EFFICIENCY AND ENERGETICS OF ARTEMIA (Artemia salina) CYSTS HATCHING IN DIFFERENT OSMOLARITY MEDIA

Hatching rate of Artemia salina cysts in the hatching process is variable due to many factors. Osmolarity of the medium is one of the factors determining hatching process of A. salina cysts. The purpose of this study is to assess the hatching process of A. salina cysts in a various osmotic condition on the hatching energetics efficiency and rate. The experimental design used was a 2 x 5 factorial completely randomized design. The first factor is an addition of chlorine (non-decapsulation and decapsulation) and the second factor is osmolarity of medium (640.27; 787.02; 901.76; 1080.51 and 1227.25 mOsm.L-1H2O). The results showed that hatching of A. salina cyst on various osmotic condition has significantly differed the hatching rate. No significant differences in the hatching energetics efficiency were obtained from each experimental groups. Media with osmolarity level of iso-osmotic to hyperosmotic (901.76-1227,25 mOsm.L-1H2O) provides a high hatching rate. Energetics efficiency of artemia cysts hatching is ranged from 640.27 to 1227.25 mOsm.L-1H2O in both hypoosmotic, isosmotic and hyperosmotic media. Keywords: artemia, decapsulation, energetics, hatching, salinity Tingkat penetasan kista Artemia salina dalam proses penetasan bervariasi karena banyak faktor. Osmolaritas medium merupakan salah satu faktor yang menentukan proses penetasan kista A. salina. Tujuan dari penelitian ini adalah untuk menilai proses penetasan kista A. salina dalam berbagai kondisi osmotik pada efisiensi dan laju penetasan energetika. Desain eksperimen yang digunakan adalah rancangan acak lengkap 2 x 5 faktorial. Faktor pertama adalah penambahan klorin (non-dekapsulasi dan dekapsulasi) dan faktor kedua adalah osmolaritas medium (640,27; 787,02; 901,76; 1080,51 dan 1227,25 mOsm.L-1H2O). Hasil penelitian menunjukkan bahwa penetasan kista A. salina pada berbagai kondisi osmotik secara signifikan berbeda dengan tingkat penetasan. Tidak ada perbedaan yang signifikan dalam efisiensi energetika penetasan yang diperoleh dari masing-masing kelompok eksperimen. Media dengan tingkat osmolaritas iso-osmotik menjadi hyperosmotic (901,76-1227,25 mOsm.L-1H2O) memberikan tingkat penetasan yang tinggi. Energetika efisiensi penetrasi kista A. salina berkisar antara 640,27 sampai 1227,25 mOsm.L-1H2O pada media hypoosmotic, isosmotic dan hyperosmotic. Kata kunci: artemia, dekapsulasi, energetika, penetasan, salinita

Factors determining spawning success in Penaeus monodon Fabricius

Spawning success in relation to the size of spawner, clumping of eggs, percentage of spawning and frequency of spawning was studied in Penaeus monodon collected off Tamil Nadu, India. The results indicated positive correlation between the size of spawner and the fecundity and hatching percentage, but not the start of hatching. Hatching characteristics were influenced by clumping of eggs or abortive spawning; the greater the clumping, the longer the time taken for hatching, resulting in a lower hatching percentage. The start of hatching time increased when the frequency of spawning increased. Lower hatching rate was observed as the frequency of spawning increased

Effect of temperature and salinity on the hatching of eggs and larval development of sugpo, Penaeus monodon

