Methods for quantifying eggs and oviposition rate of Dawestrema cycloancistrium (Monogenea: Dactylogyridae), monogenean parasite of Arapaima gigas (Teleostei: Osteoglossidae)

2018 ◽  
Vol 94 ◽  
Author(s):  
P.O. Maciel ◽  
R.R. Alves
Keyword(s):  
Egg Production ◽  
Production Capacity ◽  
Biological Data ◽  
Oviposition Rate ◽  
Adult Parasite ◽  
Counting Method ◽  
Monogenean Parasite ◽  
Monogenean Species ◽  
Arapaima Gigas ◽  
Total Counting

AbstractDawestrema cycloancistrium is the main ectoparasite causing mortality in fingerlings of pirarucu (Arapaima gigas) in Amazonian aquaculture. Very little is known about the D. cycloancistrium reproductive index and appropriate methods of collecting eggs for investigation. This study aimed to determine the oviposition rate of D. cycloancistrium. To achieve this aim, two egg quantification methods were tested: the estimative method (ME) and the total counting method (MT). Compared with the MT, the ME overestimated the number of eggs counted, which were 2943.5 ± 2840.6 and 1041.5 ± 533 eggs, and the oviposition rate, which was 80.1 ± 58.7 and 31.4 ± 16.4 eggs/parasite/day, for ME and MT, respectively. These results show that for studies quantifying D. cycloancistrium eggs, the total eggs in the sample must be counted, as the estimates made using subsamples are not representative. Using the MT, the oviposition rate for D. cycloancistrium was determined to be 31.4 ± 16.4 eggs per adult parasite per day. The present study demonstrates the egg production capacity of a monogenean species parasite of A. gigas, providing basic biological data for D. cycloancistrium.

Temperature-dependent survival and reproduction within populations of the ectoparasitic digenean Transversotrema patialense on the fish host

Parasitology ◽  
1980 ◽  
Vol 81 (1) ◽  
pp. 91-102 ◽  
Author(s):  
C. A. Mills
Keyword(s):  
Life Span ◽  
Egg Production ◽  
Fish Host ◽  
Adult Parasite ◽  
Optimum Temperature ◽  
Brachydanio Rerio ◽  
Temperature Dependent ◽  
Parasite Survival ◽  
Survival And Reproduction ◽  
Increasing Temperature

SUMMARYThe reproduction and survival of the ectoparasitic digenean Transversotrema patialense on the fish host Brachydanio rerio are shown to be temperature-dependent. Survival is reduced by any deviation from an optimum temperature of approximately 23°C. With increasing temperature the rate of egg production per surviving fluke rises progressively faster to a higher peak up to 29°C but falls to zero by 35°C. The span of egg production varies closely with the life-span of the parasite at each temperature. The optimum temperature for the total number of eggs produced by each cohort of parasites is also 23°C. This number is a function of both adult parasite survival and the rate of egg output.

Egg Production Capacity of Paragonimus pulmonalis in Cats

1998 ◽  
Vol 84 (6) ◽  
pp. 1282 ◽  
Author(s):  
P. C. Fan ◽  
H. Lu ◽  
L. H. Lin
Keyword(s):  
Egg Production ◽  
Production Capacity

scholarly journals Estimated egg production of Fasciola gigantica (Japanese strain) in goats experimentally infected with 50 metacercariae

2010 ◽  
Vol 47 (4) ◽  
pp. 199-203 ◽  
Author(s):  
K. Taira ◽  
Y. Saitoh
Keyword(s):  
Single Dose ◽  
Experimental Infection ◽  
Count Data ◽  
Egg Production ◽  
Production Capacity ◽  
Fasciola Gigantica ◽  
Confidence Limits ◽  
Japanese Strain ◽  
The Mean

