Microstructure of the otoliths of the glacier lanternfish, Benthosema glaciale

2015 ◽  
Vol 66 (1) ◽  
pp. 70 ◽  
Author(s):  
E. García-Seoane ◽  
I. Meneses ◽  
A. Silva
Keyword(s):  
Otolith Microstructure ◽  
Resolution Power ◽  
North West ◽  
Growth Increments ◽  
Otolith Core ◽  
Spawning Time ◽  
Back Calculation ◽  
The Mean ◽  
June July ◽  
Daily Deposition

Ageing using otolith microstructure is based on the assumption that growth increments are deposited daily. Individuals of the glacier lanternfish (Benthosema glaciale) were collected in the Flemish Cap (north-west Atlantic) during June–July 2010. A total of 44 individuals (ranging from 28 to 49mm standard length; <2 years old) were selected to analyse otolith microstructure using light microscopy in order to assess the reliability of the use of microincrements to infer the true age of this species. Three distinct zones were distinguished: the larval zone, the postlarval zone and the postmetamorphic zone. The otolith core was, on average, 8±0.7μm. The mean microincrement number in the larval zone was 42±7.5 within a radius of 0.095±0.010mm whereas in the postlarval zone it was 25±3.0 within a segment of 0.104±0.015mm. SEM examinations in a subsample of otoliths showed that the resolution power of the light microscope was sufficient to study both the larval and the postlarval zones. Back-calculation from the time of capture suggests a hatching period from mid-June to mid-December with a peak in September. The spawning time and daily deposition of the microincrements in B. glaciale are discussed.

scholarly journals Specific Merluccius otolith growth patterns related to phylogenetics and environmental factors

2003 ◽  
Vol 83 (2) ◽  
pp. 277-281 ◽  
Author(s):  
A. Lombarte ◽  
G.J. Torres ◽  
B. Morales-Nin
Keyword(s):  
Environmental Influence ◽  
Growth Patterns ◽  
Previous Knowledge ◽  
Otolith Growth ◽  
Growth Increments ◽  
Mean Width ◽  
Otolith Core ◽  
The Mean ◽  
Mature Fish ◽  
Immature Fish

A comparative morphological study was performed on the otolith growth patterns of 11 species of the genus Merluccius. The otolith growth pattern, based on the radius of the first eight growth increments (GI) from the otolith core, was determined from transverse sections of sagitta otoliths. The structure and periodicity of the GI were identified based on previous knowledge. Two cluster analyses were performed using GI width as a proxy for otolith growth. The first cluster analysis corresponded to the juvenile (immature) period of the fish including the mean width of the first four GI. The second analysis compared the mean width of the next four GI, i.e. those corresponding to mature fish. The results showed an important environmental influence in immature fish; while after maturation, the GI pattern was also related to an endogenous influence depending on the phylogenetic line.

Beef production from native pastures sown to fine-stem stylo in the Burnett region of south-eastern Queensland

1979 ◽  
Vol 19 (97) ◽  
pp. 140 ◽  
Author(s):  
EJ Bowen ◽  
KG Rickert
Keyword(s):  
Stocking Rate ◽  
Management Options ◽  
North West ◽  
Heteropogon Contortus ◽  
South Eastern ◽  
Continuous Grazing ◽  
Weight Gains ◽  
The Mean ◽  
Native Pastures ◽  
Stocking Rates

At Gayndah, south-eastern Queensland, a native Heteropogon contortus pasture, sown to fine-stem stylo (Stylosanthes guianensis var. intermedia), and invaded by red natal grass (Rhynchelytrum repens), was grazed by weaner steers from June 1 in three treatments : heavy and light put-and-take grazing for five years from 1971, and set-stocked at 1.37 animals ha-1 for two years from 1974. Weight gains in the put-and-take treatments were not significantly different. The mean annual liveweight gain was 167 kg animal-1 at a mean equivalent stocking rate of 1.47 animals ha-1. Over the same period unsown native pasture, cleared of timber, gave a gain of 62 kg animal-1 at 0.62 animals ha-1. In all seasons except summer, weight gains declined linearly with stocking rate and in 1972-73, with a mean equivalent stocking rate of 2.66 animals ha-1, the annual gain was almost halved. When equivalent stocking rates were 0.9, 0.9, 1.8 and 1.2 animals ha-1 in winter, spring, summer and autumn, the respective gains were 4, 73, 65 and 45 kg animal-1. The set-stocked treatment had a mean annual gain of 147 kg animal-1. At another site 116 km north-west of Gayndah, two paddocks of Heteropogon contortus and fine-stem stylo were set-stocked with weaners over four years. One paddock had four applications of superphosphate of 250 kg ha-1. The mean annual liveweight gains were significantly different, being 154 and 143 kg animal-1 in the fertilized and unfertilized paddocks at mean stocking rates of 0.83 and 0.74 animals ha-1, respectively. In a grazing protection experiment the density of fine-stem stylo declined exponentially with an accumulation of pasture dry matter in spring and summer. Heavy continuous grazing, an annual hay cut and an accidental fire all increased the density of fine-stem stylo. Management options to maintain the density of fine-stem stylo and the relative importance of the legume and grass to animal production are discussed.

