Quality assessment of rotating and solar tunnel dried marine fish product

Studies were conducted to evaluate the quality aspects of marine dried fish i.e. silver jew fish (Johnius argentatus), Bombay duck (Harpodon nehereus) and ribbon fish (Trichiums haumela) products produced in rotating and solar tunnel dryers. On the basis of organoleptic characteristics such as colour, odour, texture, broken pieces, insect infestation and overall quality, four member panels of experts evaluated the quality of the dried products obtained from both rotating and solar tunnel dryers and all the products were found in acceptable quality. Reconstitutions properties of samples were in the range of 51.05 to 98.75% for the dried fish produced in rotating dryer, while 24.64 to 76.76% for dried fish produced in solar tunnel dryer. The highest reconstitution rate was found in dried silver jew fish and lowest in ribbon fish produced in rotating dryer. On the other hand, the highest reconstitution was observed in dried silver jew fish and lowest in dried Bombay duck produced in solar tunnel dryer. Proximate composition such as moisture, crude protein, lipid and ash content of the dried fish muscles produced in rotating dryer ranged from 16.36% to 19.1%, 62.35% to 67.37%, 6.37% to 10.75% and 7.00% to 8.05%, respectively and in solar tunnel dried fish products, they were in the range of 14.05% to 19.71%,57.64% to 69. 21%,6.92% to 15.40%and 7.69% to 8.80 %, respectively. The TVBN values of dried fish products obtained from rotating dryer were in the range of 15.02 to 19.05 mg/100g, while in solar tunnel dried fish products, the values were in the range of 15.46 to 19.21 mg/100g. The results of the studies indicated that dried fish produced from both rotating and solar tunnel drier were acceptable quality in terms of organoleptic and food quality aspects.

Preparation of smoke cured fillets from oil sardine

A method of preparation of smoke cured fillets of oil sardine is described. Various procedural steps like brining, smoking, packaging etc. have been described and the shelf life assessed. Sodium propionate treatment is recommended to enhance storage life; BHA to control rancidity; and thermal treatment to overcome the insect infestation. The product has good consumer appeal.

Preparation of mussel meat by drying

The paper describes a simple and cheap process for the preservation of mussel meat by drying. The method involves blanching the mussel meat shucked from purified live mussels in 5% boiling brine for 5 min followed by drying to moisture of 10 to 15%. The product stored in glass bottles or polythene bags suitably sealed, has a storage life of about six months after which the organoleptic qualities begin to deteriorate. No preservative is used at any stage of processing and the yield of the product is approximately 20%. The major type of spoilage during storage is brown discoloration. Spoilage due to insect infestation is also common unless packed properly.

Quality characteristics of cured fish of commerce

A survey was conducted at the fish curing yards at Shakthikulangara (Quilon), fish market at Vizhinjam, fish curing yards, fish market as well as dry fish godowns in and around Tuticorin. A total of 23 samples of different varieties of fishes collected from the markets and curing yards and 8 samples of anchovies collected from different godowns at Tuticorin were analysed to evaluate the quality and extent of fungal and insect infestation. Samples were analysed for proximate composition and estimated their water activity. About 70% of the 23 samples of different varieties of fish were found to be unfit for consumption and 12.5% of the samples of anchovies were found to be infested with beetle, after 3 weeks of storage after collection from these centres.

Distribution, prevalence and intensity of protozoan and monogenean parasites of carp fingerlings in selected nursery ponds

