Investigation of nematode Eustrongylides larvae infections in mudfish Clarias gariepinus and C. anguillaris from Bida floodplain of Nigeria

This is the first report and record of the determination whether mudfish Clarias were infected with the larvae of the nematode Eustrongylides. Also, documented the assessment of the socio-economic perceptions of three groups of fisher folks on the economy of infected mudfish Clarias fishing activities. Fifty-six (67.5%) of 83 mudfish Clarias caught by artisanal fisher folks were examined for the presence of the larvae of the nematode Eustrongylides. All the 8 sampled fishing localities in Bida floodplain of Nigeria had a mean intensity and abundance of at least 3 and 1 worm per fish per site, respectively. Two hundred and one (96.2%) of 209 worms recovered were from the musculatures at different depths resulting in undulations on the skin surfaces as grub-like presentations. The three groups of fisher folks assessed encountered economic losses from nematode infected mudfish Clarias which attract much debates or rejections during marketing due to its aesthetically displeasing appearance, faster deterioration, higher fragility in smoked form coupled with poorer taste compared to the wholesome ones. Infected female mudfish Clarias had higher worm burden than the males, for each fishing locality

Saprolegnia infections of salmonid fish

This paper deals firstly with the identification and characteristics of fungal pathogens that colonize salmonids and then considers the relative importance of the condition of the host fish and the environmental factors which may influence the interaction between pathogen and host.

Pathology of mixed infections of saprolegniasis-myxosporidiosis in Indian major carp (Catla catla Ham.)

An outbreak of saprolegniasis in Catla catla in composite carp culture ponds were recorded during winter season. The typical cotton wool growths were observed on whole body surfaces of catla along with sporadic mortality. The fungal invasion was only restricted to skin and no fungal elements were visible in any internal organs after periodic acid schiff staining. On histology, periportal accumulation of mononuclear cells in liver, presence of myxosporidean cysts in antieror kidney, eosinophilic granular cells reaction in submucosa of stomach and intestine, dilated and engorged blood vessels of brain along with sloughing of epidermis and hyperplasia at gill lamellar base were pronounced changes. The possible role of release of Saprolegnia toxin in producing internal organs pathology has been discussed.

Bacteriological investigations of prawn canneries 2. Incidence of Clostridium perfringens

Prawn processing factories of the three major fish processing centres of the West Coast of India, viz., Cochin, Mangalore and Calicut were surveyed to determine the occurrence of Clostridium perfringens in processing areas, and in processed products. Direct plating on Sulphite-polymyxin- sulphadiazine Agar and enrichment techniques were used. Samples of prawn, prawn guts, frozen prawns, canned prawns, water, ice, swab from utensils and soil from the factory premises were examined. Among a total of 461 samples examined, only 32 (6.9%) gave positive results. The incidence of C. perfringens was more in prawn guts (80%), followed by soil (50%), prawn (38%), ice (33.3%), frozen prawns (11%), swab (5.0%) and water (1.1%). No C. perfringens was isolated from canned prawns.

Incidence of Clostridium perfrigens in fishes

Fish collected from local landing centres and also from local markets were examined for the presence and enumeration of Clostridium perfringens. A medium described by Beerens et al. (1982) was used for the detection and enumeration of C. perfringens. C. perfringens occurs in low numbers in fishes compared to prawns. Proper handling of fishes after landing can reduce the chance of any public health hazard by C. perfringens.

Comparison of media and methods for the detection and enumeration of Clostridium perfringens in seafoods

Three direct plating methods and two most probable number (MPN) procedures were compared for the enumeration of Clostridium perfringens in seafoods the sulfitecycloserine (SC) agar, sulfite-polymyxin-sulfadiazine (SPS) agar, tryptone-sulfite- neomycin (TSN) agar, LS medium MPN procedure and iron milk MPN procedure. Isolates were confirmed as C. perfringens. The two MPN procedures compared very well with the three plating media tested with stock culture of C. perfringens from our laboratory collection and the reference strain NCIB 6125. But in fish samples, the two liquid media were found to be more sensitive and hence the MPN procedure using LS medium for the detection of C. perfringens in seafoods is suggested.

Summary study of gill ectoparasite infections and their histopathologic effects in four species of freshwater ornamental fishes

Ornamental fish are more expensive in comparison with the other fish. It especially highlights in non-breeding fish (in imported one for importation costs). But of course, with entering the new and unhealthy fishes to aquarium or ponds, they may transmit a pathogen to others (interfere with Iran ornamental fish parasitic fauna). In this study (Dec. 2008- Sep. 2009), 400 fish gill arch from 4 species of ornamental fish (within focus on imported fish); namely, i.e. Goldfish (Carassius auratus), platyfish (Xiphophorus maculatus), Dwarf gourami (Colisa lalia) and Catfish (Hypostomus plecostomus) were inspected for gill ectoparasites and then pathologic effects (but in high- affected gill). In this study, seven protozoan and ten metazoan species, indeed seventeen parasite species were identified. Protozan parasites consist of: Trichodina spp. and Ichthyophthirius multifiliis were found in four fish species; Ichthyobodo necatrix (Costia necator/C. necatrix) and Cryptobia branchialis, were respectively found in Dwarf gourami and goldfish. The highest prevalence belongs to Ichthyophthirius (47%) in platyfish. Metazoan parasites consist of: Ancyrocephalus sp. (Dwarf gourami), Ancylodiscoides spp. (catfish and platyfish), Dactylogyrus vastator, D. baueri, D. formosus (only in goldfish) and Gyrodactylus spp. (in four fish species). The highest prevalence was related to Dactylogyrus vastator(82%) in goldfish. Histological effects in case with high prevalence of parasite were also observed, e.g., hypertrophy, Lamellar hyperplasia and fusion. In high-parasitized gill, there is dysfunction of gill.