scholarly journals Microhabitat preferences of the freshwater prawn Macrobrachium jelskii (Decapoda: Palaemonidae)

2019 ◽  
Vol 109 ◽  
Author(s):  
Jersei N. Silva ◽  
Guilherme de Oliveira ◽  
Sérgio S. da Rocha
Keyword(s):  
Sex Ratio ◽  
Water Reservoir ◽  
Habitat Choice ◽  
Freshwater Prawn ◽  
Adult Males ◽  
Adult Females ◽  
Males And Females ◽  
Microhabitat Preferences ◽  
Lower Depth ◽  
Juvenile Males

ABSTRACT We analyzed the microhabitat preferences of Macrobrachium jelskii (Miers, 1877) males and females inhabiting an urban water reservoir in Cruz das Almas, Bahia, Brazil. Prawns were collected monthly, from March 2015 to February 2016, in three microhabitats, using a sieve. Each microhabitat was dominated by one macrophyte species: Eleocharis sp. (M1), Cabomba sp. (M2), and Nymphaea sp. (M3). The prawns were measured (carapace length), and categorized as juvenile males, adult males, juvenile females, non-ovigerous adult females and ovigerous adult females. An analysis of variance (ANOVA) was used to compare the number and size of individuals. The sex ratio and frequency of ovigerous females in the three microhabitats were also calculated. The sex ratio was biased towards females in M1 and did not deviate from 1:1 in M2 and M3. When prawns were separated into five categories we observed that non-ovigerous adult females were more abundant in M1, while adult males were the most abundant demographic category in M2 and M3. Juveniles of both sexes and ovigerous females showed no microhabitat preference, although M1 and M2 appeared to be more suitable for the latter. Adult females were the largest individuals in all microhabitats. Food availability, lower depth and lower predation pressure in M1 are the main factors that make M1 more suitable for M. jelskii, particularly non-ovigerous adult females and larger adult males. Intraspecific competition for shelter in M1 might also occur and adult females win this competition due to their larger body size. Therefore, adult males are found in higher abundance in M2 and M3 and the juvenile of both sexes spread evenly across all microhabitats. Our results help to understand the ecological role and the niche used by M. jelskii. Future studies on the habitat choice and predation under laboratory conditions should help to understand the behavior of this species.

scholarly journals Sighting heterogeneity of right whales in the western North Atlantic: 1980-1992

2020 ◽  
pp. 245-250
Author(s):  
Moira W. Brown ◽  
Solange Brault ◽  
Philip K. Hamilton ◽  
Robert D. Kenney ◽  
Amy R. Knowlton ◽  
...  
Keyword(s):  
North Atlantic ◽  
Eubalaena Glacialis ◽  
Adult Males ◽  
Adult Females ◽  
Right Whales ◽  
North Atlantic Right Whales ◽  
Males And Females ◽  
The Mean ◽  
Lower Variability ◽  
Juvenile Males

The population of western North Atlantic right whales (Eubalaena glacialis) is distributed primarily between Florida, USA and NovaScotia, Canada, aggregating seasonally in five geographically distinct, high-use areas. To test the effectiveness of monitoring alldemographic classes (juvenile and adult males and females) of the population in these five habitat areas, an evaluation was carried out ofthe identification records of catalogued right whales collected between 1980 and 1992, for which the age, sex and reproductive status (foradult females) were known. The mean annual identification frequency of adult females was significantly lower than that of adult males,juvenile females and juvenile males. Among adult females, reproductively active females were seen significantly more often than expectedwhen lactating (with a calf) than during their pregnancy or resting years. These data suggest that, while research efforts in the five high-usehabitat areas have had relatively equal success at monitoring juvenile males and females and adult males, many adult females are segregatedat times from the rest of the population. Lower variability in annual identification frequencies of adult females indicates that they may bemore site specific in their distribution than males, particularly during the years when they are pregnant or resting from a previous pregnancy.Re-running these analyses using sighting records updated through 2000 will help determine if the trends continue to be documentedregardless of changes in survey effort and patterns of habitat use of some animals.

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 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.

