FISH PATHOLOGY Research Papers - Academia.edu (original) (raw)

The growth, reproduction, gametophyte(G)/tetrasporophyte(T) ratio, and diseases of Chondrus ocellatus populations were examined at 3 sites (Samcheok, Youngduk, Pohang) of East coast and at 2 sites (Hakampo, Manripo) of West coast in... more

The growth, reproduction, gametophyte(G)/tetrasporophyte(T) ratio, and diseases of Chondrus ocellatus populations were examined at 3 sites (Samcheok, Youngduk, Pohang) of East coast and at 2 sites (Hakampo, Manripo) of West coast in between July and August, 2013. Average plant lengths were 6.10∼9.69 cm and it was minimum at Manripo and maximum at Pohang population. In general, average plant length and weight of C. ocellatus were greater on East coast than West coast populations. The proportion of vegetative plant was between 26.7∼66.7 %, and G/T ratio of total plants including vegetative plants after testing resorcinol method was 3:2 on the East coast where is gametophyte dominant area. However, G/T ratio was 1:1 at Hakampo and 1:2.3 at Manripo representing tetrasporophyte dominance. In the present study, Korean C. ocellatus have various diseases (white colour and green colour), an endophytic alga(Ulvella sp.), and many epiphytic macroalgae and diatoms. Healthy C. ocellatus plants were about 20∼40 % in summer population and most of plants had disease. Chondrus ocellatus had a filamentous green alga, endophytic Ulvella sp. which was not identified. The endophyte is easily observed in C. crispus growing in Europe and Canada and it is recognised as a pathogen destroying population and reducing yield of C. crispus. Thus more interest and research on the endophytic algae and disease of C. ocellatus are required.

Özet: Çalışmada, 2 yaşlı, 6 adet sazanda (Cyprinus carpio L.) gözlenen deri lezyonları makroskobik, histopatolojik ve elektron mikroskobik olarak değerlendirildi. Deride, boz beyaz fokal odaklar halinde gözlenen lezyonlardan alınan doku... more

Özet: Çalışmada, 2 yaşlı, 6 adet sazanda (Cyprinus carpio L.) gözlenen deri lezyonları makroskobik, histopatolojik ve elektron mikroskobik olarak değerlendirildi. Deride, boz beyaz fokal odaklar halinde gözlenen lezyonlardan alınan doku örneklerinde, epidermal hiperplazi, vakuoler dejenerasyon ve intrasitoplazmik inklüzyon cisimciklerine rastlanırken, elektron mikroskobik incelenmesinde hücre içi virus partiküllerine rastlandı. Gözlenen makroskobik ve mikroskobik bulguların, çiçek hastalığına bağlı olarak şekillendiği sonucuna varıldı.

Trichodinids are ciliated protozoa that are widely known as one of the main groups of fish parasites. The genus Trichodina presents the greatest species diversity. However, records of Paratrichodina species are scarce, and little is known... more

Trichodinids are ciliated protozoa that are widely known as one of the main groups of fish parasites. The genus Trichodina presents the greatest species diversity. However, records of Paratrichodina species are scarce, and little is known about their pathogenicity in hosts. The present study provides new records of Paratrichodina africana Kazubski and El-Tantawy (1986) in Nile tilapia from South America and descriptions of pathological changes and seasonality. A total of 304 farmed fish were examined. From gill scraping, parasites were identified using Klein's nitrate impregnation method. Gill samples were fixed for histopathological analysis. Small trichodinid found in this study have a prominent blade apophysis and narrow central part and blade shape that corresponds to the characteristics of P. africana . Gill lesions were proportional to parasite intensity, in which the gill tissue was compromised in heavy infestation. Proliferative disturbances were found, including epithelial hyperplasia, desquamation, and mononuclear and eosinophilic infiltrate that culminated in necrosis. We did not observe a seasonality effect on the occurrence of P. africana. This ciliated protozoan causes compromised respiratory capacity that leads to severe gill lesions and currently is an important pathogen that afflicts intensive tilapia cultures in Brazil.

We report the first isolation, identification and characterization of a group of Chilean strains of atypical Aeromonas salmonicida isolated from freshwater farmed Atlantic salmon, Salmo salar. Affected fish showed superficial ulcers and... more

We report the first isolation, identification and
characterization of a group of Chilean strains of
atypical Aeromonas salmonicida isolated from
freshwater farmed Atlantic salmon, Salmo salar.
Affected fish showed superficial ulcers and pale liver
with or without petechial haemorrhages. Outbreaks
of the disease occurred in two farms in the south of
Chile about 2200 km apart. Five strains were isolated
in pure culture and identified by serological
assays and immunofluorescence tests as belonging
to Aeromonas salmonicida. Although the bacterial
isolates were phenotypically homogeneous, minor
differences with the reference strain A. salmonicida
subsp. salmonicida ATCC 33658 were noted. Three
specific primer sets and partial 16S rRNA gene
sequencing allowed the identification of the Chilean
isolates as atypical A. salmonicida, with A. salmonicida
subsp. achromogenes and A. salmonicida subsp.
masoucida as their closest relatives (100% sequence
similarity). Molecular typing indicated that the
atypical isolates belong to two genetic groups that
were associated with the geographical origin.

