Factors affecting reproductive success in free-ranging convict cichlids (Cichlasoma nigrofasciatum)

1994 ◽  
Vol 72 (12) ◽  
pp. 2177-2185 ◽  
Author(s):  
Brian D. Wisenden

This study examines the effect of parent size, fry growth rate, and habitat-related brood predation pressure on two measures of reproductive success (percent brood survival and fry number at independence from their parents) of free-ranging convict cichlids (Cichlasoma nigrofasciatum). Four populations in Costa Rican streams were studied, two in "pool" habitat and two in "stream" habitat. The number of fry that emerged from the spawning site (as free-swimming young) was positively correlated with female standard length (SL) for sites with a relatively wide size range of breeding females. SL of males had no effect on fry number at emergence, nor did size of either parent affect the probability of a brood reaching fry independence. Large parents reared more fry to independence than small parents in stream habitat but not in pool habitat. There was a significant difference among sites in fry number at emergence but not at independence (mean = 27 fry), suggesting a maximum number of fry that two parents can economically defend. Fry growth rate had no effect on either measure of reproductive success. Reproductive success was largely determined by the effect of habitat. Adult Cichlasoma dovii in pool habitat may have reduced mean brood survival from 47% (n = 126 broods) in stream habitat to 14.9% (n = 141 broods) in pool habitat. Predators such as juvenile C. dovii may be more effective in the dim ambient light in pool habitat, overwhelming the effect of parent size on brood defence.

Animals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2053
Author(s):  
Junsong Shi ◽  
Baohua Tan ◽  
Lvhua Luo ◽  
Zicong Li ◽  
Linjun Hong ◽  
...  

How to maximize the use of the genetic merits of the high-ranking boars (also called superior ones) is a considerable question in the pig breeding industry, considering the money and time spent on selection. Somatic cell nuclear transfer (SCNT) is one of the potential ways to answer the question, which can be applied to produce clones with genetic resources of superior boar for the production of commercial pigs. For practical application, it is essential to investigate whether the clones and their progeny keep behaving better than the “normal boars”, considering that in vitro culture and transfer manipulation would cause a series of harmful effects to the development of clones. In this study, 59,061 cloned embryos were transferred into 250 recipient sows to produce the clones of superior Pietrain boars. The growth performance of 12 clones and 36 non-clones and the semen quality of 19 clones and 28 non-clones were compared. The reproductive performance of 21 clones and 25 non-clones were also tested. Furthermore, we made a comparison in the growth performance between 466 progeny of the clones and 822 progeny of the non-clones. Our results showed that no significant difference in semen quality and reproductive performance was observed between the clones and the non-clones, although the clones grew slower and exhibited smaller body size than the non-clones. The F1 progeny of the clones showed a greater growth rate than the non-clones. Our results demonstrated through the large animal population showed that SCNT manipulation resulted in a low growth rate and small body size, but the clones could normally produce F1 progeny with excellent growth traits to bring more economic benefits. Therefore, SCNT could be effective in enlarging the merit genetics of the superior boars and increasing the economic benefits in pig reproduction and breeding.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Wenliu Zhang ◽  
Jiangyun Gao

Abstract Background Most orchid species have been shown to be severely pollination limited, and the factors affecting reproductive success have been widely studied. However, the factors determining the reproductive success vary from species to species. Habenaria species typically produce nectar but exhibit variable fruit set and reproductive success among species. Here, we investigated the influence of the flowering plant density, inflorescence size, breeding system, and pollinator behaviour on the reproductive success of two rewarding Habenaria species. Results Our observations indicated that Habenaria limprichtii and H. petelotii co-occur in roadside verge habitats and present overlapping flowering periods. Both species were pollination limited, although H. limprichtii produced more fruits than H. petelotii under natural conditions during the 3-year investigation. H. petelotii individuals formed distinct patches along roadsides, while nearly all H. limprichtii individuals clustered together. The bigger floral display and higher nectar sugar concentration in H. limprichtii resulted in increased attraction and visits from pollinators. Three species of effective moths pollinated for H. limprichtii, while Thinopteryx delectans (Geometridae) was the exclusive pollinator of H. petelotii. The percentage of viable seeds was significantly lower for hand geitonogamy than for hand cross-pollination in both species. However, H. limprichtii may often be geitonogamously pollinated based on the behaviours of the pollinators and viable embryo assessment. Conclusions In anthropogenic interference habitats, the behaviours and abundance of pollinators influence the fruit set of the two studied species. The different pollinator assemblages in H. limprichtii can alleviate pollinator specificity and ensure reproductive success, whereas the more viable embryos of natural fruit seeds in H. petelotii suggested reducing geitonogamy by pollinators in the field. Our results indicate that a quantity-quality trade-off must occur between species with different breeding strategies so that they can fully exploit the existing given resources.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
V.L Malavasi ◽  
E Fantecchi ◽  
V Tordoni ◽  
L Melara ◽  
A Barbieri ◽  
...  