scholarly journals On tho proportions of the prevailing winds, the mean temperature, and depth of rain in the climate of London, computed through a cycle of Eighteen Years, or periods of the Moon’s declination

1843 ◽  
Vol 4 ◽  
pp. 300-300
Keyword(s):  
The Moon ◽  
Fair Weather ◽  
North West ◽  
West Wind ◽  
North East ◽  
East Wind ◽  
The North ◽  
The Common ◽  
The Mean ◽  
Solar Influence

In this paper the author investigates the periodical variations of the winds, rain and temperature, corresponding to the conditions of the moon’s declination, in a manner similar to that he has already followed in the case of the barometrical variations, on a period of years extending from 1815 to 1832 inclusive. In each case he gives tables of the average quantities for each week, at the middle of which the moon is in the equator, or else has either attained its maximum north or south declination. He thus finds that a north-east wind is most promoted by the constant solar influence which causes it, when the moon is about the equator, going from north to south; that a south-east wind, in like manner, prevails most when the moon is proceeding to acquire a southern declination ; that winds from the south and west blow more when the moon is in her mean degrees of declination, going either way, than with a full north or south declination ; and that a north-west wind, the common summer and fair weather wind of the climate, affects, in like manner, the mean declination, in either direction, in preference to the north or south, and most when the moon is coming north. He finds the average annual depth of rain, falling in the neighbourhood of London, is 25’17 inches.

scholarly journals Back-Calculation of Fish Size in Diet Analysis of Piscivorous Predators: A New Index for the Alien Silurus glanis

2021 ◽  
Vol 13 (8) ◽  
pp. 4322
Author(s):  
Renato Bacchetta ◽  
Andrea Marotta ◽  
Alessandro Nessi ◽  
Paolo Tremolada
Keyword(s):  
Diet Analysis ◽  
Native Range ◽  
Top Predator ◽  
Silurus Glanis ◽  
K Index ◽  
Caudal Vertebrae ◽  
Back Calculation ◽  
Control Capability ◽  
The Mean ◽  
Bone Remains

The wels catfish Silurus glanis has been constantly spreading in many European basins, outside its native range. Being a voracious predator, it is considered to have a severe impact on local fish communities. In the Ticino River (Northern Italy), bones of S. glanis were found in feces from the top predator Lutra lutra. To estimate the control capability of L. lutra for this species and to back-calculate S. glanis’ size from its bone remains, whole skeletons from 27 differently sized S. glanis specimens were analyzed. A double pharyngeal element and all caudal vertebrae emerged as significant items for species identification. The mean length of the pharyngeal element was directly related to fish mass, while for vertebrae, a K-index was proposed to identify the position of each vertebra along the spine and, from this, to calculate the original fish mass. This methodology allowed us to establish that the length of the preyed S. glanis was 85–435 mm, and the ages were between 0+ and 2+ years. The proposed methodology opens new perspectives for more detailed studies on the efficiency of predation by piscivorous species on allochthonous ones.

scholarly journals Significant seasonal variations in the rate of women diagnosed with gestational diabetes: A observational single centre study of 28,128 women

2021 ◽  
Author(s):  
Matthew Cauldwell ◽  
Yolande VanDerI'isle ◽  
Ingrid Watt-Coote ◽  
Philip Steer
Keyword(s):  
Gestational Diabetes ◽  
Glucose Tolerance Test ◽  
Tolerance Test ◽  
Oral Glucose ◽  
Test Design ◽  
Single Centre ◽  
June July August ◽  
Single Centre Study ◽  
The Mean ◽  
June July

