AbstractA new and putatively endemic species ofHydroclathrus,Hydroclathrus rapanuii, is described from the geographically isolated Easter Island in the southeastern Pacific based on morphological and molecular phylogenetic data. It is distinguished from otherHydroclathrusby thalli of unevenly furrowed thin membranes, and angular, block-like plurangial sori. Our phylogenetic analyses indicated thatH. rapanuiiis closely related to the generitypeHydroclathrus clathratus. We also report on the morphology and phylogeny ofChnoospora minimafrom Easter I. and elsewhere in the Indo-Pacific Ocean, noting the previously unreported presence of hollow portions in its medulla. Although not collected from Easter I., we herein propose the recognition of two new genera,Dactylosiphongen. nov. andPseudochnoosporagen. nov., based on our three-gene phylogeny and their known morphologies and anatomies.Dactylosiphonis based on the three species currently assigned toColpomenia(C. bullosa,C. durvillei, andC. wynnei) that are genetically and morphologically (i.e. thalli with erect and finger-like tubes arising from a common saccate base) distinct from other members ofColpomenia. The monotypic genusPseudochnoosporais represented by the decumbent, branching, and inter-adhesive species currently known asChnoospora implexa. With the above proposals, we further increase the genus-level diversity of Scytosiphonaceae in the Indo-Pacific Ocean.
The 2004 Sumatra tsunami in the Southeastern Pacific Ocean: New Global Insight from Observations and Modeling
