World Congress of Malacology Antwerp ... - Unitas Malacologica

The allozyme data showed no sign of obligate selfing in A. ater rufus and A. lusitanicus and low
selfing levels in A. ater ater. Morphological, allozyme and mtDNA results suggested that multiple
invasions and population admixture have occurred in Denmark.
Further, mtDNA and allozyme data could not discriminate among the three large Arion taxa. The
morphological data did not allow to discriminate between A. ater rufus and A. ater ater.
A Spanish investigation showed that the non-Iberian European A. lusitanicus is closely related to A.
ater ater and A. ater rufus. The Portuguese topotype of A. lusitanicus is more distantly related to A.
ater ater and A. ater rufus. This and my results support the belief that non-Iberian A. lusitanicus are
closely related to the other taxa in the A. ater rufus complex than it is to Iberian A. lusitanicus.
Seasonal foraging activity during spring and neap tide in Patella ferruginea
Espinosa, Free 1 ; Rivera-Ingraham, Georgina 2 ; García-Gómez, Jose Carlos 2
1. Gibraltar Museum, 18-20 Bomb House Lane, Gibraltar, UK,
Email: free@us.es
2. Laboratorio de Biología Marina, Departamento de Fisiología y Zoología, Facultad de Biología,
Universidad de Sevilla, Avda. Reina Mercedes 6, 41012, Sevilla, Spain,
Email: g.rivera@gmail.com
The protected limpet Patella ferruginea (Gmelin 1971) has important populations in North Africa.
One crucial point is Ceuta, a Spanish settlement on the northern most tip of this continent. Many
studies have been conducted on this coasts, but very little is known about the foraging activity of its
individuals, specially during spring and neap tides.
During spring of 2006, a total number of 15 individuals of this limpet were marked in order to obtain
data related to the foraging activity of the species and taking into account that individuals of all sizes
were selected. These individuals were marked using epoxi Eporai 1127© on both the shell and the
rock adyacent to the individual´s home scar in order to detect possible movement activity. Before
drying, a number was stamped on the shell mark so as to identify each individual.
Monitoring was done during continuous periods of 24 hours, two times per season, once during neap
tide and another during spring tide. During this 24 hours, each 30 minutes data about physical
parametres was taken as well as the position of each of the marked individuals, using three predetermined
points. The real distance from each point to the neareast shell side was determined using
a thin string. This data is afterwards recreated in the laboratory using milimetric paper with the result
being a precise record of their movement. These maps are then scanned and compared as to sizes,
individuals, seasons and tide conditions.
Evidence of limpets changing home-scars and also of permanent changes in position within the same
home-scar were found. It also can be seen that smaller individuals have clearly less activity than the
bigger ones. Ethological implications are discussed.
Behavioural and reproductive biomarkers of organophosphate pesticide (Delvap) in the giant
land snail Archachatina marginata (Swainson)
Fadina, Opeyemi A; Otitoloju, Adebayo A; Egonmwan, Rosemary I
Department of Zoology, University of Lagos, Akoka, Lagos, Nigeria,
Email: oafadina@yahoo.com; bayotitoloju@yahoo.com; egone@infoweb.com.ng
The lethal and sublethal effects of an organophosphate insecticide Delvap on a non-target organism,
Archachatina marginata (Swainson) were investigated to identify easy to recognize biological
responses in exposed snails that can serve as early warning signals of pollution. On the basis of 168h
mortality data, the derived LC50 for Delvap was 11.24 mg / kg. The avoidance reaction experiment
however revealed that concentrations of Delvap that is as low as 1.5 mg / kg caused about 50% of
exposed snails to avoid the test media. For sublethal test, exposure of the snails to fractions (1/10 th ,
1/100 th , 1/1000 th ) of the 168h LC50 values over a 28 days observation period resulted in the thinning
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