An experiment was carried out on the distribution, prevalence and intensity of infestation of protozoan and monogenean parasites of carp fingerlings in two selected areas of Bangladesh. Six hundred and forty fingerlings of seven species viz. Catla calla, Hypophthalmicthys molitrix, Labeo rohita, Ctenophalyngodon idella, Cyprinus carpio, Barbodes gonionotus and Cirrhinus cirrhosus from different nursery ponds of Shambhuganj, Mymensingh, and Santaher, Bogra were examined during this investigation. This study revealed that carp fingerlings carried a large number of protozoan and monogenean parasites. Different protozoan parasites viz Trichodina domerguei, Trichodina reticulata, Myxobolus koi, Chilodonella cyprini and monogenean parasites such as Dactylogyrus extensus, Dactylogyrus catlarius and Dactylogyroides tripathi were identified in the experimental fishes throughout the study period. It has been observed that distribution, prevalence and intensity of parasite in carp fingerlings are species and zone specific. In case of C. cirrhosus, the highest prevalence of protozoan parasite viz Trichodina domerguei were 93.75% and 75.92% in Santhahar and Shambhuganj area respectively. Irrespective of host, the most prevalent ectoparasite was Dactylogyrus extensus, followed by Myxobolus koi, Chilodonella cyprini and Dactylogyroides tripathi. Relatively higher mortality of carp fingerlings was found at younger stage. The highest prevalent parasitic species was identified as Trichodina domerguei followed by Trichodina reticulata and Dactylogyrus catlarius were found 93.75% in Cirrhinus cirrhosus, 68.75% in Cyprinus carpio and 39.44% in Hypophthalmicthys molitrix respectively.

Occurrence of Zoothamnium sp. infection in Penaeus monodon (Fabricius, 1798) of the coastal shrimp culture ponds of Cox's Bazar Bangladesh

Penaeus monodon (Fabricius, 1798) is a popular cultivable species and valuable foreign exchange earning item among all the fishery commodities in Bangladesh. At present with semi-intensive and intensive shrimp culture practices, disease is a problem. Protozoan infection, caused by the Zoothamnium sp. is one of the causes of damage in the total production by growth retardation and mortality. No work has yet been done on shrimp disease in Bangladesh. The present account therefore, constitutes the first report on it from the shrimp culture ponds of Cox's Bazar. The present work includes the occurrence and prevalence of protozoan disease, its seasonal variations and level of infestation in different length groups in Penaeus monodon.

Management of water hyacinth, Eichhornia crassipes, in Lake Victoria Basin

Water hyacinth is a free-floating waterweed native to the Amazon River Basin in South America. In its native range, water hyacinth is not an environmental problem, although the weed is one of the most invasive alien plants in freshwater environments. Water hyacinth has the potential to become invasive through fast vegetative reproduction and rapid growth to accumulate huge biomass and extensive cover in freshwater environments. Over the last 150 years water hyacinth has invaded most countries in the tropics and sub-tropics, introduced by man, mainly for ornamental purposes. Such introductions led to the infestation of most freshwater-ways in the southern United States of America, parts of Australia, the pacific islands, and most countries in Asia and Africa. The extensive tightly packed mats of water hyacinth are often associated with devastating socio-economic and environmental impacts. Invasion by the weed has, therefore, often generated urgent costly problems associated with the weed biomass and its management. A classic example of such problems was triggered by the invasion and proliferation of water hyacinth in the Lake Victoria Basin during the 1980s (Freilink 1989, Taylor 1993, Twongo et al., 1995). The weed infestation marked the beginning of a decade of intensive and systematic campaign by the three riparian states (Kenya, Tanzania and Uganda) to bring weed proliferation under control. The discussions in this Chapter span over ten years of dealing with the challenges paused by the imperative to manage infestations of water hyacinth in the Lake Victoria Basin. The challenges included the need to understand the dynamics of water hyacinth infestation; its distribution, proliferation and impact modalities; and the development and implementation of appropriate weed control strategies and options. Most specific examples were taken from the Ugandan experience (NARO, 2002).