This study examines different forms of skeletal deformities detected in fish species collected from two Egyptian aquaculture facilities during two harvest seasons in 2008. Various patterns of skeletal deformities were observed in 19 of... more

This study examines different forms of skeletal deformities detected in fish species collected from two Egyptian aquaculture facilities during two harvest seasons in 2008. Various patterns of skeletal deformities were observed in 19 of 959 fish collected. Deformities were diagnosed using a number of techniques including clinical, radiographic, sonographic and histopathological evaluations. Observed deformities included: lordosis and kyphosis in African catfish (Clarius gariepenius); lateral projection of the mandible, parrot-like head, scoliosis, kyphosis, lordosis and fusion of dorsal with anal fins in Nile tilapia (Oreochromis niloticus); and stump body, scoliosis and mandibular joint deformity in common carp (Cyprinus carpio). Relative incidences of deformities in fish from a facility located in the Sharkia province were 5.12%, 2.66% and 2.85% among catfish, Nile tilapia and common carp, respectively. At a second fish farm located in the Kafr Elsheikh province, the incidences of deformities were 1.02%, 1.55% and 0% among catfish, Nile tilapia and common carp, respectively. Some of the deformities were confirmed using both sonographic and histopathological evaluations. The reasons for the observed deformities could not be definitively determined, but possible aetiologies are discussed.

Objective: Seahorses (Familia: Syngnathidae), 3 species (Hippocampus hippocampus, Hippocampus guttulatus and Hippocampus fuscus) of which inhabit Turkey’s seas, are included in vulnerable or data deficient categories by IUCN. This lack of... more

Objective: Seahorses (Familia: Syngnathidae), 3 species (Hippocampus hippocampus, Hippocampus guttulatus and Hippocampus fuscus) of which inhabit Turkey’s seas, are included in vulnerable or data deficient categories by IUCN. This lack of information makes better understanding of the current and future status of these species more difficult. For this purpose, touching upon the different aspects of these species will yield a better view for consideration. To serve this aim, studies about pathogens and diseases of seahorses were examined for this compilation study.
Methods: In this compilation, scientific studies about pathogens and diseases of the world’s seahorses have been compiled. Tissues, organs, pathogens and diseases involved have been briefly touched upon and underlined. According to the results of literature research, there is no such study in Turkey and also few international studies were encountered.
Results and Discussion: During the research for related sources, studies about the pathogens and diseases of seahorses and many general references were found. According to the results of the scientific studies, diseases like hyperplasy, tail rot disease, necrotic foci in kidneys and liver, sloughing of epidermis, depigmentation of skin, white necrotic tail tips, gas bubble formation, external gas bubble formation, deep skin ulceration and white patch disease were identified from seahorses. These disease causing effects and organisms were categorized as microbiological, parasitological and physically. Tissues and organs like mouth epithelium, liver, heart, blood, digestive tract, gut wall, body cavity, stomach, intestine, trunk, operculum, bile duct and gallbladder were showing the effects of these diseases. Studies about the pathogens of seahorses are needed in Turkey. By responding this need, more data related with the health of natural and cultural seahorse populations, would be collected. Also this compilation will serve to better understanding of biodiversity in Turkey and contribute to the possible future conservation biology studies.
Keywords: Hippocampus sp., seahorse, pathogen, biodiversity, conservation biology.

Pemeriksaan patologi Ikan meliputi kohabitasi, pemeriksaan parasit, identifikasi bakteri, pemeriksaan darah, histopatologi dan analisis PCR (Cracking)

Dans le cadre du Plan National de Développement Aquacole (1985‐2009), 15 espèces (Huître, Crustacé, Poissons) ont été importées et plus de 56 hydrosystèmes ont fait l'objet de multiples introductions de poissons totalisant un effectif de... more

Dans le cadre du Plan National de Développement Aquacole (1985‐2009), 15 espèces (Huître, Crustacé, Poissons) ont été importées et plus de 56 hydrosystèmes ont fait l'objet de multiples introductions de poissons totalisant un effectif de 36 millions d'alevins. Pour la pisciculture continentale, les importations de Hongrie (1985‐2001) ont concerné Aristichthys nobilis, Hypophthalmichthys molitrix, Ctenopharyngodon idella, Cyprinus carpio, Sander lucioperca et Silurus glanis ainsi que trois introductions accidentelles, Lepomis gibbosus, Carassius gibelio et Lampetra fluviatilis. Les Cichlidés O.niloticus x O.mossambicus et Oreochromis niloticus importés d'Egypte (2002‐2006) sont destinés à la Tilapiculture en zone semi‐aride et aride. L'huître japonaise Crassostrea gigas a été introduite dans la lagune Mellah, et plus récemment (2008‐2009), des alevins de Sparus aurata et Dicentrarchus labrax importés d'Espagne et d'Italie sont introduits dans l'Est du littoral algérien soit à des fins d'élevages intensifs en race‐ways en béton (Cap Djenet) ou en cages flottantes (Azzefoune). La crevette Penaeus monodon (Marsa‐Skikda) est en phase d'élevage préliminaire. Ces importations massives sont à l'origine d'introduction en Algérie de divers bioagresseurs incluant deux viroses (Virus de l'inflammation de la vessie gazeuse et Virus de la virémie printanière de la carpe, une bactérie pathogène Flexibacter maritimus chez D.labrax et 15 Cyprinidés et Tilapias selon la spécificité parasitaire). Les impacts environnementaux les plus importants au niveau du Parc National d'El Kala concernent l'eutrophisation du lac Oubeira et la prolifération de Cyanophycées responsables de mortalités régulières de l'ichtyofaune ainsi que l'envahissement du réseau hydrique de la wilaya de Tarf par Carassius gibelio.