Demography of Eurotestudo hermanni in a mesic area of Central Italy

2007 ◽  
Vol 28 (1) ◽  
pp. 87-95 ◽  
Author(s):  
Valeria Ramacciato ◽  
Massimo Capula ◽  
Anna Loy ◽  
Federica Gentilotti
Keyword(s):  
Sex Ratio ◽  
Central Italy ◽  
Average Density ◽  
High Density ◽  
Environmental Constraints ◽  
Adult Males ◽  
Males And Females ◽  
European Populations

AbstractHermann's tortoise (Eurotestudo hermanni) from a mesic area of Central Italy (Isernia, Molise) was investigated during a two-year period (2003-2004). The population is characterized by a fairly high density when compared to other Italian and European populations, with density ranging from 16.16 individuals/ha in 2003 to 25.08 individuals/ha in 2004 (average density 20.84/ha). The sex ratio was 1:1 both in 2003 and 2004. Females were captured in higher percentages from May to July in both years, while males were most abundant from August to October. These differences can be related to the different needs and behaviour of males and females in the two periods, and to the environmental constraints of the study area. All the marked tortoises were found aged between 10 and 21 years. Adult males and females from the study area were small-sized when compared to those from other Italian and European populations.

The effect of non-immune stresses on the development of Strongyloides ratti

Parasitology ◽  
2005 ◽  
Vol 131 (3) ◽  
pp. 383-392 ◽  
Author(s):  
M. CROOK ◽  
M. E. VINEY
Keyword(s):  
Immune Response ◽  
Parasitic Nematode ◽  
Host Immune Response ◽  
Natural Host ◽  
Adult Males ◽  
Free Living ◽  
Developmental Effects ◽  
Adult Females ◽  
Males And Females ◽  
Living Adult

Strongyloides ratti is a parasitic nematode of rats. The host immune response against S. ratti affects the development of its free-living generation, favouring the development of free-living adult males and females at the expense of directly developing, infective 3rd-stage larvae. However, how the host immune response brings about these developmental effects is not clear. To begin to investigate this, we have determined the effect of non-immune stresses on the development of S. ratti. These non-immune stresses were subcurative doses of the anthelmintic drugs Ivermectin, Dithiazanine iodide and Thiabendazole, and infection of a non-natural host, the mouse. These treatments produced the opposite developmental outcome to that of the host immune response. Thus, in infections treated with subcurative doses of Ivermectin, Dithiazanine iodide and in infections of a non-natural host, the sex ratio of developing larvae became more female-biased and the proportion of female larvae that developed into free-living adult females decreased. This suggests that the mechanism by which the host immune response and these non-immune stresses affect S. ratti development differs.

scholarly journals Insulin-Like Growth Factor I and Prolactin Levels in Chimpanzees (Pan troglodyte) Across the Lifespan

2021 ◽  
Author(s):  
Anat Ben-Shlomo ◽  
Sandra M McLachlan ◽  
Jennifer Hwe ◽  
Holly Aliesky ◽  
Dana Hasselschwert ◽  
...  
Keyword(s):  
Growth Factor ◽  
Similar Rate ◽  
Delayed Puberty ◽  
Insulin Like Growth Factor ◽  
Adult Males ◽  
Normal Height ◽  
Igf I ◽  
Physical Examinations ◽  
Males And Females ◽  
Juvenile Males

Abstract As human and chimpanzee genomes show high homology for IGF1 and PRL, we analyzed sera of 367 healthy chimpanzees obtained during routine physical examinations in a single colony and measured chimpanzee insulin-like growth factor (IGF)-I and prolactin (PRL) levels across the lifespan using standard human immunoassays. Assuming chimpanzee IGF-I levels peak during puberty as in humans, we randomly defined puberty as the age at which most IGF-I levels were equal to or above the 90 th percentile for each sex (males, ages ≥7.00 but <9.20 years; females, ≥5.00 but <8.00 years). IGF-I levels steadily increased at a similar rate in juvenile males and females and peaked in puberty, strongly correlating with age, then slowly decreased faster in adult males than in adult females. As a group, males had higher mean IGF-I level than did females, but comparison by age category showed similar mean IGF-I levels in males and females. PRL levels increased with age in females more than males and levels were twice as high in females than in males. One pubertal male reported to have short stature had lower IGF-I and weight compared with other males in the age group, confirming suspected GH deficiency; a second male of normal height but low IGF-I may have had delayed puberty. Overall, results show differences in IGF-I levels over the lifespan in this cohort of chimpanzees largely mimic those seen in humans, while patterns of PRL changes are less similar.