Abstract Background Natural history of atrial fibrillation (AF) shows a progression of arrhythmia from non-permanent to permanent AF. Permanent AF was found associated with a worse prognosis than non-permanent one. Aim To assess the factors associated with progression to permanent AF in an unselected population of AF patients with non-permanent AF. Methods In this prospective study we enrolled in- as well as out-patients with non-permanent AF and age ≥18 years, with at least one episode of ECG-documented AF within 1 year. The patients were followed-up at 1 month and every 6 months thereafter. Results Out of 523 patients, 314 (60%) were in non-permanent AF (80 [25.5%] paroxysmal AF, 165 [52.5%] persistent AF, 69 [2%] first diagnosed AF), mostly male (188, 59.9%), median age 71 years (IQ range 62–77), median CHA2DS2VASc 3 (1–4), median HATCH score 1 (1–2). After a median follow-up of 701 (IQ range 437–902) days, 66 patients (21%) showed permanent AF. CHA2DS2VASc and HATCH scores were incrementally associated to progression to permanent AF (CHA2DS2VASc χ2 p=0.001; HATCH χ2 p=0.017; p for trend CHA2DS2VASc <0.001, HATCH p=0.001). At multivariable Cox proportional hazard regression the following variables were significantly associated with AF progression: age (hazard ratio [HR] 1.041; 95% CI: 1.004–1.079; p=0.028), at least moderate left atrial (LA) enlargement (>42 ml/m2) (HR 2.092; 95% CI: 1.132–3.866; p=0.018), antiarrhythmics drugs after the enrollment (HR 0.087; 95% CI: 0.011–0.662; p=0.018), EHRA score >2 (HR 0.351; 95% CI: 0.158–0.779; p=0.010) and Valvular HD (HR 2.161; 95% CI: 1.057–4.420; p=0.035). Adding LA dilation to HATCH score (HATCH-LA) and assigning 2 points based on multivariable Cox regression, HATCH-LA was statistically better in ROC curves in prediction of AF progression vs HATCH score (area under the curve 0.695 vs 0.636; DeLong p=0.0225). Survival-free curves on freedom from permanent AF using as discriminator HATCH-LA score ≤2 vs >2 led to a statistically significant difference (χ2=16.080 p<0.001), but the same was not found for HATCH score (χ2 =3.099; p=0.078). Conclusions In patients without permanent AF, progression of AF was independentely related to age, LA dilation, AF symptoms severity, antiarrhythmic drugs and Valvular HD. HATCH score predicted AF progression and adding to it LA dilation (at least moderate) improved patients stratification for the risk of evolution to permanent AF. Funding Acknowledgement Type of funding source: None


2021 ◽  
pp. 1-7
Author(s):  
Gamze Aytaş ◽  
Rümeyza Kazancıoğlu ◽  
Ömer C. Elçioğlu ◽  
Meltem Gürsu ◽  
A. Serra Artan ◽  
...  

<b><i>Introduction:</i></b> Orthostatic hypotension (OH) affects 5–20% of the population. Our study investigates the presence of OH in diabetic nephropathy (DNP) patients and the factors affecting OH in comparison with nondiabetic chronic kidney disease (NDCKD) patients. <b><i>Method:</i></b> Patients presented to the nephrology clinic, and those who consented were included in the study. DNP was defined by kidney biopsy and/or clinical criteria. NDCKD patients of the same sex, age, and eGFR were matched to DNP patients. Demographic parameters and medications were obtained from the records. OH was determined by Mayo clinic criteria. The same researcher used an electronic device to measure blood pressure (BP). All samples were taken and analyzed the same day for biochemical and hematologic parameters and albuminuria. <b><i>Results:</i></b> 112 (51 F, 61 M, mean age: 62.56 ± 9.35 years) DNP and 94 (40 F, 54 M, mean age: 62.23 ± 10.08 years) NDCKD patients were included. There was no significant difference between DNP and NDCKD groups in terms of OH prevalence (70.5 vs. 61.7%, <i>p</i> = 0.181). Male patients had significantly higher OH prevalence than female patients (74.7 vs. 60.0%, <i>p</i> = 0.026). There was no significant difference in change in systolic BP between the groups (24.00 [10.00–32.00] mm Hg vs. 24.00 [13.75–30.25] mm Hg, <i>p</i> = 0.797), but the change in diastolic BP was significantly higher in the DNP group (8.00 [2.00–13.00] mm Hg vs. 6.00 [2.00–9.00] mm Hg, <i>p</i> = 0.025). In the DNP group, patients with OH had significantly higher uric acid levels than those without OH (7.18 ± 1.55 vs. 6.36 ± 1.65 mg/dL, <i>p</i> = 0.017). And, 73.7% of patients on calcium channel blockers developed OH (<i>p</i> = 0.015), and OH developed in 80.6% of 36 patients on alpha-blockers (<i>p</i> = 0.049). <b><i>Conclusion:</i></b> OH prevalence is very high in CKD, and etiology of CKD does not have a statistically significant effect on the frequency of OH, despite a difference that could be meaningful clinically. Therefore, patients with CKD are checked for OH, with or without concurrent diabetes mellitus. Evaluation of postural BP changes should be a part of nephrology practice.