Bilan des investigations parasitaires (1986-1999) au Lac Oubeira et dans la Lagune Mellah (Parc National d'El Kala) avec une revue détaillée du programme piscicole de repeuplement de l'Oubeira en Cyprinidés C.carpio, A.nobilis,... more

Bilan des investigations parasitaires (1986-1999) au Lac Oubeira et dans la Lagune Mellah (Parc National d'El Kala) avec une revue détaillée du programme piscicole de repeuplement de l'Oubeira en Cyprinidés C.carpio, A.nobilis, H.molitrix, S.lucioperca.

The utilization of treated duckweed (Lemna pauciscostata) as soybean supplement in the diet of African mud catfish (Clarias gariepinus) was carried out for 6 weeks (42 days). Freshly harvested duckweed was given varying treatments (raw,... more

The utilization of treated duckweed (Lemna pauciscostata) as soybean supplement in the diet of African mud catfish (Clarias gariepinus) was carried out for 6 weeks (42 days). Freshly harvested duckweed was given varying treatments (raw, soaked in potash (maize cob as solution), sundried and blanched (at 100°C)) were included at 50% inclusion level. The experimental set up was in triplicate. The result showed highest mean weight gain in the diet 1 (Control diet) and followed by the diet 5 (blanched diet) while diet 2 (raw duckweed) gave the lowest mean weight gain. The food conversion ratio, specific growth rate and protein efficiency ratio followed the same pattern. There was no significant difference between the net profit value of control diet (601.1) and the blanched diet (592.66) (p>0.05) and the blanched diet gave the best benefit cost ratio (BCF). Apart from been viable supplement for soybean meal in the diet of Clarias gariepinus, blanching of duckweed gave better performance than other treatments.

In the present study, a novel species of Fusarium oxysporum involved in the disease outbreak among freshwater murrel, Channa striatus was identified from natural lake in India and the pathogenesis was confirmed by infection studies. Using... more

In the present study, a novel species of Fusarium oxysporum involved in the disease outbreak among freshwater murrel, Channa striatus was identified from natural lake in India and the pathogenesis was confirmed by infection studies. Using Illumina paired-end sequencing technology, we have sequenced, assembled and annotated the transcriptome of F. oxysporum isolate. A total of 53,397,192 high quality paired-end reads were assembled into 27,886 unique reads and gene ontology (GO) analysis revealed that the transcripts of F. oxysporum belonged to 1656 unique GO terms. An in-depth search for the genes with putative virulence functions revealed well-represented virulence-associated domains containing proteins such as cellulose binding proteins, proteases, ki-nases, kinase inhibitor and toxins. Sequence alignment revealed clear insights into the diversity and similarity of those virulence genes with plant pathogens. qRT-PCR analysis of five genes with putative virulence genes confirms the virulence roles of those genes in the pathogenesis of F. oxysporum in C. striatus. This study provides novel information regarding the transcriptome of fungal pathogen and delivers insights into the virulence genes associated with the pathogenesis of the F. oxysporum isolate which might be useful for the control of the fungal pathogenesis.

This study was conducted for isolation and identification of Streptococcus iniae from Oreochromis niloticus fish farms using traditional and molecular PCR techniques. Forty-seven isolates of Streptococcus were recovered from 232 fish... more

This study was conducted for isolation and identification of Streptococcus iniae from Oreochromis niloticus fish farms using traditional and molecular PCR techniques. Forty-seven isolates of Streptococcus were recovered from 232 fish samples from successive 4 seasons during 2015. Summer showed the highest prevalence with 34.9%. S. iniae was identified as the causative agent for streptococcosisin 3 seasons by PCR using S. iniae specific-16S rRNA primers. Experimental infection was performed to determine the pathogenicity of S. iniae for O.nloticusand the best antibiotics to be used for treatment of streptococcosis. S. iniae caused 70% mortalities in experimentally infected fish. Several histopathological alterations were observed in the liver, spleen, kidney and gills of the infected fish. The most effective antibiotics for treatment were Ampicillin with no mortalities, followed by Penicillin and Tetracycline with 10% mortality for both.

The biochemical, serological and molecular characteristics of 8-pigmented isolates phenotypically related to Flavobacterium psychrophilum were determined. The bacteria were isolated in 2006 from diseased Atlantic salmon (Salmo salar) and... more

The biochemical, serological and molecular characteristics of 8-pigmented isolates phenotypically related to Flavobacterium psychrophilum were determined. The bacteria were isolated in 2006 from diseased Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss) cultured in the South of Chile. The F. psychrophilum type strain ATCC 49418 T and isolate B97026, obtained from rainbow trout in UK, were included in the study as a comparison. Their potential to cause pathology in Atlantic salmon was also investigated. The 8 isolates were biochemically identical, however were completely different to F. psychrophilum. Slide agglutination and Dot blot allowed us to confirm that the isolates constituted a homogeneous, but distinctive serological group to the F. psychrophilum isolates. Similar homogeneity was observed using RAPD-PCR with identical DNA patterns obtained, regardless of the source of isolation or geographic origin. Therefore, any of the above tests can be used to discri...