AbstractEgg production capacity in Fasciola gigantica (Japanese strain) was estimated from egg count data obtained by the experimental infection of two goats. The goats were inoculated with a single dose of 50 metacercariae. The first goat was necropsied 132 days after infection (DAI) and the second goat 732 DAI. After patency, daily faecal production was collected and weighed and number of eggs per gram was counted. At necropsy, 23 flukes were recovered from the liver of the first goat, and five from the second goat. The mean number of eggs produced per day per worm (± 95 % confidence limits) was 9 477.9 (± 764.92) for the first goat at 106 to 132 DAI, and 8,064.1 (± 416.49) at 195 to 561 DAI for the second goat. The number of eggs produced per day per worm in F. gigantica (Japanese strain) has thus reached values ranged from approximately 8 000 to 10 000 eggs.

Studies on the oviposition of Rhyzopertha dominica (F.) in rice and paddy

1963 ◽  
Vol 53 (4) ◽  
pp. 621-637 ◽  
Author(s):  
Michael H. Breese
Keyword(s):  
Egg Production ◽  
Feeding Rate ◽  
No Reduction ◽  
Oviposition Rate ◽  
Rhyzopertha Dominica ◽  
Nutritional Values ◽  
Egg Distribution ◽  
Short Period ◽  
The Difference ◽  
Oviposition Sites

No reduction in the amount of feeding or in the oviposition rate was observed when females of Rhyzopertha dominica (F.) were supplied with whole rather than with cut wheat grains. Although there was a marked reduction in feeding when females were supplied with cut grains of paddy and a further reduction when they were supplied with cut grains of hulled rice, the oviposition rate observed on these two types of grain was only slightly lower than on wheat.The difference in the oviposition rates observed on wheat and rice may be due to a difference in the nutritional values of these grains or it is possible that the harder texture of the rice kernel limits the feeding rate of the female sufficiently to affect the rate of egg production.Eggs are laid preferably in crevices and on rough surfaces rather than on smooth, and these preferences often overweigh the tendency shown by the female to avoid laying on the grain on which it is feeding.The results of experiments on egg distribution in paddy are in agreement with Crombie's (1942) observation that females of R. dominica tend to lay all the eggs for a given day in one short period of intense ovipositing activity. Thus, although suitable oviposition sites may be numerous, if they are individually able to accommodate all the eggs laid on one day, eggs will usually be concentrated in fewer oviposition sites than are available.

scholarly journals Identification of 6-(piperazin-1-yl)-1,3,5-triazine as a chemical scaffold with broad anti-schistosomal activities

2020 ◽  
Vol 5 ◽  
pp. 169
Author(s):  
Gilda Padalino ◽  
Iain W. Chalmers ◽  
Andrea Brancale ◽  
Karl F. Hoffmann
Keyword(s):  
Virtual Screening ◽  
Small Molecules ◽  
Adult Worm ◽  
In Silico ◽  
Egg Production ◽  
Homology Modelling ◽  
Homology Model ◽  
Biological Data ◽  
Significant Activity ◽  
Starting Point

Background: Schistosomiasis, caused by infection with blood fluke schistosomes, is a neglected tropical disease of considerable importance in resource-poor communities throughout the developing world. In the absence of an immunoprophylactic vaccine and due to over-reliance on a single chemotherapy (praziquantel), schistosomiasis control is at risk should drug insensitive schistosomes develop. In this context, application of in silico virtual screening on validated schistosome targets has proven successful in the identification of novel small molecules with anti-schistosomal activity.   Methods: Focusing on the Schistosoma mansoni histone methylation machinery, we herein have used RNA interference (RNAi), ELISA-mediated detection of H3K4 methylation, homology modelling and in silico virtual screening to identify a small collection of small molecules for anti-schistosomal testing. A combination of low to high-throughput whole organism assays were subsequently used to assess these compounds’ activities on miracidia to sporocyst transformation, schistosomula phenotype/motility metrics and adult worm motility/oviposition readouts. Results: RNAi-mediated knockdown of smp_138030/smmll-1 (encoding a histone methyltransferase, HMT) in adult worms (~60%) reduced parasite motility and egg production. Moreover, in silico docking of compounds into Smp_138030/SmMLL-1’s homology model highlighted competitive substrate pocket inhibitors, some of which demonstrated significant activity on miracidia, schistosomula and adult worm lifecycle stages together with variable effects on HepG2 cells. Particularly, the effect of compounds containing a 6-(piperazin-1-yl)-1,3,5-triazine core on adult schistosomes recapitulated the results of the smp_138030/smmll-1 RNAi screens. Conclusions: The biological data and the structure-activity relationship presented in this study define the 6-(piperazin-1-yl)-1,3,5-triazine core as a promising starting point in ongoing efforts to develop new urgently needed schistosomicides.