2001 ◽  
Vol 17 (3) ◽  
pp. 431-447 ◽  
Author(s):  
SHALINI PANDIT ◽  
B. C. CHOUDHURY

Pollinator visitation to, and the reproductive success of, Sonneratia caseolaris (Sonneratiaceae) and Aegiceras corniculatum (Myrsinaceae) was investigated in a mangrove forest in India. S. caseolaris was shown to be primarily outcrossed and A. corniculatum was shown to be a selfing species. The flowers of both plant species attracted several diurnal and nocturnal visitors. Earlier reports had indicated that S. caseolaris flowered for one night and was exclusively night-pollinated. But flowers of this species were found to be in bloom both at night and during the day, and diurnal visitors to the flowers were more diverse and frequent than nocturnal ones. This was related to the higher volume and energy value of nectar in the morning. The effects of time of day and temperature on visitation rates were quantified. The importance of visitors to plant reproductive success was investigated via controlled visitor-exclusion experiments. Pollinators were expected to be more important for the outcrossing species than for the selfing species, and this was confirmed by the results of the exclusion experiments. In S. caseolaris reproductive success was determined both by pollinator availability and the intensity of flower and fruit predation, while in A. corniculatum it is likely to be resource limited.


2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Jianru Pan ◽  
Huocong He ◽  
Ying Su ◽  
Guangjin Zheng ◽  
Junxin Wu ◽  
...  

GST-TAT-SOD was the fusion of superoxide dismutase (SOD), cell-permeable peptide TAT, and glutathione-S-transferase (GST). It was proved to be a potential selective radioprotector in vitro in our previous work. This study evaluated the in vivo radioprotective activity of GST-TAT-SOD against whole-body irradiation. We demonstrated that intraperitoneal injection of 0.5 ml GST-TAT-SOD (2 kU/ml) 2 h before the 6 Gy whole-body irradiation in mice almost completely prevented the splenic damage. It could significantly enhance the splenic antioxidant activity which kept the number of splenic white pulp and consequently resisted the shrinkage of the spleen. Moreover, the thymus index, hepatic antioxidant activity, and white blood cell (WBC) count of peripheral blood in irradiated mice pretreated with GST-TAT-SOD also remarkably increased. Although the treated and untreated irradiated mice showed no significant difference in the growth rate of animal body weight at 7 days postirradiation, the highest growth rate of body weight was observed in the GST-TAT-SOD-pretreated group. Furthermore, GST-TAT-SOD pretreatment increased resistance against 8 Gy whole-body irradiation and enhanced 30 d survival. The overall effect of GST-TAT-SOD seemed to be a bit more powerful than that of amifostine. In conclusion, GST-TAT-SOD would be a safe and potentially promising radioprotector.


2020 ◽  
Vol 45 (2) ◽  
pp. 7900-7915
Author(s):  
Mostakim Lahcen ◽  
Fetnassi Nidal ◽  
Ghamizi Mohamed

Measuring the phytodiversity and determining environmental factors affecting the abundance and distribution of riparian plants of Zat sub-basin in Morocco were carried out in this study. A hypothesis was tested whether there is any statistically significant difference in environmental parameters and plants communities among the Zat River and its tributaries. For this purpose, water quality parameters such as temperature, pH, salinity, electrical conductivity, Dissolved Oxygen, nitrate and phosphorus concentration, and riparian plants diversity were estimated at 17 stations along the Zat River and its tributaries during the periods (2018 and 2019). The Canonical Correspondence Analysis (CCA) and Pearson correlation were preformed to assess the relationship between environmental parameters, and the distribution and abundance of riparian plants inventoried. The presence of 113 species was recorded, distributed between 43 families and 97 genera, 9 of which were floating-leaved, 24 submerged, and 80 emergent plants. The rare and threatened species inventoried were represented by 7 taxa, whereas 6 species are reported as endemic. Raunkiaer classification showed a dominance of therophytes (38.39%) over the other groups. According to CCA, the abiotic parameters (DO, elevation, salinity and nitrate concentration) were statistically significant parameters governing the distribution and abundance of the riparian plants inventoried. The results obtained reveal the state of the riparian vegetation in the Zat subBasin, therefore we can consider them as a reliable component for the assessment of the ecological status of the aquatic environment.


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