scholarly journals Reproduction of Cubaris murina (Crustacea: Isopoda) under laboratory conditions and its use in ecotoxicity tests

2009 ◽  
Vol 69 (1) ◽  
pp. 137-142 ◽  
Author(s):  
JC. Niemeyer ◽  
VC. Santos ◽  
PB. Araújo ◽  
EM. da Silva
Keyword(s):  
Culture Conditions ◽  
Adult Males ◽  
Offspring Number ◽  
Terrestrial Ecotoxicity ◽  
Significant Difference ◽  
Incubation Periods ◽  
Ecotoxicity Testing ◽  
Ecotoxicity Tests ◽  
Males And Females ◽  
The Mean

Reproduction of the isopod Cubaris murina was studied in the laboratory in order to observe the offspring number per brood, the number and duration of the incubation periods, and the influence of repeated mating on number of young per brood. An experiment was conducted with two different groups: female/male pairs and females that were isolated after mating. No significant difference was found between the two reproductive female groups for the mean number of young per brood (x = 25) and the duration of the incubation periods (x = 17 days). One mating was enough for at least five broods, with no reduction in brood size. There was no significant difference between the number of adult males and females. Low-density cultures had a significantly higher growth rate compared to high-density cultures. Furthermore, the experimental results for optimization isopod culture conditions for terrestrial ecotoxicity testing are reported.

Some Population Parameters and Seasonal Changes in the Weights of Internal Organs of Rabbits, Oryctolagus cuniculus (L.), at Macquarie

1980 ◽  
Vol 7 (2) ◽  
pp. 235 ◽  
Author(s):  
IJ Skira
Keyword(s):  
Sex Ratio ◽  
Age Distribution ◽  
Food Plants ◽  
Adult Males ◽  
Internal Organs ◽  
Significant Difference ◽  
Quality Of Food ◽  
Males And Females ◽  
The Mean

The sex ratio, age distribution and seasonal variations in body weight and weight of several internal organs of rabbits were studied, between December 1973 and February 1975 on subantarctic Macquarie Island. The sex ratio (male : female) was 1 : 0.84. Rabbits over 18 months old predominated in the population in summer 1973-74, but from April 1974 the population was composed equally of adults and rabbits less than 18 months old. The second half of the 1973-74 breeding season contained only 36% of the births of that season, but supplied 70% of the young rabbits that entered the population. Females weighed more than male rabbits in the summer but males were heavier in the winter. The mean weights of liver, kidneys and spleen in adult females were significantly heavier in the summer, when food plants were growing and the quality of food highest, than in winter. In adult males these mean weights were similar in summer and winter. Both males and females showed no significant difference in the mean weight of adrenal glands between seasons.

Population parameters of ringed seals (Phoca hispida Schreber, 1775) in the Svalbard area

1987 ◽  
Vol 65 (4) ◽  
pp. 1021-1027 ◽  
Author(s):  
Christian Lydersen ◽  
Ian Gjertz
Keyword(s):  
Sex Ratio ◽  
Ringed Seal ◽  
Adult Males ◽  
Population Parameters ◽  
Phoca Hispida ◽  
Age Class ◽  
Ringed Seals ◽  
Males And Females ◽  
The Mean ◽  
Sexually Mature

Samples were taken from 284 ringed seals (Phoca hispida) in the Svalbard area during April–July 1981 and March–April 1982. The age of 283 seals was determined by reading annuli in the cementum of the canine teeth. The mean age of the males was 11.3 years, and of the females, 14.9 years. Females were found to be significantly older than males. The mean length of sexually mature ringed seals was 128.9 cm for both sexes. The mean weight of adult males and females was 53.5 and 61.4 kg, respectively. Females were found to be significantly heavier than males. The sex ratio was 47.8% males and 52.2% females. Studies of microscopic sections of testis and epididymis from ringed seal males showed that 63, 75, and 80% of 5-, 6-, and 7-year-old animals, respectively, were sexually mature. The weights of testis and epididymis, diameters of tubuli, and the size of testis all showed a marked increase in the 5-year age-class. Macroscopic sections of ovaries from ringed seal females showed that 20, 60, and 80% of 3-, 4-, and 5-year-old animals, respectively, were sexually mature. The size of the ovaries showed a marked increase in the 5-year age-class. The ovulation rate of ringed seals from Svalbard was calculated to be 0.91.

scholarly journals Quantitative electroencephalography as a tool for objective neurophysiological seizure diagnosis: A retrospective study

2020 ◽  
Vol 0 ◽  
pp. 1-6
Author(s):  
Rajesh Kumar ◽  
Tribhuwan Kumar ◽  
Kamlesh Jha ◽  
Yogesh Kumar
Keyword(s):  
Energy Level ◽  
Matched Control ◽  
Age Groups ◽  
Quantitative Electroencephalography ◽  
Beta Band ◽  
Significant Difference ◽  
Males And Females ◽  
The Mean ◽  
The Difference ◽  
Electrical Activities

