Estimation of age-dependent survival rates of female tsetse flies (Diptera: Glossinidae) from ovarian age distributions

1999 ◽  
Vol 89 (6) ◽  
pp. 515-521 ◽  
Author(s):  
M. Jarry ◽  
J.P. Gouteux ◽  
M. Khaladi

AbstractExisting attempts to estimate the survival rate of tsetse flies from ovarian age distributions generally assume that the population is stationary. The fact that the survival rate cannot be dissociated from the growth rate by these methods poses a problem. Under the assumption of a stable age distribution, we propose a maximum likelihood method to estimate the ‘apparent survival rate’ for three categories of females: nulliparous (β0), young parous (β1) and old parous flies (β2). The rate depends both on ‘real survival rates’ a0, a1 and a2, and a growth rate λ: β0 = a0/λ, β1 = a1/λ, and β2= a2/λ. We used a matrix model, which can be parameterized if the pupal survival rate and the pupal period are known. Replacing a0, a1 and a2 by β0,λ, β1λ, and β2λin the projection matrix, the problem amounts to calculating its dominant eigen-value λ, and hence a0, a1 and a2. The application to a field population of Glossina palpalis gambiensis Vanderplank in Burkina Faso showed there was a marked difference in survival rate according to age category. The average survival rate increased with age with decreasing variability. The results suggested that sampling (by trapping) may have had an effect on the dynamics of this tsetse population by ageing it artificially. This method may be a useful tool for monitoring tsetse control.

2019 ◽  
Vol 14 (1) ◽  
pp. 15
Author(s):  
Indra Pratama ◽  
Hatim Albasri

This study was aimed to evaluate different types and combinations of live foods in relation to the survivability of newly hatched Lysmata vittata and Lysmata intermedia larvae. The experiment consisted of three trials (different species, combinations, and densities of live foods) arranged in a completely randomized design. The first and second trials were subjected to L. vittata with three treatments for each trial (1A, 1B, 1C for trial-1; 1D, 1E, 1F for trial-2). The third trial consisted of two treatments (2A and 2B) tested on L. intermedia. Each treatment had three replicates. The results showed that the survival rates were low in all treatments. However, each treatment showed a significant effect (P<0.05) on the average survival rate of L. vittata and L. intermedia larvae. In the first trial, treatment 1C was the only one that had survived larvae after day 35 with 4.44% of final average survival rate (FASR). Four of the larvae reached the post-larval stage. In the second trial, treatment 1F showed a better condition than the other treatments with 5.56% FASR. Nevertheless, no larvae in the second trial had transformed to post-larval stage before the experiment ended at day 46. In the third trial, no larvae survived to reach the post-larval stage. In spite of this, treatment 2B had better daily average survival rate (DASR) than treatment 2A. This research concludes that the use of copepods as live food at an early larval stage and Artemia at a later stage is relatively more effective to improve the survival rate of peppermint shrimp larvae.


2020 ◽  
Vol 5 (86) ◽  
pp. 45-50
Author(s):  
O.V. Mazneva ◽  
◽  
L.V. Tashmatova ◽  
T.M. Khromova ◽  
V.V. Shakhov ◽  
...  

The research was conducted in order to develop an effective protocol for introducing strawberry plants into in vitro culture. The objects of the research were the most popular varieties of strawberries of domestic and foreign selection: Tsaritsa, Bereginya, Florence, Frida, Kimberly, etc. Mercurial preparations mertiolate at a concentration of 0.01% and sulema at a concentration of 0.1% were used as sterilizing agents. The isolation of explants was performed in several periods: the beginning of the growth was in February, active growth was in June, the decline of growth was in August. The studies have shown that the maximum aseptic cultures were obtained when processing strawberry plant material with mercurycontaining sulema preparation in the concentration of 0.1%. At the first stage of micropropagation, explants had a high viability during all periods of the isolation, the average survival rate for varieties was 74.8-80.7%. A significant influence of the genotype (varietal characteristics) on the survival rates of explants was noted. The number of explants suitable for cloning did not depend on the overall level of regeneration. Stabilization of the crop during winter introduction was much faster than in other periods. Using the winter term of the isolation of strawberry explants allowed to increase the yield of explants capable of further cloning, accelerate the stabilization of the culture in vitro and reduce the time for obtaining micro-plants suitable for planting in non-sterile conditions. On average, 75.2% of explants capable of further cloning for the varieties were obtained. As a result of the research, the conditions and methods for obtaining the largest number of viable sterile strawberry explants were worked out, which will be included into the process of reproduction in vitro and further research.


