scholarly journals Cocoon production and hatching rates of Branchiura sowerbyi Beddard (Oligochaeta: Tubificidae)

2008 ◽  
Vol 25 (1) ◽  
pp. 16-19 ◽  
Author(s):  
Haroldo L. S. Nascimento ◽  
Roberto da G. Alves

Branchiura sowerbyi Beddard, 1892 is a Tubificidae species abundant in tropical limnic environments and associated with sediments rich in organic matter and elevated temperatures. The present study aimed at obtaining information on laying and hatching rates of B. sowerbyi cocoons under laboratory conditions. In order to do this, specimens of B. sowerbyi were placed in beakers (250 ml) containing clay sediment and distilled water and kept at 25ºC. The obtained cocoons were placed in beakers of 100 ml and kept in conditions similar to the mature individuals. Fifty seven cocoons were collected, with a mean of 0.13 cocoons·individual-1·day-1 and 1.21 (±0.08) eggs·cocoon-1. Hatching time was approximately two weeks and hatching rate was 44.93%. The results obtained were different from the ones found by other authors for B. sowerbyi. According to the literature, different populations of the same species can present distinct biological aspects, such as the number of cocoons, hatching rates and growth.

2021 ◽  
Vol 21 (4) ◽  
pp. 149-159
Author(s):  
Dulon Roy ◽  
Ashish Kumer Sarker ◽  
Abu Musa Mohammad Khairul Abedin ◽  
Smita Sarker ◽  
Kazi Nahida Begum ◽  
...  

An experiment was conducted to observe some biological aspects including growth, sex ratio, gonadal maturity, artificial insemination, fecundity, fertilization, hatching and larval development of O. pabda in a private hatchery. Total weight of the sampled fish varied from 1.60±0.43 to 111.12±6.83 g and length varied from 3.57±0.65 to 21.22±1.84 cm with the SGR 2.85±0.18 and ADG 0.73±0.05. The length and weight of the fish had a strong correlation (r²=0.966). Female dominance over male has been observed in the species. The male to female ratio was 1:1.48. Females were 16.8 cm in length at first maturity, while males were 16.6 cm in length. The GSI of female were ranged from 2.93 to 4.77 with the mean of 3.77±0.60 during the study period. The fecundity of O. pabda was ranged from 5675 to 19626 with the mean of 12503±4192 for the corresponding length 21.23±1.71, body weight 111.12±7.6 and gonad weight 4.19±0.87. Fertilization rate, hatching rate and larval development observed during the experiment. Scattered diagram for length-weight, fecundity-length, fecunditybody weight and fecundity-gonad weight relationship shows a perfect correlation both arithmetically and logarithmically.


PeerJ ◽  
2019 ◽  
Vol 6 ◽  
pp. e6138 ◽  
Author(s):  
Rohit Rekulapally ◽  
Lakshmi Narsimha Murthy Chavali ◽  
Mohammed M. Idris ◽  
Shashi Singh

The potential of environmental release enhances with increased commercial applications of the nanomaterials. In this work, a simple and efficient test to estimate the acute toxicity of nanoparticles is carried out on Artemia species and their hatching rates. We have tested six different engineered nanoparticles (silver, gold, copper oxide, zinc oxide, TiO2 and SiO2 nanoparticles) and three soluble salts (CuSO4, ZnSO4 and AgNO3) on Artemia sp. The physicochemical properties of the nanoparticles involved in this study were analyzed in normal water and marine water. Hydrated and bleached Artemia cysts were allowed to hatch in continuously aerated, filtered sterile salt water containing nanoparticles; hatching of viable nauplii and total hatchlings have been recorded. In parallel, standard Artemia toxicity test was conducted on the nauplii monitoring the viability. In hatching experiments, a reduction in hatching rate was observed along with mortality of newly hatched nauplii. The results of the hatching experiment and of the standard Artemia test showed a good correlation. The toxicity of the nanoparticles was compared and the order of toxicity was estimated as Ag>CuO>ZnO>Au>TiO2>SiO2. The study thus suggests that the hatching test itself is a reliable assay for determining the toxicity of nanomaterials.


