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The genus
Dysdera includes roughly 250 species of middle size, ground
dwelling, nocturnal hunter spiders, mostly circumscribed to the
Mediterranean basin. The genus also colonized the Macaronesian
archipelagoes, in the north Atlantic Ocean, and in some of them
undergone remarkable local diversification. In spite of
extensive fieldwork, the Azores stands as the only archipelago
were endemic Dysdera have never been reported so far.
Several years
ago, we located a vial from the British Museum containing three
individuals of an undescribed Dysdera species collected
in 1953 in the island of Pico. However, because of their
uncertain affinities and the lack of new records, we considered
either the species extinct.
Our ongoing
research on the systematics of Madeiran Dysdera has
recently unraveled a new species, inhabiting the intertidal of
Ilhéu de Cima (Porto Santo), unrelated to the remaining endemic
species. Surprisingly, this species showed clear morphological
affinities with the Pico specimens.
Given the
specialized ecology of the new Madeira species, we returned to
Azores to collect in coastal habitats and found similar
specimens in two separate islands. Our morphological and
molecular data confirm the existence of endemic Dysdera
species in Azores and support their close relationship to the
intertidal species from Madeira. |