A benedeniid parasite infecting the body surface of cobia Rachycentron canadum cultured in net cages in Taiwan was identified as Neobenedenia girellae. This is the first confirmed case of N. girellae infection of marine fish from Taiwan.... more

A benedeniid parasite infecting the body surface of cobia Rachycentron canadum cultured in net cages in Taiwan was identified as Neobenedenia girellae. This is the first confirmed case of N. girellae infection of marine fish from Taiwan. N. girellae was not randomly distributed on the host; it concentrated on the dorsal side of the head area (59.7%), especially on the eyes (23.7%), while it was less frequent on the ventral side and not detected on the fins. N. girellae caused considerable histological damage to the host through the attachment by the haptor and possibly through feeding activity by the pharynx. In infected eyes, epithelial cells of the cornea were often partially lost, and the collagenous stroma was considerably thickened and edematous, associated with massive inflammatory cell infiltration.

For shrimp with low-level white spot syndrome virus (WSSV, = PRDV) infection, environmental or physiological stresses can trigger replication of the virus and lead to a full-blown outbreak of white spot disease. This review will describe... more

For shrimp with low-level white spot syndrome virus (WSSV, = PRDV) infection, environmental or physiological stresses can trigger replication of the virus and lead to a full-blown outbreak of white spot disease. This review will describe how pathogenomic studies have revealed some of the mechanisms that underlie this aspect of WSSV pathology. In the model that emerges, stressors activate shrimp STAT (signal transducer and activator of transcription), which is then annexed by the virus and used to activate the promoter of the immediate early gene WSSV ie1. This in turn leads to rapid replication of the virus.

We report the first isolation, identification and characterization of a group of Chilean strains of atypical Aeromonas salmonicida isolated from freshwater farmed Atlantic salmon, Salmo salar. Affected fish showed superficial ulcers and... more

We report the first isolation, identification and characterization of a group of Chilean strains of atypical Aeromonas salmonicida isolated from freshwater farmed Atlantic salmon, Salmo salar. Affected fish showed superficial ulcers and pale liver with or without petechial haemorrhages. Outbreaks of the disease occurred in two farms in the south of Chile about 2200 km apart. Five strains were isolated in pure culture and identified by serological assays and immunofluorescence tests as belonging to Aeromonas salmonicida. Although the bacterial isolates were phenotypically homogeneous, minor differences with the reference strain A. salmonicida subsp. salmonicida ATCC 33658 were noted. Three specific primer sets and partial 16S rRNA gene sequencing allowed the identification of the Chilean isolates as atypical A. salmonicida, with A. salmonicida subsp. achromogenes and A. salmonicida subsp. masoucida as their closest relatives (100% sequence similarity). Molecular typing indicated that the atypical isolates belong to two genetic groups that were associated with the geographical origin.

Protozoan isolates from the gills of marine-reared Atlantic salmon Salmo salar smolts were cultured, cloned and 8 dominant isolates were studied in detail. The light and electron-microscopical characters of these isolates were examined,... more

Protozoan isolates from the gills of marine-reared Atlantic salmon Salmo salar smolts were cultured, cloned and 8 dominant isolates were studied in detail. The light and electron-microscopical characters of these isolates were examined, and 7 were identified to the generic level. Structure, ultrastructure, a species-specific immunofluorescent antibody test (IFAT), and PCR verified the identity of the Neoparamoeba sp. isolate. Five other genera of amoebae, comprising Platyamoeba, Mayorella, Vexillifera, Flabellula, and Nolandella, a scuticociliate of the genus Paranophrys, and a trypanosomatid (tranosomatid-bodonid incertae sedis) accompanied Neoparamoeba sp. in the gills. The pathogenic potential of the isolated organisms, occurring in conjunction with Neoparamoeba sp. in the gills of cultured Atlantic salmon smolts in Ireland, remains to be investigated KEY WORDS: Amoebic gill disease · Neoparamoeba sp. · Amoebae · Platyamoeba sp. · Scuticociliates · Trypanosomatids Resale or republication not permitted without written consent of the publisher

Rash" , a subchronic, debilitating and non-fatal inflammatory skin disease has been found in cultured rainbow trout (Oncorhynchus mykiss) in several areas of Japan over the past five years. This condition was observed from small fish... more

Rash" , a subchronic, debilitating and non-fatal inflammatory skin disease has been found in cultured rainbow trout (Oncorhynchus mykiss) in several areas of Japan over the past five years. This condition was observed from small fish (11cm in body length) to mature-size animals, however, most of the affected fish were market size (in Japan, 20cm/120g). Morbidity sometimes reaches as high as 48% and causes a significant economic impact, since those fish loose commercial value. A self-limited clinical course and healing of the lesion could be observed after 6 to 8 weeks. "Rash" signs included the presence of bright red, non-raised, ulcerated or not, defined to petechial scattered lesions on the ventral and/or lateral surfaces of the fish. Histopathological features included a subchronic focal to non-focal, non-suppurative dermatitis with various degrees of ulceration and an extensive mononuclear inflammatory infiltration. "Rash" etiology still remains unknown .

