| Abstract |
Numerous specimens of the genus _Munidopsis_ from the East Pacific, and including the East Pacific Rise (EPR), are reviewed using
morphological characters and mitochondrial cytochrome oxidase subunit I (COI) sequences. Six new _Munidopsis_ species from the East
Pacific are described (_M. bracteosa, M. hirsuta, M. kensmithi, M. scotti, M. segonzaci,_ and _M. tiburon_), and the status of _M. recta_ is
revised. A seventh new species (_M. vrijenhoeki_) from Fiji Basin (SW Pacific) is also included. A combined morphological and molecular
analysis revealed that the most common species on the EPR is _Munidopsis recta_. Most of the new species can be differentiated from
closely related species by subtle morphological characters, which correspondingly match the molecular phylogeny and large molecular
divergence, confirming the existence of sibling species in the genus _Munidopsis_. Most _Munidopsis_ individuals formerly considered
_M. subsquamosa_ from the East Pacific Rise appear to be members of _M. recta_. One potential sister taxa to _M. recta_ is _M. bracteosa_, which
is found at the Juan de Fuca hydrothermal vents, the Mendocino Fracture Zone, and a Monterey Bay whalefall. Our findings suggest that
_Munidopsis_ populations are tightly interconnected between distant and discrete locations, and challenge models for the predicted dispersal
of these species. Additional sampling of _Munidopsis_ populations on localized habitats (wood, hydrothermal vents, and whale falls), as well
as intervening abyssal areas, are required to fully understand the complex evolutionary history and diversity of this group. |
