Three new species of the genus Caridina are described from the northernmost part of Australia. Caridina darwin n. sp. resembles Caridina temasek Choy and Ng, 1991 but differs in the armature of the ...rostrum, the development of epipods on the pereiopods and the absence of an appendix interna on the male first pleopods. Caridina magnovis n. sp. resembles Caridina serratirostris de Man, 1892 but differs in the armature of the ventral margin of the rostrum, a shorter stylocerite, a stouter carpus of the first pereiopod, the number and size of spiniform setae on the third and fifth pereiopods, the shape of the preanal carina and the size of the embryos (referred to as “eggs” in most previous publications). Caridina wilsoni n. sp. resembles Caridina gracilirostris de Man, 1892 but differs in the size of the embryos and in some length to width ratios of the segments of the pereiopods. Detailed morphological descriptions of all three new species are given. A molecular phylogeny (mt DNA 16S) supports the morphospecies hypothesis and illustrates the phylogenetic relationship with morphologically similar species from outside Australia.
is described from streams in Guangxi, south-western China. The new species clearly belongs to "
group" of the genus and shows a morphological similarity with
Yu, 1938,
Stimpson, 1860 and
Do et al. ...2020.
is distinguished from congeners, based on differences in its male first pleopod and appendix masculina morphology, along with COI and 16S rRNA molecular evidence. The first pleopod endopod in male is rectangle, about 0.70 × length of exopod, about 3.7-3.9 × as long as proximally wide, inner margin concave, bearing nearly equal spine setae, outer margin bearing nearly equal long and dense spine setae; appendix interna well developed, arising from distal 1/5 of endopod, reaching to end of endopod, with cincinuli distally. The new species displays a unique and brightly coloured pattern and, therefore, can be easily recognised in the field. Liang & Zhou, 1993 described
from the Lenggu Cave, Du'an County, Guangxi. However, the description was based exclusively on two females. We have collected specimens of both sexes near the type locality and describe herein the previously unknown male and present morphological data on females. Data on the habitat, ecology and levels of threat of the two species are provided and suggest that they should be categorised as vulnerable (VU) under the current IUCN Criteria.
Groundwater ecosystems have a diverse and unique fauna, often dominated by Crustacea and generally characterised by short range endemics confined to single aquifers. Much of this knowledge has come ...from studies conducted either in fractured rock aquifers or alluvial aquifers. Karstic subterranean environments are present in the Cambrian Limestone Aquifer (CLA) in the Northern Territory, Australia, a freshwater aquifer which spans an area of ~28,000 km2. The presence of underground caverns and channels potentially allows extensive connectivity within this groundwater system. The emerging shale gas industry in the Beetaloo region, which underlies the CLA, provided the impetus to undertake the first survey of the potential existence of a stygofaunal community. Twenty-six groundwater wells (bores) and two springs were sampled in August and October 2019, across a distance of ~500 km, from the sub-tropical Mataranka region in the north to the semi-arid Barkly Tablelands in the south. Plankton nets and motorised pumps were used to collect water samples and conventional microscope-based morphological examinations in conjunction with environmental DNA (eDNA) were used to determine the presence of stygofauna. COI barcoding and 16S rRNA regions were also used for phylogenetic analysis. All stygofaunal communities were dominated by crustaceans, namely shrimps, amphipods, ostracods, copepods and syncarids. This fauna showed little affinity with the stygofauna recorded from more extensively sampled aquifers in north-western Australia, with new genera and species present in the CLA. eDNA analysis showed the presence of diverse biota at sites where direct water sampling for intact animals was difficult. COI and 16S analysis confirmed that a species of blind shrimp, Parisia unguis, occurred extensively throughout the aquifer, over a distance of at least ~300 km. The presence of Pa. unguis at widely separated sites across the CLA is consistent with substantial connectivity within the aquifer. This connectivity indicates that the risk of groundwater contamination from fracking chemicals needs to be adequately mitigated to prevent widespread effects.
Display omitted
•Stygofaunal surveys were undertaken as a pre-condition of shale gas extraction.•Stygofauna were sampled using both physical and eDNA methods.•New stygofaunal species, predominantly Crustacea, were detected.•Low genetic divergence in a widespread atyid indicated high aquifer connectivity.•Aquifer preservation will require mitigation of groundwater contamination risks.
