scholarly journals PRELIMINARY STUDY OF LARVAL DEVELOPMENT Oryzias javanicus IN INDONESIA

2017 ◽  
Vol 9 (1) ◽  
pp. 105
Author(s):  
Rachma Puspitasari ◽  
. Suratno

<p><em>Java medaka </em><em><span style="text-decoration: underline;">Oryzias</span> <span style="text-decoration: underline;">javanicus</span> potentially developed as test organism, represents the coastal region because it has a high adaptability in freshwater, brackishwater and marine environments. Utilization of it as a test organism has some obstacles such as lack of number of test organisms with same size or age. The fulfillment of number can be solved if the test organism is cultivated exclusively in the laboratory. This study was a preliminary study to get information about suitable salinity for spawning and hatching. Parameter observed were spawning ability in 0 and 20 ppt and hatching rate of egg among 0. 15 and 30 ppt and development of larval fish in 0 ppt. Result indicated that the fish was be able to spawn in 0 and 20 ppt. Eggs were hatched within 9 days in 30 ppt, faster than in freshwater and 15 ppt. In general, O. javanicus was be able to spawn either in freshwater or seawater, but there are differences in the behavior of fish in the laying of egg. Fish will carried their eggs in the abdomen in freshwater, while 20 ppt salinity fish tends to release the eggs. O. javanicus be able to live and lay eggs on freshwater and seawater. Selection of salinity is adjusted to test requirement in egg phase, pascalarva or adult. In general, breeding of fish easier and faster done in fresh water while hatching eggs take place more quickly in high salinity.</em></p><p><em><br /></em></p><p><strong><em>Keywords: </em></strong><em>Indonesia, Java Medaka, <span style="text-decoration: underline;">Oryzias</span> <span style="text-decoration: underline;">javanicus</span>, test organism</em><strong><em></em></strong></p>

2017 ◽  
Vol 9 (1) ◽  
pp. 105-112 ◽  
Author(s):  
Rachma Puspitasari ◽  
. Suratno

Java medaka Oryzias javanicus potentially developed as test organism, represents the coastal region because it has a high adaptability in freshwater, brackishwater and marine environments. Utilization of it as a test organism has some obstacles such as lack of number of test organisms with same size or age. The fulfillment of number can be solved if the test organism is cultivated exclusively in the laboratory. This study was a preliminary study to get information about suitable salinity for spawning and hatching. Parameter observed were spawning ability in 0 and 20 ppt and hatching rate of egg among 0. 15 and 30 ppt and development of larval fish in 0 ppt. Result indicated that the fish was be able to spawn in 0 and 20 ppt. Eggs were hatched within 9 days in 30 ppt, faster than in freshwater and 15 ppt. In general, O. javanicus was be able to spawn either in freshwater or seawater, but there are differences in the behavior of fish in the laying of egg. Fish will carried their eggs in the abdomen in freshwater, while 20 ppt salinity fish tends to release the eggs. O. javanicus be able to live and lay eggs on freshwater and seawater. Selection of salinity is adjusted to test requirement in egg phase, pascalarva or adult. In general, breeding of fish easier and faster done in fresh water while hatching eggs take place more quickly in high salinity.Keywords: Indonesia, Java Medaka, Oryzias javanicus, test organism


Author(s):  
A. R. Milner ◽  
S. E. K. Sequeira

ABSTRACTA new temnospondyl amphibian Balanerpeton woodi gen. et sp. nov. is represented by over 30 complete or partial skeletons from the Viséan limestones, shales and tuffs in East Kirkton Quarry, Bathgate, near Edinburgh, Scotland. It is the commonest tetrapod represented in the East Kirkton assemblage and grew to about half a metre in length. Although superficially like the later Dendrerpeton, it is more advanced in possessing small premaxillaries each bearing a pronounced alary process, large external nares, large rounded interpterygoid vacuities, broadly bordered by the vomers anteriorly, a narrow vomer-pterygoid suture and a rod-like stapes. It is characterised by an unusual dental configuration in which each dentary bears a smaller number of larger teeth than the corresponding upper jaw ramus. A second probable temnospondyl is represented by two straight ribs of a much larger form.The relationships of basal temnospondyls and other amphibian groups are discussed and it is proposed that the sister-group of the temnospondyls is the Microsauria and that neither colosteids nor Caerorhachis can be considered to be temnospondyls, as both fall outside the temnospondyl-microsaur clade. A preliminary study of character distribution across a selection of primitive temnospondyls, including Balanerpeton, suggests that it is more advanced than the long-snouted Edopoidea and the Dendrerpetontidae despite its Viséan age. This implies that by the Viséan, significant diversification of temnospondyls had taken place.


