Infectivity of Trypanosoma murmanensis to leeches (Johanssonia sp.)

1977 ◽  
Vol 55 (10) ◽  
pp. 1698-1700 ◽  
Author(s):  
R. A. Khan
Keyword(s):  
Marine Fish ◽  
Gadus Morhua ◽  
Developmental Stages ◽  
Infected Fish ◽  
Winter Flounder ◽  
Pseudopleuronectes Americanus

Experiments were designed to test the infectivity of trypomastigotes of Trypanosoma murmanensis to leeches at intervals after metatrypomastigotes had initiated infections in marine fish. Infectivity was determined by the presence of developmental stages in recently emerged leeches (Johanssonia sp.) that had fed on experimentally infected fish. A total of 1235 leeches were used in this study. The results indicate that the three morphotypes can initiate infections in leeches. Moreover, some trypanosomes are infective at least 24 h after transmission (16 (67%) leeches became infected). Few leeches acquired infections after feeding on infected winter flounder (Pseudopleuronectes americanus) between 2 and 12 days and on a cod (Gadus morhua) 4–5 days, but all those which fed 7 through 93 day s on five species of marine teleosts became infected. Some of the leeches transmitted infections to uninfected cod. It is believed that the leeches which harboured no developmental stages might not have ingested trypanosomes.

The leech as a vector of a fish piroplasm

1980 ◽  
Vol 58 (9) ◽  
pp. 1631-1637 ◽  
Author(s):  
R. A. Khan
Keyword(s):  
Marine Fish ◽  
Blood Meal ◽  
Gadus Morhua ◽  
Infected Fish ◽  
Binary Fission ◽  
Gut Contents ◽  
Pseudopleuronectes Americanus ◽  
Infected Blood ◽  
Fish Blood ◽  
Anarhichas Lupus

A piroplasm, Haemohormidium beckeri, is redescribed from two marine fish, Lycodes lavalaei and Lycodes vahlii (Zoarcidae). The parasite divided by both binary fission and schizogony. In the latter process, up to eight merozoites were produced and these developed within mature erythrocytes. Infections were prevalent among fish from areas off the Labrador coast. Parasitemias, which varied from light infections to estimates of 60 parasites/1000 erythrocytes, were recorded in 15 fish for about 6 months. Subinoculation of infected blood initiated infections in two perciform fish, Myoxocephalus octodecemspinosus and Anarhichas lupus, but not in a pleuronectiform, Pseudopleuronectes americanus, or a gadiform, Gadus morhua. Natural infections were present in three leeches, Platybdella olriki, that had fed on an infected L. lavalaei. Piroplasms were also observed in the gastrointestinal content of all 94 laboratory-reared leeches, Johanssonia arctica, dissected 7 through 109 days after engorgement on infected fish blood. Inoculations of gut contents from leeches after digestion of a blood meal produced infections in uninfected fish. Natural transmission occurred when leeches were fed again on susceptible fish, whereas pipetting entire leeches into the stomach of fish did not initiate infections. This is the first evidence that leeches transmit piroplasms in nature to fish.

Pathogenesis of Trypanosoma murmanensis in marine fish of the northwestern Atlantic following experimental transmission

1985 ◽  
Vol 63 (9) ◽  
pp. 2141-2144 ◽  
Author(s):  
R. A. Khan
Keyword(s):  
Marine Fish ◽  
Gadus Morhua ◽  
Condition Factor ◽  
Atlantic Cod ◽  
Infected Fish ◽  
Pathological Feature ◽  
Pseudopleuronectes Americanus ◽  
Potential Pathogen ◽  
Myoxocephalus Scorpius ◽  
Hemopoietic System

The susceptibility of four species of marine fish (Gadus morhua, Pseudopleuronectes americanus, Myoxocephalus scorpius, and Myoxocephalus octodecemspinosus) to leech-transmitted Trypanosoma murmanensis was assessed 49–60 days after infection by comparing condition factor, organ somatic indices, parasitological, hematological, and histological findings with corresponding uninfected animals. The fish were maintained at temperatures (0–1 °C) to simulate the environment where transmission occurs naturally. High mortality occurred in juvenile Atlantic cod and winter flounder, but deaths decreased with increasing fish size. No adult fish died except flounder when fin rot was present. Anemia was the most common pathological feature observed in young fish at necropsy, but its severity was not always correlated with the level of parasitemia. The persistent anemia was probably associated with an inactive rather than an impaired hemopoietic system. Condition factor and somatic indices of liver, spleen, and heart were altered in some infected fish groups. It is concluded that T. murmanensis is a potential pathogen, especially to juvenile American plaice, Hippoglossoides platessoides, in which high prevalences of natural infections have been observed in some areas of the northwestern Atlantic Ocean.

