This study analyzed the parasitism by Clinostomum sp. metacercariae of the neotropical fish Cichlasoma paranaense (Kullander 1983) and environmental variables' influence on their host-parasite ...relationship in Central Brazil. Fish were collected in five impoundments (I) from three towns: Itauçú (n = 2), Inhumas (n = 1), and Goiânia (n = 2), Goiás State, Brazil. Ninety-five fish were analyzed, weighted and length measured. Afterward, the presence of metacercariae in the gills, muscles, fins, and body cavities was investigated. The metacercariae were fixed in AFA solution, kept in 70% alcohol, and stained with carmine. The infection prevalence revealed that 0.64, 0.56 and 0.91% of fish was infected. The abundance was 4.14, 3.22 and 5.88, with a mean intensity of 6.44, 5.80 and 6.42 per impoundment (I 13, I 15 and I 16), respectively. The frequency of metacercariae was higher in fish collected in Goiânia. High frequency of parasites was observed in the gills, muscles, and fins. The limnological variables did not present direct interference in the parasitism. The fish' standard length influenced the number of metacercariae positively but did not differ to the relative condition coefficient.
The success of Procamallanus (Spirocamallanus) inopinatus infection in fish involves a complexity of variables. This study aims to evaluate the relationship between abundance of P. (S.) inopinatus ...with biometric and somatic parameters, sex, relative condition factor (Kn) and hosts diet, as well as to evaluate length relationship of the parasites and the hosts. The fishes were collected by the mesh method and data, length, weight, sex, gonad and liver weight, Gonadosomatic index (GSI) and hepatosomatic index (HSI), Kn and stomach content were recorded. Twenty-seven specimens of P. (S.) inopinatus were collected in the intestine from Serrasalmus rhombeus and 52 from Leporinus friderici. In general, the prevalence, mean intensity and mean abundance of infection was higher in L. friderici. The total abundance was explained by the variables GSI, HSI total length, gonad and liver weight. Fish relative condition factor (kn) and sex were not influenced by the infection, being that the parasite infection did not impair the body condition of the hosts. There is no relationship between host length and parasite length in any of the evaluated fish species. On average, S. rhombeus parasites are 0.69 cm larger than L. friderici parasites.
The Pacific silverstripe halfbeak, Hyporhamphus naos is one of the most commercially important fish species in Mazatlán Bay, north-western Mexico. Irrespective of its relatively small size, it is ...highly appreciated in the local gastronomy Every year between April and May adults congregate to spawn in Mazatlán Bay; however, information about their parasite fauna is lacking. This study reports on the metazoan parasite fauna of H. naos. Thirty individuals were sampled during the 2022 fishing season. Nine parasite taxa were collected, including five species of ectoparasites, that is, the monogeneans Axinoides sp. and Kuhnia sp., the copepods Ergasilus sp. and Lepeophtheirus sp., and the isopod Mothocya gilli Bruce, 1986, and four endoparasites, the nematode Philometra sp., and three metacercariae including the heterophyid Opisthometra planicollis (Rudolphi, 1819), the strigeid Cardiocephaloides medioconiger (Dubois and Vigueras, 1949), and cyathocotylid Mesosteph anus microbursa Caballero, Grocott and Zerecero, 1953. Parasites were identified using morphology, or a combination of morphology and DNA sequences. This study includes new host records for all metazoan parasites collected, except for Philometra sp. which has been previously documented infecting the gonads of H. naos. Philometra sp. was the species with the lowest prevalence (<10%), whereas O. planicollis and C. medioconiger reached the highest prevalence values with 63.3% and 50%, respectively. We discuss the factors that potentially determine the infection parameters of the metazoan parasites in the area, and the potential zoonotic importance of the cyathocotylid M. microbursa.
The aim of this study was to characterize potential fungal species affecting mangrove species in Mexico. The phytopathogens were identified based on morphological and molecular characteristics using ...internal transcribed spacer (ITS1/ITS4) primers then sequenced and compared with the other related sequences in GenBank (NCBI). Three fungal species were identified as Colletotrichum queenslandicum (Weir and Johnst, 2012) from black mangrove (Avicennia germinans); Colletotrichum ti (Weir and Johnst, 2012) from white mangrove (Laguncularia racemosa) and buttonwood mangrove (Conocarpus erectus); Fusarium equiseti (Corda) from red mangrove (Rhizophora mangle). In addition, C. ti and F. equiseti were identified from mango Mangifera indica L. sampled close by the mangrove area. This study provides first evidence of anthracnose on four mangrove species caused by Colletotrichum and Fusarium species in the “Términos” coastal lagoon in Campeche State southern Mexico. This is the first time that C. queenslandicum and C. ti are reported in Mexico. F. equiseti has not been reported affecting M. indica and R. mangle until the present work. Little is known regarding fungal diseases affecting mangroves in Mexico. These ecosystems are protected by Mexican laws and may be threatened by these pathogenic fungus. This is the first report of the effect of Trichoderma harzianum TRICHO-SIN as an effective biological control against of Colletotrichum and Fusarium species.