Filter-feeding shrimp with distinctive live colorations were collected from small streams draining to the east coast of Taiwan and from Panay Island, Philippines. Morphological examination revealed ...that these specimens belong to the genus Australatya, Chace, 1983. In this paper the species is proposed as new to science and described in detail as Australatya obscura, new species. Beside the striking banded live coloration, the new species could be differentiated from Australatya striolata (McCulloch & McNeill, 1923) by a smaller body size, the length of the rostrum, the shape of the pterygostomial margin of the carapace, a row of plumose setae on the outer margin of pereiopods 3-5 and biunguiculated dactyli of the fifth pereiopod. The separation of the genus Australatya from Atyopsis Chace, 1983 and Atyoida Randall, 1840 is confirmed and a revised diagnosis for Australatya is given.
Abstract The release of ornamental pets and associated pathogens outside their native range might directly or indirectly impact the recipient community. In temperate regions, e.g., central Europe, ...feral freshwater species of tropical and sub-tropical origins are mainly constrained to thermally polluted waters and thermal springs. However, species with high environmental plasticity and reproduction rates, such as the shrimp Neocaridina davidi , may adapt to colder water regimes over time. A widening thermal niche may eventually overcome thermal barriers, further expanding the range and enhancing transmission opportunities for host generalist parasites. This study assesses the observed (field observations) and theoretical (species distribution models) range expansion of N. davidi and associated parasites in Europe. We report three newly established N. davidi populations from thermally polluted waters in central Europe (Germany, Hungary, and Slovakia) and provide further evidence of its range expansion into colder environments. Species distribution models predict thermally suitable habitats in the Mediterranean and a foreseeable expansion into Western Europe and the Balkans by 2050. We confirm the presence of the microsporidian parasite Ecytonucleospora hepatopenaei in feral N. davidi populations across Europe and expand the list of microsporidians found in this host from two to four. Furthermore, we provide the first evidence of parasite spillover from/to the invasive crayfish Procambarus clarkii, suggesting that parasite exchange with native biota might be possible. Such possibility, coupled with an ongoing range expansion of N. davidi bolstered by human-mediated introductions and climate change, will likely exacerbate the impact on native biota.
Abstract
Based on material collected during the mid- to late 1980s new distributional records for the anchialine shrimp, Caridina rubella Fujino & Shokita, 1975 are presented. Asides from the ...Ryukyus, Palawan and Sulawesi, the species is now also recorded from Tahiti, Niue, Tonga, Western Samoa, the Loyalty Islands, Solomon Islands, Bohol and Panglao. Attention is drawn to the considerable rostral variation in the species.
Abstract The caridean shrimps comprise one of the largest groups of amphidromous species, sharing their life cycle between freshwater habitats and the ocean. Key species of tropical ecosystems, some ...of which are also targets for local or international markets without any regulations being implemented, make carideans particularly vulnerable to the threats facing natural populations. We present an inventory of amphidromous carideans and an overview of their habitats, the interests they arouse, because of their ecological role as well as for their commercial importance and the threats they face. We suggest directions for future research following an experimental-biology approach, that may help to assess risks and impacts on natural habitats and ultimately prioritize conservation and management projects.
The Yucatán Peninsula, Mexico is a carbonate platform well-known for extensive karst networks of densely stratified aquifer ecosystems. This aquifer supports diverse anchialine fauna, including ...species of the globally distributed anchialine shrimp genus Typhlatya (Atyidae). Four species (T. campecheae, T. pearsei, T. dzilamensis and T. mitchelli) are endemic to the Peninsula, of which three are federally listed in Mexico. This first integrative evaluation (i.e., molecular, morphological, broad geographic and type locality sampling, and environmental data) of Yucatán Typhlatya reveals considerable species identity conflict in prior phylogenetic assessments, broad species ranges, syntopy within cave systems and five genetic lineages (of which two are new to science). Despite sampling from the type locality of endangered T. campecheae, specimens (and molecular data) were indistinguishable from vulnerable T. pearsei. Ancestral/divergence reconstructions support convergent evolution of a low-salinity ancestor for a post-Paleogene arc Yucatán + Cuba Typhlatya clade within the anchialine Atyidae clade. A secondary adaptation for the coastal-restricted euryhaline (2-37 psu), Typhlatya dzilamensis (unknown conservation status) was identified, while remaining species lineages were low-salinity (< 5 psu) adapted and found within the meteoric lens of inland and coastal caves. This study demonstrates the need for integrative/interdisciplinary approaches when conducting biodiversity assessments in complex and poorly studied aquifers.
PDF
