New stygobiont copepods (Calanoida; Misophrioida) from Bundera Sinkhole, an anchialine cenote in north-western Australia

Abstract

Two new taxa in the copepod orders Calanoida and Misophrioida are described from the flooded coastal karst of north-western Australia. Stygocyclopia australis sp. nov. is the first pseudocyclopiid calanoid to be reported from the continent, with other congeners distributed in anchialine environments of the Philippine, Balearic, and Canary archipelagos. The presence of a supernumerary spine on the outer margin of the first exopod segment of leg 3 in this species is discussed in the context of the Neocopepodan groundpattern. Speleophria bunderae sp. nov. is the first representative of the order Misophrioida known from Australia, with other congeners in the Balearics, Bermuda, and the Yucatan peninsula of Mexico. Both taxa co-exist in the deeper higher salinity layers of a single sinkhole in Cape Range peninsula. The placement of these taxa in strictly stygobiont genera represented by very localized and disjunct species distributed over regions flooded by the late Mesozoic seas, lends support to their interpretation as true Tethyan relicts, and hence to the inclusion in the past of the Northwest portion of Australia in the Tethyan realm. The remains of S. bunderae in the gut contents of a stygobiont epacteriscid calanoid is recorded.