Anisakidae) on Mugilids from Senegalese Estuaries (original) (raw)
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Journal of Biology and Life Science, 2013
Anisakis sp. and Contracaecum sp. are nematodes belonging to the family of Anisakidae. They are worldwide distributed and use a great number of fish species as intermediate, paratenic or final host. Despite their effects on fish and human beings, they play ecological role as biological tags to identify fish population or bioindicators of marine pollution. From January to December 2009, the helminthological examinations of 129 and 167 specimens of Mugil cephalus originating from Saloum and Senegal estuaries respectively revealed the presence of Anisakis sp. and Contracaecum sp. larvae. Generally, whatever the season or locality, the kidney lodges more larvae of Anisakis sp. than the liver or the general cavity. All Contracaecum sp. larvae were found in the mesentery of Mugil cephalus whatever the locality and season. In each locality, the prevalence of Anisakis sp. larvae was higher in rainy season than in dry season whereas the larvae of Contracaecum sp. were more frequent in dry season than in wet season. Mean intensity of the Anisakidae larvae showed significant differences according to the season in the estuary of Saloum and non significant variation in the estuary of Senegal. The mean abundance of these larvae varied significantly depending on the locality, the season or the site of infection. These results are explained by factors related to the host (fat content in infested organs), factors in relation to the environment (temperature, salinity) and the presence of birds, final hosts. In the Saloum estuary, Anisakis sp. was dominant in rainy season, while Contracaecum sp. dominates in dry season. However, in the estuary of Senegal, Anisakis sp. was dominant all the year. So we can say that Anisakis sp. is characteristic of the estuary of Senegal while Contracaecum sp. is characteristic of the Saloum estuary. Distribution of anisakidae larvae is more related to the locality, the season and the site of infection rather than the fish gender.
Journal of Biology and Life Science, 2014
Consumption of mugilids is widespread in Senegal, especially in the estuaries, where there production is of economic importance. The prevalence, mean intensity and pathologic effects of Anisakis sp. and Contracaecum sp. larvae which infected mugilids from Senegalese estuaries were investigated. In 2009, individuals of mugilids belonging to 6 and 5 species were trapped from the estuaries of Saloum, Senegal and Casamance rivers respectively. The prevalence and mean intensity of Anisakis sp. and Contracaecum sp. are higher in Senegal and Saloum estuaries respectively. The increase in the load of Contracaecum sp., related to the season in L. falcipinnis, the season, the size, the weight and/or the sex in M. cephalus from the estuaries of Saloum and Senegal and M. curema from Saloum estuary were due to an accumulation of parasites over time. Liver, kidney, body cavity and mesentery and ovaries are the respective sites of infection of Anisakis sp. and Contracaecum sp. larvae. The immune response observed is the formation of a fibrous capsule surrounding the parasites with melanin granules all around the capsule. The implementation of the capsule and the presence of melanin granules suggest the involvement of lymphocytes, monocytes, neutrophils and macrophages. The lesions caused by Anisakis sp. and Contracaecum sp. larval settlement in target organs may cause the death of the host and/or a reduction in fertility.
Biodiversitas Journal of Biological Diversity, 2021
This study aimed to investigate the prevalence, mean intensity, and type of Anisakis larvae infecting hairtail (Trichiurus lepturus) caught at Pangandaran Waters, West Java, Indonesia. It was conducted using 869 samples sourced from local fishermen. The parameters measured were the total length and weight of each T. lepturus. Furthermore, parasitological examination was carried out to investigate the occurrence of Anisakis larvae in the fishes. The selected samples of Anisakis were identified through morphological and molecular analysis. The results showed that the larvae were found either free in the abdominal cavity of the fishes or coiled and attached to the serosal layer of the gastrointestinal tract, gonad, liver, and muscle. It also showed that their prevalence in the T. lepturus was at a moderate level (45.5%), with the mean intensity at 4.4 larvae/fish. Moreover, the larvae were mostly in the abdominal cavity (89%), as only a few were found in another part of the fishes. Morphological identification showed that Anisakis infecting the hairtail was Type I, which is characterized by the presence mucron and ventriculus without caecum.. Molecular analysis was carried out by sequencing the ITS region, and it confirmed that the nematode was Anisakis typica, which until recently was recognized as a non-zoonotic parasite.. These parasites were not present in the edible portion/muscle of the fishes, and had a relatively moderate prevalence and low intensity. Therefore, their presence posed a relatively low risk to human health. However, due to consumption patterns and the increasing popularity of seafood, being served raw or undercooked, the incidence of anisakiasis may increase in the future. In the other hand, the presence of these larvae might be used as a biological indicator for several ecological studies.
