Molecular systematics of the Australian freshwater shrimp, Paratya australiensis

Molecular genetic date was used to test the taxonomic hypothesis of a single species of the freshwater shrimp, Paratya australiensis. While the results identified significant cryptic diversity, clear species boundaries could not be defined. The results of this study defy a simple taxonomic conclusion but are suggestive of incipient speciation.

Genetic connectivity between trans-oceanic populations of Capreolia implexa (Gelidiales, Rhodophyta) in cool temperate waters of Australasia and Chile.

Capreolia is a monospecific genus of gelidioid red algae and has been considered to be endemic to Australasia. This is the first report on the occurrence of Capreolia implexa outside of Australasian waters, based on investigations of fresh collections in southern Chile as well as Australia and New Zealand. Thalli are prostrate and form entangled turfs, growing on high intertidal rocks at three locations in Chile. Analyses of rbcL and cox1 revealed that C. implexa was of Australasian origin and also distinct from its relatives. Analyses of 1356. bp of cox1 revealed cryptic diversity, consisting of two genealogical groups within C. implexa; one present in Australia and New Zealand, and the other in Chile and Stewart Island, New Zealand. The extremely low genetic diversity found in C. implexa in Chile and the absence of shared haplotypes between Chile and Australasia suggest genetic bottleneck possibly as a result of colonization after dispersal by rafting from Stewart Island, New Zealand to Chile. © 2014 Elsevier B.V.

An integrative approach to characterize Malagasy bats of the subfamily Vespertilioninae Gray, 1821, with the description of a new species of Hypsugo

© 2015 The Linnean Society of London. Although important advances have been made in recent years in the taxonomy of different families and subfamilies of Malagasy bats, those belonging to the Vespertilioninae remain partially unresolved. Herein using a mitochondrial marker (cytochrome b) as the point of departure for 76 specimens of Malagasy vespers and appropriate African taxa, we diagnose the six taxa of this subfamily on the island by overlaying different morphological and bioacoustic characters on the clade structure of sequenced animals. The species include: endemic Neoromicia matroka, which is sister to African N. capensis; endemics N. malagasyensis and N. robertsi, which form sister species; a member of the genus Hypsugo, which is sister to African H. anchietae and described herein as new to science; Pipistrellus hesperidus for which Madagascar animals are genetically close but distinct from African populations of the same species; and endemic P. raceyi, which shows segregation of eastern (mesic) and western (dry) populations and its sister species relationships are unresolved. While the external and craniodental measurements, as well as bioacoustic variables, allow only partial differentiation of these six species of Vespertilioninae, molecular characters provide definitive separation of the taxa, as do male bacular morphology.

The molecular systematics of Leiopotherapon unicolor (Günther, 1859): testing for cryptic speciation in Australia’s most widespread freshwater fish

Leiopotherapon unicolor is the most widespread freshwater fish species in Australia. A comprehensive allozyme and mitochondrial DNA 16S rRNA data set was assembled from 141 specimens of L. unicolor collected Australia-wide in order to test for cryptic speciation in this far-ranging species. Surprisingly, little genetic diversity was observed within L. unicolor and provided no evidence for the existence of cryptic species within this lineage. In contrast, a small sample set of L. aheneus used as the outgroup showed two highly divergent haplotypes strongly suggestive of cryptic speciation. L. unicolor has a number of ecological and life history attributes that may explain the lack of significant genetic divergence over substantial geographical distances. The occurrence of other widespread fish and crustacean species that also display only limited genetic diversity indicate that climate conditions more favourable to dispersal across central and northern Australia than is suggested by the extent of present-day aridity have occurred in the relatively recent geological past.

Invertebrate diversity of the unexplored marine western margin of Australia: taxonomy and implications for global biodiversity