Du r i n g a p a r a s i t o l o g i c a l s u r v e y o f t h e d a ms e l f i s h Ch r o mi s c h r o mi s f r o m t h e B l a c k S e a c o a s t s o f S i n o p , T u r k e y , wh e r e t h e r e i s n o a q u a c u l t u r e f a c i... more

Du r i n g a p a r a s i t o l o g i c a l s u r v e y o f t h e d a ms e l f i s h Ch r o mi s c h r o mi s f r o m t h e B l a c k S e a c o a s t s o f S i n o p , T u r k e y , wh e r e t h e r e i s n o a q u a c u l t u r e f a c i l i t i e s n e a r b y , i n t h e mo n t h s J u n e a n d J u l y 2 0 1 3 , a n d f r o m a r e s e a r c h f a c i l i t y i n t h e F a c u l t y o f F i s h e r i e s a n d A q u a t i c S c i e n c e s i n J u n e 2 0 1 3 , a my x o s p o r e a n p a r a s i t e wa s e n c o u n t e r e d . Nu me r o u s y o u n g p l a s mo d i a a n d s p o r e s we r e o b s e r v e d i n t h e g a l l b l a d d e r a n d i n t e s t i n e o f h e a v i l y i n f e c t e d 2 d e a d f i s h , p r e v i o u s l y c o l l e c t e d f r o m t h e B l a c k S e a , h e l d i n a n a q u a r i u m a n d o n l y i n t h e i n t e s t i n e o f s l i g h t l y i n f e c t e d o n e o f 2 5 wi l d f i s h . F r e s h p a r a s i t e s we r e e x a mi n e d wi t h a n Ol y mp u s BX 5 1 mi c r o s c o p e u s i n g p h a s e -c o n t r a s t , a n d p h o t o g r a p h e d b y DP -2 5 d i g i t a l c a me r a u s i n g d a t a -p r o c e s s i n g s o f t wa r e DP 2 -B S W. I n t h e g a l l b l a d d e r s , n u me r o u s y o u n g p l a s mo d i a wi t h i mma t u r e s p o r e s we r e o b s e r v e d a n d v e g e t a t i v e s t a g e s we r e d i s p o r i c p l a s mo d i a ( F i g . 1 A ) . P l a s mo d i a ( n = 2 0 ) me a s u r e d 1 7 . 6 m m ( 1 4 . 7 -2 0 . 0 m m) i n l e n g t h a n d 1 5 . 5 m m ( 1 4 . 0 -1 7 . 3 m m) i n wi d t h .

The growth pattern of Oreochromisniloticus and Sarotherodongalilaeus in Lake Geriyo of Adamawa State was investigated. One hundred (100) samples of each species were collected from fishermen catches at the landing site. They were... more

The growth pattern of Oreochromisniloticus and Sarotherodongalilaeus in Lake Geriyo of Adamawa State was investigated. One hundred (100) samples of each species were collected from fishermen catches at the landing site. They were transported to the Department of Fisheries Laboratory for identification, sexing morphometric measurement. The results showed that 58.0% and 56.0 % of the O.niloticus and S.galilaeus were female respectively while 42.0% and 44.0% were male respectively.. The length-weight relationship of O.niloticus showed a strong regression coefficient (r = 0.944) (p<0.05) for the combined sex, (r =0.903) (p<0.05) for female and (r=0.986) (p<.05) for male with b-value of 2.5, 3.1 and 2.8 respectively. The S.galilaeus also showed a regression coefficient of r=0.970; p<0.05 for the combined sex, r=0.953; p<0.05 for the female and r= 0.979; p<0.05 for the male with b-value of 3.4, 3.1 and 3.6 respectively. O.niloticus showed an isometric growth pattern both in male and female. The condition factor in O.niloticus are 1.93 and 1.95 for male and female respectively while that of S.galilaeus is 1.95 for both sexes.Positive allometric was observed in both species except the male O.niloticusthat showed negative allometric growth pattern. From the results of this study, the growth pattern of the two species indicated a good healthy environment.

Chile is considered the second largest producer of farmed salmon in the world. This intensive fish farming has resulted in growing problems as bacterial diseases, and infections by Flavobacterium psychrophilum, Chryseobacterium species... more

Chile is considered the second largest producer of farmed salmon in the world. This intensive fish farming has resulted in growing problems as bacterial diseases, and infections by Flavobacterium psychrophilum, Chryseobacterium species and other yellow-pigmented strains are considered to be one of the major problems in the freshwater stage in Chilean aquaculture where infections can result in 5 to 90% mortality rate of fingerlings, particularly in Atlantic salmon. The infections are frequently found in association with infectious pancreatic necrosis virus (IPNV), saprolegnia or parasitic fish pathogens as Ichthyophthirius multifilis, but the significance of these combinations is unclear. According to the distribution of the diagnosis informed by the laboratories showed that flavobacteriosis is the second pathology affecting salmon cultures, after Piscirickettsia salmonis. In the present article we review current knowledge on these bacterial pathogens, focusing on important aspects such as biochemical, serological and genetic characterization of the microorganisms. The diagnostic procedures employed in Chile are also discussed. We include the current status of prevention and control strategies, studies of virulence, and we attempt to highlight fruitful areas for continued research.