Objective To test the hypothesis that there is seasonal variation in the rates of gestational diabetes (GDM) diagnosed using a 2 hour oral glucose tolerance test. Design Monthly assessment of the percentage of women screened from 1st April 2016 to the 31st December 2020 who were diagnosed as having gestational diabetes Setting London Teaching Hospital Population 28,128 women receiving antenatal care between April 1st 2016 and 31 December 2020. Methods Retrospective study of prospectively collected data. Main Outcome Measures Proportion of women screened diagnosed as having gestational diabetes. Results The mean (SD) percentage of women diagnosed with GDM was 14.78 (2.24) in summer (June, July, August) compared with 11.23 (1.62) in winter (p < 0.001), 12.13 (1.94) in spring (p = 0.002), and 11.88 (2.67) in autumn (p = 0.003). There was a highly significant positive correlation of the percentage testing positive for GDM with the mean maximum monthly temperature (R2 = 0.248, p < 0.001). There was a statistically significant 33.8% increase in the proportion of GDM diagnoses from June 2020 onwards, possibly related to a reduction in exercise secondary to the Covid-19 pandemic. Conclusions There is a 23.3% higher rate of GDM diagnoses in the warmer summer months. There has been a 33.8% rise in GDM diagnoses associated with the Covid-19 pandemic.

scholarly journals Biochemical parameters variations with season, age, sex, parity and pregnancy in crossbred goats raised in Tiaret, Algeria

2021 ◽  
Vol 8 (1) ◽  
pp. 69-79
Author(s):  
Berrani Abdelkader ◽  
Meliani Samia ◽  
Bourabah Akila
Keyword(s):  
Significant Influence ◽  
Biochemical Parameters ◽  
Physiological State ◽  
Mean Values ◽  
North West ◽  
The North ◽  
Nutritional Conditions ◽  
Physiological Stage ◽  
The Mean ◽  
Calcium And Phosphorus

Abstract The aim of this study was to determine the influence of season, age, sex, parity and gestation status on some biochemical parameters in local cross-bred goats raised in Tiaret, Algeria. Ninety cross bred local goats, from 2019 to 2020, aged between nine and seventy-two months at different physiological stage were used. Animals belong to different farms in Tiaret located at the north-west Algeria (35°22’ N, 1°19’ E). The mean values of triglycerides, creatinine and calcium were significantly (p<0,05) higher in winter than in spring. The physiological state of the goat had a significant influence (p<0,05) on cholesterol, urea, total proteins, calcium and phosphorus, with a high average values in non-pregnant goats, while triglycerides and globulin had significant higher values in postpartum and pregnant femals, respectively. In our work, parity had a significant influence (p<0,05) on cholesterol, calcium and phosphorus, with high average values in young goats and a significant influence (p<0,05) on triglycerides and creatinine with high average values in primiparous ones. Age significantly influenced (p<0,05) cholesterol, triglycerides, total protein, calcium and globulin. The results obtained from this study could serve as reference values for the local goats and other regions or countries with similar climatic and nutritional conditions.

scholarly journals Digenetic Trematode Parasites in Two Fresh Water Fishes Ophiocephalus Punctatus and Xenentodon Cancila From North West Himalayas

2021 ◽  
Author(s):  
Sukanya Rajput ◽  
Seema Langer
Keyword(s):  
Fresh Water ◽  
Digenetic Trematode ◽  
Host Fish ◽  
Mean Intensity ◽  
North West ◽  
Trematode Infection ◽  
Xenentodon Cancila ◽  
The Mean ◽  
Union Territory ◽  
Trematode Parasites

Abstract The study was conducted during September 2018-August 2019 to study the digenetic trematode infection in fresh water fishes of some of the water bodies viz. Gho-manhasan, Chakrali and Chadwal of Jammu region of J&K union territory A total of 220 fishes comprising Ophiocephalus punctatus and Xenentodon cancila belonging to families Channidae and Belonidae respectively were examined. A total of 4 digenetic trematode parasites belonging to 4 different families i.e., Euclinostomum heterostomum (Clinostomidae Luhe, 1901); Phyllodistomum tripathi (Gorgoderidae Looss, 1901); Genarchopsis piscicola (Hemiuridae, Luhe, 1901), and Bucephalopsis karvei (Bucephalidae Poche, 1907) were detected. The overall prevalence of digenetic trematode infection was 65.90% and the mean intensity was 3.58. Among these Genarchopsis piscicola showed the highest prevalence (40.38%) with mean intensity 2.95 in the host fish Xenentodon cancila, while in other species the prevalence ranged between 26.23% and 34.62%. Present study authenticates the presence of several species of digenetic trematode parasites in the fishes inhabiting freshwater of J&K union territory.

