Paracamallanus Cyathopharynx Research Articles

Modulation of the intestinal mucosal and cell-mediated response against natural helminth infection in the African catfish Clarias gariepinus

Fish gut is a versatile organ serving as the primary pathway for invasion by pathogens, particularly parasites, playing a crucial role in modulating the intestinal adaptive immune response. This study aimed to investigate the cellular-mediated reaction, mucosal acidity, and the expression of proliferating cell nuclear antigen (PCNA), vascular endothelial growth factor (VEGF), and CD68 in the intestines of catfish, Clarias gariepinus, naturally infected with helminths. Forty catfish were collected from the Nile River and examined for intestinal parasites. The intestinal tissues of the control and infected fish were fixed for histochemical and immunohistochemical studies. Two groups of helminths were found: cestodes Tetracampos ciliotheca and Polyonchobothrium clarias, and nematodes Paracamallanus cyathopharynx, with a prevalence rate of 63.63%, 18.0%, and 18.0%, respectively. Our results showed that the infected fish had a statistically significant rise in the activity of immune cells, including mast cells, eosinophil granular cells, and dendritic cells. This correlated with upregulation in the expressions of PCNA, VEGF, and CD68. Histochemical analyses demonstrated a marked increase in acidic mucus production, Sudan black B, and bromophenol mercury blue. This study enriches our understanding of the evolution of vertebrate immunity in combating intestinal parasitic infections and the host’s adaptive responses.

Endohelminth diversity in the invasive Clarias gariepinus (Burchell, 1822) from two freshwater lakes: Naivasha and Ol'Bolossat, Kenya.

Fish parasitology contributes to our understanding of the potential risks posed by diverse groups of parasitic organisms on fish stocks in either wild and culture systems. This study was conducted in May 2023 and aimed at assessing the diversity of endohelminths in the invasive North African catfish Clarias gariepinus (Burchell, 1822) obtained from two freshwater lakes, Naivasha and Ol'Bolossat, in Kenya. Parasitological examination of 66 and 35 fish samples collected from the two lakes respectively was achieved using light and scanning electron microscopy methods. Results revealed endohelminth diversity broadly classified as four digeneans, two nematodes, and one cestode. Seven taxa of endohelminths were found in C. gariepinus samples, but only four of these taxa could be identified up to the species level. Six of the taxa (Diplostomum sp., Tylodelphys mashonense, Plagiorchioidea sp., Paracamallanus cyathopharynx, Contracaecum sp., and Tetracampos ciliotheca) were common in samples from the two lakes. Glossidium pedatum only occurred in samples from Lake Ol'Bolossat. Parasite prevalence ranged from 8.6 (T. mashonense) to 100% (Diplostomum sp., T. ciliotheca, and Contracaecum sp.) and mean intensity from 1.4 (T. mashonense) to 16.9 (Diplostomum sp.). The diversity and richness indices were comparatively higher in fish samples from Lake Ol'Bolossat and attributed to the occurrence of G. pedatum in the Ol'Bolossat. However, parasitic infestation of fish samples from the two lakes depicted close similarity, both in diversity and prevalence. These findings form an important baseline data for further follow-up studies, and they suggest the need for further molecular analyses to fully describe three of the taxa only identified up to the genus level.

An improved method for isolating camallanid (Nematoda) spicules for scanning electron microscopy.

In nematodes, the structure of male copulatory organs is a significant taxonomic distinguisher and includes the morphometry of the spicules. The description of these structures mainly relies on the study of whole mounts using light microscopy. In rare instances, protruding spicules have been described with scanning electron microscopy. Even fewer studies have described the ultrastructure of isolated spicules following their isolation. In the present study, two different methods of spicule isolation were performed on two parasitic camallanid nematodes, Procamallanus (Procamallanus) pseudolaeviconchus Moravec & van As, 2015 and Paracamallanus cyathopharynx (Baylis, 1923), from African sharptooth catfish to determine the practicality and efficiency of the methodologies. The first method involved using sharpened tungsten needles and microdissection of the spicule pouch to free the spicules, followed by soft tissue digestion if necessary. Alternatively, the spicules were isolated through mechanical release instead of dissection in a method developed in the current study. This involved freeing the spicules from surrounding soft tissue by placing live specimens between a coverslip and a glass slide in a drop of water and exerting pressure with small rotational movements. Both methods yielded favourable results, but Method 2 is recommended for future studies due to the many advantages.