2007 ◽  
Vol 4 (1) ◽  
pp. 17 ◽  
Author(s):  
Kukuh Nirmala ◽  
R. Wulandari ◽  
D. Djokosetiyanto

<p>This study was conducted to determine the effect of hardness on growth and survival rate of barb fish (<em>Barbus conchonius</em> Hamilton-Buchanan) reared in the 3 ppt of water salinity.  Fish were reared in three different hardnesses, i.e., 54, 72,<sub> </sub>and 90 mg/L CaCO<sub>3 </sub>for 30 days.  The results of study showed that fish reared in water hardness of 72 mg/L CaCO<sub>3</sub> had higher daily growth rate (1.15%) compared with other treatments.  Daily growth rate of fish reared in water hardness of 54 and 90 mg/L CaCO<sub>3</sub> were 0.76 and 0.37%, respectively.  There was no effect of hardness on survival rate of barb fish.</p> <p>Keywords: barb fish, <em>Barbus conchonius</em>,  hardness, salinity</p> <p> </p> <p>ABSTRAK</p> <p>Penelitian ini bertujuan untuk mengetahui pengaruh kesadahan yang berbeda terhadap laju pertumbuhan dan tingkat kelangsungan hidup ikan barbir (<em>Barbus conchonius</em> Hamilton-Buchanan) yang dipelihara <a name="OLE_LINK2"></a><a name="OLE_LINK1">pada air bersalinitas 3 ppt.  </a>Ikan dipelihara dalam 3 tingkat kesadahan yang berbeda, yaitu 54 mg/L CaCO<sub>3</sub>, 72 mg/L CaCO<sub>3</sub>,<sub> </sub>dan 90 mg/L CaCO<sub>3 </sub>selama 30 hari.  Hasil penelitian menunjukkan bahwa laju perumbuhan harian tertinggi diperoleh pada ikan yang dipelihara pada kesadahan 72 mg/L CaCO<sub>3 </sub>(1,15%) dibandingkan dengan perlakuan lainnya. Laju pertumbuhan harian ikan yang dipelihara pada kesadahan 54 dan  90 mg/L CaCO<sub>3</sub> masing-masing mencapai 0,76% dan 0,37%.  Kelangsungan hidup ikan barb tidak dipengaruhi oleh kesadahan.</p> <p>Kata kunci: ikan barbir, <em>Barbus conchonius</em>, kesadahan, salinitas</p>


2018 ◽  
Vol 54 (4A) ◽  
pp. 205
Author(s):  
Nguyen Van Cong

The larvae of white leg shrimp (Litopenaeus vannamei Boone, 1931) at phase nauplii 6 fed with a stocking density of 150 pcs per litre and 3 formula including formula 1 with dry microalgae Spirulina + artemia as main ingredients, formula 2 with microalgae Thalasiosira weissflogii + artemia as main ingredients and formula 3 with microalgae Thalasiosira pseudonana + artemia as main ingredients. Experiments were carried out in 18 tanks fifty-litre composite at Quang Binh branch of C.P Vietnam Corporation. The study results show that, with formula 3, white leg shrimps larvae at zoea stage have the highest growth and survival rates (86.57 %), followed by formula 2 (76.03 %) and finally formula 1 (67.90 %). White leg shrimps larvae at zoea stage in formula 3 have the shortest metamorphosis time (78.61 hours), followed by formula 2 (83.25 hours) and the longest in formula 1 (94.10 hours).