The current study aimed to describe the massive mortality of farmed Nile tilapia Oreochromis niloticus associated with the monogenean Gyrodactylus cichlidarum from the northwestern Mexican Pacific ...coast. The ectoparasite was identified using measurements of the hard parts and compared with previous literature. Approximately 20,000 tilapias were subjected to subsequent losses over a three day period, a total of 2% of the initial seed stocked died due to the presence of this gyrodactylid parasite. The presence of the monogenean was the principal cause for chemical treatments. There is no doubt that infections by parasites have major consequences for species of small fish in culture and must consequently be considered as a fundamental factor within any system of aquaculture. A histo-pathological examination of the gills of fish showed the presence of the monogenean attached to the fi laments was causing hyperplasia. The fish showed no signs of bacteria or virus infection. This study reports for the first time the occurrence of massive mortality caused by this monogenean in a tilapia fish farm in the Mexican Pacific and also extends their known geographical distribution.
This study examines the distribution and depletion of stored lipids in Gyrodactylus gasterostei Gläser, 1974, migrating off its three-spine stickleback host Gasterosteus aculeatus L., with the ...prospect that it might prove informative for interpreting the biology of other gyrodactylids species more generally. Nonfeeding life cycle stages, such as the dispersal stages of parasites, are dependent for survival upon finite energy reserves gathered during feeding phases. Thus, those individuals with more limited reserves will die sooner and consequently have less time available to find a new host once detached. At this stage, the principal energy reserves in gyrodactylids are stored as large lipid droplets. Confocal laser scanning microscopy has been used to investigate the distribution of lipid droplets in Gyrodactylus, which have migrated off their fish host, testing the hypothesis that these droplets function as a proxy for the nutritional state. This study demonstrated that the lipid droplets were particularly associated with the gut and that there is a significant variability in the volume of stored lipid carried out by each individual. Transmission electron microscopy showed that gyrodactylids carry lipid droplets at all stages of their life cycle, including at release from the birth pore. It is likely that transferring worms requires stored energy reserves to survive in the event of failure to establish contact with a new host. These reserves could allow the parasite to survive without a host for several days.
The aim of this study was to characterize potential fungal species affecting mangrove species in Mexico. The phytopathogens were identified based on morphological and molecular characteristics using ...internal transcribed spacer (ITS1/ITS4) primers then sequenced and compared with the other related sequences in GenBank (NCBI). Three fungal species were identified as Colletotrichum queenslandicum (Weir and Johnst, 2012) from black mangrove (Avicennia germinans); Colletotrichum ti (Weir and Johnst, 2012) from white mangrove (Laguncularia racemosa) and buttonwood mangrove (Conocarpus erectus); Fusarium equiseti (Corda) from red mangrove (Rhizophora mangle). In addition, C. ti and F. equiseti were identified from mango Mangifera indica L. sampled close by the mangrove area. This study provides first evidence of anthracnose on four mangrove species caused by Colletotrichum and Fusarium species in the "Términos" coastal lagoon in Campeche State southern Mexico. This is the first time that C. queenslandicum and C. ti are reported in Mexico. F. equiseti has not been reported affecting M. indica and R. mangle until the present work. Little is known regarding fungal diseases affecting mangroves in Mexico. These ecosystems are protected by Mexican laws and may be threatened by these pathogenic fungus. This is the first report of the effect of Trichoderma harzianum TRICHO-SIN as an effective biological control against of Colletotrichum and Fusarium species.
The monogenean Gyrodactylus gasterostei and its host, the three-spined stickleback Gasterosteus aculeatus, were employed as a model system to investigate the influence of gyrodactylid maturity on ...host transfer. Laboratory experiments included the determination of maturity (presence of a male copulatory organ) and reproductive status (presence of a daughter parasite) of the transmitting worms. Parasites with a male copulatory organ were more likely to abandon the host and attempt a host transfer. Additionally, in vivo video observation suggested that detached worms employ water turbulence to assist their effective transfer onto a new host.
Trichodiniasis is one of the major diseases found in fish aquaculture worldwide causing massive fish mortality and costly effects. In this study, fresh smears of gills and skin were prepared and ...analyzed for the presence of trichodinids under light microscopy, revealing the presence of Trichodina pediculus Ehrenberg, 1831, T. compacta Van As & Basson, 1989, and T. nigra Lom, 1960 and T. centrostrigeata (Basson, Van As & Paperna, 1983). The effectiveness of treatment with sodium chloride and formaldehyde was evaluated for controlling infection caused by these parasites in tilapia Oreochromis niloticus Linnaeus, 1758 in aquaculture facilities in southeastern Mexico. A total of 240 fish were examined. The results showed that all doses using sodium were effective for controlling trichodinids and eliminated the parasites (100%) however, fish exposed to doses of formalin showed a higher level of stress than those exposed to sodium chloride. Bathing in formalin 0.250 mL L"1 for 10 min and 30 g L"1 of sodium chloride for 10 min, significantly reduced parasitic infection in tilapia under captive conditions (P < 0.05). This is the first record of a trichodinids species for native wild freshwater fish in a culture environment in southeastern Mexico since all previous records were from exotic cultured fish. The species found were Trichodina pediculus, T. compacta, T. nigra and T. centrostrigeata are new records of host and geographic location.
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