Camallanid nematodes from Clarias gariepinus (Burchell, 1822) in the Crocodile River, Gauteng, South Africa: Exploring diversity and divergence in an acid-mine drainage impacted environment.

Clarias gariepinus collected from Lake Heritage, Crocodile River, were found to harbour camallanid nematodes. Previously, Boomker (1982) surveyed the Hartbeespoort Dam, downstream of the current study site, and identified a high prevalence of Procamallanus (Procamallanus) laeviconchus and Paracamallanus cyathopharynx. Since then, Procamallanus (Procamallanus) pseudolaeviconchus was described from C. gariepinus suggesting reconsideration of the identifications of Procamallanus species in historical studies from clariids. The aim of the current study was to definitively identify the nematodes collected from C. gariepinus in Lake Heritage, using morphological and molecular analyses. Morphological study consisted of light and scanning electron microscopy which confirmed the identity P. (P.) pseudolaeviconchus and P. cyathopharynx. This included descriptions of the detailed morphology of isolated buccal capsules for both species using soft tissue digestion, notably for the first time for P. (P.) pseudolaeviconchus. The morphology of isolated spiculae of both species was described for the first time using SEM. Molecular analyses included genetic characterisation of the small ribosomal subunit (18S) rDNA and cytochrome oxidase 1 (CO1) mtDNA. Genetic data supported the morphological identification of both species, however, divergence was detected in CO1 mtDNA data for P. cyathopharynx indicating two distinct lineages. Due to this variation, the morphometry of P. cyathopharynx specimens were revisited including statistical re-evaluation. No robust morphological traits were identified to support CO1 mtDNA lineages and all specimens were considered conspecific. In terms of camallanid biodiversity in the Crocodile River system, it is similar to that in Boomker (1982), despite the altered water quality from past acid mine pollution in the river.

Helminth parasites of cultured Clarias gariepinus and Tilapia zillii in Uyo, Akwa Ibom State, Nigeria

The study examined helminth parasites of cultured Clarias gariepinus and Tilapia zillii in Uyo, Akwa Ibom State. A total of 60 fish samples (30 each of C.gariepinus and T. zillii) were subjected to parasitological examinations. Results revealed a total of 47(78.33%) fishes infected with various species of parasites: Nematodes (Camallanus polypteri, Paracamallanus cyathopharynx, and Procamallanus laevionchus), Cestodes (Polyonchobothrium torulosus and P. clariae) and Trematodes (Dactylogyrus extensus and Glossiduim pedatum) in decreasing order of abundance. Out of the 60 fish samples examined, 47 were infected with 219 parasites: 142(64.84%) nematodes, 40(18.26%) cestodes and 37(16.89%) trematodes. A total of 159(72.60%) parasites were recovered from C. gariepinus out of which 103(64.78%) were nematodes, 19(18.45%) were cestodes and 37(35.92%) were trematodes. While 60(27.40%) parasites were recovered from T. zilli, of which 39(65.00%) were nematodes and 21(35.00%) cestodes. No trematode was observed in the tilapia. The overall prevalence of parasitic infection was 78.33%. The results of chi square analysis showed that females of both species had significantly higher (P<0.05) prevalence of infection 27(84.4%) than males 20(71.4%). Also, C. gariepinus had higher infection rate of 25(83.33%) when compared to 22(73.33%) recorded in T. zillii.
 Key words: fish parasites, aquaculture, prevalence, C. gariepinus, T. zillii