Spatial distribution and habitat characterisation of Anopheles larvae along the Kenyan coast
Journal of vector borne diseases, 2007
A study was conducted to characterise larval habitats and to determine spatial heterogeneity of the Anopheles mosquito larvae. The study was conducted from May to June 1999 in nine villages along the Kenyan coast. Aquatic habitats were sampled by use of standard dipping technique. The habitats were characterised based on size, pH, distance to the nearest house, coverage of canopy, surface debris, algae and emergent plants, turbidity, substrate, and habitat type. A total of 110 aquatic habitats like stream pools (n=10); puddles (n=65); tire tracks (n=5); ponds (n=5) and swamps (n=25) were sampled in nine villages located in three districts of the Kenyan coast. A total of 7,263 Anopheles mosquito larvae were collected, 63.9% were early instars and 36.1% were late instars. Morphological identification of the III and IV instar larvae by use of microscopy yielded 90.66% (n=2377) Anopheles gambiae Complex, 0.88% (n=23) An. funestus, An. coustani 7.63% (n=200), An. rivulorum 0.42% (n=11), ...
2011
The prevalence, intensity and distribution of Anisakis sp. larvae which infected some fishes at the southern coast of Kulon Progo District were investigated. Totally 95 fish specimens were collected during December 2007. Results of the present study indicated that the Anisakis sp. larvae infected various fish species i.e: Trichiurus lepturus, Parupeneus sp., Lutjanus malabaricus, Terapon jarbua and Caesio sp. Prevalence and mean intensity of infection showed the differences between fish species. The highest mean intensity of infection was found in L. malabaricus (7.71 larvae/infected host) and T. Lepturus (3.18 larvae/infected host), while the lowest intensity of infection was found in Parupeneus sp., T. jarbua and Caesio sp. (1 larvae/infected host). Infected host organs were body cavities (peritoneum), digestive tract, gonads, and liver. Presence of this parasite may be harmful for consumer; however it can be used for several ecological studies as biological tags.
Brazilian Journal of Veterinary Medicine, 2014
ABSTRACT. Mattos D.P.B.G., Lopes L.M.S., Verícimo M.A., Alvares T.S. & São Clemente S.C. Anisakidae larvae infection in five commercially important fish species from the State of Rio de Janeiro, Brazil. [Infecção por larvas Anisakidae em cinco espécies de peixes comercialmente importantes do Rio de Janeiro, Brasil.] Revista Brasileiro de Medicina Veterinária, 36(4):375-379, 2014. Laboratório de Inspeção e Tecnologia de Pescado, Faculdade de Veterinária, Universidade Federal Fluminense, Rua Vital Brazil, 64, Santa Rosa, Niterói, RJ 24230-340, Brasil. E-mail: scsc@vm.uff.br From March 2009 to March 2012, 213 teleostei fish were obtained from fish markets and fishermen from Niteroi and Cabo Frio municipalities, Rio de Janeiro State, Brazil. The fish belonged to the species Micropogonias furnieri (107); Trichiurus lepturus (35); Centropomus undecimalis (22); Genypterus brasiliensis (18); Pagrus pagrus (18); Pomatomus saltatrix (7) e Merluccius hubbsi (6). Nematode larvae of Anisakidae w...
Role of some fish in harbouring zoonotic Anisakid nematodes at Damietta Governorate in Egypt
This study was carried out to clarify the role of some fish in harbouring Anisakid nematode larvae in Damietta, Egypt. For this purpose, a total of247 fish samples including 8 different species were collected from markets in Damietta province from February 2014 to January 2015 which represented 202 fresh fish (101 of 4 marine water fish species and 101 of 4 freshwater fish species) and 45 salted fish. Marine water fish species samples including 20Sardinella aurita,20Scomber japonicus,22Trachurus mediterraneus and 39Mugil cephalus;whereas, freshwater fish speciessamples compromised24Bagrus bajad, 20Clarious lazera,37Oreochromis niloticus and20Cyprinus carpio. Meanwhile, 45 salted fish species were 20Mugilcephalus and25Sardinella aurita. Samples were examined parasitologically using direct macroscopical and microscopical methods after pepsin digestion to determine the occurrence of anisakid species and frequency distribution of anisakid larvae in fish samples. The results showed that the overall occurrence of anisakid third stage larvae was 21.05% (52 out of 247) with mean intensity of 2.38. The total occurrence of anisakids in marine water fish was found to be 29.7% (30 out of 101) and the mean intensity was 2.8. Moreover, the total occurrence of anisakids in freshwater fish was 9.9% (10 out of 101) with mean intensity of 1.1. However, the total occurrence rate of infection in salted fish was 26.66% (12 out of 45) with mean intensity of 2.41. Fish species as Sardinella aurita, Scomber japonicus, Trachurus mediterraneus,Bagrus bajadand saltedSardinella auritacarrying different speciesof anisakid larvae with the percentages (50, 35, 59.09, 41.66 and 48) of infection and
Predation efficiency of Anopheles gambiae larvae by aquatic predators in western Kenya highlands
Parasites & Vectors, 2011