scholarly journals Population of Proboscis Monkey (Nasalis lavatus) in Manggar River, Balikpapan City, Indonesia

2021 ◽  
Vol 886 (1) ◽  
pp. 012068
Author(s):  
Ike Mediawati ◽  
Teguh Muslim ◽  
Amir Ma’ruf ◽  
Mukhlisi ◽  
Hery Seputro ◽  
...  
Keyword(s):  
Population Density ◽  
Sex Ratio ◽  
Anthropogenic Activities ◽  
Proboscis Monkey ◽  
Adult Males ◽  
Conservation Area ◽  
Nasalis Larvatus ◽  
Survey Technique ◽  
Males And Females ◽  
Proboscis Monkeys

Abstract A population estimation of proboscis monkeys (Nasalis larvatus) has been conducted in Manggar River, Balikpapan. In this non-conservation area, the anthropogenic activities threaten the proboscis monkey habitat. Boat survey technique was applied along ± 17 km of the river in the morning and evening. The number of proboscis monkeys in the surveyed area was estimated to range from 57 to 69 individuals with estimated population density of 4.75 individuals/Km2. Moreover, the population of this primates was divided into 4 groups and the sex ratio between adult males and females was 1:2.33. The proboscis monkeys were distributed in the middle of the river to the upstream. The highest population was found in the upstream area with less human activities. Conservation efforts in the Manggar River need to be carried out considering the proboscis monkey habitat in the area has been fragmented and isolated. These efforts could involve local economic communities.

Home-Range Size and Fidelity of Western Grey Kangaroos (Macropus Fuliginosus) Living in Remnants of Wandoo Woodland and Adjacent Farmland.

1992 ◽  
Vol 19 (2) ◽  
pp. 137 ◽  
Author(s):  
GW Arnold ◽  
DE Steven ◽  
A Grassia ◽  
J Weeldenburg
Keyword(s):  
Home Range Size ◽  
Home Ranges ◽  
Adult Males ◽  
The Core ◽  
Adult Females ◽  
Radio Transmitters ◽  
Core Areas ◽  
Males And Females ◽  
Eucalyptus Wandoo ◽  
Older Males

The home ranges were studied from 1977 to 1981 of western grey kangaroos (Macropus fuliginosus) living in a 300-ha remnant of wandoo [Eucalyptus wandoo] surrounded by farmland at Baker's Hill, Western Australia. The M. fuliginosus population varied from 140 to 200 animals during the study. In 1979, four females (>30 kg) and 2 adult males (31 kg and 47 kg) were fitted with radio-transmitters and their movements recorded. The home ranges of these animals varied from 39 to 70 ha; the average overlap in the area used during the day and that used at night was 16.4%. Many of the kangaroos fed on farmland at night. The night ranges of 51 marked kangaroos were recorded using a spotlight. The animals showed a strong fidelity to their home ranges. Only 3 males (about 5-yr-old) shifted their night ranges; the centres of the ranges moved only 600-800 m. Older males had significantly larger night ranges than younger males and females. Individual females and the younger males showed preferences for using particular access points to get onto farmland; the older males showed no preferences. The core areas of the night ranges of many adult females overlapped closely in 'groups', but there was no evidence of 'mob' home ranges that were socially separated.