Abstract only.Incubation of Penaeus monodon eggs and rearing of different larval stages were undertaken at nine temperature-salinity combinations. The eggs, nauplii, zoea and mysis from one spawner kept as stock culture at ambient temperatures of 26-30°C and salinity of 32-33 ppt were exposed to temperature levels of 23, 28 and 33°C and salinity levels of 23, 28 and 33 ppt. Eggs and nauplii survived the sudden change of temperature and salinity (from ambient to experimental) but the zoea and mysis did not. However, salinities of 23 and 28 ppt in combination with any of the temperature levels produced weak larvae. Highest mean hatching rate was obtained at the temperature-salinity combination of 23°C-33 ppt, followed by 28°C-33 ppt and 33°C-33 ppt. Incubation periods for these treatments were 22, 16 and 14 hr, respectively. Survival rate of nauplius (taken from stock cultures) to first zoeal stage was highest at 28°C-33 ppt, followed by 33°C-33 ppt and 23°C-33 ppt with molting time of 50, 45 and 75 hr, respectively. The nauplii exposed to 33°C-33 ppt molted to zoea stage within 38 to 40 hr but later died. Those exposed to 23°C-33 ppt and 28°C-33 ppt reached zoea stage within 57 to 60 hr and 48 to 50 hr, respectively. Similarly, the nauplii taken from the stock cultures and reared until postlarval stage (P1) under experimental conditions completed the zoea and mysis stages in 9 to 11 days at 28°C C-33 ppt, 7 to 9 days at 33°C-33 ppt, and 13 to 15 days at 23°C-33 ppt. Statistical analysis showed that salinity had highly significant effect on rates of hatching of eggs and survival from nauplius to first zoeal stage but not temperature although the latter had an apparent effect. However, both factors affected time of hatching of eggs and time of molting from nauplius to zoea. Interaction effect was significant only on rate and time of hatching. Different sources (spawners) of eggs and nauplii did not have significant effect on time of hatching and molting from nauplius to zoea, but significantly affected the hatching rate of eggs and survival rate of nauplii to zoea stage

Morphometric Characteristics and Time to Hatch as Efficacious Indicators for Potential Nanotoxicity Assay in Zebrafish

Although the effects of nano-sized titania (nTiO2) on hatching events (change in hatching time and total hatching) in zebrafish have been reported, additional consequences of nTiO2 exposure (i.e., the effects of nTiO2-induced changes in hatching events and morphometric parameters on embryo-larvae development and survivability) have not been reported. To address this knowledge gap, embryos 4 h postfertilization were exposed to nTiO2 (0, 0.01, 10, and 1000 μg/mL) for 220 h. Hatching rate (58, 82, and 106 h postexposure [hpe]), survival rate (8 times from 34 to 202 hpe), and 21 morphometric characteristics (8 times from 34 to 202 hpe) were recorded. Total hatching (rate at 106 hpe) was significantly and positively correlated to survival rate, but there was no direct association between nTiO2-induced change in hatching time (hatching rate at 58 and 82 hpe) and survival rate. At 58, 82, and 106 hpe, morphometric characteristics were significantly correlated to hatching rate, suggesting that the nTiO2-induced change in hatching time can affect larval development. The morphometric characteristics that were associated with change in hatching time were also significantly correlated to survival rate, suggesting an indirect significant influence of the nTiO2-induced change in hatching time on survivability. These results show a significant influence of nTiO2-induced change in hatching events on zebrafish embryo-larvae development and survivability. They also show that morphometric maldevelopments can predict later-in-life consequences (survivability) of an embryonic exposure to nTiO2. This suggests that zebrafish can be sensitive biological predictors of nTiO2 acute toxicity

Influence of salinity on hatching rate, larval and early juvenile rearing of sea cucumber Holothuria scabra Jaeger

The fertilized eggs, auricularia larvae and one month old juveniles of Holothuria scabra, obtained from induced spawning were used for various experiments to assess the effect of salinity on hatching rate and larval and early juvenile growth. The experiments were conducted for two days on hatching rate of fertilized eggs, for ten days on larval survival, growth and development and for 30 days on juvenile’s growth rate. The maximum hatching of 39% at 35 ppt, followed by 32% at 33 ppt indicated the suitability of an ambient salinity of 33 to 35 ppt for effective hatching of fertilized eggs. High survival, growth rate and fastest development of auricularia were obtained at salinity between 33 and 35 ppt. The maximum growth rate in length and weight, was at 30 ppt, which may be the optimum for juvenile rearing. The one way ANOVA on differences in the hatching rate, larval growth and survival rate and juvenile growth rate at different salinities indicated high level of significance (p<0.001 )