scholarly journals Identification of 6-(piperazin-1-yl)-1,3,5-triazine as a chemical scaffold with broad anti-schistosomal activities

2020 ◽  
Vol 5 ◽  
pp. 169
Author(s):  
Gilda Padalino ◽  
Iain W. Chalmers ◽  
Andrea Brancale ◽  
Karl F. Hoffmann
Keyword(s):  
Virtual Screening ◽  
Small Molecules ◽  
Adult Worm ◽  
In Silico ◽  
Egg Production ◽  
Homology Modelling ◽  
Homology Model ◽  
Biological Data ◽  
Significant Activity ◽  
Starting Point

Background: Schistosomiasis, caused by infection with blood fluke schistosomes, is a neglected tropical disease of considerable importance in resource-poor communities throughout the developing world. In the absence of an immunoprophylactic vaccine and due to over-reliance on a single chemotherapy (praziquantel), schistosomiasis control is at risk should drug insensitive schistosomes develop. In this context, application of in silico virtual screening on validated schistosome targets has proven successful in the identification of novel small molecules with anti-schistosomal activity.   Methods: Focusing on the Schistosoma mansoni histone methylation machinery, we herein have used RNA interference (RNAi), ELISA-mediated detection of H3K4 methylation, homology modelling and in silico virtual screening to identify a small collection of small molecules for anti-schistosomal testing. A combination of low to high-throughput whole organism assays were subsequently used to assess these compounds’ activities on miracidia to sporocyst transformation, schistosomula phenotype/motility metrics and adult worm motility/oviposition readouts. Results: RNAi-mediated knockdown of smp_138030/smmll-1 (encoding a histone methyltransferase, HMT) in adult worms (~60%) reduced parasite motility and egg production. Moreover, in silico docking of compounds into Smp_138030/SmMLL-1’s homology model highlighted competitive substrate pocket inhibitors, some of which demonstrated significant activity on miracidia, schistosomula and adult worm lifecycle stages together with variable effects on HepG2 cells. Particularly, the effect of compounds containing a 6-(piperazin-1-yl)-1,3,5-triazine core on adult schistosomes recapitulated the results of the smp_138030/smmll-1 RNAi screens. Conclusions: The biological data and the structure-activity relationship presented in this study define the 6-(piperazin-1-yl)-1,3,5-triazine core as a promising starting point in ongoing efforts to develop new urgently needed schistosomicides.

scholarly journals The Oviposition Responses of Calandra Granaria Linn

1943 ◽  
Vol 20 (1) ◽  
pp. 35-42
Author(s):  
L. E. S. EASTHAM ◽  
SHELIA B. McCULLY
Keyword(s):  
Relative Humidity ◽  
Water Content ◽  
Low Temperatures ◽  
Egg Production ◽  
Oviposition Rate ◽  
Preoviposition Period ◽  
Dry Food ◽  
Food Grain ◽  
Length Of Life ◽  
Low Rate

