Globalization pressure and habitat change: Pacific rocky shore crabs invade armored shorelines in the Atlantic Wadden Sea

Abstract

Florence, was a brilliant Italian zoologist and ethologist, and one of the most well-known and active experts on alien aquatic species. Since her masters degree in Biology (1979) and her PhD in Animal Biology (Ethology) (1987), both obtained at the University of Florence, Francesca studied the behaviour and ecology of aquatic animals. Initially, most of her research concerned social recognition in crustaceans: she was particularly renowned for her studies on hermit crabs and crayfish, her principal model organisms.Then, from the 1990's onwards she worked in the field of invasion biology, her main interest until her death. Francesca devoted herself with enthusiasm and energy, not only to the problem of the invasive red swamp crayfish Procambarus clarkii, by revealing several aspects of its behavioral ecology, and by developing with her collaborators different methods for its control, but she gradually became an international expert on crayfish and more generally on aquatic alien species. In all aspects of her life, she was constantly driven by a continuous curiosity, thirst for knowledge and a will to face challenges; this was expressed by exploring and frequently opening new research fields. And she transmitted her drive and passion to the many students she supervised. One of the last papers with her contribution is published in this issue of Aquatic Invasions by Vera Gonçalves, her Portuguese PhD student working on the interaction between Procambarus clarkii and the zebra mussel Dreissena polymorpha, an issue of recent increasing interest in Francesca's team.

Climate change and parasite transmission: how temperature affects parasite infectivity via predation on infective stages

“…In addition, predation effects of different cercarial predators may also be additive when they cooccur, resulting in further reductions of infection levels (Thieltges et al 2009). With all three cercarial predators co-occurring locally in the Wadden Sea (Troost 2010, Witte et al 2010, Landschoff et al 2013, the actual total cercarial consumption will thus depend on the species composition around target mussels. Interestingly, the mussels themselves will also act as sentinels, i.e., increasing mussel densities will lead to reduced infection levels per individual host (Thieltges et al 2009).…”

First GB records of the invasive Asian shore crab, Hemigrapsus sanguineus from Glamorgan, Wales and Kent, England

“…In the northern Wadden Sea, the Asian shore crab has survived three consecutive winters (2010 -2012) during which ice covered the shore and water temperatures dropped to 228C (Landschoff et al, 2013). According to Gittenberger et al (2010), Hemigrapsus sanguineus is also only found at locations with a salinity of ≥19.…”

“…The breeding season lasts from May to September and a female can produce 2-4 batches of eggs, 50,000 eggs per spawning (Fukui, 1988;McDermott, 1998a). However, Landschoff et al (2013) reported that on the ice-covered shores of the northern Wadden Sea, with water temperatures at 228C, H. sanguineus aggregated, slowly crawling, even with ovigerous females, under boulders at low-tide level. This suggests that the Asian shore crab can be ovigerous all year round in north-east Europe.…”

“…Hemigrapsus sanguineus can cling to surfaces, hide in narrow crevices, travel on ship trunks, in anchor boxes, on ropes and inside ballast water systems (Landschoff et al, 2013). Dispersal by human assistance via the transportation of shellfish, such as mussels and oysters, is also a potential vector.…”

Flexible prey handling, preference and a novel capture technique in invasive, sub-adult Chinese mitten crabs

“…These include competition for resources, e.g. Hemigrapsus sanguineus (de Haan, 1853) being able to displace juvenile Carcinus maenas (Linnaeus, 1758) from shelter (Landschoff et al, 2013) and as vectors for disease, e.g. Pacifastacus leniusculus (Dana, 1852) a known carrier of crayfish plague which has caused rapid decline in populations of Austropotamobius pallipes (Lereboullet, 1858) within the UK (Lilley et al, 1997).…”