scholarly journals The influence of black spot disease on the relative condition factor of Astyanax paranae Eigenmann, 1914 (Characiformes: Characidae) in Brazilian subtropical streams

2021 ◽  
Vol 43 ◽  
pp. e56164
Author(s):  
Germano Henrique Costa Barrilli ◽  
Evelise Nunes Fragoso de Moura ◽  
Odete Rocha ◽  
José Roberto Verani

Environmental disturbances and their consequences require constant studies to understand how communities and their ecological relationships respond to these processes. Through analysis of the host-parasite relationships, it is observed that the effect of these disturbances is variable and can change the physiology or behavior of organisms. Black spot disease, caused by endoparasitic helminths, is a pathology observed in natural environments, however, there is not much information about the consequences of this infestation. We separated the specimens from each stream into parasitized and non-parasitized groups, which were subjected to biometric analysis. The biometrics involved cysts count and weight-length measures, which were used to analyze the average relative condition factor. Additionally, we correlate these measures with the parasitic burden of infected individuals. Finally, the parasitized individuals were submitted to histological sections to recognize the parasite. The results demonstrate a low physiological condition in the parasitized group, when compared with non-parasitized groups from the same stream and from different streams. This suggests that pollution, in addition to effects of infestation worsen the fish condition. Besides, the parasite burden was negatively correlated with the condition factor, weight and length measures. We conclude that the parasite burden negatively affects Astyanax paranae individuals´ physiological condition and that trematodes also occur in polluted environments.

2005 ◽  
Vol 65 (3) ◽  
pp. 513-519 ◽  
Author(s):  
A. T. Silva-Souza ◽  
G. Ludwig

The infection, known as yellow spot disease, produced by metacercariae of Clinostomum spp. was studied in fishes of the Taquari river, located in Jataizinho, Paraná State, Brazil. A total of 1,582 specimens, belonging to 36 species, were collected between March 1999 and April 2001. Yellow spot disease was observed only in Gymnotus carapo Linnaeus, 1814 (Gymnotiformes, Gymnotidae) and Cichlasoma paranaense Kullander, 1983 (Perciformes, Cichlidae). This parasitism was generated by metacercariae of Clinostomum complanatum (Rudolphi, 1814) (Digenea, Clinostomidae). Among the 88 specimens of G. carapo examined, 7 (prevalence = 8%) had cysts of the parasite. Four of them were captured in July 1999 and three in October 1999. In the other months, no specimen found was infected. Using relative condition factor (Kn) analysis, it was determined that both infected and non-infected specimens had a total weight equal to the theoretically expected value for each total length (Kn = 1.0). Among 56 individuals of Cichlasoma paranaense, 6 (prevalence = 10.7%) had between 1 and 27 metacercariae of C. complanatum (mean intensity of infection = 9.3 ± 9.6). In March 1999 and April of both 2000 and 2001, the specimens examined were not infected. The infected fish had a total weight higher than the expected value (Kn > 1.0), while the non-infected fish had a weight equal to the expected value (Kn = 1.0).


2016 ◽  
Vol 03 (04) ◽  
Author(s):  
Yasin NA ◽  
Ahmed S ◽  
Khan WU ◽  
Ashraf Y

1994 ◽  
Vol 62 (4) ◽  
pp. 701-706 ◽  
Author(s):  
Kenji Murata ◽  
Kenichi Kitagawa ◽  
Testuo Masuda ◽  
Kosuke Inoue ◽  
Kazuo Kotobuki ◽  
...  

Mycologia ◽  
1997 ◽  
Vol 89 (6) ◽  
pp. 867-875 ◽  
Author(s):  
Akihiko Tsuneda ◽  
Shigeyuki Murakami ◽  
Warwick M. Gill ◽  
Nitaro Maekawa

Author(s):  
Atima Komhorm ◽  
Suttipong Thongmee ◽  
Todsawat Thammakun ◽  
Thanaprasong Oiuphisittraiwat ◽  
Arom Jantasorn

Genome ◽  
2007 ◽  
Vol 50 (8) ◽  
pp. 735-741 ◽  
Author(s):  
S. Terakami ◽  
Y. Adachi ◽  
H. Iketani ◽  
Y. Sato ◽  
Y. Sawamura ◽  
...  

Black spot disease, which is caused by the Japanese pear pathotype of Alternaria alternata (Fr.) Keissler, is one of the most harmful diseases in Japanese pear cultivation. We identified the exact positions and linkage groups (LGs) of the genes for susceptibility to black spot in the Japanese pear ( Pyrus pyrifolia Nakai) cultivars ‘Osa Nijisseiki’ (gene Ani) and ‘Nansui’ (gene Ana). Segregation of susceptibility and resistance fitted the expected ratio of 1:1 in progeny of ‘Nansui’ but showed a slight distortion in progeny of ‘Osa Nijisseiki’. We mapped the genes for susceptibility to black spot in both populations using a genome scanning approach. The simple sequence repeat (SSR) markers CH04h02 and CH03d02 showed tight linkage to Ani and Ana. Although Ani and Ana are derived from different sources, both genes are located at the top region of LG 11. Information about the positions of the susceptibility genes and the molecular markers linked to them will be useful for marker-assisted selection in pear breeding programs.


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