MAY 2025
Jaera nordmanni balearica (Margalef, 1952) MBCN26611
Jaera nordmanni balearica is a subspecies of freshwater isopod crustacean, endemic to the town of Sóller. This means that, worldwide, it can only be found in a few irrigation channels in this specific locality. These are very small animals, reaching up to 3.6 mm in length. Their body is semi-transparent orange, oval in shape, and strongly flattened.
The species Jaera nordmanni is marine. However, at some point in the past, a population migrated upstream along the stream, eventually establishing a freshwater population isolated from marine influence. Over time, this population evolved into a slightly different form, which led to its description as a distinct subspecies. A similar phenomenon occurred in the Esporles stream, where the species Jaera nordmanni brevicaudata is found.
Origin: Sóller, Mallorca.
Age: Present day.