Background: The current status of insecticide resistance in mosquitoes and the effects of insecticides on nontarget insect species have raised the need for alternative control methods for malaria vectors. Predation has been suggested as one of the important regulation mechanisms for malaria vectors in long-lasting aquatic habitats, but the predation efficiency of the potential predators is largely unknown in the highlands of western Kenya. In the current study, we examined the predation efficiency of five predators on Anopheles gambiae s.s larvae in 24 hour and semi-field evaluations. Methods: Predators were collected from natural habitats and starved for 12 hours prior to starting experiments. Preliminary experiments were conducted to ascertain the larval stage most predated by each predator species. When each larval instar was subjected to predation, third instar larvae were predated at the highest rate. Third instar larvae of An. gambiae were introduced into artificial habitats with and without refugia at various larval densities. The numbers of surviving larvae were counted after 24 hours in 24. In semi-field experiments, the larvae were counted daily until they were all either consumed or had developed to the pupal stage. Polymerase chain reaction was used to confirm the presence of An. gambiae DNA in predator guts. Results: Experiments found that habitat type (P < 0.0001) and predator species (P < 0.0001) had a significant impact on the predation rate in the 24 hour evaluations. In semi-field experiments, predator species (P < 0.0001) and habitat type (P < 0.0001) were significant factors in both the daily survival and the overall developmental time of larvae. Pupation rates took significantly longer in habitats with refugia. An. gambiae DNA was found in at least three out of ten midguts for all predator species. Gambusia affins was the most efficient, being three times more efficient than tadpoles. Conclusion: These experiments provide insight into the efficiency of specific natural predators against mosquito larvae. These naturally occurring predators may be useful in biocontrol strategies for aquatic stage An. gambiae mosquitoes. Further investigations should be done in complex natural habitats for these predators.
Hydrology and Earth System Sciences Discussions, 2010
Entomological studies to determine the effect of the physical characteristics of mosquito larval breeding water bodies and reservoir water level changes on the occurrence of Anopheles mosquito larvae were conducted in two villages at Koka reservoir in central Ethiopia between August and December 2007. Of the two study villages, Ejersa is located close to the reservoir, and Kuma is 5 km away from it. Data on the type, number and physical characteristics of Anopheles larval breeding habitat, species composition and densities of anopheles mosquitoes in and around the study villages were investigated and recorded. Meteorological and reservoir water level data were compared with availability of Anopheles larval breeding sites and densities. Entomological data, derived from weekly larval collections, showed that Anopheles pharoensis Theobald, Anopheles gambiae s.l. Giles, Anopheles coustani Laveran and Anopheles squamosus Theobald were breeding in the study area. The mean larval density of An. gambiae s.l. in this study was higher in slightly turbid and shallow aquatic habitat than in turbid and relatively deep aquatic habitat. The density of An. pharoensis in habitat with floating vegetation and with relatively shady conditions was significantly higher than that of less shaded aquatic habitat and greater emergent vegetation. There was also a positive correlation between the occurrence of Anopheles larvae with the water and daily minimum atmospheric temperature. Similarly at Ejersa, over the sampling period, there was a positive correlation between falling reservoir water levels and the num-Correspondence to: B. M. Teklu (birhanme@yahoo.com) ber of positive breeding habitats. These results confirm that physical characteristics of the water bodies play an important role in the species composition, total Anopheles larval count, and the density of Anopheles mosquitoes. Suitable breeding habitat in the vicinity of the reservoir village was strongly associated with the reservoir. This is particularly important for An. pharoensis and An. gambiae s.l. which are important vectors of malaria in the area.
The current study aimed to study the use of larvivorous fish against larvae of Anopheles gambiae malaria vector in laboratory conditions in Dogbo district in southwestern Benin, West Africa. Larvae of Anopheles gambiae s.l mosquitoes were collected from breeding sites using the dipping method in June 2020 during the rainy season in Dogbo district. Alive Hemichromis fasciatus fishes were bought immediately once catched by fishers of Ganvié location in So-Ava district and carried by car from Ganvié location to the Laboratory. Laboratory evaluation for larvivorous efficacy was conducted. The results showed that larvivorous fishes ate more larvae of Anopheles gambiae s.l. when they were unfed than when they were fed. The results obtained after the introduction of unfed larvivorous fishes in glass jars showed high larva-eating capacity of these fishes.