scholarly journals A monogamous pipefish has the same type of ovary as observed in monogamous seahorses

2008 ◽  
Vol 4 (4) ◽  
pp. 362-365 ◽  
Author(s):  
Atsushi Sogabe ◽  
Koji Matsumoto ◽  
Mizuki Ohashi ◽  
Aki Watanabe ◽  
Hiromi Takata ◽  
...  
Keyword(s):  
Teleost Fish ◽  
Egg Production ◽  
Dorsal Side ◽  
Entire Length ◽  
The Other ◽  
Distinct Difference ◽  
Rolled Sheet ◽  
Corythoichthys Haematopterus ◽  
Ovarian Structure

Syngnathid fish (pipefish and seahorses) are unique among teleost fish in that their ovary consists of a rolled sheet with germinal ridge(s) on the dorsal side running along the entire length of the sheet. A distinct difference is seen in the ovarian structure between polygamous Syngnathus pipefish and monogamous seahorses ( Hippocampus spp.), the former having one germinal ridge and the latter with two ridges. This study examined the ovarian structure and the mode of egg production in a monogamous pipefish Corythoichthys haematopterus . The ovary of C. haematopterus had two germinal ridges like that observed in monogamous seahorses. There were two distinct groups of follicles in the ovary, one being a cohort of extremely small follicles and the other a cohort of follicles developing and increasing in size with the passage of time. We suggest that the ovarian structure and the mode of egg production in this pipefish are adaptations to monogamy.

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 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 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.

scholarly journals A NEW SPECIES OF MALDIVEA GERLACH, 1962 (NEMATODA, OXYSTOMINIDAE) FROM FELIDHOO ATOLL (MALDIVES, INDIAN OCEAN) AND AN EMENDED DIAGNOSIS OF THE SUB-FAMILY AND GENUS

2019 ◽  
Vol 20 ◽  
pp. 1-9
Author(s):  
Federica Semprucci ◽  
Maria Balsamo
Keyword(s):  
New Species ◽  
Indian Ocean ◽  
Type Species ◽  
Distal Part ◽  
Complex Structure ◽  
Dorsal Side ◽  
The Other ◽  
Ventral Part ◽  
Endemic Genus ◽  
A New Species

Maldivea Gerlach, 1962 is a possible endemic genus of the Maldivian archipelago for which only M. xarifae Gerlach, 1962 has been described so far. A new species of this genus, M. complexa n.sp., was recently found in Felidhoo atoll. It reveals a more complex structure of gubernaculum than in type species which appears to be divided into two pieces: one is a sort of long wing in the ventral part of the spicule and the other one, more complex, is characterized by several curved stripes which envelop the dorsal side of the spicule distal part. According to the present considerations, diagnoses of Paroxystomininae and Maldivea are emended.

scholarly journals Dorsoventral decoupling of Hox gene expression underpins the diversification of molluscs

2019 ◽  
Vol 117 (1) ◽  
pp. 503-512 ◽  
Author(s):  
Pin Huan ◽  
Qian Wang ◽  
Sujian Tan ◽  
Baozhong Liu
Keyword(s):  
Gene Expression ◽  
Hox Genes ◽  
Expression Patterns ◽  
Dorsal Side ◽  
The Other ◽  
Strongly Correlated ◽  
Expression Data ◽  
Shell Formation ◽  
Hox Gene ◽  
Evolutionary Diversification

In contrast to the Hox genes in arthropods and vertebrates, those in molluscs show diverse expression patterns with differences reported among lineages. Here, we investigate 2 phylogenetically distant molluscs, a gastropod and a polyplacophoran, and show that the Hox expression in both species can be divided into 2 categories. The Hox expression in the ventral ectoderm generally shows a canonical staggered pattern comparable to the patterns of other bilaterians and likely contributes to ventral patterning, such as neurogenesis. The other category of Hox expression on the dorsal side is strongly correlated with shell formation and exhibits lineage-specific characteristics in each class of mollusc. This generalized model of decoupled dorsoventral Hox expression is compatible with known Hox expression data from other molluscan lineages and may represent a key characteristic of molluscan Hox expression. These results support the concept of widespread staggered Hox expression in Mollusca and reveal aspects that may be related to the evolutionary diversification of molluscs. We propose that dorsoventral decoupling of Hox expression allowed lineage-specific dorsal and ventral patterning, which may have facilitated the evolution of diverse body plans in different molluscan lineages.

A Contribution to the Knowledge of the Bot-flies, Gastrophilus intestinalis, DeG., G. haemorrhoidalis, L., and G. nasalis, L.

1918 ◽  
Vol 9 (2) ◽  
pp. 91-106 ◽  
Author(s):  
S. Hadwen ◽  
A. E. Cameron
Keyword(s):  
The Body ◽  
Entire Length ◽  
Equal Length ◽  
The Other ◽  
Brownish Black

The eggs of the three species of bot-flies discussed in this paper are distinguished by the fact of that of G. haemorrhoidalis being the only one stalked. It is also longer than those of the other two species, which are of about equal length. Further, it is brownish black in colour, that of G. intestinalis being whitish yellow and G. nasalis yellow. The egg of G. intestinalis adheres to the hair by clasping flanges, which run only two-thirds of its length, whilst the flanges of the G. nasalis egg run almost the entire length.The egg of G. haemorrhoidalis is not inserted nor screwed into the skin of the host. The eggs of G. intestinalis are laid indiscriminately on the body of the host, but preferably on the long hairs investing the inside of the foreleg. G. nasalis lays its eggs on the hairs of the intermaxillary space, and G. haemorrhoidalis on the hairs of the lips, preferably the lower.

scholarly journals II.—Circular Magnetisations accompanying Axial and Sectional Currents along Iron Tubes

1895 ◽  
Vol 37 (1) ◽  
pp. 7-16
Author(s):  
Cargill G. Knott
Keyword(s):  
Magnetic Induction ◽  
Entire Length ◽  
The Other ◽  
External Diameter ◽  
Diameter Measurement ◽  
Current Passing ◽  
The Mean ◽  
Iron Tube ◽  
Different Diameters ◽  
A Current

The experiments now to be described have for their object the investigation of the magnetic induction in an iron conductor under the influence of a current passing through it. The method of experiment was briefly in this wise. An iron tube was magnetised circularly by a current passed from end to end along its entire length; and the induction so produced in the iron was measured in terms of the current induced in a coil of wire wound longitudinally round the walls of the tube.In the experiments four tubes were used, all of the same length and nearly the same external diameter. The internal diameters of one pair were approximately double those of the other. The various dimensions are given accurately in the following table, the tubes being distinguished as A, B, a, b. Each diameter measurement is the mean of eight measurements taken across different diameters.

Contrast between Modification Methods for Magnetism Absorbents

2016 ◽  
Vol 852 ◽  
pp. 73-78
Author(s):  
Chao Wu ◽  
Xue Song Cao ◽  
Jing Chang Ji ◽  
Wei Zhong
Keyword(s):  
Carbon Fiber ◽  
The Other ◽  
Distinct Difference ◽  
The Difference

Two methods are widely used to improve absorbing properties of the microwave magnetism absorbing agent: mixing with the other material such as resistance carbon fiber absorbent, or wrapping the microwave magnetism-absorbing agent in that material. However, do these two methods coincide with each other? If not, which method should be used as better way to represent the absorbing properties of magnetism-absorbing agents? To answer these questions, both methods are carried out on the same magnetism absorbing agents, of which the results are compared. Distinct difference between these measured results is found, and the possible reasons for the difference are also discussed.

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