Does the IUCN Red-Listing ‘Criteria B’ do justice for smaller aquatic plants? A case study from Sri Lankan Aponogetons

The IUCN Red List of threatened species is recognised as the accepted standard for species global extinction risk worldwide, and the criteria led down for evaluation are considered as one of the best methods to evaluate extinction risk of species at the global and regional levels.The IUCN’s Red List categories are given more emphasis in determining the conservation status of species and for prioritizing conservation strategies upon these threatened species. The guidelines for evaluation are laid down comprehensively to minimize errors and to maintain consistency of Red List assessments across taxa. However in some cases, it seems that the assessments based on current IUCN criteria do not accurately reflect the real extinction risk of some taxonomic groups. This is not owing to the quality or quantity of the data produced, but rather to some methodological artifacts that affects certain groups of taxa. In this paper we discuss such an event considering an aquatic plant group; genus Aponogeton; from Sri Lanka. All the known Sri Lankan Aponogeton species have been evaluated under the Criteria B adhering to the given IUCN guidelines and the results suggest that such smaller aquatic plants with high habitat specificity are at a disadvantage when securing their conservation statuses, and thereby lose the protection they deserve through legislations. This study emphasises the obligation of much comprehensive evaluation criteria to estimate the AOO in different plant categories.</p

Divergent east-west lineages in an Australian fruit fly, (Bactrocera jarvisi), associated with the Carpentaria Basin divide

Bactrocera jarvisi is an endemic Australian fruit fly species (Diptera: Tephritidae). It occurs commonly across tropical and subtropical coastal Australia, from far-northern Western Australia, across the ‘Top End’ of the Northern Territory, and then down the Queensland east coast. Across this range, its distribution crosses several well documented biogeographic barriers. In order to better understand factors leading to the divergence of Australian fruit fly lineages, we carried out a population genetic study of B. jarvisi from across its range using genome-wide SNP analysis, utilising adult specimens gained from trapping and fruit rearing. Populations from the Northern Territory (NT) and Western Australia were genetically similar to each other, but divergent from the genetically uniform east-coast (= Queensland, QLD) population. Phylogenetic analysis demonstrated that the NT population derived from the QLD population. We infer a role for the Carpentaria Basin as a biogeographic barrier restricting east-west gene flow. The QLD populations were largely panmictic and recognised east-coast biogeographic barriers play no part in north-south population structuring. While the NT and QLD populations were genetically distinct, there was evidence for the historically recent translocation of flies from each region to the other. Flies reared from different host fruits collected in the same location showed no genetic divergence. While a role for the Carpentaria Basin as a barrier to gene flow for Australian fruit flies agrees with existing work on the related B. tryoni, the reason(s) for population panmixia for B. jarvisi (and B. tryoni) over the entire Queensland east coast, a linear north-south distance of >2000km, remains unknown.</p

Conservation genetics of Notelaea lloydii (Oleaceae) in south‐eastern Queensland, Australia

Abstract Habitat fragmentation can increase the chance of population bottlenecks and inbreeding, and may ultimately lead to reduced fitness and local extinction. Notelaea lloydii is a native olive species endemic to Australia and listed as vulnerable due to its restricted distribution. A recent molecular systematics study has revealed there might be some geographic structuring among N. lloydii populations. Therefore, we undertook a genome‐wide single nucleotide polymorphism (SNP) analysis to determine levels and patterns of genetic diversity, inbreeding and gene flow within and among N. lloydii populations in south‐eastern Queensland. Furthermore, as the reproductive phase of a plant's life history has a profound influence on genetic diversity, life history reproductive traits were also studied. Our SNP analysis revealed low genetic diversity, inbreeding and significant genetic structuring even among proximate populations. Results of a flower and fruit bagging experiment in two consecutive seasons revealed that N. lloydii produced many flowers but only a few fruits survived to maturity. There were no differences in bagged and un‐bagged flowering and fruiting rates, and therefore, we conclude that the high fruit abortion rate was probably due to inbreeding depression and/or suboptimal conditions, rather than pollinator availability and insect attack. Overall, results of this study indicate that the populations of N. lloydii are small, inbred and genetically isolated and represent unique management units that require local conservation management due to ongoing threats associated with urbanisation