Mixodiaptomus laciniatus
The appearance of the last thorax in Mixodiaptomus laciniatus is laterally produced into two very conspicuous lobes. It has colonized a number of lakes after liming and is categorized as a weakly acid-sensitive species.
Key characteristics
Mixodiaptomus laciniatus is a medium sized, rather robust calanoid species. Adult females can not be mixed up with any other species because of the appearance of the last thorax segment. On both sides this segment laterally is produced into two very conspicuous lobes. P5 can easily be used to identify adult males. The colour of M. laciniatus is sometimes dark blue and sometimes reddish orange.
Female: Length 1.0–1.6 mm
Male: Length 1.0–1.4 mm
Ecology and distribution
Except for the areas east of Oslo, M. laciniatus is widely distributed and found in more than 10 % of the localities. Except for very small ponds (< 0.01 ha), surface area doesn't seem to affect its distribution. It occurs at all elevations, but is the only copepod which occurs with highest frequency in water bodies above 1000 m a.s.l. M. laciniatus has colonized a number of lakes after liming and is categorized as a weakly acid-sensitive species. Except for a few, all records are from localities with pH ranging from 5.5 to 7.7. It is rare in very electrolyte rich water (>10 mS/m).
Conductivity (m S/m)
Surface area (da)
Elevation (m a.s.l.)