The water hyacinth problem and the biological control option in the highland lake region of the upper Nile basin: Uganda's experience

The rapid proliferation and extensive spread of water hyacinth Eichhornia crassipes (Mart) Solms in the highland lakes of the Nile Basin within less than 15 years of introduction into the basin in the 1980s pauses potential environmental and social economic menace if the noxious weed is not controlled soon. The water weed has spread all round Lake Victoria and, in Uganda where infes tation is mos t severe, water hyacinth estimated at 1,330,000 ton smothers over 2,000 ha of the lakeshore (August,1994). Lake Kyoga which already constantly supplies River Nile with the weed is infested with over 570 ha, while over 80% of the river course in Uganda is fringed on either side with an average width of about 5m of water hyacinth. As the impact of infestation with water hyacinth on water quality and availability, transportation by water, fishing activities, fisheries ecology, hydro-power generation etc becomes clear in Uganda, serious discussion is under way on how to control and manage the noxious weed. This paper pauses some of the questions being asked regarding the possible application of mechanical and chemical means to control the water weed.Uganda has already initiated the use of biological control of water hyacinth on Lake Kyoga with a strategy to use two weevils namely Neochetinabruchi and Neochetina eichhorniae. The strategy to build capacity and infrastructure for mass multiplication and deployment of biological control of the weevils in the field developed in Uganda by the Fisheries Research Insti tu te (FIRI) and the Namulonge Agricultural and Animal production Research Insti tute (NAARI) is proposed in outline for evaluation. Plans to deploy this strategy on lake Kyoga are under way

The contribution and status of physical removal in sustainable management of water hyacinth

Physical control of water hyacinth consists of removing the plants from the water by hand or machines. It is considered over effetive because it involves removing the whole plants from water. The first attempt on physical control was in 1992 when weed infestation was causing serious problems to the fishing communities in Lake Kyoga. The fishermen had problems of accessing the lake as huge masses of mobile weed blocked landing sites. Furthermore, the fishers lost their nets, which were swept away by mobile water hyacinth. As a result, an integrated control strategy involving physical control (manual and mechanical removal) was put in place. Through this method, the fishers were able to open up access routes to fishing grounds even though weed mats often reblocked the access routes. In the infested lakes, manual removal offered remedial relief to fish Iandings and other access sites. Sites of strategic importance such as hydro-electric power generation dam, water intake points and docking points which had large masses of water hyacinth required heavy machinery and mechanical harvesters were used at these sites.

Aquatic weeds hotspots in the Lake Victoria basin Uganda and on Lake Kyoga: implications for their management

Proliferation of invasive aquatic weeds has developed into a major ecological and socio economic issue for many regions of the world. As a consequence, inference on where to target control and other management efforts is critical in the management of aquatic weeds (Ibáñez et al., 2009). Notwithstanding, aquatic systems in Uganda in general and in the basins of Lakes Victoria and Kyoga in particular, have fallen victims to aquatic weeds invasion and subsequent infestation. If these aquatic weeds infestations are to be minimized and their impacts mitigated, management decisions ought to be based on up-to-date data and information in relation to location of infestation hotspots. Aquatic systems in the basins of the two production systems are important sources of livelihoods especially from fish production and trade yet they are prone to infestation by aquatic weeds. Thus, the invasion and subsequent infestation of aquatic ecosystems by aquatic weeds pose a major conservation threat to various aquatic resources (Catford et al., 2011; Kayanja, 2002). This paper examines the extent to which aquatic weeds have infested aquatic ecosystems in the basins of Lakes Victoria and Kyoga. The information is expected to guide management of major aquatic weeds through rational allocation of the scarce resources by targeting hotspots.

A report on the survey of Lakes Opeta and Bisina to further collect data on presence of Hydrilla verticilata and potential biological control agents

Reports of hydrilla (Hydrilla verticilata) infestation lakes Bisina and Opeta were verbally communicated by some members of FIRRI who undertook surveys during the LVEMP 1 phase (1997 to 2004) to assess the diversity and stocks of fishes in the Kyoga basin satellite lakes. This issue was taken up by FIRRI and NAARI staff who work on aquatic weeds management to ascertain and quantify the presence of H. verticilata and other aquatic weeds, with the sole aim of finding ways and means of controlling one of the world's worst aquatic weeds, H. verticilata.The survey on Lake Opeta indicated that this weed was rare since only a few small broken pieces were sited at the lake's outflow through an extensive wetland to Lake Bisina. It was therefore concluded that it was not economically viable to allocate resources for further survey of H. verticilata on Lake Opeta. This finding therefore discredited the previous (informal) reports that H. verticilata was well established on Lake Opeta. It should be noted that the reports came from scientists who were not well versed with systematics of aquatic plants.