Author(s):  
Ayi Yustiati ◽  
Mahmud Sa’id ◽  
. Junianto ◽  
Ibnu Bangkit Bioshina Suryadi

This research aimed to determine the optimal dosage of potassium diformate addition to commercial feed in order to increase the growth and survival rate of common carp seeds. The method used in this research was experimental in a completely randomized design (CRD) consisting of five treatments and four replications. The treatments used were A (control), B with addition of potassium diformate (0.2%), C (0.3%), D (0.4%), and E (0.5%). For test fish, there were 200 of Common carp seeds with a size of 2-3 cm. The media used was 20 aquariums with a size of 40x30x40 cm3 and a stocking density of 10 individuals/aquarium. The rearing period was 35 days and the amount of feed given was 3% of the fish body weight. The parameters observed included water quality (temperature, pH, and dissolved oxygen) which were observed every 7 days for 35 days. Other parameters  monitored were daily growth rate, survival rate, feed efficiency, and the acidity level of the intestine. The results showed that 0.3% addition of potassium diformate gave the best results with a daily growth rate value of 3.21%, highest survival of 98%, efficiency of feed utilization of 64.83%, and a decrease in intestinal pH which helped the process of protein absorption in the fish body. In conclution, the addition of potassium diformate has good effect on growth and survival rates of common carp.


2021 ◽  
Vol 29 (2) ◽  
pp. 69-79
Author(s):  
Iwona Piotrowska ◽  
Bożena Szczepkowska ◽  
Michał Kozłowski

Abstract The aim of the study was to determine the influence of the size and form of Artemia sp. feed on the rearing indices of Atlantic sturgeon larvae. In the experiment, the nauplius sizes used were 480 µm (group AD), 430 µm (group AM), and 430 µm frozen nauplii (group AI). After three weeks of rearing, the sturgeon from group AD had the highest mean body weight of 0.131 g that was statistically significantly different from groups AM (0.071 g) and AI (0.033 g). The longest total length was noted in group AD (2.8 cm) and was statistically different from the others (P ≤ 0.05). Specific growth rate in groups AD and AM was 14.7 and 11.8% d−1, respectively, and these values differed statistically from those in group AI at 7.8% d−1. The highest survival rate was recorded in group AD at 60.6%, while the lowest was noted in group AI at 15.6%, and the differences between these two groups were statistically significant. The results of the experiment indicated that a feed of live 480 µm Artemia sp. nauplius significantly accelerated the growth rates and increased the survival rates of Atlantic sturgeon larvae.


2019 ◽  
Vol 76 (11) ◽  
pp. 2027-2034 ◽  
Author(s):  
Paul E. Kanive ◽  
Jay J. Rotella ◽  
Salvador J. Jorgensen ◽  
Taylor K. Chapple ◽  
James E. Hines ◽  
...  

For species that exist at low abundance or are otherwise difficult to study, it is challenging to estimate vital rates such as survival and fecundity and common to assume that survival rates are constant across ages and sexes. Population assessments based on overly simplistic vital rates can lead to erroneous conclusions. We estimated sex- and length-based annual apparent survival rates for white sharks (Carcharodon carcharias). We found evidence that annual apparent survival differed over ontogeny in a system with competitive foraging aggregations, from 0.63 (standard error (SE) = 0.08) for newly recruiting subadults to 0.95 (SE = 0.02) for the largest sharks. Our results reveal a potential challenge to ontogenetic recruitment in a long-lived, highly mobile top marine predator, as survival rates for subadult white sharks may be lower than previously assumed. Alternatively, younger and competitively inferior individuals may be forced to permanently emigrate from primary foraging sites. This study provides new methodology for estimating apparent survival as a function of diverse covariates by capture–recapture study, including when sex assignment is uncertain.


The Condor ◽  
2020 ◽  
Vol 122 (2) ◽  
Author(s):  
Dmitry Shitikov ◽  
Viktoria Grudinskaya ◽  
Tatiana Makarova ◽  
Tatiana Vaytina ◽  
Svetlana Fedotova ◽  
...  

