Predicting the predatory impacts of the “demon shrimp” Dikerogammarus haemobaphes, on native and previously introduced species

Biological invasions continue to exert pressure on ecosystems worldwide and we thus require methods that can help understand and predict the impacts of invasive species, on both native species and previously established invaders. Comparing laboratory derived functional responses among invasive and native predators has emerged as one such method, providing a robust proxy for field impacts. We used this method to examine the likely impacts of the Ponto–Caspian amphipod Dikerogammarus haemobaphes, known as the “demon shrimp”, a little investigated invader in European freshwaters that has recently established in the British Isles. We compared the functional responses on two prey species of D. haemobaphes with two other amphipod species: Dikerogammarus villosus, a congeneric invasive with well-documented impacts on macro-invertebrate communities and a native amphipod, Gammarus pulex. Prey species were native Chironomus sp. and the invasive Chelicorophium curvispinum, a tube-building amphipod also originating from the Ponto–Caspian region. D. villosus showed higher Type II functional responses towards both prey species than did D. haemobaphes and G. pulex, with the latter two predators exhibiting similar impacts on the native prey. However, D. haemobaphes had higher functional responses towards the invasive C. curvispinum than did G. pulex, both when prey individuals were tubeless and resident in their protective mud tubes. Thus, we demonstrate that functionally equivalent invasive congeners can show significantly different impacts on prey, regardless of shared evolutionary history. We also show that some predatory invaders can have impacts on native prey equivalent to native predator impacts, but that they can also exert significant impacts on previously introduced prey. We discuss the importance of invasion history and prey identity when attempting to understand and predict the impacts of new invaders.

Differential lifetime success and performance of native and non-native Atlantic salmon examined under communal natural conditions.

The lifetime success and performance characteristics of communally reared offspring of wild native Burrishoole (native), ranched native (ranched) and non-native (non-native) Atlantic salmon Salmo salar from the adjacent Owenmore River were compared. Non-native year parr showed a substantial downstream migration, which was not shown by native and ranched parr. This appears to have been an active migration rather than competitive displacement and may reflect an adaptation to environmental or physiographic conditions within the Owenmore River catchment where the main nursery habitat is downstream of the spawning area. There were no differences between native and ranched in smolt output or adult return. Both of these measures, however, were significantly lower for the non-native group. A greater proportion of the non-native Atlantic salmon was taken in the coastal drift nets compared to the return to the Burrishoole system, probably as a result of the greater size of the non-native fish. The overall lifetime success of the non-native group, from fertilized egg to returning adult, was some 35% of native and ranched. The ranched group showed a significantly greater male parr maturity, a greater proportion of 1+ year smolts, and differences in sex ratio and timing of freshwater entry of returning adults compared to native, which may have fitness implications under specific conditions.

Classical Romantic: Identity in the Latin Poetry of Vincent Bourne

This monograph examines a selection of Vincent Bourne's Latin verse in its classical, neo-Latin and vernacular contexts, with particular attention to the theme of identity (and differing forms of identity). Its aim is to initiate the resurrection from silence of an author whose self-fashioning is achieved by investigating the identity of the self in relation to the other and by foregrounding multiple attempts to fashion other selves.

From Back Cover of published book:

Through close and perceptive analysis of Bourne's negotiation of poetic identity, Haan argues in new ways for the blend of classicism and Romanticism informing his marginalized status. As such, the book promises to revive scholarship on Bourne, and to be of use to students and scholars of Latin as well as vernacular verse.
Carla Mazzio, Professor of English, University of Chicago.


Estelle Haan is the UK's most eminent neo-Latinist. Her books with the APS on Milton (From Academia to Amicitia, Transactions 88, part 6) and Addison (Vergilius Redivivus, Transactions 95, part 2) are both important contributions to our knowledge of those authors, and their scholarship is presented in a way that accommodates the growing number of specialists who do not read Latin. Much of the content of this study is entirely new, and it is written in a way that will make it accessible to non-Latinists. The connections with English-language poets that Professor Haan adduces page after page will be a very considerable resource for students of vernacular poetry.
Gordon Campbell, Professor of Renaissance Literature, University of Leicester.


I have long thought that a modern study of Vincent Bourne was very much needed, and am greatly pleased that one has now been written. Estelle Haan offers a thoughtful and sensitive study that has remarkable depth. She capitalizes on the familiarity with other eighteenth-century English poets about whom she has previously written (Cowper, Gray, and most recently Addison) and she makes use of contempoary literary theory without becoming dependent on any single approach or disfiguring her writing with critical jargon. This work will, one hopes, provoke further research into Bourne and his poetry.
Dana F. Sutton, Professor Emeritus of Classics, The University of California, Irvine.

The Violent Maintenance of the Portuguese Colonial Identity and the Search for a Postcolonial one: literary images of Portugal as a colonial and postcolonial nation

Through the examination of Camões's Os Lusíadas , Sena's Os Grão-Capitães and Saramago's A Jangada de Pedra , this article explores violence as a means of shaping Portuguese identity in different historical contexts, and how these works portray the continued recourse to violence as Portugal moves from colonizing to postcolonial nation.