Zygote ◽  
2019 ◽  
Vol 28 (1) ◽  
pp. 80-82
Author(s):  
Raoani Cruz Mendonça ◽  
Sarah Pittigliani Ikebata ◽  
Sérgio Leandro Araújo-Silva ◽  
João Vitor Azevedo Manhães ◽  
Mônica Yumi Tsuzuki

SummaryThe flameback pygmy angelfish Centropyge aurantonotus, highly appreciated and valued by the aquarium market, is heavily harvested and traded. Temperature is one of the abiotic factors that has the most influence on fish development, especially in the early stages of life. For captive production, it is essential to know the appropriate environmental parameters for each species. In this sense, this study aimed to evaluate the influence of temperature on the embryonic development and hatching rates of C. aurantonotus incubated at six different temperatures (20, 22, 24, 26, 28, 30°C). Embryonic development events were very similar in terms of morphological and chronological characteristics compared with other species of the genus Centropyge. Incubation time was inversely proportional to temperature. The treatment at 22°C required twice the time of that required by 30°C treatment for hatching to occur. The best incubation temperature range was 24–28°C. Values below 22°C and at 30°C showed lower hatching rates compared with other treatments. Based on these results, the recommended temperature at which to incubate C. aurantonotus eggs is between 24–28°C.


2008 ◽  
Vol 20 (1) ◽  
pp. 200
Author(s):  
T. H. C. De Bem ◽  
R. Rochetti ◽  
P. R. L. Pires ◽  
F. F. Bressan ◽  
P. R. Adona ◽  
...  

Prematuration provides an additional time for oocyte capacitation and maturation in an attempt to improve in vitro embryo production (IVP) rates and allows media supplementation during this period for IVP. The aim of this study was to use brain-derived neurotropic factor (BDNF) in prematuration to improve maturation of bovine oocytes subjected to parthenogenetic activation and cultured with different media. Oocytes were subjected to prematuration in TCM-199 medium supplemented with 10 µm butyrolactone I, 2.0 mm pyruvate, and 10 µg mL–1 gentamicin for 24 h in the absence of BDNF (control) or in the presence of 10 ng mL–1 BDNF (BD). Oocytes were then in vitro-matured (IVM) in TCM-199 medium supplemented with 10% FCS, 0.5 µg mL–1 FSH, 5.0 µg mL–1 LH, 2.0 mm pyruvate, and 10 µg mL–1 gentamicin at 38.5�C under 5% CO2 in air. After 19 h oocytes were denuded using hyaluronidase and vortexing for 3 min for the 1st polar body (1PB) selection. Those which extruded the 1PB were maintained in IVM until 26 h, when parthenogenetic activation was performed (5 min in 5 µm ionomycin, followed by 3 h in 2 mm 6-DMAP). Activated oocytes were then transferred to in vitro culture (IVC) for embryo development evaluation. Embryos from both groups were cultured in SOF medium with 2.5% FCS, 0.05 g mL–1 BSA, 0.2 mm pyruvate, and 10 mg mL–1 gentamicin. Cleavage rates on the second day of in vitro culture (D2), embryo production at Days 7 and 8 (D7 and D8), and hatching rate at Day 8 were evaluated. Data regarding 1PB extrusion, cleavage, blastocyst development on D7 and D8, and blastocyst D8 hatching rates of three replicates were analyzed by chi-square test at 5% significance using the BIOESTATS 4.0 software. Control and BD, respectively, did not show differences (P > 0.05) regarding 1PB extrusion (n = 164, 63.81%, and n = 175, 66.79%) or cleavage (n = 117, 71.34%, and n = 138, 78.86%). However, for control and BD, respectively, blastocyst development on D7 (n = 63, 38.41%, and n = 89, 50.86%), D8 (n = 63, 38.41%, and n = 91, 52.00%), and hatching on D8 (n = 22, 34.92%, and n = 39, 43.82%) were all significantly higher for BD when compared with control (P < 0.05). In conclusion, BDNF during prematuration improved in vitro embryo development by increasing blastocyst and hatching rates of parthenogenetic embryos.


2014 ◽  
Vol 74 (3) ◽  
pp. 642-648 ◽  
Author(s):  
LPM Brandão ◽  
DGF Pujoni ◽  
PM Maia-Barbosa

The effect of dormancy in zooplankton populations is still unknown, largely because of the lack of methods to estimate hatching and production of the dormant stages. This study aimed to compare the production and hatching rates of ephippia of Daphnia laevis between thermal stratification and mixing periods in Jacaré Lake (Middle Rio Doce, Minas Gerais, Brazil). For this, we collected ephippia on the sediment with core sampler and we created a device called the “Ephippial Collector”. There was a significant difference in ephippia hatching in situ between stratification and mixing periods (Pearson's Chi-squared test p <0.001), being higher in the second one. Significant differences in the hatching rates between periods was observed in the laboratory only for ephippia collected with Ephippial Collectors (Pearson's Chi-squared test p <0.001), being higher during the mixing period (∼8%). The core sample allows the collection of a certain fraction of the sediment that may contain a mixture of ephippia produced in different periods, i.e., may contain old and not viable ephippia, which masks the hatching rate. Thus, seasonality in hatching rates of ephippia was reported only by Ephippial Collectors. The higher hatching rate observed during the mixing period in the lake suggests that individuals hatched from ephippia may contribute to the increase in the population of D. laevis in the water column at this time.