Creatine kinase (CK) isoenzymes were examined as diagnostic indicators for patho physiological changes in yellowtail infected with Lactococcus garvieae. Three isoenzymes of CK similar to those found in human were detected by agarose... more

Creatine kinase (CK) isoenzymes were examined as diagnostic indicators for patho physiological changes in yellowtail infected with Lactococcus garvieae. Three isoenzymes of CK similar to those found in human were detected by agarose electrophoresis. CK isoenzymes in the brain, heart and intestine consisted of CK-MM, CK-MB and CK-BB. CK-BB was not detected in other tissues or plasma. Normal yellowtail plasma contained CK-MM and CK-MB, while CK-BB and CK-SP appeared in the plasma of infected fish. This phenomenon was found in both naturally and artificially infected fish. These results suggest that appearance of CK-BB and CK-SP in the plasma may reflect the pathophysiological changes due to the infection. Therefore, we consider that the examination of plasma CK isoenzymes is a pathophysiological diagnostic tool for the strep tococcal infection in yellowtail.

EL-NAGGAR M. M. and KEARN G. C. 1983. Glands associated with the anterior adhesive areas and body margins in the skin-parasitic monogenean Entobdella soleae. International Journalfor Parasitology 13: 67-81. Using the light microscope and... more

EL-NAGGAR M. M. and KEARN G. C. 1983. Glands associated with the anterior adhesive areas and body margins in the skin-parasitic monogenean Entobdella soleae. International Journalfor Parasitology 13: 67-81. Using the light microscope and TEM, a detailed study has been made of the different kinds of gland cell opening on the body surfaces of the adult and the oncomiracidium of E. soleae. Particular attention has been paid to the gland cells supplying the anterior adhesive areas and to those gland cells opening along the margins of the head region and body of the parasite. The oncomiracidia as well as immature parasites have three adjacent adhesive sacs on each side of the head and the adhesive regions of adults and oncomiracidia are supplied with two kinds of secretion. The most abundant secretion takes the form of rod-shaped bodies which, in the oncorniracidium and in the adult, are transported through ducts with multiple apertures, each aperture usually permitting the passage of a single rod. The second secretion consists of roughly spherical vesicles which differ in appearance in oncomiracidia and adults. Most of these ducts appear to have single apertures but there is evidence in the adult that some of them branch and lead to more than one opening. The roles of these two kinds of secretion in attachment and detachment of the head region, in immature and in adult parasites, were studied experimentally. In immature and mature parasites ultrastructural studies reveal similarities between the secretory bodies produced by the anterior median head glands and those produced by gland cells opening on or near the body margins. Possible functions of the secretions of the marginal gland cells are discussed.

Eight bacterial strains isolated from diseased rainbow trout (n55) and Atlantic salmon (n53) were characterized by phenotypic and molecular taxonomic methods. The isolates were negative for the Gram-reaction, non-motile, rod-shaped and... more

Eight bacterial strains isolated from diseased rainbow trout (n55) and Atlantic salmon (n53) were
characterized by phenotypic and molecular taxonomic methods. The isolates were negative for the
Gram-reaction, non-motile, rod-shaped and catalase- and oxidase-positive. Colonies on solid
media were yellow, smooth, shiny and circular with regular edges. Growth occurred at 4–28 6C
(optimum, 15 6C) and with 0–3% NaCl (optimum, 0.5 %). Analysis of the 16S rRNA gene
sequence allocated the micro-organisms to the genus Chryseobacterium, with Chryseobacterium
soldanellicola PSD1-4T and Chryseobacterium soli JS6-6T as their closest relatives (96.9 and
97.1% sequence similarity, respectively). The levels of DNA–DNA hybridization towards these
nearest phylogenetic neighbours were below 17.1 %. The DNA G+C contents of strains
VQ-6316sT and VQ-4836s were 32.5 and 32.3 mol%, respectively. The predominant
menaquinone was MK-6 and the major fatty acids were iso-C15 : 0, anteiso-C15 : 0, iso-C17 : 1v9c,
iso-C17 : 0 3-OH and summed feature 3 (comprising C16 : 1v7c and/or C16 : 1v7t and/or iso-C15 : 0
2-OH). The eight isolates were classified as representatives of a novel species, Chryseobacterium
piscicola sp. nov., with strain VQ-6316sT (5CECT 7357T5DSM 21068T) as the type strain.