Marine Fish Tissue Culture

1963 ◽  
Vol 20 (3) ◽  
pp. 679-684 ◽  
Author(s):  
P. M. Townsley ◽  
H. G. Wight ◽  
M. A. Scott
Keyword(s):  
Tissue Culture ◽  
Marine Fish ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
White Perch ◽  
Kidney Tissue ◽  
Fish Tissue ◽  
Pseudopleuronectes Americanus ◽  
Myoxocephalus Scorpius ◽  
Raja Radiata

Cell proliferation of tissue explants of different organs from marine fish has been achieved in a nutrient solution composed of Medium 199 plus 10% human serum. Fin, spleen, heart, kidney, liver, gonad, brain, uterus, and thymus tissues have been cultured. The tissues were obtained from sexually mature Atlantic cod (Gadus morhua), white perch (Roccus americanus) winter flounder (Pseudopleuronectes americanus), thorny skate (Raja radiata), American goosefish (Lophius americanus), pollock (Pollachius virens), and shorthorn sculpin (Myoxocephalus scorpius). An actively dividing cell culture of flounder kidney cells prepared by mechanical disruption of the kidney tissue was maintained through serial transfers over several months. Heart explants from the cod vigorously pulsated in tissue culture.

Swimming Endurance of Some Northwest Atlantic Fishes

1966 ◽  
Vol 23 (3) ◽  
pp. 341-347 ◽  
Author(s):  
F. W. H. Beamish
Keyword(s):  
Swimming Speed ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Winter Flounder ◽  
Pseudopleuronectes Americanus ◽  
Northwest Atlantic ◽  
Sea Raven ◽  
Longhorn Sculpin ◽  
Hemitripterus Americanus ◽  
Swimming Endurance

Endurance was determined in relation to swimming speed and temperature for Atlantic cod, Gadus morhua Linnaeus, redfish, Sebastes marinus (Linnaeus), winter flounder, Pseudopleuronectes americanus (Walbaum), and to swimming speed at 8 C for longhorn sculpin, Myoxocephalus octodecimspinosus (Mitchill), sea raven, Hemitripterus americanus (Gmelin), and ocean pout, Macrozoarces americanus (Block and Schneider).In an activity chamber at a swimming speed of 4 body lengths per second (BL/sec) Atlantic cod swam for about equally long periods at 5 and 8 C, and redfish and winter flounder each about equally long at 5, 8, and 11 C. The pattern was similar for higher speeds. At 14 C winter flounder swam longer at 6 BL/sec than at the lower temperatures. For swimming speeds less than 4 BL/sec all species swam longer at the higher temperatures. At 8 C, the only temperature at which all species were tested, endurance at comparable swimming speeds was greatest for winter flounder, followed by cod, redfish, longhorn sculpin, ocean pout, and sea raven.

On a trypanosome from the Atlantic cod, Gadus morhua L.

1972 ◽  
Vol 50 (7) ◽  
pp. 1051-1054 ◽  
Author(s):  
R. A. Khan
Keyword(s):  
New Zealand ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Infected Fish ◽  
Tautogolabrus Adspersus ◽  
Pseudopleuronectes Americanus ◽  
Blood Samples ◽  
Limanda Ferruginea

Trypanosomes were found in 145 (24%) of 610 Atlantic cod, Gadus morhua L., following examination of centrifuged blood samples. The smallest infected fish measured 26 cm. Generally, parasitemias were higher in cod 26–35 cm long than in larger fish, but were more prevalent among fish 56–70 cm. The parasite could not be transmitted experimentally to Pseudopleuronectes americanus, Myoxocephalus octodecemspinosus, M. scorpius, Tautogolabrus adspersus, or Limanda ferruginea, but uninfected cod were susceptible. The trypanosome appears distinct from Trypanosoma coelorhynchi Laird, 1951 from gadiform fishes in New Zealand waters. It is tentatively identified as T. murmanensis Nikitin, 1927 reported from the same host, G. morhua, captured at Murmansk, U.S.S.R.

