摘要:

Abstract.During the laboratory culture of the California mud‐fiat oetopus.Octopus bimaculoides(Pickford&McConnaughey, 1949), concurrent infestations of ectoparasitic flagellate and ciliate protozoans were discovered when examining sick and dying animals. The flagellates, similar to the bodonid parasite,Ichthyobodo necator(Henneguy, 1883), were small (3–9 μm total length) and infested any surface epithelia exposed to sea water. The larger ciliates (l5–30 μm total length), believed to be ancistrocomids, were found only on the gills. This is the first documented report of ciliate or flagellate ecto‐parasites infesting cephalopod molluscs. Flagellate infestations were first manifest on the dorsal arms and mantle surfaces ofO. bimaculoidesas white spots visible when the octopuses were in dark colouration. Lesions formed at the centres of the spots and the interspersed lesions eventually connected. Once the parasites damaged the epidermis, secondary bacterial infections caused lesioning. Both parasites heavily infested the gills. Clinical signs first appeared at 2 months post‐hatching (0‐5 g). Octopuses seemed to become refractory to the disease beyond a size of 25 g. No effective treatment was found for these infestations. It was possible to eliminate parasite spread in the laboratory by prefiltering water to l μm. The source of the parasites was the wild octopus population of the southern Ca

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1991.tb00595.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract.The putative virulence factors ofAeromonas salmonicida, the aetiological agent of furunculosis in salmonids, are candidates for protective antigens in effective vaeeines against furunculosis. In this report, the authors have compared the immunogenieily of eell‐associated and extracellular antigens ofA. salmonicidain Atlantic salmon,Salmo salarL., to that in rabbit. The animals were immunized with formalin‐killed whole cells and formalin‐inactivated extracellular products (ECP), either separately or in combination. The ability of the antigens to induce antibody production was studied byelisaand Western blotting techniques. These results confirm previous reports that far more structures are immunogenie in rabbit compared to the antibody responses elicited in salmon. However, in both species, some antigens were dominant, including a caseinolytic protease in addition to the A‐protein and high and low

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1991.tb00596.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract.The histopathological effects of intramuscular (i.m.) and intraperitoneal injections of the purified lethal cytolytic toxin ofA. salmonicidain Atlantic salmon,Salmo salarL., were restricted to extensive degranulation of eosinophilic granular cells (EGCs) in the gills (both routes) and a limited coagulative necrosis of muscle fibres at the site of i.m. injection. The severity of these lesions did not apparently differ amongst fish that were moribund within 48 h and the surviving fish at 90 h. Previous studies indicate a maximum time to death caused by this toxin of 48 h. Thus, it is difficult to account for death of the fish from the toxin solely on the grounds of the histopathological features. It is suggested that a complex metabolic dysfunction results in death. The mechanism of ‘furuncle’ formation was demonstrated to result from a combined effect of the cytolysin and the purified 70‐kDa protease present in the ECP. When i.m.‐injected singly, the purified cytolysin produced a limited coagulative necrosis and the purified protease produced a limited liquefaction and haemorrhaging. In combination, they induced the extensive liquefactive haemorrhagic ‘furuncle’ characteristic of th

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1991.tb00597.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract.Bacterial lipopolysaccharide (LPS) is known to have binding affinity for mammalian erythrocyte membranes but does not cause haemolysis. In this study, LPS from eight different bacterial species all possessed haemolytic activity for salmonid erythrocytes. There were some differences in haemolytic activity among the different bacterial LPS after 2 h incubation. Lytic titres continued to increase with time for some LPS species reaching extremely high litres after 20 h incubation for theSalmonella minnesotaLPS. The LPS extracted by the hot‐phenol method from extracellular products (ECP) ofAeromonas salmonicidawas more haemolytic than that extracted from the bacterial cell walls. Separated lipid A‐ and O‐antigen fractions ofA. salmonicidaLPS had a similar low haemolytic activity. WhenA. salmonicidaLPS, lipid A‐ and O‐antigen were pre‐incubated with bovine serum albumin, only LPS extracted from ECP retained any haemolytic activity. The LPS types used in this study were not haemolytic for rabbit e

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1991.tb00598.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract.Cracked‐skull disease, previously unrecorded in Nigeria, affected fish in 80% of the homestead ponds investigated in this study. It was peculiar to mud catfish,Clariasspp., under intensive culture in urban Lagos, Nigeria. Male and female fish that were more than 10cm in length were equally vulnerable. The accessory respiratory structures were involved, but the liver, kidney, heart and the other internal organs were not. At its peak, the infection was characterized by a lateral crack in the skull, which resulted in death. Dip treatment in either 2‐0ppm potassium permanganate or 0‐5ppm formalin (with alcohol) for 30s day1resulted in 65‐0 and 41‐3% full recovery in 7 days, respectively. The implications of the disease for homestead fish culture are

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1991.tb00599.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract.Atlantic salmon,Salmo salarL., suffering from ‘Hitra disease’ showed an increase in activated partial thromboplastin time and prothrombin time values, and a decrease to very low levels of plasma fibrinogen when compared to healthy controls. Together with a marked thrombocytopenia, these results present firm evidence of consumptive coagulopathy with disseminated intravascular coagulation in diseased fish. When the control pen was retested after 4 weeks, a consumptive coagulopathy was evident also in this group of fish. The fact that this pen came down with ‘Hitra disease’ about 8 weeks later strongly supports our hypothesis that DIG is a basic pathologic process in this

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1991.tb00600.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1991.tb00601.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1991.tb00602.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1991.tb00603.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1991.tb00604.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY