The Ethiopian water mouse Nilopegamys Osgood, with comments on semi-aquatic adaptations in African Muridae

A highly distinctive rodent from the highlands of Ethiopia is currently being confused with a very different mouse from the Zaire Basin. The Ethiopian water mouse, Nilopegamys Osgood 1928, can be distinguished from Colomys and all other African murids by external, cranial, post-cranial and dental characters. Adaptations of Mlopegamys for swimming are more extreme than those of any other African murid; as noted by Osgood, it is the only one with specializations reminiscent of Neotropical ichthyomyines or Australasian hydromyines. However, the African mice Colomys, Malacomys , and Deomys also exhibit varying degrees of semi-aquatic specializations. These genera constitute a previously unrecognized guild of 'waders'. Without swimming and while perched on elongate hind feet, all three consume insects and other small animals in shallow forest streams and pools. Both waders and swimmers show neurological adaptations to life in water, but Nilopegamys redefines certain extremes of cerebral development among African murids. Resurrected from synonymy with Colomys , this genus further accentuates the distinctiveness and imperilled status of the Ethiopian highland fauna.     

Reproduction in an Irish lake population of the crayfish Austropotamobius pallipes (Lerehoullet)

SUMMARY. 1. Mature crayfish were collected in 1984 from an alkaline Irish lake before and after the mating season.
2. There was some correlation between frequency of mating and decrease in vasa deferentia weight in captive males, but in the field vasa deferentia weight losses were highly variable. The data indicate that one third of adult males may not have mated in the wild.
3. All females appear to have spawned, whether or not mated, with an average 85% reduction in ovary weights over the season.
4. Pleopodal egg counts directly after laboratory spawning were on average 81% of ovarian counts; in the field, an estimated 50 days after spawning, they were only 61% of estimated ovarian egg numbers.
5. Average ovarian egg size was positively correlated with female size. Also, larger crayfish had a wider range of egg sizes than smaller crayfish.
6. It is suggested that aggression and competition for shelter among brooding females may result in a progressive loss of eggs.     

IN FAVOUR OF FREEZING EGGS FOR NON-MEDICAL REASONS

This article explores the social benefits and moral arguments in favour of women and couples freezing eggs and embryos for social reasons. Social IVF promotes equal participation by women in employment; it offers women more time to choose a partner; it provides better opportunities for the child as it allows couples more time to become financially stable; it may reduce the risk of genetic and chromosomal abnormality; it allows women and couples to have another child if circumstances change; it offers an option to women and children at risk of ovarian failure; it may increase the egg and embryo pool. There are strong arguments based on equal concern and respect for women which require that women have access to this new technology. Freezing eggs also avoids some of the moral objections associated with freezing embryos.     

Coupling long-term studies with meta-analysis to investigate impacts of non-native crayfish on zoobenthic communities

1. Biological invasions are widely recognised as a significant component of human‐caused environmental change and a primary threat to native biodiversity. The negative impacts of species invasions are particularly evident for freshwater crayfish faunas. 2. This study provides novel insight into the ecological effects of native and non‐native crayfish on zoobenthic communities (with emphasis on the non‐native rusty crayfish, Orconectes rusticus) across broad scales by combining a meta‐analysis of small‐scale experimental studies with a long‐term observational study conducted over a 24 year period in Sparkling Lake, Wisconsin, U.S.A. (46°00′N, 89°42′W). 3. The meta‐analysis summarised quantitatively the results of cage experiments for seven species of crayfish spanning four continents. We found that total zoobenthos densities (primarily Gastropoda and Diptera) were significantly lower in treatments containing crayfish relative to controls; a result that was significant for non‐native crayfish but not for crayfish in their native range, perhaps owing to a small sample size. In contrast to other species, rusty crayfish were also negatively associated with Ephemeroptera. 4. Results from the time series analysis comparing temporal trends in rusty crayfish and invertebrate abundances from Sparkling Lake were consistent with the findings from the meta‐analysis. Rusty crayfish were negatively correlated with the abundance of total zoobenthos, Diptera, Ephemeroptera and Odonata, as well as families of Trichoptera. 5. By coupling the results from short and long‐term research, our study offers greater insight into the nature of crayfish‐invertebrate interactions in aquatic systems, revealing consistent effects of invasive crayfish on native fauna. The control and management of invasive species is facilitated by the knowledge that well executed small‐scale studies may be extrapolated to understand larger‐scale ecological interactions.     

THE MORAL OBLIGATION TO CREATE CHILDREN WITH THE BEST CHANCE OF THE BEST LIFE

According to what we call the Principle of Procreative Beneficence (PB), couples who decide to have a child have a significant moral reason to select the child who, given his or her genetic endowment, can be expected to enjoy the most well-being. In the first part of this paper, we introduce PB, explain its content, grounds, and implications, and defend it against various objections. In the second part, we argue that PB is superior to competing principles of procreative selection such as that of procreative autonomy. In the third part of the paper, we consider the relation between PB and disability. We develop a revisionary account of disability, in which disability is a species of instrumental badness that is context- and person-relative. Although PB instructs us to aim to reduce disability in future children whenever possible, it does not privilege the normal. What matters is not whether future children meet certain biological or statistical norms, but what level of well-being they can be expected to have.     

Neglected refugia of biodiversity: mountainous regions in Mozambique and Malawi yield two novel freshwater crab species (Potamonautidae: Potamonautes)

Phylogenetic relationships amongst the southern African freshwater crab fauna are reinvestigated following the recent collection of morphologically distinct Potamonautes specimens from remote mountainous regions in Malawi and Mozambique. Specimens were subjected to DNA sequencing of three mtDNA loci, cytochrome c oxidase subunit I (COI), 12S rRNA, and 16S rRNA and compared to the 14 described species from the region. Phylogenetic analysis using maximum parsimony and Bayesian inference revealed the presence of two novel evolutionary lineages. The phylogeny demonstrates that Potamonautes obesus (A. Milne‐Edwards, 1868) is sister to a morphologically distinct novel species from Mount Namuli in Mozambique. Two sympatric and genetically distinct species from Mount Mulanje, in Malawi (forms A and B) were recognized. Form B is sister to the large‐bodied South African riverine freshwater crabs and represents a novel lineage whereas the remaining species (form A) from Mulanje, in Malawi was sister to samples from Mounts Inago and Mabu, and in Mozambique was identified as Potamonautes choloensis (Chace, 1953). The two novel evolutionary lineages were genetically distinct and morphologically different from the described species in each of the respective regions. Two new freshwater crab species Potamonautes namuliensis sp. nov. and Potamonautes mulanjeensis sp. nov. , are described in the present study. The samples from Mount Mulanje in Malawi, and Mounts Mabu and Inago in Mozambique represent new distribution records for Potamonautes choloensis. © 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 164 , 498–509.