Objectives: Seizure is the fourth most common neurological disorder in the world; it affects all age groups with equal possibility of occurrence in both males and females. Many antiepileptic drugs are available today, but its diagnosis is challenging. The present study attempted to see if seizure activities could be predicted by analyzing the pre-seizure electrical activities. The prediction may help in taking preventive measures appropriately beforehand in the individuals with seizure proneness. Material and Methods: We selected 11 generalized seizure patients and 19 control patients out of total 115 patients referred for electro-diagnostics for various reasons. EEG of the subjects recorded, segmented as per protocol, and analyzed using MATLAB and EEGLAB tools. Results: The mean energy level in alpha and beta band of the study subject was significantly lower (P = 0.04 and 0.004, respectively) as compared to the age matched control subjects. Theta and delta bands did not show any significant difference between the groups. The difference between the pre- and post-electrical seizure energy and entropy was statistically insignificant. Conclusion: The study shows that the energy level remains low in the seizure patients in the alpha and beta bands. This further goes down when electrophysiological seizure activities starts. The randomness or entropy does not alter significantly among the seizure subjects in comparison to non-seizure subjects.

Cimetidine-induced prolactin release in rats The effect of sex and gonadal steroids

1987 ◽  
Vol 114 (2) ◽  
pp. 178-184 ◽  
Author(s):  
Hajime Watanobe ◽  
Kazuo Takebe
Keyword(s):  
Anterior Pituitary ◽  
Male Rats ◽  
Minor Role ◽  
Adult Males ◽  
Adult Age ◽  
Significant Difference ◽  
Males And Females ◽  
Plasma Prl ◽  
A Minor

Abstract. The cimetidine-induced plasma Prl response was examined in rats of both sexes. First, 10 week old intact adult males and females (dioestrous) were compared. There was no significant difference in the Prl response to cimetidine between the two groups, despite the fact that in adult females the anterior pituitary Prl content was 4 times greater than in males. Second, the effect of gonadal state in adult age on the Prl response to cimetidine was examined in both sexes. In male rats, gonadectomy at the age of 6 weeks significantly reduced the plasma Prl response as well as the pituitary Prl content, both of which were sufficiently restored by testosterone replacement. However, in females, neither gonadectomy at the age of 6 weeks nor subsequent oestradiol replacement affected the Prl response to cimetidine, despite the fact that gonadectomy significantly reduced and oestradiol treatment significantly enhanced the pituitary Prl content. Third, possible permanent effects of the postnatal gonadal milieu on the cimetidine-induced Prl response and the pituitary Prl content were examined in both sexes by castration at varying postnatal ages. The ratio of plasma Prl response to pituitary Prl content was similar in all castrated males. In females, however, the ratio decreased with increasing castration age. In conclusion, the mechanism of cimetidine-induced Prl release is less sex-dependent than are the mechanisms of Prl release by other Prl secretagogues. First, this may be due to a minor role of oestrogen in females in determining the Prl response to cimetidine. Second, the postnatal ovarian secretions may exert a permanent inhibition of the development of the cimetidine-mobilized anterior pituitary Prl pool.

scholarly journals Large mothers, but not large fathers, influence offspring number in a caridean shrimp

2018 ◽  
Vol 96 (10) ◽  
pp. 1106-1113 ◽  
Author(s):  
D.E. Sganga ◽  
C. Tropea ◽  
M. Valdora ◽  
M.F. Statti ◽  
L.S. López Greco
Keyword(s):  
Reproductive Output ◽  
Growth Period ◽  
Female Offspring ◽  
Growth Increment ◽  
Adult Males ◽  
Lipid Concentration ◽  
Offspring Quality ◽  
Offspring Number ◽  
Males And Females ◽  
The Relationship

The relationship between parental mass and female reproductive output, as well as offspring quality, was studied in the red cherry shrimp (Neocaridina davidi (Bouvier, 1904)) under controlled laboratory conditions. Adult males and females of the same age were paired combining different shrimp masses. The number of hatched juveniles from large females was higher than that from small ones, but no influence of paternal mass was detected on this variable. Both the mass of newly hatched juveniles and their growth increment during a 60-day period were similar for all parental masses. Shrimps reached sexual maturity at the end of the growth period in all treatments, and their biochemical reserves (glycogen, lipid, and protein concentrations) were not associated with maternal and paternal masses. However, lipid concentration was higher in female offspring than in male offspring. The present results show that, unlike maternal mass, paternal mass had no effect on female reproductive output and offspring quality, suggesting that the contribution of males to offspring development was adequate regardless of male size.

