On new or insufficiently-known Chytridinae [Translation from: Archiv fur Protistenkunde 54 168-173 + pl.9, 1926]

This partial translation of a larger paper provides taxonomic descriptions of 5 fungal zoospores species: Olpidium vampyrellae, 0. pseudosporearum, 0. leptophrydis, Rhizophidium leptophrydis and Chytridium lateoperculatum.

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.

The impact of molecular biology on assessment of water quality: advantages and limitations of current techniques

The advent of molecular biology has had a dramatic impact on all aspects of biology, not least applied microbial ecology. Microbiological testing of water has traditionally depended largely on culture techniques. Growing understanding that only a small proportion of microbial species are culturable, and that many microorganisms may attain a viable but non-culturable state, has promoted the development of novel approaches to monitoring pathogens in the environment. This has been paralleled by an increased awareness of the surprising genetic diversity of natural microbial populations. By targeting gene sequences that are specific for particular microorganisms, for example genes that encode diagnostic enzymes, or species-specific domains of conserved genes such as 16S ribosomal RNA coding sequences (rrn genes), the problems of culture can be avoided. Technical developments, notably in the area of in vitro amplification of DNA using the polymerase chain reaction (PCR), now permit routine detection and identification of specific microorganisms, even when present in very low numbers. Although the techniques of molecular biology have provided some very powerful tools for environmental microbiology, it should not be forgotten that these have their own drawbacks and biases in sampling. For example, molecular techniques are dependent on efficient lysis and recovery of nucleic acids from both vegetative forms and spores of microbial species that may differ radically when growing in the laboratory compared with the natural environment. Furthermore, PCR amplification can introduce its own bias depending on the nature of the oligonucleotide primers utilised. However, despite these potential caveats, it seems likely that a molecular biological approach, particularly with its potential for automation, will provide the mainstay of diagnostic technology for the foreseeable future.

Aphanomycosis of crayfish: crayfish plague

This is the Aphanomycosis of crayfish: crayfish plague report produced by the Environment Agency in 2000. Crayfish plague is an extremely virulent fungal disease of European crayfish species, the white clawed or stone crayfish of Western Europe Austropotamobius pallipes, the Noble crayfish of northern Europe Astacus astacus and the narrow clawed crayfish of Eastern Europe, Astacus leptodactylus. The white claw crayfish A. pallipes is the indigenous native crayfish of the British Isles. Until the early 1980s there were extensive healthy populations of this crayfish in almost all suitable alkaline river and lake environments in England and Wales as far north as Northumberland. The conservation importance of this native crayfish is widely recognised. This report provides a general review of the literature of crayfish plague, including an overview of its spread through the British Isles from CEFAS records. Information on current diagnostic methods from the Office International des Epizooties (OIE) Aquatic Disease Manual is provided. Information on the taxonomy, morphology and physiology of the pathogen is reviewed, together with the pathogenicity and pathology of the disease and current means of prevention and control.

On the trail of interannual variability in phytoplankton and climate [abstract and figures]

EXTRACT (SEE PDF FOR FULL ABSTRACT): A selective but nontheless real record of phytoplankton activity over the Santa Barbara Basin can be obtained from the underlying varved sediments. The phytoplankton groups preserved are: diatoms (frustrules and spores), silicoflagellates, dinoflagellates (cysts) and coccoliths.

Use of homeo drug for curing ulcerative syndrome in fishes

Fungal infection was observed in Catla catla and Labeo rohita cultured in two private fish farms. The later stage of the infection resulted in ulcerations followed by haemorrhage on the dorsal surface of the body. Initially, usual treatments of copper sulphate, potassium permanganate and common salt solution were tried, but no improvement was observed. Then repeated intramuscular injections of homeopathic drug Heaper Sulpher and Arnica spray were given with encouraging results. Infection reported in another farm was also successfully controlled using a similar treatment.

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.

