The helminth fauna of brown trout (Salmo trutta) from a sub-alpine lake revisited after 40 years with introduced European minnow (Phoxinus phoxinus) Author Borgstrøm, Reidar Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, PO Box 5003 NMBU, NO- 1432 Ås, Norway Author Mestrand, Øyvind Hatleli Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, PO Box 5003 NMBU, NO- 1432 Ås, Norway Author Brittain, John E. Natural History Museum, University of Oslo, PO Box 1172 Blindern, NO- 0318 Oslo, Norway Author Lien, Leif Vollsveien 62, NO- 1358 Jar, Norway text Fauna norvegica 2021 2021-05-27 41 15 26 https://doi.org/10.5324/fn.v41i0.3952 journal article 312116 10.5324/fn.v41i0.3952 13a2e256-da0e-4f1e-9d5f-379c05bf6317 1891-5396 16906961

Table 4. Summary of the helminth fauna of brown trout from the lake Øvre Heimdalsvatn, as relative density (abundance) of the different helminth species recorded in the age-classes 3-4, 5, 6, and ≥7 winters in 1969-72 (Lien 1976), and in the present study from 2011. Numbers in parentheses represent total number of examined fish.

		1969 – 1972 Age-class (winters)				2011 Age-class (winters)
Helminth species	3–4 (69)	5 (84)	6 (78)	≥7 (98)	3–4 (22)	5 (16)	6 (15)	≥7 (59)
Discocotyle sagittata	0.5	1.7	2.4	4.7	0.6	2.6	5.6	6.8
Phyllodistomum umblae	13.7	10.8	9.2	6.3	0.6	5.2	9.3	5.0
Crepidostomum spp. (two species)	147.0	229.0	234.0	233.0	11.2	16.7	18.9	26.5
Diplostomum sp.	12.0	10.8	5.9	17.2	17.0	59.6	54.8	78.4
Proteocephalus sp.	13.5	11.8	11.4	7.8	0.1	0.0	0.5	0.9
Cyathocephalus truncatus	3.1	4.9	7.3	9.7	0.3	0.6	1.2	2.0
Dibothriocephalus ditremus	0.0	0.0	0.0	0.1	0.5	4.1	3.0	13.7
Dibothriocephalus dendriticus	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.02
Capillaria sp.	1.1	1.6	0.8	0.6	0.2	0.9	0.9	1.0
Eustrongylides sp.	0.0	0.0	0.0	0.01	0.0	0.0	0.0	0.0