1996 ◽  
Vol 59 (7) ◽  
pp. 768-771 ◽  
Author(s):  
SCOTT W. KELLER ◽  
JOSEPH E. MARCY ◽  
BARBARA A. BLAKISTONE ◽  
GEORGE H. LACY ◽  
CAMERON R. HACKNEY ◽  
...  

Test organism motility, concentration, aerosol exposure time, hole diameter and length were evaluated to determine their influence on microbial ingress into a flexible plastic pouch. Microtubes with 10- and 20-μm hole diameters and of 5- and 10-mm lengths were used as defects in 128 flexible pouches. A bioaerosol with a 2.68-μm mean particle size comprised of 102 or 106 CFU/ml source concentrations of motile or nonmotile Pseudomonas fragi TM 849 was introduced into a 119,911-cm3 chamber for exposures of 15 or 30 minutes. Six pouches showed test organism growth after a 72-h incubation period. Microbial ingress was significant (P &lt; .05) for motile test organisms with source concentrations of 106 CFU/ml.


1958 ◽  
Vol 35 (3) ◽  
pp. 584-601
Author(s):  
P. A. G. WILSON

1. The influence of solutions of NaCl on the hatching of eggs of Trichostrongylus retortaeformis is studied. It is shown that the effects are not the consequence of colligative properties, but are related to ionic phenomena. 0.05 N-NaCl slows down the rate of hatch without impairing the ultimate ‘hatchability’ of the eggs. Processes of development up to hatching are not slowed down. 2. The effect demonstrated in the case of NaCl is shown to be shared by eight other electrolytes, the depression in the rate of hatch being proportional to the mobility of the ions in solution. On the assumption that the effect of the ions is due to a penetration of the egg membrane(s) the rate of entry is shown to be controlled by the speed of the slower ion in any one salt. 3. The influence of NaCl on the permeability of hatching eggs to water is studied. It is shown that the rate of increase in permeability is slowed down sufficiently in NaCl to control the rate of hatch. The inference that water permeability is a necessary prerequisite for hatching is made, a further hypothetical process being invoked to account for the rate of hatch in the absence of NaCl, since it is not then controlled by changes in water permeability. 4. The probability that the net effect of ionic solutions on the eggs is one concerned with the rate of breakdown of the inner wax-like layer of the egg is strengthened by experiments demonstrating that the depressing influence of NaCl is antagonized by ‘Teepol’, though the comparable influence of other, non-emulsifying, compounds cannot be explained. 5. The role of water permeability in the hatching mechanism is investigated. 6. A hatching mechanism of strongyloid eggs is proposed which involves two processes, the first dependent upon the osmotic relationships of the unhatched larva to its environment, the second being some sort of chemical weakening of the outer shell. 7. It is suggested that the effect of ions on hatching rate assists the ‘embryonated egg’ to survive under natural conditions when the hatched first-stage larva might otherwise be destroyed by desiccation.


Author(s):  
Amaka, John I. ◽  
Attah, D. Daniel ◽  
Obisike, Victor U. ◽  
Benedict, Aboje G.

This study evaluated the larvicidal potential of the ethanolic and aqueous leaf extracts of Hyptis suaveolens Poit on the 4th larval instar of laboratory-reared Anopheles spp at varying concentrations of 0.1ml, 0.2ml, 0.3ml, 0.4ml and 0.5ml for specified periods of 24hrs, 48hrs and 72hrs. Qualitative phytochemical screening of the leaf extracts identified bioactive components like alkaloid, saponin, phenol, anthraquinone and flavonoid. The LC50 and LC90 values obtained indicate that the ethanolic leaf extracts of Hyptis suaveolens Poit had the greatest toxicity on the test organisms within 24hrs of exposure at median LC50 value of 0.485ml compared to the LC50 value of 0.625ml by its aqueous extract. The relative median potency estimates indicate that within 24 hrs, the ethanolic Hyptis suaveolens Poit was 0.161 times more potent on the test organism than aqueous Hyptis suaveolens Poit. The result of this research, therefore, underscores the efficacy of Hyptis suaveolens Poit as an eco-friendly alternative in Anopheles mosquito control. It is, therefore, recommended that quantitative phytochemical screening, application of column chromatography as well as thin layer chromatography be carried out on the extracts to isolate and purify toxic phytochemicals with larvicidal potentiality.