Microbiological quality of some iced fishes of Imphal market, Manipur

Imphal is the main marketing centre of fish in Manipur. As fish production of the state is not sufficient to meet the demands, about 120 metric tons of iced fishes are annually brought from other states and sold in this market. Microbiological quality of iced Wallago attu, Labeo rohita, L. gonius and Aorichthy aor in respect of total fungal count (TFC), total plate count of bacteria (TPC), Most Probable Number (MPN) of coliforms, Streptococci, Staphylococcus, Salmonella and Escherichia coli in four tissues (skin, muscle, gill and intestine) were analysed. In all cases, the counts were highest in the gills and lowest in the muscles. The values of TFC, TPC, coliforms, Streptococci and Staphylococci were 0-10³/g 10(sup)6-10⁸/g, 2-α/g, 10-10⁵/g, 10-10⁵/g respectively. E. coli and Salmonella were not detected in any of the samples while the ice used in the preservation contained 10⁵-10⁷ of TPC per gram. The microbiological qualities of the iced fishes of Imphal market were adjudged poor. The extremely high counts of bacteria might be due to (1) poor quality and left over fishes being packed, (2) contact with contaminated ice and (3) repeated thawing and freezing during the process of marketing and transportation.

Toxigenic molds on fish feeds-1: impact of climatic change

The present communication is a survey report carried out to assess the incidence of toxic mycoflora on seven types of agriculture products/by products incorporated during fish culture as supplementary dietary items. Samples were obtained from various sources at Darbhanga, Madhubani and Samashtipur districts during summer, winter and monsoon months. Out of the total 1774 samples, only 894 appeared to be fresh visually reflecting average incidence of contamination around 46.6%. However, the apparently fresh samples, when subjected to culture, 26.9% of them were found to be contaminated. Thus, degree of fungal spoilage in feed ingredients in parts of north Bihar appears to be significantly high (73.5%). The present study illustrates the facts with special reference to Aspergillus flavus, A. parasiticus (elaborating aflatoxins) A. ochraceous, Penicilium viradicatuin (elaborating ochratoxins) and A. versicolor (elaborating sterigmatocystin). The other strains already known for their toxigenic potentials that appeared on the present substrates included A. niger, A. fumigatus, A. candidus, P. islandicum, Rhizopus spp. and Mucur spp. Studies indicate that the prevalent climatic factors like temperature and relative humidity facilitate a congenial condition almost all through the year and in particular during summer and monsoon months. But water content of the substrates is a vital factor that further accelerates the pace of mycobial spoilage. A thorough sun-drying of the agricultural commodities before prolonged storage to bring water content below the "low risk limit" may significantly reduce the incidence of molds.

Survey on the quality of Jaadi available [in] Sri Lankan market

A quality of survey was conducted at the fish curing yards in a northwest coast and the southern coast in Sri Lanka. A total of 40 samples different varieties of fishes were collected from the market and jaadi curing yards and all were evaluated for the quality, fungal and insect infestation. Samples were analyzed for proximate composition chemical, microbiological and sensory quality. Thirty percent of the total analyzed samples of fish were found to be unfit for consumption. Samples collected from Negombo were found to the infected with maggots. Only 42% samples had dry matter above 50%. All the samples showed a protein content above 20%. The highest protein content was 27.92% in hurulla. Over 90% of the samples had TVN at acceptable quality limits (>40). The TBC for 33% of the samples were in the range 104-105/g range, while 48% were in the range of 107-108/g due to contamination of maggots and fungi. The Survey showed jaadi had a high level of protein in its composition. But defects of curing process such on imperfect cleaning inadequate salting resulted in low (Chemical and microbiological) quality of the product.

Histopathological studies of EUS affected shing, Heteropneustes fossilis (Bloch) from a fish farm of Mymensingh, Bangladesh

An investigation was carried out to observe histopathological changes in liver and kidney of suspected epizootic ulcerative syndrome (EUS)-affected shing fish, Heteropneustes fossilis (Bloch) collected from the "Agro-3 fish farm" situated at Boilor, Trishal, Mymensingh. Focal necrosis, haemorrhages and atrophy of the sinusoidal region were observed in the liver tissue. Fungal granulomas were found both in liver and kidney. In some cases fatty depositions were observed in all over the hepatic tissue. Degeneration and necrosis of renal tubular epithelial cells were also occurred. Missing of glomerulus and necrosis surrounding the Bowman's capsule in the kidney tissue were found.

