scholarly journals Predator Environment Does Not Predict Life History in the Morphologically Constrained Fish Alfaro cultratus (Cyprinodontiformes: Poeciliidae)

2021 ◽  
Vol 9 ◽  
Author(s):  
Kaitlyn B. Golden ◽  
Mark C. Belk ◽  
Jerald B. Johnson
Keyword(s):  
Life History ◽  
Body Shape ◽  
Ventral Surface ◽  
Dry Mass ◽  
Physical Constraints ◽  
Significant Difference ◽  
History Of ◽  
High Predation ◽  
Different Populations ◽  
Livebearing Fish

Predation is known to have a significant effect on life history diversification in a variety of species. However, physical constraints of body shape and size can sometimes limit life history divergence. We test this idea in the Costa Rican livebearing fish Alfaro cultratus. Individuals in this species have a narrow body and keeled ventral surface, and females do not develop a distended abdomen when pregnant like other livebearing fishes. Here, we describe the life history of A. cultratus from 20 different populations across both high-predation and low-predation environments. We found significantly lower reproductive allotment in females from high-predation environments than in females from low-predation environments, but no significant difference in female or male size at maturity, number of offspring produced by females, or size of offspring. We found that A. cultratus exhibit isometric patterns of allocation for clutch dry mass in relation to female dry mass in high-predation and low-predation environments. Our results suggest that body shape constraints in this species limit the life history divergence we typically see between populations from high-predation and low-predation environments in other species.

Aggregation Status and Cue Type Modify Tadpole Response to Chemical Cues

2014 ◽  
Vol 6 (1) ◽  
pp. 199-207 ◽  
Author(s):  
Devin B. Preston ◽  
M. R. J. Forstner
Keyword(s):  
Life History ◽  
Chemical Cues ◽  
Response Strength ◽  
Population Viability ◽  
Antipredator Response ◽  
History Effects ◽  
Honestly Significant Difference ◽  
Significant Difference ◽  
History Of ◽  
Reduced Activity

Abstract Many anuran larvae exhibit an antipredator response to chemical cues released by potential predators. The genus Bufo is no exception, as many bufonids exhibit an antipredator response (e.g., reduction in activity) to the presence (recent and current) of predators. Using a mesocosm experiment in a field laboratory setting, we tested solo and groups of Bufo (Incilius) nebulifer tadpoles for an antipredator response to chemical cues produced by 1) the presence of anisopteran nymphs (kairomone cue) and 2) the predation of conspecifics by anisopteran nymphs (a combination of diet and alarm cues, which we termed predation cue). We quantified the magnitude of the response by calculating response strength. We analyzed data with a blocked ANOVA followed by a Tukey's honestly significant difference analysis. We found that chemical cue type (kairomone vs. predation) affected response strength, but aggregation status (solo vs. group) did not. Furthermore, solo tadpoles and groups of tadpoles reduced their activity in response to predation cues, whereas only solo tadpoles reduced their activity in response to kairomone cues, a heretofore unobserved phenomenon. Our results suggest that B. nebulifer tadpoles modulate their response to specific types of chemical cues depending on their aggregation status. As reduced activity comes at a cost to resource acquisition and growth, aggregation status may indirectly affect the life history of B. nebulifer. The elucidation of these potential life history effects may aid managers in estimating anuran population viability.

scholarly journals Aspects of the life history of the Atlantic poacher, Leptagonus decagonus, in Svalbard waters

2015 ◽  
Vol 36 (1) ◽  
pp. 79-87
Author(s):  
Kristin Heggland ◽  
Camilla A. Meyer Ottesen ◽  
Jørgen Berge
Keyword(s):  
Life History ◽  
Reproductive Strategies ◽  
Age Distribution ◽  
Gut Content ◽  
Sex Distribution ◽  
Male Population ◽  
Female Population ◽  
Significant Difference ◽  
History Of ◽  
Age Range

Abstract The aim of the study is to describe aspects of the life history of the Atlantic poacher (Leptagonus decagonus) obtained during early October 2010 and late September 2011 from the Hinlopen Strait, located between Nordaustlandet and the Spitsbergen Archipelago. Length was measured for 142 individuals, and 82 out of these were weighed, sexed and the age in years determined. The sex distribution in the population was 45% females and 55% males. Gut content examination revealed the domination of the mesopelagic and hyper−benthic calanoid Bradyidius similis that was recorded in 87% of the stomachs analysed. Overall there was a significant difference in size (length and weight) between the sexes, and a difference in length and weight at age between the sexes. There was no difference in age distribution between the sexes, but there was a larger age range within the male population than in the female population. The sexual dimorphism in size is likely linked to different reproductive strategies. This study represents the first data on the life history of the Atlantic poacher in Svalbard waters.