Rates of Digestion of Different Prey in Atlantic Cod (Gadus morhua), Ocean Pout (Macrozoarces americanus), Winter Flounder (Pseudopleuronectes americanus), and American Plaice (Hippoglossoides platessoides)

1982 ◽  
Vol 39 (5) ◽  
pp. 651-659 ◽  
Author(s):  
J. Stevenson Macdonald ◽  
Kenneth G. Waiwood ◽  
Roger H. Green
Keyword(s):  
Goodness Of Fit ◽  
Gadus Morhua ◽  
Prey Species ◽  
Atlantic Cod ◽  
Graphical Analysis ◽  
Winter Flounder ◽  
Pseudopleuronectes Americanus ◽  
Evaluation Procedures ◽  
Visual Index ◽  
Hippoglossoides Platessoides

Stomachs of ocean pout (Macrozoarces americanus), Atlantic cod (Gadus morhua), winter flounder (Pseudopleuronectes americanus), and American plaice (Hippoglossoides platessoides) were removed and dissected 5, 12, 20, and 30 h after the fish had fed voluntarily to test the evacuation rates of three different prey species. Two evaluation procedures were used: a visual index of recognizabiiity, and a graphical analysis of percent of each prey recovered versus time since feeding. Three decay models were tested for goodness of fit to the evacuation data. The polychaete worms were the first to become unrecognizable, followed by amphipods. These species showed significantly different rates of evacuation when compared with the bivalves which were recognizable for the longest time. The exponential decay curve gave the best overall fit to the data. However, a linear model gave a good or better fit to the decay rate of the bivalve. The evacuation rates of different prey should be considered in estimating daily rations of fish in their environment.Key words: digestion, stomach content, food organism, Yoldia sapotilla, Tmetonyx cicada, Nephtys incisa

Biology of Crassicutis cichlasomae, a parasite of cichlid fishes in Mexico and Central America

1995 ◽  
Vol 69 (1) ◽  
pp. 69-75 ◽  
Author(s):  
T. Scholz ◽  
M.C.F. Pech-Ek ◽  
R. Rodriguez-Canul
Keyword(s):  
Central America ◽  
Developmental Stages ◽  
Infected Fish ◽  
Constant Darkness ◽  
Intermediate Hosts ◽  
Cichlid Fishes ◽  
Feeding Experiments ◽  
Light Darkness ◽  
Higher Temperature ◽  
Cichlasoma Urophthalmus

AbstractField study on the biology of Crassicutis cichlasomae Manter, 1936 (Digenea: Homalometridae) was carried out in a small swamp in a limestone factory near Mérida, Yucatán, Mexico. Aquatic snails, Littorina (Littoridinopsis) angulifera, harbouring C. cichlasomae rediae, cercariae and metacercariae, served both as the first and second intermediate hosts. Feeding experiments confirmed the conspecificity of metacercariae from naturally infected snails with adults from naturally infected fish. Gravid C. cichlasomae worms were obtained from experimentally infected fish 19 days post exposure at 22–24°C. Examination of fish from the swamp in Mitza and other localities in the Yucatan Peninsula showed that the cichlids Cichlasoma urophthalmus and C. meeki were definitive hosts of C. cichlasomae. There was no pronounced preference of C. cichlasomae adults for the site of their location in the intestine of the definitive host; a slightly higher proportion (41%) of worms was only found in the anterior third of the gut. The time of miracidium development varied from 18.5 to 27.5 days; different temperature (20.1–35.7°C) or light/darkness regimes influenced only slightly the rate of embryonic development, with shorter development times at higher temperature (34.8–35.7°C) and constant darkness and/or light. With the exception of the sporocyst, all developmental stages are described and figured.

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