Regulation and Stability of a Free-Living Host-Parasite System: Trichostrongylus tenuis in Red Grouse. II. Population Models

10.2307/5339 ◽  
1992 ◽  
Vol 61 (2) ◽  
pp. 487 ◽  
Author(s):  
Andrew P. Dobson ◽  
Peter J. Hudson
Keyword(s):  
Population Models ◽  
Free Living ◽  
Red Grouse ◽  
Host Parasite ◽  
Trichostrongylus Tenuis

Development and survival of the free-living stages of Trichostrongylus tenuis, a caecal parasite of red grouse Lagopus lagopus scoticus

Parasitology ◽  
1989 ◽  
Vol 99 (1) ◽  
pp. 105-113 ◽  
Author(s):  
J. L. Shaw ◽  
R. Moss ◽  
A. W. Pike
Keyword(s):  
Soil Surface ◽  
Winter Survival ◽  
Free Living ◽  
Red Grouse ◽  
Lagopus Lagopus ◽  
Infective Larvae ◽  
Surface Temperatures ◽  
The Mean ◽  
Lagopus Lagopus Scoticus ◽  
Trichostrongylus Tenuis

SUMMARYIn the laboratory, yields of infective 3rd-stage larvae of Trichostrongylus tenuis were determined by temperature when moisture was adequate. On the moor, eggs in caecal faeces did not develop to infective larvae during the winter. In summer, development did occur and yields of infective larvae were related to temperature: greatest yields were obtained when mean monthly soil surface temperatures ranged between 76 and 103°C. Rainfall was unimportant, as was desiccation. During summer the mean monthly mortality of infective larvae was 44% but over winter survival was negligible.

Faecal egg counts provide a reliable measure of Trichostrongylus tenuis intensities in free-living red grouse Lagopus lagopus scoticus

2004 ◽  
Vol 78 (1) ◽  
pp. 69-76 ◽  
Author(s):  
L.J. Seivwright ◽  
S.M. Redpath ◽  
F. Mougeot ◽  
L. Watt ◽  
P.J. Hudson
Keyword(s):  
Storage Time ◽  
Free Living ◽  
Red Grouse ◽  
Lagopus Lagopus ◽  
Counting Methods ◽  
Faecal Egg Counts ◽  
Lagopus Lagopus Scoticus ◽  
Trichostrongylus Tenuis ◽  
High Parasite ◽  
Exact Relationship

AbstractThe reliability of different egg counting methods for estimating the intensity of Trichostrongylus tenuis infections in red grouse, Lagopus lagopus scoticus, was investigated in the autumn, when grouse may harbour high parasite intensities. Possible limitations to the use of these methods were also examined. Faecal egg counts were found to accurately estimate T. tenuis worm intensities, at least up to an observed maximum of c. 8000 worms. Two egg counting methods (smear and McMaster) gave consistent results, although the exact relationship with worm intensity differed according to the method used. Faecal egg counts significantly decreased with increasing length of sample storage time, but egg counts were reliable for estimating worm intensity for three weeks. The concentration of eggs in the caecum was also found to reliably estimate worm intensity. However, egg counts from frozen gut samples cannot be used to estimate worm intensities. These results conclude that, despite some limitations, faecal and caecum egg counts provide useful and reliable ways of measuring T. tenuis intensities in red grouse.

scholarly journals Nematode parasites reduce carotenoid-based signalling in male red grouse

2007 ◽  
Vol 3 (2) ◽  
pp. 161-164 ◽  
Author(s):  
Jesús Martínez-Padilla ◽  
François Mougeot ◽  
Lorenzo Pérez-Rodríguez ◽  
Gary R Bortolotti
Keyword(s):  
Nematode Parasite ◽  
Negative Effects ◽  
Free Living ◽  
Red Grouse ◽  
Carotenoid Concentration ◽  
Nematode Parasites ◽  
Parasite Infections ◽  
Lagopus Lagopus Scoticus ◽  
Trichostrongylus Tenuis ◽  
First Time

Carotenoids determine the yellow–red colours of many ornaments, which often function as signals of quality. Carotenoid-based signalling may reliably advertise health and should be particularly sensitive to parasite infections. Nematodes are among the commonest parasites of vertebrates, with well-documented negative effects on their hosts. However, to date, little is known about the effects that these parasites may have on carotenoid-based signalling. Tetraonid birds (grouse) exhibit supra-orbital combs, which are bright integumentary ornaments pigmented by carotenoids. We tested the effect of the nematode parasite Trichostrongylus tenuis on signalling in free-living male red grouse Lagopus lagopus scoticus . We show that experimentally reduced nematode infection increases plasma carotenoid concentration and comb redness, demonstrating for the first time that nematodes can influence carotenoid-based signals.