Life history of Amblyseius fustis (Pritchard and Baker), an indigenous predator of the cassava red mite, Oligonychus gossypii (zacher) in south western Nigeria

1985 ◽  
Vol 6 (2) ◽  
pp. 193-197 ◽  
Author(s):  
T. O. Ezulike ◽  
J. A. Odebiyi
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Relative Humidity ◽  
Developmental Stages ◽  
Developmental Period ◽  
Life Stages ◽  
Male And Female ◽  
Significant Difference ◽  
History Of ◽  
Male To Female

AbstractThe life history of Amblyseius fustis (Pritchard and Baker) was studied in the laboratory at a fluctuating temperature and relative humidity ranging from 24.4 to 28.0°C and 55.5 to 75.6%, respectively. The developmental stages consist of egg, larva, protonymph, deutonymph and adult. The life cycle, from egg to adult of both male and female was about 8 days, while longevity was about 19.2 days. Mated female laid an average of 18.8 eggs. There was no significant difference in the longevity and fecundity of predators fed on different life stages of the host. The proportion of male to female in the progeny of mated females was 1:4.A. fustis has a shorter developmental period and lives longer than its prey, but the latter is more fecund (26.9 eggs/♀) and has a higher proportion of females in its progeny (1:4.8). The shorter developmental period and the longer life span of the predator are likely to offset the higher fecundity of the prey.

scholarly journals Association study of BDNF Val66Met gene polymorphism with bipolar disorder and lithium treatment response in Indian population

2021 ◽  
pp. 026988112110326
Author(s):  
Pradip Paul ◽  
Ravi Kumar Nadella ◽  
Somdatta Sen ◽  
Dhruva Ithal ◽  
Jayant Mahadevan ◽  
...  
Keyword(s):  
Bipolar Disorder ◽  
Treatment Response ◽  
Allele Frequency ◽  
Lithium Treatment ◽  
Significant Difference ◽  
History Of ◽  
Bdnf Val66met Polymorphism ◽  
Different Populations ◽  
Control Set ◽  
The Brain

Background: The association of the Val66Met (rs6265) polymorphism in the brain-derived neurotrophic factor ( BDNF) gene with bipolar disorder (BD) and response to lithium treatment has been suggested, though inconsistently. The considerable diversity of allele frequency across different populations contributes to this. There is no data from South Asia till date. Hence, we examined the association of this polymorphism in BD cases from India, and its association with lithium treatment response. Methods: BD patients ( N = 301) were recruited from the clinical services of National Institute of Mental Health and Neurosciences (NIMHANS), India. Lithium treatment response for 190 BD subjects was assessed using Alda scale by NIMH life charts. Patients with total score ⩾7 were defined as lithium responders ( N = 115) and patients with score <7 were defined as lithium non-responders ( N = 75). Healthy controls ( N = 484) with no lifetime history of neuropsychiatric illness or a family history of mental illness were recruited as control set. Genotyping was performed by TaqMan genotyping assay. Results: Genotype and allele frequency of BDNF Val66Met SNP was significantly different (χ2 = 7.78, p = 0.02) in cases compared to controls, and the Val(G) allele was more frequent (χ2 = 7.08, p = 0.008) in BD patients. However, no significant difference is noted in genotype or allele frequencies of this polymorphism between the lithium responders and non-responders. Conclusions: The Val(G) allele of BDNF Val66Met polymorphism is associated with risk of BD in this sample, but it is not related to response to lithium.

scholarly journals Life history of a short-lived squid (Sepioteuthis australis): resource allocation as a function of size, growth, maturation, and hatching season

2006 ◽  
Vol 63 (6) ◽  
pp. 995-1004 ◽  
Author(s):  
Gretta T. Pecl ◽  
Natalie A. Moltschaniwskyj
Keyword(s):  
Life History ◽  
Body Shape ◽  
Adult Life ◽  
Reproductive Investment ◽  
Reproductive Condition ◽  
Trade Offs ◽  
Size Growth ◽  
History Of ◽  
Slow Growing ◽  
Alternation Of Generations

