Groundwater annelids from Gran Canaria and Fuerteventura (Canary Islands), with the description of two new species of Namanereis (Namanereidinae, Nereididae, Polychaeta)

Abstract

The Canary Islands are the richest volcanic region in the world in subterranean adapted fauna, followed by the Hawaiian Islands and the Undara Cave in Australia. Most of the subterranean adapted aquatic fauna from the Canary Islands is restricted to the anchialine environments in La Corona lava tube in Lanzarote, while the oligohaline stygobiont fauna, usually found in groundwater or interstitial freshwaters, is scarcer and represented by a few species of amphipods, copepods, and a single polychaete annelid recorded from Fuerteventura and doubtfully identified as Namanereis hummelincki (non Augener, 1933) (Hartmann-Schröder, 1988). Two new species of polychaete annelids belonging to the subfamily Namanereidinae are described from Gran Canaria and Fuerteventura. Both species live in groundwater, are depigmented and eyeless, and have bifid jaws. Although they are seemingly more related to each other than to other members of the bifid-jaw group, Namanereis canariarum sp. nov. can be diagnosed by its relatively longer tentacular cirri and parapodial dorsal cirri, as well as the presence of pseudospiniger chaetae. In contrast, Namanereis llanetensis sp. nov. has shorter cirri and usually lacks pseudospiniger chaetae. Namanereis canariarum sp. nov. and Namanereis llanetensis sp. nov. increase to 20 the total number of currently described species within this enigmatic genus. More than half of those species are adapted to live in groundwaters.