English

The study was carried out between September 2011 and August 2013, using 328 Clarias gariepinus in Oba reservoir, Oyo State, Nigeria. Standard methods were used to determine gonado-somatic index (GSI), fecundity values, and enteroparasitic infestation of the fish. Sex ratio was 1.3:1, male to female, and females on an average invested 20.54% of its body weight in egg production while male GSI was 6.05 ± 0.19%. Spawning was prominent in rainy season; the fish was highly fecund (31,169 eggs) with relative fecundity of 222 ± 10 eggs per gram weight of fish. Fecundity correlated linearly (positive) with gonad weight, body weight, total length and GSI. Over fishing, led the fish to invest its body weight and growth in egg production, to increase and enhance its chances of survival. Parasites recovered were Procamallanus laevionchus, Paracamallanus cyathopharynx, Anomotaenia species, Monobothrium species, Polyonchobothrium clariae, and Neoechinorhynchus rutili. Prevalence and intensity were higher in female than in male and more in dry than rainy season. Parasitic infestation reduces weight growth in the fish; this influenced the values of reproductive indices in which body weight was a numerator or denominator. Keywords: Clarias gariepinus, enteroparasites, fecundity, gonado-somatic.

Nematode infections of Clariid and Claroteid catfish species in River Galma, Zaria, Nigeria

Two clariids, Heterobranchus bidorsalis (65) and Heterobranchus longifilis (15), and two claroteids, Auchenoglanis occidentalis (31), and Chrysichthys auratus (19) from River Galma were examined for gastrointestinal nematodes from May 2016 to February 2017. Overall, five species of nematodes were recovered from the clariids and claroteids. The nematodes were distributed as follows: in Heterobranchus bidorsalis, Procamallanus laevionchus (12.31%), Paracamallanus cyathopharynx (9.23%) and Rhabdochona sp. (1.54%); in Heterobranchus longifilis; Paracamallanus cyathopharynx (6.67%); in Auchenoglanis occidentalis: Procamallanus laevionchus (25.81%); in Chrysichthys auratus: Procamallanus laevionchus (5.26%), Contracaecum sp. (5.26%) and Spirocamallanus spiralis (15.79%). Nematode prevalence in C. auratus was higher in the wet than in the dry season; however, prevalence of infection in A. occidentalis, H. longifilis and H. bidorsalis was higher in the dry than in the wet season. Prevalence of nematode infection was also higher in male than in female H. longifilis while it was higher in female A. occidentalis, C. auratus and H. bidorsalis than males of the same species. Nematode prevalence was higher in larger (24.0-31.9cm) Heterobranchus bidorsalis and Auchenoglanis occidentalis. Prevalence of infection was higher in smaller (8.0- 15.9cm) Chrysichthys auratus. It is recommended that a larger sample size of especially Heterobranchus longifilis and Chrysichthys auratus, of which only 15 and 19 specimens respectively, were examined during the period of this study, be examined, to have a clearer picture of their infection by nematodes in River Galma.
 Keywords: Nematode; catfish; clariid; claroteid; infection; prevalence.

Additional Morphological Features and Molecular Data of Paracamallanus cyathopharynx (Nematoda: Camallanidae) Infecting Clarias gariepinus (Actinopterygii: Clariidae) in Kenya

This study provides additional taxonomic features based on scanning electron microscopy (SEM) and molecular data for Paracamallanus cyathopharynx ( Baylis, 1923 ) (Nematoda: Camallanidae). Parasites were collected from the posterior end of the intestine of cultured freshwater Sharptooth catfish Clarias gariepinus (Burchell, 1822) from Kibos fish farm, Kisumu County, Kenya, from December 2017 to March 2018. Additional taxonomic features recorded for P. cyathopharynx include the occurrence of 4-5 equal length digitate processes on the caudal end of the female, 4 processes (2 smaller and 2 larger) on the male caudal end, and a description of the shape of the distal tip of the right spicule. The study provides SEM images of the exposed sclerotized buccal capsule. This gives more information on the tridents, the sclerotized plate that extends laterally from the buccal capsule, and the narrow isthmus separating the anterior buccal capsule from the posterior. The prevalence, intensity, mean intensity, and mean abundance was 52.91%, 2-38, 12.37 and 6.54, respectively. 18S rDNA fragments were amplified, sequenced, and compared to other camallanid taxa, and 18S data confirmed the identity of the newly obtained sequences (MN396556) as that of P. cyathopharynx, being identical to sequence DQ813445 from Tanzania. This represents the first geographical record of P. cyathopharynx in Kenya.

