Two new endemic species of leucothoid amphipods (Amphipoda: Leucothoidae) from New Zealand and northeastern Indonesia

Abstract

Abstract Leucothoid amphipods are commensal associates of invertebrate hosts, displaying a wide range of host specificity. Amphipods also demonstrate high levels of endemism, long thought to be due to their lack of a planktonic dispersal stage. The biodiversity of endemic species can be compared biogeographically, making amphipods useful proxies in monitoring ecosystem change. Two new species are described herein, both apparently endemic to their respective regions: Leucothoe panjangsp. nov. from Raja Ampat Archipelago, eastern Indonesia and Leucothoe wheromurasp. nov. from New Zealand. Both new species demonstrate host specificity and fit into a group of Leucothoe species that share the “Paraleucothoe” form of gnathopod 1, with an expanded basis, curved propodus, and short dactylus. The distribution of these new species supports the 12 realms of biogeography for amphipods, suggesting that patterns of amphipod endemicity are less likely due to a lack of dispersal than they are dependent on geological history.