1. The oviposition responses of Calandra granaria as manifested by the rate of oviposition, total eggs laid, length of life, length of life, length of ovipository life and length of preoviposition period, have been investigated under controlled conditions of temperature and saturation deficiency of air, grain having been acclimatized in its water content to the relative humidity of the air. 2. Calandra lives for a shorter time under high than under low temperatures but lays eggs at a greater rate, thus compensating for the shorter life. 3. There is evidence for the existence of an optimum saturation deficiency at each temperature for oviposition rate. 4. Weevils are shorter lived at high saturation deficiencies than they are at low. 5. The total number of eggs laid by weevils is smaller at high than at low saturation deficiencies of air. 6. Water content of the food grain contributes to these results in that dry food is conducive to low rate of oviposition, low total egg production and shorter life.

The biology of Leptocotyle minor, a skin parasite of the dogfish, Scyliorhinus canicula

Parasitology ◽  
1965 ◽  
Vol 55 (3) ◽  
pp. 473-480 ◽  
Author(s):  
G. C. Kearn
Keyword(s):  
Outer Surface ◽  
Adult Parasite ◽  
Monogenean Parasite ◽  
Hard Surface ◽  
Scyliorhinus Canicula

Leptocotyle minor is a monogenean parasite specialized for living on the denticlecovered skin of the dogfish Scyliorhinus canicula. Each adult parasite attaches itself to the outer surface of a single denticle. Small postlarvae are found on the inner surfaces of the denticles. The denticles have hard enamel on both inner and outer exposed surfaces. Haptoral hooks, such as are present in other monogenean oncomiracidia, would be unable to penetrate this hard surface and are absent in postlarval and adult parasites which attach themselves by cement. The oncomiracidium possesses six haptoral spicules which may be homologues of the marginal hooks of other monogeneans, but these spicules disappear early in postoncomiracidial development.Adult parasites feed on the host's epidermis which lies between the denticles. The position of small postlarvae on the inner surfaces of the denticles enables them to reach the epidermis for feeding purposes. Growth then permits young parasites to migrate away from the epidermis on to the outer surfaces of the denticles.Adult parasites move from one denticle to another in a leech-like manner, and copulation occurs between parasites which meet as a result of these movements.I am grateful to the Director and Staff of the Plymouth Laboratory for their hospitality and particularly to Mr J. E. Green for his interest and co-operation.

The ultrastructure and immunogold labelling of pancreatic polypeptide-immunoreactive cells associated with the egg-forming apparatus of a monogenean parasite, Diclidophora merlangi

Parasitology ◽  
1991 ◽  
Vol 102 (3) ◽  
pp. 429-436 ◽  
Author(s):  
D. W. Halton ◽  
G. P. Brennan ◽  
A. G. Maule ◽  
C. Shaw ◽  
C. F. Johnston ◽  
...  
Keyword(s):  
Fine Structure ◽  
Pancreatic Polypeptide ◽  
Egg Production ◽  
Immunogold Labelling ◽  
Muscle Fibres ◽  
Microscopical Examination ◽  
Monogenean Parasite ◽  
Electron Microscopical Examination ◽  
Golgi System ◽  
Electron Microscopical

An electron microscopical examination has been made of the fine structure and disposition of pancreatic polypeptide immunoreactive cells associated with the egg-forming apparatus in Diclidophora merlangi. The cell bodies are positioned in the parenchyma surrounding the ootype and taper to axon-like processes that extend to the ootype wall. The terminal regions of these processes branch and anastomose and, in places, the swollen endings or varicosities form synaptic appositions with the muscle fibres in the ootype wall. The cells are characterized by an extensive GER-Golgi system that is involved in the assembly and packaging of dense-cored vesicles. The vesicles accumulate in the axons and terminal varicosities, and their contents were found to be immunoreactive with antisera raised to the C-terminal hexapeptide amide of pancreatic polypeptide. It is concluded that the cells are neurosecretory in appearance and that, functionally, their secretions may serve to regulate ootype motility and thereby help co-ordinate egg production in the worm.

Sign in / Sign up

Export Citation Format

Share Document