Novel information on the morphology, phylogeny and distribution of camallanid nematodes from marine and freshwater hosts in South Africa, including the description of Camallanus sodwanaensis n. sp.

Four species of previously known nematodes from the family Camallanidae were found from different hosts in South Africa: Batrachocamallanus xenopodis from the frog Xenopus muelleri, Paracamallanus cyathopharynx and Procamallanus pseudolaeviconchus from the catfish Clarias gariepinus and Spirocamallanus daleneae from the catfish Synodontis zambezensis. In the material collected from various marine fishes, several specimens of nematodes from the genus Camallanus clearly differed from all previously known species. Based on morphological differences these specimens are assigned to a new species, C. sodwanaensis. Molecular data of 18S and 28S rDNA and COI sequences are provided for the collected species and a phylogenetic analyses based on 28S gene fragmets are presented.

Morphometric Indices and Enteroparasitic Infestation of <i>Clarias gariepinus</i> (Burchell, 1822) in a Tropical Reservoir

The study was carried out using 328 Clarias gariepinus specimens over a period of two years, from Oba reservoir (08°3'N to 08°12'N and 004°6'E to 004°12'E) Ogbomoso, Oyo State, Nigeria. Standard methods were used to determine length-weight relationship, condition factor, and enteroparasitic infestation of the fish in the reservoir. Generally, Fish growth was positively allometric, while infested male and female fishes had negative allometric growth. The general well-being of the male fish was better than that of the female fish. Smaller sized fishes were better adapted to the ecological conditions of the reservoir than the bigger fishes. Parasites recovered were two Nematodes (Procamallanus laevionchus, Paracamallanus cyathopharynx), three Cestodes (Anomotaenia sp. Monobothrium sp., Polyonchobothrium clariae), and one Acanthocephalan (Neoechinorhynchus rutili). Sex ratio was 1.3:1 (male: female). Parasitic prevalence and intensity in the fish were sex and season dependent. The effect of enteroparasites in the life of infested C. gariepinus was found to probably be a major factor responsible for the low percentage of good fit to the line of regression (R2) in females. Infestation also led to loss of weight in infested fishes and this affected morphometric values in which body weight was an index.

PREVALENCE OF GASTROINTESTINAL PARASITES INFECTING FISH (CLARIAS GARIEPINUS) IN QENA GOVERNORATE

Parasites of fish are of concern since they often produce a weakening of the host`s immune system thereby increasing their susceptibility to the secondary infections, resulting in the nutritive devaluation of fish ,compete for food, depriving fish of essential nutrients, inhibiting growth leading to morbidity and mortality and subsequent economic losses. Few data has been reported to identify major parasite of fish in Qena Governorate, Egypt. Accordingly,the study aimed to estimate the prevalence of gastrointestinal parasite infecting fish. Afield study was conducted during the period from the beginning of January 2015 to the end of December 2016.A total of 144 Clarias gariepinus (Carmoot) fish samples were collected either alive from fishermen or fresh as possible from fish markets at Qena Governorate for parasitological studies. Parasite collected and prepared then identified under the microscope. Out of 144 examined fish 84 (58.3%) samples were infected with different gastrointestinal parasites. The obtained results found that the most frequent parasitic infection among examined fish was cstodes with an infection rate of (35.4%) ,followed by trematodes infection (27%), while the lowest infection rate, were recorded in nematodes infection(16.7%),Regarding to the seasonal prevalence of the recovered parasites, we concluded that the highest rate of parasite infection was observed during Spring season (83.3%), followed by Winter (66.7%), Summer recorded (50%) and Autumn season which represented the lowest rate of infection (33.3%). The most common species of cestodes were Monobothrium sp which recorded the highest infection rate (27.8%) and Polyonchobothrium clarias (5.6%), followed by trematode species Orientocreadium batrachoides (24.3%) and nematode species Paracamallanus cyathopharynx (10.4%) and Procamallanus laevionchus (5.6%).