Rev. Bras. Med. Vet., 34(3):235-240, jul/set 2012 235 RESUMO. Este estudo avaliou as infestações parasitárias que acometem alevinos de surubim híbrido (Pseudoplatystoma reticulatum ♀ x P. corruscans ♂) durante a fase inicial de criação.... more

Rev. Bras. Med. Vet., 34(3):235-240, jul/set 2012 235 RESUMO. Este estudo avaliou as infestações parasitárias que acometem alevinos de surubim híbrido (Pseudoplatystoma reticulatum ♀ x P. corruscans ♂) durante a fase inicial de criação. 50 peixes com tamanho variando de 5,7 a 20,3 cm e pesando de 1,2 a 48,8 g foram examinados. Entre os peixes examinados, somente 15 (30%) estavam livres de qualquer parasito e os demais apresentaram infestação por pelo menos um tipo de parasito 35 (70%). Entre estes, foram observados os protozoários Ichthyophthirius multifiliis, Epistylis sp. e Trichodina sp. Foram observados mixosporídeos, representado por Henneguya sp. e um metazoário pertencen-

The serological relationships between a non-motile variant of Edwardsiella tarda isolated from sea breams, Pagrus major and Evynnis japonica, and typical strains of E. tarda isolated from Japanese eel, Anguilla japonica and Japanese... more

The serological relationships between a non-motile variant of Edwardsiella tarda isolated from sea breams, Pagrus major and Evynnis japonica, and typical strains of E. tarda isolated from Japanese eel, Anguilla japonica and Japanese flounder, Paralichthys olivaceus, were studied. Cross-absorption test revealed that all strains shared a similar O-antigen. Agglutination tests showed the presence of heat-labile antigens on the cell surface of the non-motile strains from sea breams. Immunoelectrophoretic analysis demonstrated the relatedness of cell surface antigens among the strains from various fish species. The possibility of usage of a common vaccine for edwardsiellosis among sea breams and other fish species is suggested.

ABSRTACT-We describe a polymerase chain reaction (PCR)-based approach to the detection and identification of Aphanomyces piscicida (=Aphanomyces invadans). Three primer sets were designed based on the sequences of cloned expression genes... more

ABSRTACT-We describe a polymerase chain reaction (PCR)-based approach to the detection and identification of Aphanomyces piscicida (=Aphanomyces invadans). Three primer sets were designed based on the sequences of cloned expression genes of A. piscicida NJM 9803 (accession numbers: AB 104634, AB 104635 and AB 104636). They were used to detect the genomic DNA of 42, 18, 10 and 1 isolates of Aphanomyces spp., Saprolegnia spp., Achlya spp. and Dictyuchus sp., respectively. Out of 3 primer sets, a primer set (1APM 1F, 1APM 6R) detected only fish pathogenic A. piscicida but not the other non-fish pathogenic Aphanomyces species. In addition, the PCR revealed sensitivity sufficient for detecting A. piscicida in artificially infected goldfish. From the results, it was demonstrated that the PCR method with the primer set is effective for detection of A. piscicida from infected fishes and diagnosis of mycotic granulomatosis.

A humoral immune response of the Japanese eel (Anguilla japonica) against major antigens from the microsporean Pleistophora anguillarum was detected. Sonicated spores recovered from the skeletal muscle of infected "beko" eels were run on... more

A humoral immune response of the Japanese eel (Anguilla japonica) against major antigens from the microsporean Pleistophora anguillarum was detected. Sonicated spores recovered from the skeletal muscle of infected "beko" eels were run on sodium-dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) under reducing conditions. The separated proteins were then electroblotted onto nitrocellulose and incubated in dilutions (1: 100, 1: 200 and 1: 300) of sera from infected or non-infected eels. For secondary and tertiary incubations, a rabbit anti eel Ig serum and peroxidase conjugated swine anti rabbit Ig antibodies were used, respectively. The reaction pattern varied among eels, but it was demonstrated that the sera of infected eels responded strongly to at least one of the proteins with approximate molecular weights of > 94, 89, 62, 52, 45, and 32 kDa. Some sera of non-infected eels from the same culture ponds showed a lower reactivity to the > 94, 62, 52 and 32 kDa proteins (serum dilution 1: 100) but no sera responded to any proteins when they were diluted 1: 200 and 1: 300.

Infectious diseases in fish are generally diagnosed by histological and/or molecular biological analyses, following visual observation. However, it is difficult to reveal the initial route of infection, the process of internal infection... more

Infectious diseases in fish are generally diagnosed by histological and/or molecular biological analyses, following visual observation. However, it is difficult to reveal the initial route of infection, the process of internal infection spreading and the localization of pathogens in the body due to the limited information obtainable from partial or 2 dimensional (2D) images. Therefore, novel techniques to more comprehensively visualize the internal anatomy of the fish body are needed. Recently, a number of tissue clearing techniques (BABB, Scale, Clear T , SeeDB, CUBIC, 3DISCO, CLARITY, PACT-PARS etc.), allowing 3 dimensional (3D) visualization of cellular structures and various tissue materials, have been developed, primarily in the field of mammalian brain and neuroscience (

"Rash" , a subchronic, debilitating and non-fatal inflammatory skin disease has been found in cultured rainbow trout (Oncorhynchus mykiss) in several areas of Japan over the past five years. This condition was observed from small fish... more

"Rash" , a subchronic, debilitating and non-fatal inflammatory skin disease has been found in cultured rainbow trout (Oncorhynchus mykiss) in several areas of Japan over the past five years. This condition was observed from small fish (11cm in body length) to mature-size animals, however, most of the affected fish were market size (in Japan, 20cm/120g). Morbidity sometimes reaches as high as 48% and causes a significant economic impact, since those fish loose commercial value. A self-limited clinical course and healing of the lesion could be observed after 6 to 8 weeks. "Rash" signs included the presence of bright red, non-raised, ulcerated or not, defined to petechial scattered lesions on the ventral and/or lateral surfaces of the fish. Histopathological features included a subchronic focal to non-focal, non-suppurative dermatitis with various degrees of ulceration and an extensive mononuclear inflammatory infiltration. "Rash" etiology still remains unknown .

