Geographic patterns of endemism and speciation in amphibians and reptiles of the Ryukyu Archipelago, Japan, with special reference to their paleogeographical implications

Abstract

This paper analyzes the phylogeographical patterns of amphibian and reptile lineages distributed in the Ryukyu islands south of the Tokara Gap on the basis of relevant distributional data and phylogenetic hypotheses hitherto published. Results indicate the numerical dominance of highly relict lineages in the central Ryukyus, and the occurences of a few more or less relict lineages in the Miyako Group as well. On the other hand, most species and subspecies endemic to the Yaeyama Group or to the Yaeyama and Miyako Groups are considered to be direct consequences of vicariance with adjacent regions. Three major hypotheses regarding the Cenozoic paleogeography of the central and the southern Ryukyus are examined in the light of the present results and a modified hypothesis is proposed accordingly.

Phylogenetic Relationships of Eublepharid Geckos (Reptilia: Squamata): A Molecular Approach

“…The relatively poor support for the closest affinity between the two Goniurosaurus species examined may be attributable to their relatively long isolation as is also implied by the highly relict distribution of the genus (Ota, 1998). This ad hoc assumption needs verifications by incorporating data for the other Goniurosaurus species, G. lichtenfelderi, into future analyses.…”

Phylogeny, Taxonomy, and Biogeography of the Oriental Pitvipers of the Genus Trimeresurus (Reptilia: Viperidae: Crotalinae): A Molecular Perspective

“…However, even if this is actually the case, it will not lead to any substantial changes in the above-mentioned view on the historical biogeography of T. flavoviridis and T. tokarensis, because geographic ranges of those four species were also confined to far inland of the continent like that of T. jerdonii (Zhao and Adler, 1993;Zhao et al, 1998). It is thus likely that the flavoviridis-tokarensis clade of the central Ryukyus is in a relict state like several other reptiles occurring in this region (Hikida and Ota, 1997;Ota, 1998).…”

Mosquito Biodiversity Patterns Around Urban Environments in South-Central Okinawa Island, Japan

“…Okinawa, as the largest and most densely populated island in the subtropical Ryukyu Archipelago, consists of approximately 200 islands (Ota 1998). Several studies have shown the mosquito fauna of the Ryukyus to be extremely diverse (Miyagi 1976, Toma and Miyagi 1986, Miyagi et al 1990, Okudo et al 2004, with more than half of Japan's mosquito species present in the archipelago, which accounts for ,1% of Japan's territory (Toma 2002).…”

“…Several studies have shown the mosquito fauna of the Ryukyus to be extremely diverse (Miyagi 1976, Toma and Miyagi 1986, Miyagi et al 1990, Okudo et al 2004, with more than half of Japan's mosquito species present in the archipelago, which accounts for ,1% of Japan's territory (Toma 2002). The Ryukyu Archipelago islands are continental and were connected with East Eurasia during the last glaciation by means of a land bridge connecting the island of Kyushu to southeastern China via Taiwan (Ota 1998). It is likely that this complex history, a relatively stable subtropical climate, widespread natural vegetation, and the abundance and diversity of natural habitats underpin the extraordinary patterns of mosquito species diversity in the archipelago (Toma and Miyagi 1986).…”