The diversity within the
genus <i>Nactus</i> is slight in comparison
to the other Australasian genus of narrow-toed geckos (<i>Cyrtodactylus</i>). The latter now has more than 290 species, with over
half of these species newly described in the twenty-first century. In contrast,
prior to this study, 12 <i>Nactus </i>species
were recognized formally in the recent herpetological literature: three species
in the Mascarene Islands, two in the Pacific Islands, three in Australia, and
six in New Guinea and associated island groups. Three of these New Guinea
species are miniature (snout–vent length ≤ 40 mm) species, and three are in the
<i>pelagicus</i> complex; with the exception
of the recently described <i>N. kunan</i>,
all other New Guinean populations were labeled <i>N. pelagicus</i> even though they were known to be bisexual species and
differed from the unisexual <i>N. pelagicus </i>of
Oceania. Considering only bisexual New Guinean “<i>pelagicus</i>,” my
morphological analyses recognize 24 distinct populations for which I provide
new names or resurrected species names from synonymies. Of these 24, two
species are extralimital (Morotai and Kei Islands). The sampling of <i>Nactus</i> in Indonesia Papua is very poor,
with only one specimen from the base of the Vogelkop, two from south coast
drainages, and more than a dozen from islands from the east coast of Cenderawasih
Bay; the remainder derive from Papua New Guinea (PNG). The Indonesia Papua
populations represent four species, two of which are shared with PNG. Papua New
Guinea thus has a total of 20 species, varying from widespread species (e.g.,
north coast of main Papua to the Sepik-Ramu area) to a single locality in
Madang or single islands in the Louisiade Archipelago. Most distributions of
the PNG species match at least one other PNG anuran or reptile species. The
greatest diversity of PNG species occurs in Madang Province to Huon Peninsula
and the Milne Bay mainland with sympatry in both areas. The “<i>pelagicus</i> complex” of species is herein
confirmed to be polyphyletic. In spite of its use in this study, its subsequent
use should be restricted to the unisexual species and their parental species,
of which only one (<i>N. multicarinatus</i>)
is known. The preceding represents a subgroup within the larger clade of
Australian and New Guinean bisexual species. For the present, I do not
recommend a name for this group because a molecular phylogenetic analysis will
be required to identify the cladogenesis of the <i>Nactus</i> species.
Investigating within-village spatial heterogeneity of malaria infection over time on the north-coast of Papua New Guinea