INTESTINAL HELMINTHS INFECTING THE CATFISH, CLARIAS LAZERA IN RELATION TO SEASONAL VARIATIONS AND SOME BIOLOGICAL FACTORS

The present study aims to investigate the relationship between the occurrence of helminths infecting Clarias lazera and the seasonal variations. Moreover, the relationship between helminthes and host length and sex was studied. C. lazera fish were collected from Ismailia canal (Ismailia city) and examined for intestinal helminths. The total species recorded were three trematodes (Allocreadium sp, Astiotrema reniferum and Orientochreadium batrachoides); two cestodes (Monobothrioides sp and Polyenchobothrium clarias) and two nematodes (Procamallanus laeviconchus, Paracamallanus cyathopharynx). The highest prevalence of infection was observed in winter (72.5%), while the lowest was recorded in summer (52%). Prevalence of infection with intestinal helminthes was higher in males than in females. The medium-sized and large fish showed the highest prevalence and intensity of infection, while the small fish showed low infection rates. Further studies are recommended on C. lazera helminths taking in to consideration the effect of seasonal variations, length and sex of the fish on the prevalence and intensity of infection along Ismailia canal.

English

This study aimed to investigate the diversity, abundance, intensity, and seasonal distribution of parasites of Oreochromis niloticus. A total of 254 specimens of O. niloticus was sampled in Loumbila and Ziga reservoirs in both rainy and dry season and examined for parasites. The total prevalence was 55.90% and the highest seasonal prevalence, abundance and intensity were observed during the rainy season. Recorded parasites were the myxozoan Myxobolus tilapiae, the copepode Lamproglena monodi, the monogeneans Cichlidogyrus tilapiae, Cichlidogyrus halli, the digenetic trematode Clinostomum species, the nematode Paracamallanus cyathopharynx, and the acanthocephalan Acanthogyrus tilapiae. The latter species had higher prevalence (45.67%) and high abundance. L. monodi, C. tilapiae, C. halli, and P. cyathopharynx were only observed in Loumbila reservoir. A. tilapiae, Clinostomum spp. and M. tilapiae were found in both reservoirs with a high abundance. In conclusion, it was found out that O. niloticus specimens were heavy infection with a broad number of parasites. This situation could eventually reduce performance and productivity of the species, especially in aquaculture. Key words: Oreochromis niloticus, parasites, Loumbila reservoir, Ziga reservoir, Burkina Faso.

Studies on some spirurids (Nematoda: Spirurida) from fishes of the Okavango River, Botswana.

Based on light and scanning electron microscopical studies, three adult spirurid nematode species, Camallanus (Zeylanema) ctenopomae Vassiliadès & Petter, 1972, Paracamallanus cyathopharynx (Baylis, 1923) (both Camallanidae) and Spinitectus polli Campana-Rouget, 1961 (Cystidicolidae), are redescribed from specimens collected in fishes of the Okavango River, Botswana: C. (Z.) ctenopomae from Ctenopoma sp. (Anabantidae), P. cyathopharynx from Clarias stappersi Boulenger, C. theodorae Weber (both new hosts, Clariidae) and C. gariepinus (Burchell), as well as S. polli from Synodontis nigromaculatus Boulenger (new host, Mochokidae). Moreover, spirurid larvae of an additional three species were found in fishes from the same locality: Rhabdochona paski Baylis, 1928 fourth-stage larva (Rhabdochonidae) in S. nigromaculatus (Mochokidae), Physalopteridae gen. sp. 1 third-stage larva in C. gariepinus (Clariidae) and Physalopteridae gen. sp. 2 third-stage larva in Serranochromis angusticeps (Boulenger) (Cichlidae), all representing new host and geographical records. Spinitectus zambezensis Boomker, 1993 is considered a junior synonym of S. polli.