However derived, predictions of global marine species diversity rely on existing real data. All methods, whether based on past rates of species descriptions, on expert opinion, on the fraction of undescribed species in samples collected, or on ratios between taxa in the taxonomic hierarchy, suffer the same limitation. Here we show that infaunal macrofauna (crustaceans and polychaetes) of the lower bathyal depth range are underrepresented among available data and documented results from Australia. The crustacean and polychaete fauna (only partially identified) of the bathyal continental margin of Western Australia comprised 805 species, representing a largely novel and endemic fauna. Overall, 94.6% of crustacean species were undescribed, while 72% of polychaete species were new to the Australian fauna, including all tanaidaceans, amphipods, and cumaceans, as well as most isopods. Most species were rare, and the species accumulation rate showed no sign of reaching an asymptote with increasing area sampled. Similar data are likely for the largely unexplored bathyal regions. This leads us to conclude that the numbers upon which extrapolations to larger areas are based are too low to provide confidence. The Southern Australian and Indo-West Pacific deep-sea regions contribute significantly to global species diversity. These regions and bathyal and abyssal habitats generally are extensive, but are so-far poorly sampled. They appear to be dominated by taxonomically poorly worked and species-rich taxa with limited distributions. The combination of high species richness among infaunal taxa-compared to better known taxa with larger individuals, higher endemism than presently acknowledged because of the presence of cryptic species, the low proportion of described species in these taxa, and the vast extent of unexplored bathyal and abyssal environments-will lead to further accumulation of new species as more and more deep sea regions are explored. It remains to be tested whether ratios of 10 or more undescribed to described species, found in this study for the dominant taxa and for the deep Southern Ocean and the Indo-West Pacific, are replicable in other areas. Our data and similar figures from other remote regions, and the lack of faunal overlap, suggest that Appeltans et al.'s (Current Biology 22:1-14, 2012) estimate that between one-third and two-thirds of the world's marine fauna is undescribed is low, and that Mora et al.'s (PLoS Biol 9(8):e1001127. doi:10.1371/journal.pbio.1001127, 2011) of 91% is more probable. We conclude that estimates of global species, however made, are based on limited data. © 2014 Senckenberg Gesellschaft für Naturforschung and Springer-Verlag Berlin Heidelberg.

Insights into the evolution of a cryptic radiation of bats: dispersal and ecological radiation of Malagasy Miniopterus (Chiroptera: Miniopteridae)

The past decade has seen a proliferation of new species of Miniopterus bats (family Miniopteridae) recognized from Madagascar and the neighboring Comoros archipelago. The interspecific relationships of these taxa, their colonization history, and the evolution of this presumed adaptive radiation have not been sufficiently explored. Using the mitochondrial cytochrome-b gene, we present a phylogeny of the Malagasy members of this widespread Old World genus, based on 218 sequences, of which 82 are new and 136 derived from previous studies. Phylogenetic analyses recovered 18 clades, which divide into five primary lineages: (1) M. griveaudi; (2) M. mahafaliensis, M. sororculus and X3; (3) M. majori, M. gleni and M. griffithsi; (4) M. brachytragos; M. aelleniA, and M. aelleniB; and (5) M. manavi and M. petersoni recovered as sister species, which were in turn linked to a group comprising M. egeri and five genetically distinct populations referred to herein as P3, P4, P5, P6 and P7. Beast analysis indicated that the initial divergence within the Malagasy Miniopterus radiation took place 4.5 Myr; most species diverged between 4 and 2.5 Myr, and a secondary period was between 1.25 and 1 Myr. DNA K2P-distances between recognized taxa ranged from 12.9% to 2.5% and intraspecific variation was less than 1.8%. Of the 18 identified clades, Latin binomials are only associated with 11, which indicates much greater differentiation than currently recognized for Malagasy Miniopterus. These data are placed in a context of the dispersal history of this genus on the island and patterns of ecological diversity.

Genetic analysis along an invasion pathway reveals endemic cryptic taxa, but a single species with little population structure in the introduced range

The invasion pathways of pest arthropods can be traced using genetic tools to develop an understanding of the processes that have shaped successful invasions and to inform both pest management and conservation strategies in their non-native and native ranges, respectively. The redlegged earth mite, Halotydeus destructor, is a major economic pest in Australia, successfully establishing and spreading after arrival from South Africa more than 100 years ago. Halotydeus destructor has recently expanded its range and evolved resistance to numerous pesticides in Australia, raising questions around its origin and spread. Location: South Africa and Australia. Methods: We sampled H. destructor populations in South Africa and Australia and developed a microsatellite marker library. We then examined genetic variation using mtDNA and microsatellite markers across both native and invasive ranges to determine endemic genetic diversity within South Africa, identify the likely origin of invasive populations and test genetic divergence across Australia. Results: The data show that H. destructor comprises a cryptic species complex in South Africa, with putative climatic/host plant associations that may correspond to regional variation. A lineage similar to that found near Cape Town has spread throughout Western and eastern Australia, where populations remain genetically similar. Main conclusions: Tracing the invasion pathway of this economically important pest revealed cryptic lineages in South Africa which points to the need for a taxonomic revision. The absence of significant genetic structure across the wide invasive range of H. destructor within Australia has implications for the development (and spread) of pesticide resistance and also points to recent local adaptation in physiological traits.