Penaeid acute viremia (PAV) caused by penaeid rod-shaped DNA virus (PRDV: one of white spot baculovirus complex) is the most serious disease affecting kuruma prawn (Penaeus japonicus) culture in Japan. In this study an experimental... more

Penaeid acute viremia (PAV) caused by penaeid rod-shaped DNA virus (PRDV: one of white spot baculovirus complex) is the most serious disease affecting kuruma prawn (Penaeus japonicus) culture in Japan. In this study an experimental challenge was carried out in different larval (nauplius, zoea and mysis) and postlarval (PL 1, 6, 9 and 11-12) stages of kuruma prawn in order to elucidate the difference in susceptibility to PRDV among different developmental stages of the host. The PRDV challenge was done by immersion in all the tested groups. No infections were recorded in the larval stages and PL1. The PL6 first showed mortality due to PAV on 10th day post-inoculation. The PL9 exhibited the onset of PAV on 5th day post-inoculation.

Climate warming has created favorable conditions for the range expansion of many southern Ponto Caspian freshwater fish and mollusks through the Caspian Volga Baltic "invasion corridor." Some parasites can be used as "biological tags" of... more

Climate warming has created favorable conditions for the range expansion of many southern Ponto Caspian freshwater fish and mollusks through the Caspian Volga Baltic "invasion corridor." Some parasites can be used as "biological tags" of migration activity and generic similarity of new host populations in the Middle and Upper Volga. The study demonstrates a low biodiversity of parasites even of the most com mon estuarial invaders sampled from the northern reservoir such as the Ponto Caspian kilka Clupeonella cul triventris (16 species), tubenose goby Proterorhinus semilunaris (19 species), and round goby Neogobius (=Appollonia) malanostomus (14 species). In 2000-2010, only a few cases of a significant increase in occur rence (up to 80-100%) and abundance indexes were recorded for some nonspecific parasites such as per itricha ciliates Epistilys lwoffi, Trichodina acuta, and Ambiphrya ameiuri on the gills of the tubenose goby; the nematode Contracoecum microcephalum and the acanthocephalan Pomphorhynchus laevis from the round goby; and metacercariae of trematodes Bucaphalus polymorphus and Apophallus muehlingi from the muscles of kilka. In some water bodies, the occurrence of the trematode Bucephalus polymorphus tended to decrease after a partial replacement of its intermediate host zebra mussel Dreissena polymorpha by D. bugensi (quagga mussel). High occurrence of parthenites of Apophallus muehlingi in the mollusk Lithoglyphus naticoides was recorded in the Upper Volga (up to 70%) as compared to the Middle Volga (34%). Fry of fish with a consid erable degree of muscle injury caused by the both trematode species have lower mobility and become more available food objects for birds and carnivorous fish.

The morphological, biochemical and physiological characteristics of 23 strains of gliding bacteria isolated from diseased cultured flounder, Paralichthys olivaceous, in Japan were determined. The strains were classified into two groups:... more

The morphological, biochemical and physiological characteristics of 23 strains of gliding bacteria isolated from diseased cultured flounder, Paralichthys olivaceous, in Japan were determined. The strains were classified into two groups: Group I (83 %) was identified as Flexibacter maritimus and Group II(17%) was tentatively identified as Flexibacter sp. until further characteristics will be studied to confirm its taxonomic identity.

We have previously identified an unknown cell type in the gills of Murray cod affected with chronic ulcerative dermatopathy (CUD), a condition that causes severe erosion of epidermis surrounding cephalic and lateral line sensory canals.... more

We have previously identified an unknown cell type in the gills of Murray cod affected with chronic ulcerative dermatopathy (CUD), a condition that causes severe erosion of epidermis surrounding
cephalic and lateral line sensory canals. The condition arises in aquaculture facilities that utilize groundwater, with the cause of the condition suggested to be an unknown contaminant
(s). Light and transmission electron microscopy were used to characterize and quantify the unknown cells in CUD-affected Murray cod. The cells were identified as rodlet cells and were
characterized by their oval or round shape, basally located nucleus, thick fibrillar capsule surrounding the cell, and multiple rodlet sacs containing a central electron-dense core within the
cell. Rodlet cells were present in the gills, kidney and intestine of non-CUD-affected and CUD-affected Murray cod; however, differences in the numbers were observed between the groups of
fish. A significantly greater number of rodlet cells were observed in the gills and collecting ducts of CUD-affected fish. This is the first report of rodlet cells in Murray cod, and we suggest that the
increased rodlet cell numbers in CUD-affected Murray cod may be in response to unknown water contaminant(s) present in the groundwater that give rise to CUD.