Abstract First-year survival probability of migratory passerines during the period between fledging and first reproduction is a highly variable parameter that has a major effect on population dynamics. We used a long-term mark–recapture dataset (2002–2018) to examine first-year survival of 3 passerine species breeding in abandoned agricultural fields of northwestern Russia: Booted Warbler (Iduna caligata), Whinchat (Saxicola rubetra), and Western Yellow Wagtail (Motacilla flava). We banded 3,457 nestlings, including 1,363 Booted Warblers, 1,699 Whinchats, and 395 Western Yellow Wagtails, and resighted 12 Booted Warblers, 29 Whinchats, and 13 Western Yellow Wagtails in the year after fledging. We evaluated first-year apparent survival rates using Cormack-Jolly-Seber models in MARK program within the multispecies approach. We tested effect of fledge date on the first-year apparent survival. In all focal species, first-year apparent survival rates were low and reached the lower limits known for migratory passerines. We found no differences in first-year survival rates among the 3 species: the estimated average first-year apparent survival rate of all species was 0.05 ± 0.01. The fledge date had a considerable impact on first-year survival rate: later fledge dates negatively affected first-year survival. We suggest that first-year apparent survival rates in our study were low due to low natal philopatry and high mortality in the post-fledging period. Low apparent first-year survival may be a specific feature of open-nesting birds breeding in abandoned fields that are low-quality habitats because of high predation pressure.


Paleobiology ◽  
2011 ◽  
Vol 37 (1) ◽  
pp. 113-125 ◽  
Author(s):  
David Steinsaltz ◽  
Steven Hecht Orzack

We describe statistical methods to formulate and validate statements about survival rates given a small number of individuals. These methods allow one to estimate the age-specific survival rate and assess its uncertainty, to assess whether the survival rates during some age range differ from the survival rates during another age range, and to assess whether the survivorship curve has a particular shape. We illustrate these methods by applying them to a sample of 22 Albertosaurus sarcophagus individuals. We show that this sample is too small to provide any confidence in the claim that this species had a “convex” survivorship curve arising from age-specific survival rates that decreased monotonically with age. However, we show that a sample of 50 to 100 individuals has reasonable statistical power to support such a claim. There is evidence for the much weaker claim that average survival rates for ages 2 to 15 were higher than survival rates for later ages. Finally, we describe one way to account for size-dependent fossilization rates and show that a plausible positively-size-dependent fossilization rate results in a substantially non-convex survivorship curve for A. sarcophagus.


2021 ◽  
Vol 9 (6) ◽  
pp. 60
Author(s):  
Chris Carey ◽  
Nick Del Din ◽  
Jessica Lamb ◽  
Hazel Wright ◽  
Nigel D. Robb ◽  
...  

The aim of this retrospective study was to determine the survival rate of single-unit porcelain-fused-to-metal (PFM) and metal crowns placed by dental students at an Australian university undergraduate dental clinic over a five-year period. Complications and the incidences of crown failures were recorded. Clinical records pertaining to single-unit PFM and metal crowns inserted over a five-year period were reviewed, including patient-related, tooth-related, and procedural factors for each crown. Crowns were evaluated as surviving, surviving with complications, or failed. Kaplan–Meier statistical analysis was used to estimate survival rate., This study is based on a sample of 232 (78.4%) PFM crowns and 64 (21.6%) metal crowns inserted between 2014 and 2018. Cumulatively, 224 (75.7%) were surviving, 48 (16.2%) were surviving but previously had complications, and 24 (8.1%) failed. The 5-year cumulative survival rate of all PFM and metal crowns was 83.9% (0.839 ± 0.038, Kaplan–Meier). The average survival time for all crowns was 4.432 ± 0.089 years. Comparatively, PFM crowns had a higher survival rate at 1 year (0.972 ± 0.010) and 2 years (0.919 ± 0.017), compared to metal crowns at 1 year (0.964 ± 0.011) and 2 years (0.894± 0.018). The survival rate of metal crowns remained constant from 2 years to 4 years and thereafter, whereas there was a continued decline in the survival rate of PFM crowns to 83.2% (0.832 ± 0.038) at 4 years and thereafter. Crowns placed on premolars had the highest cumulative survival rate whereas those placed on molars exhibited the lowest survival rate for the duration of the study period. Despite single-unit PFM crowns having a higher 1- and 2-year survival rate compared to metal crowns, metal crowns had a higher survival rate at 4 years and thereafter. Survival rates are comparable to previous studies.


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