of eggs laid. Our iodine-restricted diet successfully decreased both circulating and yolk iodine concentrations compared to the supplemented diet, but not circulating or yolk THs. This indicates that mothers may not be able to independently regulate hormone exposure for self and their embryos. However, egg production was clearly reduced in the I- group, with fewer females laying eggs. This result shows that restricted availability of iodine does induce a cost in terms of egg production. Whether females reduced egg production to preserve THs for themselves or to prevent embryos from exposure to low iodine and/or THs is as yet unclear.

scholarly journals Molecular identification of Mycoplasma synoviae from breeder chicken flock showing arthritis in Egypt

2019 ◽  
Vol 12 (4) ◽  
pp. 535-541
Author(s):  
Mohamed M. Amer ◽  
Hoda M. Mekky ◽  
Hanaa S. Fedawy
Keyword(s):  
Vaccine Strain ◽  
Molecular Identification ◽  
Egg Production ◽  
The Other ◽  
Phylogenetic Study ◽  
Chicken Flock ◽  
Mycoplasma Synoviae ◽  
Broiler Breeder ◽  
Field Isolates ◽  
Other Hand

Aim: Arthritis is one of the most economic problems facing poultry industry worldwide. The study was done to detect possible causes of arthritis in breeder chicken flock with emphasis on molecular identification of Mycoplasma synoviae (MS). Materials and Methods: This study was carried on chicken from broiler breeder flock of 57 weeks' age in Dakahlia, Egypt, suffered from arthritis with frequently 5-7% decrease in egg production, reduced fertility, and hatchability. Forty blood samples were randomly collected from individual birds in sterile tubes and used for serum separation. Serum samples were tested using serum plate agglutination (SPA) test against colored antigens for Mycoplasma gallisepticum (MG), MS, and Salmonella gallinarum-pullorum (SGP). On the other hand, 24 joint samples were collected. Of those 24 samples, 12 joint samples were subjected to bacteriological examination, while the other 12 were utilized for molecular diagnosis by polymerase chain reaction (PCR) for MS and avian reovirus (ARV). Results: SPA test results revealed the presence of antibodies against MG, MS, and SGP in tested sera in rates of 14/40 (35%), 35/40 (87.5%), and 9/40 (22.5%), respectively. Furthermore, 19 bacterial isolates were recognized from joint samples and identified as five Staphylococcus spp., nine Escherichia coli, three SGP, one Citrobacter, and one Proteus. The identified Staphylococcal isolates were three coagulase-positive staphylococci (two Staphylococcus aureus and one Staphylococcus hyicus) and two coagulase-negative staphylococci (one Staphylococcus epidermidis and one Staphylococcus lentus), while E. coli isolate serotypes were 1 O11, 2 O55, 3 O78, 1 O124, 1 O125, and 1 untyped. PCR proved that 12/12 (100%) samples were positive for MS variable lipoprotein hemagglutinin A (vlhA) gene, while ARV was not diagnosed in any of the examined samples. Four amplified vlhA gene of MS isolates (named MS-2018D1, MS-2018D2, MS-2018D3, and MS-2018D4) was successfully sequenced. Analysis of phylogenetic tree revealed the presence of 100% identity between each two sequenced isolates (isolates MS-2018D1 and MS-2018D4 and also isolates 2018D2 and MS-2018D3). However, the nucleotide similarity between four isolates was 88.6%. On the other hand, our field isolates MS-2018D1, MS-2018D4, MS-2018D2, and MS-2018D3 showed nucleotide identity with vaccine strain MS-H 98.4%, 98.4%, 88.1%, and 88.1%, respectively. Furthermore, the nucleotide similarities with field strains from Argentina ranged between 87.8% and 98.6%. Conclusion: Four field isolates of MS were identified in examined broiler breeder flock. A phylogenetic study of these isolates revealed the variation between isolated MS strains and vaccine strain. Therefore, further studies are required for evaluating the vaccine efficacy against the present field isolates of MS. In addition, application of MS immunization of breeder flocks is necessary for proper control of the disease.

scholarly journals Heritability of egg production in laying hens under cumulative, multitrait and repeated measurement animal models

2008 ◽  
Vol 52 (No. 8) ◽  
pp. 254-260 ◽  
Author(s):  
A. Wolc ◽  
M. Lisowski ◽  
T. Szwaczkowski
Keyword(s):  
Animal Models ◽  
Variance Components ◽  
Egg Production ◽  
Genetic Parameters ◽  
Laying Hens ◽  
Genetic Effects ◽  
Repeated Measurement ◽  
Repeated Measurements ◽  
The Other ◽  
Highly Correlated

Six generations of three layer lines (13 770 recorded individuals of A22 line, 13 950 of A88, 9 351 of K66) were used to estimate genetic effects on egg production under cumulative, multitrait and repeatability models. Variance components were estimated by the AI-REML algorithm. The heritability of cumulative records ranged from 0.08 to 0.1. For the repeated measurements model the following genetic parameters were obtained: heritability 0.02–0.03, repeatability 0.04–0.38. The first two months of egg production were found to differ from the other periods: heritability was relatively high (<i>h</i><sup>2</sup> > 0.35) and low or negative correlations with the other periods were found. Heritability was low (<i>h</i><sup>2</sup> < 0.1) from the peak production until the end of recording and the consecutive periods were highly correlated. Further studies on monthly records are suggested.

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