Blackbuck Antilope cervicapra (Mammalia: Cetartiodactyla: Bovidae) estimates in human-dominated landscape in Aligarh, Uttar Pradesh, India

2021 ◽  
Vol 13 (9) ◽  
pp. 19232-19238
Author(s):  
Mujahid Ahamad ◽  
Jamal A. Khan ◽  
Satish Kumar
Keyword(s):  
Sex Ratio ◽  
Uttar Pradesh ◽  
Adult Males ◽  
Forest Patches ◽  
Female Ratio ◽  
Adult Females ◽  
Or Groups ◽  
Feral Dogs ◽  
The Status ◽  
Antilope Cervicapra

Information on the status of the Indian Blackbuck Antilope cervicapra is mostly available from protected areas (PA), although 80% of its population occurs outside PAs. We conducted surveys to assess the status, age structure, sex ratio, and conservation issues of Blackbuck in and around Aligarh between February and June 2014. A median of 672 individuals at 18 separate locations were recorded with a group size ranging 4–216 except for solitary individuals. The abundance of Blackbuck was maximum in Sikandra Rao (range: 154–216) followed by Andla (range: 47–65), and Pala-Sallu (range: 53–62). Sex ratio was skewed towards females (1:4.5) with yearling to female and fawn to female ratio of 7.8:100 and 6.7:100, respectively. The percentage of adult males of Blackbuck (12.8% adult males, 8.4% sub-adult males) as well as adult females (56.4% adult females, 11.9% sub-adult females) was higher than other age classes or groups in the population. The preliminary observations indicate that the increasing population of free-ranging feral dogs, degradation of forest patches, social forestry plantations, competition with livestock, and poaching pressure are the major conservation issues of Blackbuck in the area. The current information is expected to serve as baseline in assessing the population of Blackbuck in the future. 

scholarly journals Toxicological and biochemical effects of some insecticides on peach fly, Bactrocera zonata (Diptera: Tephritidae)

2011 ◽  
Vol 47 (No. 3) ◽  
pp. 121-130 ◽  
Author(s):  
Y.Y. Mosleh ◽  
L.H. Yousry ◽  
A. Alo-El-Elaa
Keyword(s):  
Fruit Fly ◽  
Post Treatment ◽  
Adult Males ◽  
Glutamic Oxaloacetic Transaminase ◽  
Peach Fruit ◽  
Biochemical Effects ◽  
Adult Females ◽  
Bactrocera Zonata ◽  
Wide Range ◽  
Males And Females

The peach fruit fly, Bactrocera zonata (Saunders, Diptera: Tephritidae), has been a serious pest in the last decade attacking a wide range of fruits in Egypt. The toxicity of Malathion, Diazinon, Methoxyfenozide and Lufenuron to adult males and females of B. zonata was studied under laboratory conditions. The results showed that Diazinon was the most toxic among the tested compounds followed by Malathion, Lufenuron and Methoxyfenozide. LC<sub>50</sub> values for adult males and females were 0.20 ppm, 0.09 ppm and 0.02 ppm (for males), 0.91 ppm, 0.14 ppm and 0,01 ppm (for females), respectively. The results showed that the level of glutamic oxaloacetic transaminase (GOT) of treated adult males and females in 24 h, 48 h, and 72 h post treatment increased compared to untreated adults. The highest activities of GOT in treated adult males in 24 h, 48 h, and 72 h were 92.11&micro;M, 101.99&micro;M and 112.21&micro;M pyruvate released &times; 10<sup>3</sup>/min/g FW (fresh weight), respectively, for Methoxyfenozide LC<sub>10</sub>, and in treated adult females after 24 h, 48 h, and 72 h they were 84.24&micro;M, 94.33&micro;M, and 111.12&micro;M pyruvate released &times; 10<sup>3</sup>/min/g FW, respectively, for Diazinon LC<sub>25</sub>. The activities of acetylcholine esterase of treated adults decreased compared to untreated adults. The highest activities of acid phosphatase in adult males after 24 h and 48 h were 249.43 &micro;g and 270.52 &micro;g AchI hydrolysed/min/g FW, respectively, for Methoxyfenozide LC<sub>25</sub>. The highest activities of alkaline phosphatase in adult males were 139.04 &micro;g, 175.67 &micro;g, and 199.29 &micro;g phenol &times; 10<sup>3</sup>/min/g FW for Malathion LC<sub>10</sub> and in adult females they were 123.31 &micro;g, 162.10 &micro;g and 199.59 &micro;g phenol.10<sup>3</sup>/min/g FW, respectively, for Lufenuron LC<sub>25</sub> in 24 h, 48 h, and 72 h post treatment.

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