Abstract Many cephalopods continue growing while laying multiple egg batches over the adult life, with repro-somatic allocation continuing beyond attainment of reproductive maturity. Many species show extreme individual variation in reproductive investment. Factors driving this variation in adult Sepioteuthis australis were evaluated by examining allocation of energy to somatic and reproductive growth as a function of body shape, growth rate, maturation, and hatching season. Hatching season influence was sex-specific; males hatched in warmer months had greater reproductive investment, faster growth, and better somatic and reproductive condition, whereas females hatched in spring and summer had less reproductive investment. Seasonal impacts on life history resulted in an “alternation of generations”, with slow-growing squid in poor condition and with high levels of reproductive investment producing a generation with completely different life-history characteristics. This suggests that abiotic and biotic conditions that change seasonally could play a large role in determining energy allocated to reproduction. However, this was not driving trade-offs between size and number of offspring. Life-history trade-offs should be detectable as negative correlations between relevant traits. However, in Sepioteuthis australis there was little evidence of trade-offs between reproduction and growth or condition of individuals, suggesting a “live for today” lifestyle.

Factor V Leiden Is Associated with Repeated and Recurrent Unexplained Fetal Losses

1997 ◽  
Vol 77 (05) ◽  
pp. 0822-0824 ◽  
Author(s):  
Elvira Grandone ◽  
Maurizio Margaglione ◽  
Donatella Colaizzo ◽  
Marina d'Addedda ◽  
Giuseppe Cappucci ◽  
...  
Keyword(s):  
Protein C ◽  
Strong Association ◽  
Activated Protein C ◽  
Fetal Loss ◽  
Factor V Leiden ◽  
Factor V ◽  
Significant Difference ◽  
History Of ◽  
Fv Leiden ◽  
Caucasian Women

SummaryActivated protein C resistance (APCR) is responsible for most cases of familial thrombosis. The factor V missense mutation Arg506>Gln (FV Leiden) has been recognized as the commonest cause of this condition. Recently, it has been suggested that APCR is associated with second trimester fetal loss. We investigated the distribution of FV Leiden in a sample (n = 43) of Caucasian women with a history of two or more unexplained fetal losses. A group (n = 118) of parous women with uneventful pregnancies from the same ethnical background served as control. We found the mutation in 7 cases (16.28%) and 5 controls (4.24%; p = 0.011). A statistically significant difference between women with only early fetal loss vs those with late events (p = 0.04) was observed. Our data demonstrate a strong association between FV Leiden and fetal loss. Furthermore, they indicate that late events are more common in these patients.

PCR-RFLP Detection od PAI-2 Gene Variants: Prevelence in Ethnic Groups and Disease Relationship in patients Undergoing corony Angiography

1997 ◽  
Vol 77 (05) ◽  
pp. 0955-0958 ◽  
Author(s):  
Carole A Foy ◽  
Peter J Grant
Keyword(s):  
Gene Variants ◽  
Genotype Distribution ◽  
Pima Indians ◽  
Significant Difference ◽  
Pcr Rflp ◽  
History Of ◽  
Caucasian Patients ◽  
Clinical Conditions ◽  
Rflp Assay ◽  
Coronary Atheroma

SummaryPAI-2 is a fibrinolytic inhibitor produced predominantly by monocytes. Most PAI-2 is intracellular making study in clinical conditions difficult. Abnormalities in production may be associated with inflammation and fibrinolysis at sites of tissue damage such as the atherosclerotic plaque.PAI-2 gene variants have been described: variant A consists of Asn120, Asn404 and Ser413 and variant B consists of Asp120, Lys404 and Cys413. We designed a PCR-RFLP assay using primers spanning the region containing Asn/Lys404 and Ser/Cys413. Variant B contains an Mwol restriction site. We analysed 302 Pima Indians and 286 healthy Caucasian volunteers. To investigate relationships between genotype and vascular disease we analysed 333 Caucasian patients undergoing coronary angiography.Gene variant B was more common in the Pimas than in Caucasians (p <0.0001). There was no significant difference in genotype distribution between the volunteers and patients. In the patients there was no association between genotype and either a history of MI or extent of coronary atheroma.

Sign in / Sign up

Export Citation Format

Share Document