Author(s):  
Muh. Herjayanto ◽  
Annisa Misykah Mauliddina ◽  
Esa Rama Widiyawan ◽  
Nugroho Agung Prasetyo ◽  
Lukman Anugrah Agung ◽  
...  

Oryzias sp. from Tunda Island, Indonesia has the potential as a model organism in laboratories and also ornamental fish. Basic information regarding maintenance during adaptation post-transportation from its habitat in nature, embryo incubation and maintenance of larvae is needed as a basis for breeding activities. The results showed that Oryzias sp. from Tunda Island can adapt, spawning and produce a total 262 eggs (diameter 0.88-1.02 mm) in a controlled environment. Eggs from spawning in nature begin to hatch on the 11th incubation day, the hatching peak occurs on the 13th day with a hatching process 4-9 days at 25-27oC. The hatching rate ranges from 57.14-100% and the survival of 5 days old lavae after hatching is 72.72-100.00%. The transportation technique in this study has not been able to suppress fish mortality during post-transportation rearing.    


2021 ◽  
Vol 6 (1) ◽  
pp. 573-586
Author(s):  
Oleksandr Chekh ◽  
Olga Bordunova ◽  
Vadym Chivanov ◽  
Evgenia Yadgorova ◽  
Larisa Bondarchuk

Abstract Theoretical and applied aspects of the concept of using biomimetic protective coatings GREEN ARTICLE (ARTIficial cutiCLE) in the poultry industry, namely in the production of table and hatching eggs, are developed. The basic matrix component of the protective coatings GREEN ARTICLE is chitosan, an environmentally friendly, inexpensive, and harmless material. It is experimentally proved that electrochemical and ultrasonic technologies for modifying a solution of chitosan in peroxide compounds (peracetic acid and hydrogen peroxide) with nanoparticles of oxides like titanium, iron, zinc, and metals, such as titanium, copper, and calcite, allow to create protective coatings of double action in accordance with the technologies: (a) extending the shelf life of table eggs, food green article (FGA) and (b) preventing contamination of hatching eggs with pathogenic microflora, increasing the hatchability of eggs, and the quality of chicken, hatching green article (HGA). In the technology of storing table eggs, artificial cuticles based on chitosan FGA are characterized by the following characteristics: increased thickness of 6–10 µm, low gas and moisture permeability, and high biocidal activity against pathogenic bacteria and viruses. It is shown that the use of FGA technology in the production of table eggs can extend the period of transportation and storage of products by 33–35 days at a temperature of 24°C and maintained a grade A (Haugh unit = 71–60) through the entire 35 days period. The technology HGA reduces the rate of contamination of hatching eggs with pathogenic microflora by 99.29–99.7%, while increasing the egg hatching rate by 2.3–11.6% compared to the control, depending on the cross of the poultry and the storage conditions of the hatching eggs. It is important that these technologies have a great prospect for application in countries that develop green technologies for the production of poultry products.


1961 ◽  
Vol 39 (3) ◽  
pp. 519-530 ◽  
Author(s):  
F. R. Forsyth ◽  
C. H. Unwin

Protectant fungicidal action of mixtures of nabam, zineb, nickel chloride, and zinc sulphate was evaluated by means of a "microbeaker method" and the slide germination method, using as test organisms the fungi causing leaf rust of wheat, crown rust of oats, early blight of tomatoes, and brown rot of peaches. All of the fungicides tested were more effective against the two rusts than against the organisms causing early blight and brown rot. The relatively insoluble nickel ethylenebisdithiocarbamate was much less effective than the other chemicals tested. Ratios (w/w) of nickel chloride hexahydrate to zineb around unity and to nabam plus zinc sulphate from 2–10 to 1 showed an unfavorable effect on fungitoxic activity against urediospores of P. recondita. The ratio showing greatest antagonism varied, depending on the test organism used and whether or not tankmix or wettable powder zineb was used. The formation of nickel ethylenebisdithiocarbamate in the aqueous solution and its low fungicidal activity adequately explain the results obtained.


2021 ◽  
pp. 298-322
Author(s):  
Sebastian Höss

Abstract This chapter discusses the utility of nematodes in experimental ecotoxicology, and specifically in the study of freshwaters. Drawing on reports in which nematodes were used as test organisms in single-species tests as well as studies investigating nematode communities in model ecosystems (i.e. microcosms), the suitability of nematode-based experimental approaches in prospective and retrospective risk assessments of chemicals in freshwater sediments is examined. Several examples are presented of the use of Caenorhabditis elegans as a test organism in single-species bioassays, in order to demonstrate the versatility of this nematode for ecotoxicological investigations.


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