New subterranean Armadillidae (Crustacea, Isopoda, Oniscidea) from Western Australia

One new genus (Quatuordillo) and two new species (Quatuordillo caecus and Buddelundia eberhardi) are described from subterranean habitats in Western Australia. Both species show troglomorphic traits, such as body depigmentation, reduction or absence of eyes, and elongation of appendages. Buddelundia eberhardi is the only troglobiont in the genus, which up to date includes 26 species from Australia. Armadillo brevicauda Dollfus, 1898 from Flores Island, Indonesia, is transferred to Buddelundia. http://zoobank.org/urn:lsid:zoobank.org:pub:35F61AC8-F76D-49E8-A8D8-278B58C2FE3

Adaptation to the Baltic Sea – the case of isopod genus Idotea

The three marine isopods of the genus Idotea: I. balthica, I. chelipes and I. granulosa have an important functional role as meso-grazers in the Baltic food web. These meso-grazers are key species in the Fucus belt and in Zostera marina beds and are characterized by top-down effects through impressive feeding rates on filamentous algae as well as through their importance as prey for 23 fish species (bottom-up effects). In the Baltic Sea, the three Idotea spp. show clear habitat segregation, but may also coexist and compete for food and space. The habitat differences are also reflected in their different life history strategies. Whereas I. balthica is more of a generalist and K-selected species, I. chelipes shows characteristics of an r-selected species. The third species, I. granulosa, is displaced by I. balthica to less favorable habitats, why the adversity strategy fits best for this species. A phylogeographic study and reconstruction of demographic history indicated that after the Baltic Sea became a marine habitat, I. granulosa first invaded into the young Baltic Sea from the Atlantic followed by I. balthica and I. chelipes. Small estimated population sizes and the haplotype networks, suggest that I. balthica and I. granulosa have gone through a bottleneck during colonization, losing genetic diversity in Baltic populations. Although Baltic populations of I. chelipes were genetically distinct from populations outside the Baltic Sea, differentiation was ten times lower than in the other two species. Distribution patterns over the past 150 years, showed fairly constant large-scale distributions for the Idotea spp., but changes in distribution could be found. I. chelipes and I. granulosa shifted southwards, probably as a consequence of changes in salinity and temperature reported for the Baltic Sea. In general, the distribution patterns of Idotea spp. seem to be more determined by temperature than by salinity as supported by ecological niche modelling. Predicted distributions under a climate change scenario (ECHAM5) demonstrated a northern shift of Idotea through increased temperature, deeper into the Bothnian Sea. Such distribution changes may have serious consequences, since the endemic narrow wrack, Fucus radicans, today may be protected from intensive grazing pressure through the distribution limit of Idotea to the southern parts of the Bothnian Sea. Demographic analysis demonstrated that all three species live closely to their limits under the Baltic Sea extremes. The obvious change in life history from the North Sea to the Baltic Sea can be a cost of acclimation or adaptation. Whereas I. balthica lives close to its carrying capacity, several local extinctions of I. granulosa have been reported. As a typical r-selected species and with the highest genetic diversity, I. chelipes may have the highest capacity to adapt to further predicted climate changes. Today it is not clear if Idotea spp. are locally adapted to the Baltic extremes or showing phenotypic plasticity in response to abiotic factors, which calls for further studies

Fossil evidence of extended brood care in new Miocene Peracarida (Crustacea) from Mexico

Currently, the Peracarida contains important crustacean groups, such as Isopoda or Amphipoda, that incubate their young in a brood pouch. However, the fossil record of Peracarida is rather poor and the evolutionary pathways leading to their remarkable reproductive strategy are incompletely documented. In this study, we describe the first fossil evidence of extended brood care in Peracarida, based on two Oniscidea (Isopoda) gravid females preserved in Miocene Chiapas amber from Mexico. These adult specimens are preserved with several mancas at a terminal stage of development, some remaining trapped in the marsupial structures of the adults. The well-preserved adults and mancas are described and assigned to the family ‘Philosciidae’, currently one of the most diverse and abundant oniscidean families in tropical biotopes and wetlands habitats. A new genus–Aquitanoscia gen. nov.–and two new species–Aquitanoscia chiapasensis sp. nov. and A. maternus sp. nov.–are figured and described. Finally, the physiological, morphological and behavioural conservation of the reproductive strategies of the Peracarida is discussed. http://zoobank.org/urn:lsid:zoobank.org:pub:2F3E2805-0EC4-4DFD-BA33-BDC2C7962E61.SCOPUS: ar.jinfo:eu-repo/semantics/publishe