Tolerance of Penaeus monodon larvae to cupric sulfate added in bath

Copper is used to deter the growth of bacterial, fungal and protozoan disease organism in fishes. Zoeae (Z SUB-1 ), myses (M SUB-1 ) and postlarvae (P SUB-1 ) were exposed to copper sulfate at concentrations of 0 . 025, 0 . 05, 0 . 75, 0 . 1 and 0 . 2 ppm from 24 to 96 hours. The number of surviving larvae were counted at the end of each 24-hour period and the percentage of survival is determined for each dose level. The LC SUB-50 for each of the larval stages was interpolated from the data whenever possible. Three trials with 2 replicates per trial were conducted. The physico-chemical characteristics of the bath taken before and at the end of the experimental period show insignificant differences between initial and final values in each trial. Results indicate that mortality rates of all larval stages increased with exposure time and that mortality rates of the experimental group is higher than the control. Interpolation of the LC SUB-50 is possible only for the 48-h and 72-h exposure times for both zoeae and myses and for the 48-h exposure time for the postlarvae. This is due to the high survival percentage of the 24-h group and the low survival percentage (below 50%) of the larvae exposed for 96 hours. The 48-hour LC SUB-50 for Z SUB-1 , M SUB-1 and P SUB-1 are 0 . 225, 0 . 350 and 0 . 125 ppm respectively. Postlarvae seem to be more sensitive than either of the 2 larval stages having a lower 48-h LC SUB-50 and a low survival rate after 72 hours. The larvae were observed to lose their balance and were lethargic, producing few swimming movements so that they were mostly confined to the bottom of the aquaria. Moribund larvae observed under the microscope had a faster but weak heartbeat compared to healthy larvae. Slight or complete loss of feeding ability indicated by empty guts and delayed molting of Z SUB-1 to Z SUB-2 were also noted.

Notes on the induced maturation and spawning in four-month-old Penaeus monodon Fabricius by eyestalk ablation

The ablation technique consisted of making an incision across the eyeball to allow free flow of fluids while holding the prawn under water, squeezing the eyeball contents outwards, and pinching hard the eyestalk tissue. The cut area heals completely in about a week; no application of antibiotics is necessary. Spent spawners were tagged with thin brass rings (Rodriguez, 1976) around the unablated eyestalk for a separate experiment on rematuration. Two spawning yielding approximately 277,000 eggs were obtained three weeks after ablation, followed four days later by two more spawnings with 160,000 eggs; all four spawners weighed more than 100 g. With a hatching rate of 98% and 78% for the first and second batch, respectively, the spawnings produced viable nauplii. Water temperatures as low as 23 degree C due to a delayed cold spell in March depressed molting; weakened larvae had to be discharged at the mysis stage. Although ovarian development continued, no further spawnings were obtained due mainly to the onset of bacterial and fungal disease. Infection is initiated in injured portions of the exoskeleton, sometimes penetrating right through the muscles to the ovarian tissues. The non-flowthrough conditions and mussel meat feeding led to fouling of the culture water resulting in consecutive mortalities caused by disease. Female P.monodon held in maturation pens were ablated at the age of 15 months (Santiago, et al., 1976); they averaged only 16 g body weight after four months growth in ponds. In another experiment, pond-reared P.monodon females ranging from 50 to 80 g were ablated at approximately seven months (Aquacop, 1977). The present results show a minimum age of four months from postlarve that P.monodon is capable of ovarian development and spawning upon ablation. However, maturation is probably affected by size as well as age - the four-month old females weighed an average of 100 g in contrast to the smaller animals in the earlier experiments.

Studies on dried/smoked barracuda

Physical, chemical and organoleptic characteristics of dried and smoked barracuda (Sphyraena spp.) during storage at ambient temperature are reported. Initial increase in total volatile basic nitrogen (TVBN) content after drying as well as smoking did not have any significant effect on the organoleptic qualities of the products. Smoking was found effective in delaying the onset of fungal attack and also in improving the organoleptic qualities.

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.