Genetic structure of Australian glass shrimp,Paratya australiensis,in relation to altitude

Abstract

Paratya australiensis Kemp (Decapoda: Atyidae) is a widely distributed freshwater shrimp in eastern Australia. The species has been considered as an important stream organism for studying genetics, dispersal, biology, behaviour and evolution in atyids and is a major food source for stream dwelling fishes. Paratya australiensis is a cryptic species complex consisting of nine highly divergent mitochondrial DNA lineages. Previous studies in southeast Queensland showed that “lineage 4” favours upstream sites at higher altitudes, with cooler water temperatures. This study aims to identify putative selection and population structure between high elevation and low elevation populations of this lineage at relatively small spatial scales. Sample localities were selected from three streams: Booloumba Creek, Broken Bridge Creek and Obi Obi Creek in the Conondale Range, southeast Queensland. Six sample localities, consisting of 142 individuals in total were sequenced using double digest Restriction Site Associated DNA-sequencing (ddRAD-seq) technique. Among the 142 individuals, 131 individuals shared 213 loci. Outlier analysis on 213 loci showed that 27 loci were putatively under selection between high elevation and low elevation populations. Outlier analysis on individual streams was also done to test for parallel patterns of adaptation, but there was no evidence of a parallel pattern. Population structure was observed using both the 27 outliers and 186 neutral loci and revealed similar population structure in both cases. Therefore, we cannot differentiate between selection and drift here. The highest genetic differentiation was observed between high elevation and low elevation populations of Booloumba Creek, with small levels of differentiation in the other two streams.

Evidence of mitochondrial capture in Australian glass shrimp (

“…Influence of elevation on Paratya population was reported by Cook et al (2006) who mentioned that Paratya populations were isolated by steep stream gradients among the upland sites and between upland and lowland sites in Granite Creek in Victoria. Also, Rahman et al (2020) found highest genetic differentiation between high-elevation and low-elevation populations (Paratya) in Booloumba Creek in Queensland. So, there is evidence for influence of elevation on Paratya populations.…”

Plasticity of upper thermal limits of Australian Paratya spp. (Decapoda, Atyidae) and considerations of climate-change adaptation

“…Paratya spp. are the most widespread atyid freshwater shrimp in eastern Australia, found in upland and lowland streams, dams and retention ponds, with distribution from southern Queensland to eastern South Australia (Cook et al 2006;Rahman et al 2020). Prior to a reclassification by Suter et al (2022), it was believed that only a single highly variable Paratya species (Paratya australiensis) occurred in Australia.…”

“…Temperature is the most critical factor influencing the breeding season of Australian Paratya spp., with hydrology a secondary influence (Hancock and Bunn 1997). In contrast to the tropical regions, the breeding season of Paratya in temperate and subtropical regions is confined to the warm summer months (Hancock and Bunn 1997;Rahman et al 2020). Paratya spp.…”

“…may change and their distribution may be reduced or shifted southward as a response to increasing stream temperatures that exceed their ULT. This may mean a loss of biodiversity if some species of Australian Paratya are restricted to high elevations (Rahman et al 2020). Field examinations could assess species distribution and predict distribution limits (Chessman 2018;Terblanche and Hoffmann 2020).…”

“…As filter feeders and grazers, shrimp play a key role in stream communities (Moulton et al 2012: Suter et al 2022. They are essential in controlling periphyton biomass (Moulton et al 2012) and are a major food source for streamdwelling fishes such as Mogurnda adspersa and Tandanus tandanus; they are also preyed on by Ornithorhynchus anatinus (platypus) (Bain et al 2016;Rahman et al 2020). Their loss may also have stream health impacts because they are consumers of periphyton and, hence, important for ecosystem functioning (Moulton et al 2012).…”