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1

Cykl rozwojowy Caligus elongatus von Nordmann, 1832 [Crustacea, Cepopoda, Siphonostomatoida]

100%
Piasecki W.
Rozprawy. Akademia Rolnicza w Szczecinie
|
1995
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tom 165
69
2

Intra- or inter-specific difference in genotypes of Caligus elongatus Nordmann 1832?

100%
Oines O., Schram T.
Acta Parasitologica
|
2008
|
tom 53
|
nr 1
Two mitochondrial and one nuclear genetic marker were used to study the phylogenetic position of the two reported CO1-genotypes of Caligus elongatus in a group of closely related caligid parasites. Molecular analysis of the two mitochondrial genes (CO1 and 16S), indicate genetic distances of the two C. elongatus genotypes in the lower range of distances previously reported between other crustacean species, but higher than comparable reported within-species differences. Analyses of nuclear 18S sequences indicate no detectable differentiation between these genotypes, but may be due to expected differences in the resolution of these genetic markers. Investigation of two of three selected morphological characters reveals phenotypes supporting the division based on the molecular division. The species status on the two C. elongatus genotypes cannot be drawn conclusively, although the molecular and morphological data presented here suggests the presence of sibling species.
3
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Factors affecting the susceptibility of sea lice infection in Atlantic salmon

84%
Mustafa A., Piasecki W.
Wiadomości Parazytologiczne
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2005
|
tom 51
|
nr 4
4

Annual and spatial variability in endo- and ectoparasite infections of North Sea cod (Gadus morhua Linnaeus, 1758) larvae, post-larvae and juveniles

67%
Mehrdana F., Bahlool Q. Z. M., Skovgaard A., Kuhn J. A., Kania P. W., Munk P., Buchmann K.
Acta Parasitologica
|
2014
|
tom 59
|
nr 2
A parasitological investigation was performed on a total of 5380 Atlantic cod larvae, post-larvae and small juveniles sampled from the North Sea during a period of five years. The copepod Caligus elongatus (Von Nordmann, 1832) and the nematode Hysterothylacium aduncum (Rudolphi, 1802) were found at a relatively high prevalence of infection (4.6% and 5.2%, respectively). The infection by both parasites showed annual and spatial variability. C. elongatus showed a higher prevalence in 1992 compared to the following years, whereas the prevalence of H. aduncum increased from 1992 to 2001.We observed a relation between parasite distribution and parameters such as latitude and water depth. Adult digeneans (Lecithaster gibbosus and Derogenes varicus) and larval cestodes were also found with lower infection rates. Since changes of infection levels coincided with increasing North Sea water temperature in the studied period, it is hypothesized that temperature may affect parasite population levels. However, it is likely that other environmental factors may contribute to the observed variations. Absence of infection intensities higher than one nematode per fish in small larvae and post-larvae suggests that host survival may be affected by a high infection pressure. The relatively high levels of infection in the younger stages of cod, and the annual/spatial variability of these infections should be considered in the understanding of the early life dynamics of the species.
5

Interspecific differences between Atlantic salmon and Arctic charr in susceptibility to infection with larval and adult Caligus elongatus: effect of skin mucus protein profiles and epidermal histological differences

67%
Mustafa A., Mackinnon B. M., Piasecki W.
Acta Ichthyologica et Piscatoria
|
2005
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tom 35
|
nr 1
Background. Arctic charr, Salvelinus alpinus (L.), are known to harbour significantly more sea lice, Caligus elongatus von Nordmann, 1832, than do Atlantic salmon, Salmo salar L. This research investigated whether this is due to differences in initial infection or to resettlement/loss of mobile adults. Skin mucus protein profiles and epidermal histology were also studied as two characteristics that might help explain interspecific differences in host susceptibility. Materials and Methods. Atlantic salmon and Arctic charr were sampled from the sea-pen after 12 weeks of exposure to natural infection. Fishes were examined for sea lice counts and mucus was analysed for protein profiles using standard methods of poly-acrylamide gel electrophoresis. Epidermal tissue of fishes around chalimus attachment sites was also examined by transmission electron microscopy. Results. Interspecific differences in host susceptibility were determined not to be due to differences in initial infection rate, as charr and salmon had similar numbers of attached chalimi. Adult parasites were significantly more numerous on charr as a result of resettlement of adults lost by other fishes in the area. Gel electrophoresis indicated that salmon had a greater abundance of skin mucus proteins than charr, particularly in the 30–42 and 67–94 kDa range. Ultrastructural analysis of epidermal tissue indicated that charr had more mucous cells and showed evidence of possible osmotic stress. Interspecific differences also existed in intercellular adhesion characteristics. Salmon and charr showed a similar absence of inflammation around chalimus attachment sites. Conclusion. Artic charr had a more intense infection with Caligus elongatus than did salmon corresponding to fewer potentially antagonistic proteins in the mucus. Perhaps also, the epidermis of charr provides more easily accessible food for the sea lice. Higher levels of stress in charr in sea water may also have predisposed them to higher sea lice infections.
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