Table 1.

Prevalence (% fish infected) and mean abundance (number of parasites per fish ±SE) of the six metazoan parasite species detected in three morphs of threespine stickleback in Thingvallavatn and two morphs in Myvatn, Iceland

	Thingvallavatn			Myvatn
Parasite	Mud (warm) n = 39	Nitella (cold) n = 78	Lava (cold) n = 73	Mud (cold) n = 29	Lava (warm) n = 27
Diphyllobothrium spp. (body cavity)	56.4 2.8 ± 0.6	65.44.2 ± 0.7	41.11.3 ± 0.3	0.00.0	0.00.0
Proteocephalus sp. (intestine)	15.40.7 ± 0.5	74.43.3 ± 0.5	30.10.5 ± 0.1	3.40.03 ± 0.03	3.70.04 ± 0.04
Schistocephalus solidus (body cavity)	0.00.0	0.00.0	2.70.03 ± 0.02	6.90.07 ± 0.05	25.92.2 ± 1.0
Apatemon sp. (eye humor)	–	–	79.72.3 ± 0.2	62.11.1 ± 0.2	63.01.0 ± 0.2
Diplostomum baeri (eye humor)	97.416.2 ± 2.8	98.78.0 ± 0.6	90.45.1 ± 0.8	89.78.5 ± 1.9	100.037.1 ± 5.3
Diplostomum spp. (eye lens)	0.00.0	0.00.0	0.00.0	3.40.03 ± 0.03	40.71.0 ± 0.3

Note that Apatemon sp. was not studied in two morphs in Thingvallavatn. Warm/cold refer to water temperature in the habitat of each morph.