STUDIES ON NEMATODE PARASITES INFECTING FRESHWATER FISH IN QENA GOVERNORATE

The present study was carried out to make a spot light on nematode parasites infecting Freshwater fish at Qena Governorate; including prevalence, seasonal dynamics of infection; intensity and morphology of the recovered parasite species. It was found that the infection rate of different nematode among fresh-water fish in Qena Governorate was (13%). Lates niloticus has highest infection rate (27.8%) followed by Carias gariepinus (8.3%) the Oreochromis niloticus (2.3%). Concerning the seasonal prevalence Winter has highest infection rate followed by Autumn then Summer and Spring. Four nematodes were recovered and identified as Paracamallanus cyathopharynx (2.8%) in Clarias lazera; Procamallanus laevionchus (2.8%) in Clarias lazera; Contracaecum sp. (2.8%) in Oreochromis niloticus and Clarias lazera and (26.4%) in Lates niloticus and Dichelyne niloticus (4.2%) in Lates niloticus. The mean intensity of infection of Contracaecum sp. among Oreochromis niloticus., Clarias gariepinus and Lates niloticus was 2%, 22% and 20% respectively.

Metazoan parasite communities of catfishes (Teleostei: Siluridae) in Benin (West Africa).

The need for more precise information on the effect of dry season on fish parasite communities in Benin lead us to undergo a focus during this season in one of the major sites of collection fry by fish farmers.Metazoan parasites were then inventoried in 166 specimens of catfishes which constituted of C larias gariepinus, Clarias ebriensis, Synodontis schall, Synodontis nigrita, and Chrysichthys nigrodigitatus (Teleostei: Siluridae). Those fishes were collected from fishermen of Agonlin-Lowé at the side of Oueme River in south Benin from November 2011 to March 2012. In total, 12 parasite species were listed comprising three Monogena (Gyrodactylus sp., Synodontella sp., and Protoancylodiscoides chrysichthes), three Cestoda (Stoeksia pujehuni, Lytocestus sp., and Cestode indeterminate), five Nematoda (Paracamallanus cyathopharynx, Procamallanus laevionchus, Cithariniella petterae, Synodontisia thelastomoides, and nematode indeterminate), and one indeterminated Copepod species. Total infestation rate varied between 83.87 and 100% for the different fish species. This was high but independent of fish sex (χ(2) = 1.669, df = 4, nonsignificant). The highest mean intensity and mean abundance were, respectively, 44 and 13.33. Monogenea and Nematoda have elevated frequency of dominance, and their presence in the host is significantly correlated (r = -0.999; p < 0.05). Clariids were highly infected by Nematoda. Except for P. laevionchus and Proteoancylodiscoides, respectively, in C. gariepinus and in C. nigrodigitatus, the parasites showed clumped distribution. The component community diversity, as measured by the Shannon index (H'), revealed that S. schall had the most parasite diversity.

English

The study was carried out in Erinle Reservoir accessed through Oore (Latitude 7&deg; 58&#39; 12&quot; North; Longitude 4&ordm; 33&#39; 36&quot; East), in Osun State, Nigeria, between August 2011 and November 2013. A total of 103 live fishes purchased from local fishermen were examined. In the laboratory, morphometric parameters&nbsp; were measured, the sexes determined and the fish species Clarias gariepinus were dissected to separate the alimentary system. Parasites recovered were identified and counted and the data were subjected to statistical analyses. The parasites recovered were Procamallanus laevionchus, Paracamallanus cyathopharynx (Nematodes.), Anomotaenia sp., Monobothrium sp., Polyonchobothrium clariae. (Cestodes) and Neoechinorynchus rutili (Acanthocephalan). Using a non parametric (NPar) (Kolmogorov-Smirnov; K-S) test, infection was significant at p = 0.05 within seasons, and female fishes were more infected than male. Monobothrium sp. had the highest range of infection (0 to 44) and intensity (18.5&plusmn;2.65) while Anomotaenia sp. had the least (0 to 1) and (1.00&plusmn;0.02) respectively. Six parasites were found in the intestine, while four were in the stomach. There was high prevalence in medium and large sized fish and a direct linear relationship exist between length and intensity. The body weight was significant in relation to infection at p = 0.05 (K-S test) and was also significant in sex. Multiple infections were common, which showed a positive correlation between most of the parasites except Anomotaenia sp. which showed negative correlation with P. clariae. &nbsp; Key words:&nbsp;Clarias gariepinus, morphometric, parasite, prevalence. &nbsp; &nbsp;