Comparative study of hatching rates of African catfish (Clarias gariepinus Burchell 1822) eggs on different substrates

The hatching rates of African catfish (Clarias gariepinus) eggs on four natural substrates: the roots of Nile cabbage (Pistia stratiotes), water hyacinth (Eichhornia crassipes), pond weed (Ceratophyllum dermasum) and green grass leaves (Commelina sp.), and four artificial substrates: sisal mats, nylon mats, papyrus mats and kakaban mats, was assessed. Concrete slabs were used as control. The natural substrates performed better than the artificial ones. Pistia roots gave the best mean hatching rate of 66.2 ± 3.62%. Green grass leaves were second with a mean rate of 54.0 ± 3.46%, water hyacinth was third with 49.7 ± 3.16% and Ceratophyllum fourth with a mean of 13.0 ± 2.37%. Concrete slabs gave a mean rate of 18.6 ± 2.8%, sisal mats 18.6 ± 2.0%, papyrus 12.2 ± 1.2% and kakaban 11.8 ± 1.9%. Nylon mats were the last, with a mean rate of 4.0 ± 0.7%. The best performing natural substrates were those with the ability to float and thin fibrous roots that seemed to allow higher aeration of the eggs during incubation. The cost of using natural substrates was minimal

Variasi Lama Kejutan Panas pada Suhu yang Sama terhadap Tingkat Penetasan Telur (HR) Ikan Lele Dumbo (Clarias gariepinus)

Species, temperature shock duration, fertilization temperature from different climates can cause different hatching results, so it is necessary to do research on the treatment of variations in heat shock at the same temperature, to obtain information about the hatching rate (HR) of African catfish (Clarias gariepinus). The method used is completely randomized design (3x3). The results of the egg hatching rate (HR), with variations in the heat shock at the same temperature (35⁰C), showed the highest rate of hatching dumbo catfish eggs at heat shock one minute 233.00%, then heat shock two minutes 212.00%, and heat shock three minutes 200.00% respectively

Variasi Lama Kejutan Panas pada Suhu yang Sama terhadap Tingkat Penetasan Telur (HR) Ikan Lele Dumbo (Clarias gariepinus)

Species, temperature shock duration, fertilization temperature from different climates can cause different hatching results, so it is necessary to do research on the treatment of variations in heat shock at the same temperature, to obtain information about the hatching rate (HR) of African catfish (Clarias gariepinus). The method used is completely randomized design (3x3). The results of the egg hatching rate (HR), with variations in the heat shock at the same temperature (35⁰C), showed the highest rate of hatching dumbo catfish eggs at heat shock one minute 233.00%, then heat shock two minutes 212.00%, and heat shock three minutes 200.00% respectively

Comparative analysis of the toxicity of gold nanoparticles in zebrafish

The use of nanoparticles - particles that range in size from 1 to 100 nanometres - has become increasingly prevalent in recent years, bringing with it a variety of potential toxic effects. Zebrafish embryos were exposed during the 3-day post-fertilisation period to gold nanospheres (GSSs), gold nanorods (GNRs), gold nanorods coated with polystyrene-sulfate (PSS-GNRs), and gold nanorods coated with both polystyrene-sulfate and polyallamine hydrochloride (PAH/PSS-GNRs). All nanorods were stabilised with cetyltrimethylammonium bromide (CTAB). GNSs were the least toxic of the nanoparticles studied, with exposure resulting in no significant changes in mortality, hatching or heart rate. Exposure to GNRs and PSS-GNRs resulted in significant increases in mortality and significant decreases in hatching and heart rate. Treatment with GNRs caused significant changes in the expression of a variety of oxidative stress genes. The toxic effects of GNRs were ameliorated by coating them with polystyrene-sulfate and, to a more marked extent, with a double coating of polystyrene-sulfate and polyallamine hydrochloride