2019 ◽  
Vol 128 (3) ◽  
pp. 725-734
Author(s):  
Yasuko Kawakami ◽  
Kazuo Yamazaki ◽  
Kazunori Ohashi

Abstract Phenotypic polymorphisms are found in a wide array of taxa, and unravelling the mechanisms that maintain them is of great interest to evolutionary and ecological biologists. Temporal environmental heterogeneity may play a role in the maintenance of polymorphisms but is poorly understood. In the present study, we analysed trends in intergenerational elytral colour morph frequencies in relation to changes in fitness and life history traits (i.e. body size, mortality, fecundity, hatching rate and mate preference) in the ladybird beetle Cheilomenes sexmaculata (Coleoptera: Coccinellidae). A long-term field survey spanning nine years showed that the frequency of dark morphs increases over winter and then decreases in spring. Dark morphs may have an advantage in winter due to their higher tolerance of low temperatures compared with light morphs. Light-morph females were heavier in winter than dark-morph females. They also mated more frequently and had higher hatching rates, potentially causing an increase in light morphs in spring. These results suggest that fluctuations in morph frequencies resulting from the conflicting directions of selection pressures between overwintering and spring generations may help to maintain genetic polymorphism.


Zygote ◽  
2011 ◽  
Vol 20 (2) ◽  
pp. 117-122 ◽  
Author(s):  
Alessandra Corallo Nicacio ◽  
Renata Simões ◽  
Fabiola Freitas de Paula-Lopes ◽  
Flavia Regina Oliveira de Barros ◽  
Maria Angelica Peres ◽  
...  

SummaryThe aim of this work was to evaluate the effect of cryopreservation protocols on subsequent development of in vitro produced bovine embryos under different culture conditions. Expanded in vitro produced blastocysts (n = 600) harvested on days 7–9 were submitted to controlled freezing [slow freezing group: 10% ethylene glycol (EG) for 10 min and 1.2°C/min cryopreservation]; quick-freezing [rapid freezing group: 10% EG for 10 min, 20% EG + 20% glycerol (Gly) for 30 s]; or vitrification [vitrification group: 10% EG for 10 min, 25% EG + 25% Gly for 30 s] protocols. Control group embryos were not exposed to cryoprotectant or cryopreservation protocols and the hatching rate was evaluated on day 12 post-insemination. In order to evaluate development, frozen–thawed embryos were subjected to granulosa cell co-culture in TCM199 or SOFaa for 4 days. Data were analyzed by PROC MIXED model using SAS Systems for Windows®. Values were significant at p < 0.05. The hatching rate of the control group was 46.09%. In embryos cultured in TCM199, slow freezing and vitrification group hatching rates were 44.65 ± 5.94% and 9.43 ± 6.77%, respectively. In embryos cultured in SOFaa, slow freezing and vitrification groups showed hatching rates of 11.65 ± 3.37 and 8.67 ± 4.47%, respectively. In contrast, the rapid freezing group embryos did not hatch, regardless of culture medium. The slow freezing group showed higher hatching rates than other cryopreservation groups. Under such conditions, controlled freezing (1.2°C/min) can be an alternative to cryopreservation of in vitro produced bovine embryos.


2017 ◽  
Vol 33 (1) ◽  
pp. 139-150 ◽  
Author(s):  
Agata Stempkowska ◽  
Piotr Izak ◽  
Joanna Mastalska-Popławska

Abstract Studies on the sorption and desorption of selected Na+, Ca2+, Mg2+, Mn2+, Cu2+ and Cr3+ cations by materials based on modified brown coal were carried out. The chemical modification of the sorbent material consisted of grinding involving different inorganic substances and organic polymers. Samples were subjected to chemical modification at elevated temperatures for several hours. For comparative purposes, as apart from brown coal, pure humic acids are known for the highest cations exchange capacity, samples of brown coal before and after purification were also analyzed. The ion capacity was determined under static conditions, measuring the difference in the concentration of cations in the sorbent before and after sorption and then after rinsing the sorbent with distilled water (A), and after the desorption process with hydrochloric acid (B). Studies have shown that sorbents based on modified brown coal have rather significant exchange capacities in the range of 270-450 meq/100 g for the first stage and 90-200 meq/100 g for the second stage. It was also found that purified humic acid (450-200 meq/100 g) has the highest exchange capacity and modified brown coal obtained at 250°C has the lowest. The measurement of desorption showed that approximately 10% of the cations are already leached by distilled water and the residue is desorbed under the influence of 10% hydrochloric acid, but the total amount of cations is compatible with the measurement process of the second stage. The sorption affinity to various cations is different. In the case of the sorption measurements, modified sorbents show the highest sorption affinity with respect to calcium, while the unmodified raw brown coal with respect to chromium. The next stage of the measurement showed that the valence of the cation has the highest impact on the sorption affinity.


