The occurence of black spot disease in Astyanax aff. fasciatus(characiformes: characidae) in the Guaíba Lake basin, RS, Brazil

Black spot disease is common in freshwater fish and is usually caused by the metacercaria stage of digenetic trematodes, normally from the Diplostomidae family. The present study evaluated the prevalence and intensity of this disease in Astyanax aff. fasciatus(Teleostei: Characiformes) in the Guaíba Lake basin (RS, Brazil), including body parts assessment and the points of sampling with higher occurrence of black spots. Fish samples were taken seasonally from December 2002 until October 2004. The samples were collected with the use of a seine net at eleven points. The specimens were fixed in 10% formalin and stored in 70% ethanol. Black spot disease showed a low frequency in the Guaíba lake basin (2.07%) and no specificity to the species Astyanax aff. fasciatus was observed. A high prevalence among the individuals and high intensity of infection levels was found in the ventral and dorsal regions in relation to other body parts (e.g., pectoral, pelvic and anal regions). Among the sampling points studied, we observed a higher prevalence on samples collected at points Gasômetro, Saco da Alemoa and Sinos, located in open areas with less occurrence of mollusks.

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Assessment of environmental quality through analysis of frequency of the black spot disease in an assemblage of fish, Guaíba lake, RS, Brazil

Brazilian Journal of Biology ◽

10.1590/s1519-69842011000500012 ◽

2011 ◽

Vol 71 (4) ◽

pp. 915-923 ◽

Cited By ~ 1

Author(s):

F. Flores-Lopes ◽

AT. Thomaz

Keyword(s):

Water Quality ◽

Black Spot ◽

Spot Disease ◽

Quality Of Water ◽

Digenetic Trematodes ◽

Astyanax Fasciatus ◽

Chi Squared ◽

One Year ◽

Black Spot Disease

The frequency of the black spot disease caused by digenetic trematodes in fish was tested as an indicator of the quality of water in the watershed of Lake Guaíba. Samples were standardised and quarterly made using a seine net at eleven sites in the basin. A total of 53,408 individuals of 66 specimens pertaining to 22 families and 8 orders were collected and analysed. The highest frequency of the disease was found in Astyanax fasciatus. The simple Chi-Squared test applied to the species showed statistically significant frequency of occurrence for three sampled sites. Two of these sites showed the highest frequencies for two consecutive sampling periods of one year and the best levels of water quality. Results of this study suggest that the association between high frequency of infestation by a parasite that causes the black spot disease in fish, and environments with less degradation in water quality, recorded from physical, chemicals and microbiological variables, could be used as an indicator of water quality in these environments.

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Characterization of Alternaria alternata Causing Black Spot Disease of Pomegranate in Israel Using a Molecular Marker

Plant Disease ◽

10.1094/pdis-12-11-1041-re ◽

2012 ◽

Vol 96 (10) ◽

pp. 1513-1518 ◽

Cited By ~ 7

Author(s):

Tami Gat ◽

Orna Liarzi ◽

Yulia Skovorodnikova ◽

David Ezra

Keyword(s):

Molecular Marker ◽

Alternaria Alternata ◽

Severe Disease ◽

Outer Part ◽

Black Spot ◽

Spot Disease ◽

Black Spots ◽

Detached Leaves ◽

Pathogenicity Tests ◽

Black Spot Disease

Black spot disease of pomegranate is a relatively new disease in Israel that is caused by Alternaria alternata. The symptoms include black spots on leaves and fruit. Only the outer part of the fruit is damaged; the edible tissue remains unaffected. In this study, we obtained 50 isolates of A. alternata from infected pomegranate plants that were classified based on pathogenicity tests using detached leaves. Using an arbitrarily primed polymerase chain reaction, we identified one primer (primer CAG) that reacted only with DNA of isolates that induced the most severe disease symptoms. Based on the sequence of the amplified fragment, we generated a specific primer (primer C) that recognizes these highly virulent isolates. Therefore, we suggest that primer C can be utilized as a molecular marker for the detection of A. alternata isolates that cause black spot disease of pomegranate.

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Impact de la maladie des points noirs sur la biologie du complexe Phoxinus (Cyprinidae) du lac Fortune, Québec

Canadian Journal of Zoology ◽

10.1139/z94-214 ◽

1994 ◽

Vol 72 (9) ◽

pp. 1611-1615 ◽

Cited By ~ 2

Author(s):

Anne Reine Paradis ◽

François Chapleau

Keyword(s):

Gonadosomatic Index ◽

Black Spot ◽

Condition Index ◽

The Body ◽

Spot Disease ◽

Total Length ◽

Predictive Parameters ◽

Black Spots ◽

Black Spot Disease

The purpose of this study was to quantify the effects of the black spot disease on growth, health, and fecundity of the fish and to define predictive parameters related to the infestation. Cyprinids belonging to the Phoxinus complex (P. eos, P. eos × P. neogaeus) of Lake Fortune (Gatineau Park, Québec, Canada) were sampled periodically between June and September 1992. The highest intensity of infestation was encountered in September (0–216 black spots; [Formula: see text], SD = 26.0). Our results indicate that: (i) the condition index of the Phoxinus complex and the gonadosomatic index in females are not affected by the level of infestation; (ii) age is a better predictive parameter of the number of black spots than total length; (iii) fins are significantly more infested than the body; and (iv) infestation occurs mainly between June and September. Our results suggest that the black spot disease does not influence the biology of fish belonging to the Phoxinus complex, even in instances of severe infestation.

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