Satiation, digestive tract evacuation and return of appetite in the European minnow,Phoxinus phoxinus (Cyprinidae) following short periods of pre-prandial starvation

The helminth fauna of brown trout (Salmo trutta) in the Norwegian subalpine lake, Øvre Heimdalsvatn was studied by examination of gills, eyes, body cavity, kidney, stomach, pyloric region and intestine in a total of 112 brown trout randomly sampled in June, July, and September 2011. Ten helminth species, Discocotyle sagittata, Phyllodistomum umblae, Crepidostomum farionis, C. metoecus, Diplostomum sp., Proteocephalus sp., Cyathocephalus truncatus, Dibothriocephalus ditremus, D. dendriticus, and Capillaria sp. were identified. These data were compared to data from the period 1969 to 1972, just after the first record of the European minnow (Phoxinus phoxinus) in 1969. All ten helminth species, except D. dendriticus, were also present in 1969–72. However, a few major changes in infection intensities have occurred. The cestode D. ditremus and the trematode Diplostomum sp., both with piscivorous birds as final hosts, had markedly higher relative densities (abundance) in brown trout in 2011 compared to 1969–72, while the two Crepidostomum species showed a substantial decline in relative densities. We suggest that these changes may be indirectly related to the establishment and subsequent population increase of European minnow in the lake. The abundance of minnows may have increased the food basis for the piscivorous birds, primarily mergansers and the black-throated diver that now regularly forage in the lake. In addition, there have been changes in the littoral invertebrate community, including species serving as intermediate hosts of some of the brown trout parasites.

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Experiments on Homing in Shoals of the European Minnow, Phoxinus phoxinus (L)

Transactions of the American Fisheries Society ◽

10.1577/1548-8659(1975)104<454:eohiso>2.0.co;2 ◽

1975 ◽

Vol 104 (3) ◽

pp. 454-457 ◽

Cited By ~ 27

Author(s):

G. J. A. Kennedy ◽

T. J. Pitcher

Keyword(s):

Phoxinus Phoxinus ◽

European Minnow

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The ecology of Diplostomum phoxini infections in two minnow (Phoxinus phoxinus) populations in Scotland

Journal of Helminthology ◽

10.1017/s0022149x0001590x ◽

1997 ◽

Vol 71 (3) ◽

pp. 189-196 ◽

Cited By ~ 8

Author(s):

I. Barber ◽

D.W.T. Crompton

Keyword(s):

Environmental Conditions ◽

Fork Length ◽

Transmission Dynamics ◽

Lowland River ◽

Intensity Of Infection ◽

Phoxinus Phoxinus ◽

European Minnow ◽

Infection Dynamics ◽

The Brain ◽

Two Populations

AbstractData are presented on the infection dynamics of the brain-dwelling metacercariae of Diplostomum phoxini (Digenea: Trematoda) parasitizing European minnow (Phoxinus phoxinus) populations in a lowland river (River Endrick) and a highland loch (Loch Maragan) in central Scotland. Prevalence of the parasite approached 100% in all samples taken from both populations over a 12-month period, and within each population the intensity of infection increased with increasing host fork length. However, the two relationships differed, and size-matched minnows from the Endrick exhibited significantly higher intensities than those from Loch Maragan, suggesting that metacercarial acquisition occurred at different rates in the two populations. Data regarding seasonal trends in the acquisition of D. phoxini indicated that fish in both populations become infected with the parasites mainly during the spring and summer, with negligible infection occurring during winter months. Analysis of size-matched fish from individual samples revealed apparent differences in the distribution of D. phoxini within the two host populations. Whereas D. phoxini metacercariae appeared to be overdispersed amongst length-matched fish from Loch Maragan samples, the parasite was distributed normally amongst fish from the Endrick. Possible reasons for the observed differences in the infection characteristics of D. phoxini in the two minnow populations are discussed, with reference to the parasite's transmission dynamics and local environmental conditions.

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