1970 ◽  
Vol 6 (2) ◽  
pp. 361-366
Author(s):  
MFA Molla ◽  
MR Amin ◽  
MN Sarowar ◽  
M Muhammadullah

The paper reports the first incidence of successful induction of breeding in the riverine catfish Rita rita using carp pituitary gland (PG) extract. A breeding trial using four PG doses viz. 80, 100, 120 and 140mg/kg body weight of fish was conducted to optimize the dose of pituitary gland (PG) extract in terms of induction of ovulation in female. The male received a dose of 40mg PG/kg body weight in all cases and was sacrificed for collection of milt. The best performance was shown by the fish treated with 100mg PG/kg body weight in respect of inducing ovulation in females and fertilization and hatching rates of eggs. Keywords: Induced breeding; Rita rita; Ovulation; Fertilization rate; Hatching rate DOI: 10.3329/jbau.v6i2.4835 J. Bangladesh Agril. Univ. 6(2): 361-366, 2008


DEPIK ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 235-242
Author(s):  
Mustaqim Mustaqim ◽  
Kartini Eriani ◽  
Erlangga Erlangga ◽  
Rachmawati Rusyidi

Abstract. Temperurate is one of the important parameter in the embryo development of fish; However, to date no information this effect on the Betta splendens. Hence, this study aims to determine the effect of temperature on egg hatchability and survival of betta fish larvae. Samples of betta fish used in this study are similar in size and from the same type of broodstock. A completely randomized design used with four treatments and three replications. The parameters observed were the process of egg development, fertilization rate, hatching rate, hatching duration, survival rate, and water quality (pH, DO, temperature). The results showed that the relation between temperature and fertilization rate was not significantly different, whereas the calculated F value (0.23) ˂ F table 0.05 (4.07). The relation between temperature and hatching rate has a very significant effect, F value (18.91) ˃ F table 0.05 (4.07). The relation of temperature to hatching time showed the same difference, and the relation of temperature to survival of betta fish (Betta spelendes) larvae is significant with F ¬ values (39.98) F table 0.05 (4.07). Water quality parameters during the study were pH 7 - 7.5, DO 5.0 - 7.7 ppm and temperature at 27 - 29 oC.Keywords: Betta fish eggs, temperature, embryogenesis Abstrak.  Suhu adalah salah satu faktor menentukak proses perkembangan embrio pada ikan, namun pengaruh ini belum pernah diamati pada ikan cupang Betta splendens. Oleh karena itu, penelitian ini bertujuan untuk mengetahui pengaruh suhu terhadap perkembangan embrio, daya tetas telur dan kelangsungan hidup larva ikan cupang. Induk ikan cupang yang digunakan memiliki ukuran yang sama dan dari induk jenis yang sama. Adapun rancangan yang digunakan dalam penelitian adalah rancangan acak non factorialdengan 4 perlakuan 3 kali ulangan. Parameter yang diamati adalah proses perkembangan telur, tingkat pembuahan telur, tingkat penetasan telur, lama penetasan telur, tingkat kelangsungan hidup dan kualitas air pH, DO, suhu ruangan. Hasil penelitian menunjukkan bahwa hubungan suhu terhadap tingkat pembuahan telur tidak berbedanyata, dimana nilai F hitung (0,23) ˂ F tabel 0,05 (4,07). Hubungan suhu terhadap tingkat penetasan telur berpengaruh sangat berbedanyata, dimana nilai F hitung (18,91) ˃ F tabel 0,05 (4,07). Hubungan suhu terhadap lama penetasan menunjukkan berbeda sama, dan hubungan suhu terhadap kelangsungan hidup berpengaruh nyata terhadap kelangsungan hidup larva ikan cupang (Betta spelendes) dengan nilai F hitung (39,98) F tabel 0,05 (4,07). Parameter kualitas air selama penelitian rata-rata pH 7 – 7,5, DO 5,0 – 7,7 ppm dan suhu ruangan 27 – 29 oC.Kata kunci: Telur ikan cupang, suhu, embriogenesis


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