The energetic consequences of parasitism: effects of a developing infection of Trichostrongylus tenuis (Nematoda) on red grouse (Lagopus lagopus scoticus) energy balance, body weight and condition

Parasitology ◽  
1995 ◽  
Vol 110 (4) ◽  
pp. 473-482 ◽  
Author(s):  
R. J. Delahay ◽  
J. R. Speakman ◽  
R. Moss
Keyword(s):  
Energy Balance ◽  
Resting Metabolic Rate ◽  
Red Grouse ◽  
Lagopus Lagopus ◽  
Energy Imbalance ◽  
Daily Energy ◽  
Total Daily Energy Expenditure ◽  
Synchronous Development ◽  
Lagopus Lagopus Scoticus ◽  
Trichostrongylus Tenuis

SUMMARYThe timing of the energetic consequences of a developing, single-dose infection of Trichostrongylus tenuis larvae was investigated in captive red grouse Lagopus lagopus scoticus. At 12 days post-infection (p.i.), infected birds had a resting metabolic rate 16% greater than controls and thenceforth lost weight at a faster rate than controls. At 16 days p.i. infected birds consumed 38% less energy and excreted 33% less energy than controls. The estimated total daily energy expenditure and energy expended on activity for infected birds at 16 days p.i. were 36% and 83% lower, respectively, than for controls. Infected birds lost condition from 16 days p.i. onwards. The period of energy imbalance at 12–16 days p.i. coincided with development of late 4th-stage larvae into adult worms and the onset of patency. After this, the effects on energy balance diminished. Synchronous development of previously arrested T. tenuis larvae in wild birds in spring probably has similar effects to those reported here and places grouse under conditions of energy imbalance. The observed effects on energy balance provide a possible mechanism by which the parasite can reduce fecundity and survival of infected grouse.

No Evidence for Resistance to Fenbendazole in Trichostrongylus tenuis, a Nematode Parasite of the Red Grouse

2010 ◽  
Vol 74 (8) ◽  
pp. 1799-1805 ◽  
Author(s):  
Ruth Cox ◽  
David Newborn ◽  
David Baines ◽  
Christopher J. Thomas ◽  
Thomas N. Sherratt
Keyword(s):  
Nematode Parasite ◽  
Red Grouse ◽  
Trichostrongylus Tenuis

scholarly journals Three new red algal parasites from New Zealand: Cladhymenia oblongifoliaphila sp. nov. (Rhodomelaceae), Phycodrys novae-zelandiaephila sp. nov. (Delesseriaceae) and Judithia parasitica sp. nov. (Kallymeniaceae)

2020 ◽  
Author(s):  
Maren Preuss ◽  
Giuseppe Zuccarello
Keyword(s):  
New Zealand ◽  
Host Switching ◽  
Patchy Distribution ◽  
Free Living ◽  
Mitochondrial Markers ◽  
Reproductive Structures ◽  
Phylogenetic Studies ◽  
Red Algal ◽  
Plastid Markers ◽  
Host Parasite

2018 International Phycological Society There are over 120 species of red algal parasites (Florideophyceae) but they are often overlooked due to their small size and patchy distribution. Red algal parasites have mostly been described as independent genera but recent phylogenetic studies have shown that parasites are related to free-living relatives, often their hosts, and have been named in these genera to maintain monophyly. We investigated the morphology, distribution and phylogeny, using diverse molecular markers (mitochondrial, nuclear, plastid), of three new red algal parasites in New Zealand. We describe the parasites using morphological and anatomical observations and estimate their distribution by surveying herbarium vouchers. Analyses of reproductive structures and molecular phylogenies indicate that the closest relative of the parasite Phycodrys novae-zelandiaephila sp. nov. is its host, Phycodrys novae-zelandiae. Based on nuclear and mitochondrial markers, the closest relative of the parasite Cladhymenia oblongifoliaphila sp. nov. is its host Cladhymenia oblongifolia but plastid markers group it with Cladhymenia lyallii, suggesting that this species was a past host and the source of parasite plastids. The parasite Judithia parasitica sp. nov. groups with Judithia delicatissima but infects Blastophyllis spp., suggesting that this parasite evolved as a free-living or parasitic Judithia species, and host switching may have occurred. This study adds to our knowledge of New Zealand red algal parasites and highlights contrasting patterns of host–parasite relationships.

scholarly journals The planktonic stages of the salmon louse (Lepeophtheirus salmonis) are tolerant of end-of-century pCO2 concentrations

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7810 ◽  
Author(s):  
Cameron R.S. Thompson ◽  
David M. Fields ◽  
Reidun M. Bjelland ◽  
Vera B.S. Chan ◽  
Caroline M.F. Durif ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Fatty Acid Content ◽  
Lepeophtheirus Salmonis ◽  
Free Living ◽  
Salmon Aquaculture ◽  
Salmon Lice ◽  
Host Parasite ◽  
Lecithotrophic Development ◽  
High Treatment ◽  
Marine Parasite

The copepod Lepeophtheirus salmonis is an obligate ectoparasite of salmonids. Salmon lice are major pests in salmon aquaculture and due to its economic impact Lepeophtheirus salmonis is one of the most well studied species of marine parasite. However, there is limited understanding of how increased concentration of pCO2 associated with ocean acidification will impact host-parasite relationships. We investigated the effects of increased pCO2 on growth and metabolic rates in the planktonic stages, rearing L. salmonis from eggs to 12 days post hatch copepodids under three treatment levels: Control (416 µatm), Mid (747 µatm), and High (942 µatm). The pCO2 treatment had a significant effect on oxygen consumption rate with the High treatment animals exhibiting the greatest respiration. The treatments did not have a significant effect on the other biological endpoints measured (carbon, nitrogen, lipid volume, and fatty acid content). The results indicate that L. salmonis have mechanisms to compensate for increased concentration of pCO2and that populations will be tolerant of projected future ocean acidification scenarios. The work reported here also describes catabolism during the lecithotrophic development of L. salmonis, information that is not currently available to parameterize models of dispersal and viability of the planktonic free-living stages.

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