-
Differences in geographic distribution and habitat of some cryptic species in the Pardosa lugubris group (Lycosidae, Araneae) in Belgium
-
The habitat and distribution of some closely related species of the P. lugubris s.l. group in Belgium are described to contribute to our understanding of the coexistence and speciation of these 'cryptic' species. With a few exceptions, P. lugubris has its main distribution in the lower part of Belgium where it occurs on sandy, nutrient poor soils. P. saltans occurs widely in Belgium except for in the Campine region where the species is totally absent. P. alacris was only found at three localities where limestone outcrops are present. The habitat of P. lugubris is pine and birch forests while in Fagus woodlands, only P. saltans was found. In Quercus forests, both species were found, often in mixed populations. A combination of micro- and macroclimatological features and habitat characteristics cause the differences in distribution of these species.
Located in
Library
/
RBINS Staff Publications
-
Can multiple mating compensate for slower development and shorter adult life in a male dimorphic dwarf spider?
-
Oedothorax gibbosus (Blackwall, 1841) is a dwarf spider characterized by the occurrence of a male dimorphism: the tuberosus male does not show any remarkable differentiation at the dorsal side of the carapace; the gibbosus morph on the contrary has a hunch behind the eye region, with a transversal groove densely clothed with hairs. These structures play an important function in the gustatorial courtship, being the uptake of secretions by the female from a body part of the male during courtship. Based on standardized survival experiments we show that tuberosus has a greater overall survival strength for different humidity levels than gibbosus. The two male morphs of O. gibbosus also have a different mating strategy: tuberosus as well as gibbosus copulate with virgin females, but gibbosus copulates significantly more with already inseminated females. Because of this strategy gibbosus secures its offspring notwithstanding the faster development, the longer adult life and the greater overall survival strength of tuberosus. (C) 2004 The Linnean Society of London
Located in
Library
/
RBINS Staff Publications
-
Absence of cadmium excretion and high assimilation result in cadmium biomagnification in a wolf spider
-
Cd biomagnification in the terrestrial food chain appears to be dependent on the physiological properties of the organisms rather than on their trophic level. Although high Cd body burdens in spiders from the field have been reported many times, experimental verification of the key factors that determine the rate of cadmium accumulation is lacking. We investigated the cadmium assimilation rate in the common wolf spider Pirata piraticus fed with contaminated fruit flies. Spiders were fed for 42 days with contaminated flies, followed by a detoxicification period of 28 days. Every 14 days, a subsample of spiders and flies was taken for Cd determination. It was demonstrated that a high cadmium assimilation (69.5\%) and an excretion rate approaching zero resulted in high Cd concentration factors. The results indicate the importance of spiders in cadmium biomagnification along critical pathways. (C) 2003 Elsevier Science (USA). All rights reserved.
Located in
Library
/
RBINS Staff Publications
-
Fruits and seeds from the Tienen Formation at Dormaal, Palaeocene–Eocene transition in eastern Belgium
-
Located in
Library
/
RBINS Staff Publications
-
New species of Macrocranion (Mammalia, Lipotyphla) from the earliest Eocene of North America and its biogeographic implications
-
Located in
Library
/
RBINS Staff Publications
-
Report on the 2008 season of the Hierakonpolis expedition
-
Located in
Library
/
RBINS Staff Publications
-
Fish as indicators of trade relationships in Roman times: the example of Sagalassos, Turkey
-
Located in
Library
/
RBINS Staff Publications
-
Interdisziplinäre Untersuchungen im römischen Vicus von Tienen (Belgien). Die Integration von ökologischen und archäologischen Daten
-
Located in
Library
/
RBINS Staff Publications
-
The predictive value of dental microwear in the assessment of caprine diet
-
Located in
Library
/
RBINS Staff Publications
-
Harvesting pike at Tlokowo
-
Located in
Library
/
RBINS Staff Publications