Study of parasites native and introduced species of fish in Caspian Sea

Seven native and introduced species of fish in south east Caspian Sea coast examined for parasite infestation during 2004-2006. Native fishes include Barbus capito, Carassius auratus, Cyprinus carpio, Rutilus frisii kutum, Rutilus rutilus, Stizostidion lucioperca, Alosa caspia persica, 24 ecto and endo parasites were found in different organs of 7 species of fishes of them 2 of the metazoan 12 species of crustacean Lernaea cyprinacea , Lamproglena pukhella nematodea and cestodea parasite were found and identified to species and genus including: Asymphylodora kubanicums, Caryophylaeus fimbericep, Rhabdochona hellichii, Contracecum sp. (larvae), Pronoprymna, Aspidogaster limacoides, Raphidascaris acus, Caryophylaeus laticeps, Rhabdochona hellichi, Clinostomum complanatum, Hysterothylacium sp., Rhipidocotyle illense of the metzoan 9 monogen species were found and identified to species and genus level including Dactylogyrus frisii, Dactylogyrus nybelini, Dactylogyrus extensus, Gyrodactylus sp, Dactylogyrus baueri, D. formosus, Gyrodactylus sprostonae, Gyrodactylus sp, Mazaocraes alosae. One psecies of digenea parasites belonging to Diplostomatidea family comprised Diplostomum Spathaceum. In comprise infestation parasite of fish species Cyprinus carpio, Rutilus frisii kutum with 25 precent and Stizostidion lucioperca with 5 percent showed the highest and lowest in infection between fishes in comprise ecological region rivers with 45 percent and Estuary 16 percent showed the highest and lowest percent of parasite Infection.

Survey on parasites of Rutilus frisii Kutum in South west of Caspian Sea with the emphasis of pathology of Dactylogyrus frisii and morphological identification of Paradiplozoon sp and Anisakis sp

Rutilus frisii Kutum is one of the most precious fish in the Caspian Sea. Investigation of the various aspects of its biocharactristics. Including its parasite fauna and ecological aspects are of prime importance. In this study the farmed kutum fry were on the focus of investigation in various seasons of the year and prior to their being released in the sea. This included also the study on the kutum spawners caught both from liver and the sea. The results were that 17 external and internal parasite species were distinct within different organs which were further identified down to genus and species. The single celled parasites identified included Ichthyophthirius multifilils, Chilodonella hexastica, Chilodonella pisicola, Trichodina sp Along with the monogene parasites that included Paradiplozoon chazaricum, D. rarissimus, D. turaliensis, D. nybelini, Dactylogyrus frisii. Meanwhile Diplostomum spathaceum constituted the single eyed parasites and the intestinal termatode were Aspidogaster limacoides, Asymphyoldora kubanicum as well as Bothriocephalus gowkongeniss as the sestads. The nematodes defrentiated were Raphidascaris acus, Dioctophyma renale, and Eustrongylides excisus followed by Lernaea cyprinacea as a crustacean. In this study, infestations by single celled parasites, crustaceans and sestod were found to be present only among the farmed kutum fry which varied in terms of percentage and intensity of infection as well as the parasite species and season of the year. The highest percentage of infection among kutum fry and spawners in both fresh water and in the sea during all seasons belonged to monogene parasites (33%). This was up to 100% among spawners. Infection caused by nematodes was exclusively detected among riverine spawners (7.5-5%) and the infection by Asymphyoldora kubanicum and Aspidogaster limacoides among Spawners caught at Sea and rivers varied within different seasons of the year. The infestation of Metacercer diplostomum spathaceum among kutum fry was 12% which compared to spawners was in slightly higher level. The study could identify Dioctophyma renale for the first time in the country and Eustrongylidis excisu was also detected among Rutilus frisii kutum.