Helminth Parasites of Clarias gariepinus (Clariidae) in Lekki Lagoon, Lagos, Nigeria

A total of 360 randomly selected specimens of Clarias gariepinus (Clariidae) recovered from Lekki Lagoon were examined for intestinal helminth parasites. Parasite prevalence and worm burden were low; 17 (4.72%) of the specimens examined were infected with gastrointestinal helminths. The helminth worms recovered include, three cestodes Polyonchobothrium clarias, Stocksia pujehuni and Wenyonia acuminata and a nematode, Paracamallanus cyathopharynx. There was no statistically significant difference in the infection of the male and female Clarias gariepinus; the infection rates in male and female samples were 5.75% and 3.76% respectively. Parasite prevalence was related to the length and weight of the specimens. The fish samples were observed to show negative allometric growth and smaller samples recorded higher helminth infection.

Multiple Infections of Helminths in the Stomach and Intestine of Clarias Gariepinus (Burchell, 1822) In Oba Reservoir, Oyo State, Nigeria.

The study was carried out in Oba reservoir,( 8° 3to 8° 12N and 4° 6to 4° 12E in Oyo state, Nigeria.) between August 2011 and November 2013. A total of 246 live fishes (Clarias gariepinus),purchased from local fishermen were examined. In the laboratory, morphometric parameters were measured, sexes determined and fishes were dissected to separate the alimentary system. Parasites recovered were identified and counted; data were subjected to statistical analyses. Parasites recovered were Procamallanus laevionchus, Paracamallanus cyathopharynx (Nematodes.), Anomotaenia sp., Monobothrium sp., Polyonchobothrium clariae. (Cestodes) and Neoechinorynchus rutili (Acanthocephalan).Using non parametric (NPar), Kolmogorov-Smirnov (K-S) test, infection was significant (p = 0.05) within seasons, and females were more infected than males. Prevalence was 46.34%. Monobothrium sp. had the highest range of infection (0 - 32) and intensity (21.98+2.08) while Anomotaenia sp. had the least (0 - 1) and (1.00+0.01) respectively. Six parasites were found in the intestine, while four were in the stomach. Fishes of small sizes (< 10cm) and small weight (< 20g) were not infected; there was high prevalence in medium and large sized fish and a direct linear relationship exist between length and intensity. Body weight was significant (K-S; p = 0.05) in relation to infection and sex. Multiple infections were common, which showed a positive correlation (Spearman) between most of the parasites except Anomotaenia sp. which showed negative correlation with P. clariae.

The Occurrence of Metazoan Endoparasites ofSchilbe intermediusRüppell, 1832 from the Nwanedi-Luphephe Dams in the Limpopo River System, South Africa

The present study deals with the survey of endoparasites from Schilbe intermedins (silver catfish) at the Nwanedi-Luphephe Dams from July 2009 to May 2010. The hosts (n = 60) were collected using gill nets and examined for endoparasites. The following parasites were recorded: three species of trematodes, i.e. Clinostomum metacercariae in the body cavity (prevalence 40%), an unidentified adult digenean in the small intestine (prevalence 33.3%) and Diplostomum metacercariae from the eye (prevalence 1.7%), and two species of nematodes, i.e. Contracaecum larvae in the body cavity (prevalence 95%) and Paracamallanus cyathopharynx from the intestine (prevalence 63.3%). None of the fish examined during this study was in a notably poor state of health due to parasitism. Correlations between endoparasite infection and host size, as well as seasonal variation in their infection dynamics associated with environmental changes, were detected.