The Diet of the Common Toad (Bufo bufo) around a Pond in Mid-Wales

1987 ◽  
Vol 8 (1) ◽  
pp. 13-17 ◽  
Author(s):  
S.P. Gittins
Keyword(s):  
Bufo Bufo ◽  
Adult Males ◽  
Common Toad ◽  
Food Items ◽  
Inorganic Matter ◽  
Significant Difference ◽  
The Common ◽  
Males And Females ◽  
Toad Bufo ◽  
Toad Bufo Bufo

AbstractThere was no significant difference between the number of food items obtained by stomach-flushing toads caught in pitfall traps and from the dissection of corpses found on nearby roads. The frequencies of the different food categories were similar using the two methods. 97 % of the toads entering the pond in the spring had not recently fed, whereas 25% of toads leaving the pond had started to feed. Sloughed skin was found in 7% of stomachs. Vegetable matter was found in 15% of stomachs and inorganic matter in 6% of stomachs. The diet of the toad was found to be very varied, and the main food items were beetles, collembolans, millipedes, harvestmen and spiders. The diets of males, females and young toads were very similar, and only slight changes in diet were observed throughout the year. The size of food items ranged from 1 mm to 40 mm with most around 7 mm. There was no significant relationship between the size of the food item and the size of the toad for adult males and females, but there was for juveniles.

Sex Ratios and Lengths of Adult Sea Lampreys (Petromyzon marinus) from a Lake Ontario Tributary

1974 ◽  
Vol 31 (1) ◽  
pp. 122-124 ◽  
Author(s):  
I. C. Potter ◽  
F. W. H. Beamish ◽  
B. G. H. Johnson
Keyword(s):  
Narrow Range ◽  
Sex Ratios ◽  
Petromyzon Marinus ◽  
Lake Ontario ◽  
Sea Lamprey ◽  
Adult Males ◽  
Sea Lampreys ◽  
Males And Females ◽  
The Mean ◽  
Humber River

The mean lengths of adult males and females of the sea lamprey (Petromyzon marinus) migrating into the Humber River from Lake Ontario in each of the years 1968–1972 varied little, and were similar to those found by other workers in recently established populations in the upper lakes. In contrast, the ratio of males to females, which lay within the narrow range of 1:1 to 1.26:1, was similar to those reported for long-established populations.

Social Facilitation and Digging Behavior in the Beetle Odontotaenius floridanus Schuster (Coleoptera: Passalidae)

2007 ◽  
Vol 42 (4) ◽  
pp. 525-532 ◽  
Author(s):  
F. Punzo
Keyword(s):  
Social Facilitation ◽  
Walking Speed ◽  
Adaptive Significance ◽  
Adult Males ◽  
Laboratory Studies ◽  
Egg Carrying ◽  
Digging Behavior ◽  
Significant Difference ◽  
Males And Females ◽  
Walking Speeds

Laboratory studies assessed the effect of group size on egg-carrying behavior and walking speed of adults of the subsocial beetle, Odontotaenius floridanus Schuster (Coleoptera: Passalidae). Adult males tested solo carried significantly fewer eggs per individual when compared with males tested in groups of 4 and 8 individuals. Similarly, adult males and females in groups of 4 and 8 individuals exhibited significantly faster walking speeds when tested in a linear runway as compared with adults tested alone. There was no significant difference in the number of eggs carried or walking speed between beetles tested in groups of 4 or 8 individuals. This represents the first demonstration of social facilitation in passalid beetles. The adaptive significance of social facilitation in insects is discussed.

scholarly journals The Diet and Sexual Differences of the Caspian Bent-Toed Gecko,Tenuidactylus caspius(Squamata: Gekkonidae), in Northern Iran

2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Vida Hojati ◽  
Reza Babaei Savasari
Keyword(s):  
Sexual Dimorphism ◽  
Culex Pipiens ◽  
Tail Length ◽  
Adult Males ◽  
Northern Iran ◽  
Widespread Distribution ◽  
Adult Females ◽  
Significant Difference ◽  
Males And Females ◽  
Prey Items

The Caspian bent-toed gecko,Tenuidactylus caspius, is one of the most common nocturnal lizards of Iran with widespread distribution especially in the northern provinces. This research was done in order to study the diet and sexual dimorphism of this species in Sari County from 5 May to 20 October. During this research, 40 specimens of them including 20 males and 20 females were studied for diet and 140 specimens including 70 adult males and 70 adult females were studied for sexual dimorphism. Prey items identified were insects that belong to 15 species of 8 families and 6 orders. The most common prey items wereCulex pipiensandMusca domestica. There is no significant difference between diets of males and females. Results show that the adult males in addition of having the apparent femoral and preanal pores are heavier than females and have larger body, head, and tail length.

Sex Differences in Adults on a Test of Logical Reasoning

1956 ◽  
Vol 2 (3) ◽  
pp. 227-230
Author(s):  
Antonia Bell Morgan
Keyword(s):  
Sex Differences ◽  
Logical Reasoning ◽  
Formal Logic ◽  
Government Employment ◽  
Significant Difference ◽  
Males And Females ◽  
The Mean

The Morgan Test of Logical Reasoning, which is entirely verbal in form, was given to 133 males and 35 females. All Ss were in their 20s and applicants for government employment. All had the BA or BS degree but no other, and none had had any training in formal logic. No significant difference was found between the mean scores of males and females on this test, nor between the distribution and variation of scores.

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