scholarly journals II. Numerical elements of Indian meteorology.—Series I

1863 ◽  
Vol 12 ◽  
pp. 567-568
Keyword(s):  
Rainy Season ◽  
Cool Season ◽  
Mean Temperature ◽  
Hot Season ◽  
The Mean ◽  
June July

In this paper the author communicates Plates in which the iso-thermal lines are represented between the latitudes of 5°N. and 36°W., and longitudes of 78°E. and 98°E. of Greenwich. 1st, of the mean temperature of the year; 2nd, of the cool season, viz. December, January, and February; 3rd, of the hot season, viz. March, April, and May; 4th, of the rainy season, viz. June, July, and August; 5th, of the autumn, viz. September, October, and November.

Further Analysis of Ration and Growth Relationship of Plaice (Pleuronectes platessa)

1969 ◽  
Vol 26 (12) ◽  
pp. 3237-3241 ◽  
Author(s):  
Samir Zaky Rafail
Keyword(s):  
Maximum Growth ◽  
Growth Efficiency ◽  
Growth Increment ◽  
Mean Value ◽  
Pleuronectes Platessa ◽  
Growth Increments ◽  
Power Equation ◽  
The Mean ◽  
Relationship Of ◽  
Weight Groups

Evidence is given that the average daily rations (R) and fortnightly growth increments (ΔW) of six weight groups of Pleuronectes platessa fed on Mytilus edulis are related as in the power equation ±(ΔW−ΔWm) = ±b(|R–Rm|)B. Rm is the daily ration associated with the growth increment (ΔWm) at maximum growth efficiency; b and B are parameters. The power B has a mean value of about 0.5 and shows significant deviations from the mean especially in the case of smaller fish.

Lambing season and fertility of fat-tailed ewes under an extensive production system are associated with liveweight and body condition around mating

2009 ◽  
Vol 49 (12) ◽  
pp. 1086 ◽  
Author(s):  
A. K. Esmailizadeh ◽  
O. Dayani ◽  
M. S. Mokhtari
Keyword(s):  
Body Condition ◽  
Production System ◽  
Fixed Effects ◽  
Body Condition Score ◽  
Mating Period ◽  
Breed Group ◽  
Significant Difference ◽  
Condition Score ◽  
The Mean ◽  
June July

The objective of this study was to investigate to what extent fertility and lambing season of fat-tailed ewes raised under an extensive production system are related to liveweight, body condition and changes around mating. Ewe liveweight and body condition score (BSC) were recorded in June, July and August over a period of 3 years (1999–2001) in 11 flocks (eight flocks of Kurdi breed and three flocks of Kurdi × Sanjabi crossbred). Both Kurdi and Sanjabi are native fat-tailed breeds in western Iran. In total, 3278 lambing records relating to 1592 ewes and data on mating date, liveweight and BCS of 1930 ewes (3975 records) were used for statistical analyses. The statistical model for bodyweight and body condition data included fixed effects of breed group, flock nested within breed group, year, the future lambing status following summer breeding (barren, autumn lambing and winter lambing), ewe age and all two-way interactions. Breed group had a significant effect on ewe liveweight (P < 0.01). However, there was no significant difference between BCS of the two breed groups around mating. Ewe liveweights measured in June, July and August had significant effects on fertility and lambing season (P < 0.01). Ewes that produced lambs were generally heavier at mating than barren ewes (P < 0.01). Autumn-lambing ewes were heavier than winter-lambing ewes in June and July (P < 0.01). Effects of changes in liveweight on fertility and lambing season were significant (P < 0.01). The effects of BCS in June, July and August (P < 0.01) and changes in BCS during the mating period (P < 0.05) on fertility and lambing season were also significant. The mean BCS (in June and July) of autumn-lambing ewes was greater than that of the winter-lambing and barren ewes (P < 0.05). The proportion of autumn-lambing ewes significantly increased as BCS in July increased, whereas the proportion of barren ewes decreased (P < 0.01). Fertility was associated with age so that as the age of the ewes increased from 2 to 7 years, the proportion of barren ewes significantly decreased from 29 to 5% (P < 0.01). There was a relatively high proportion of very thin ewes of 2 and 3 years of age. These findings imply that low body condition is a particular problem in younger ewes suggesting the importance of giving special nutritional treatment to younger ewes to reduce the proportion of barren ewes.

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