The role of abiotic and biotic cues in burrow habitat selection by juvenile crayfish

Behaviour ◽  
2017 ◽  
Vol 154 (12) ◽  
pp. 1177-1196 ◽  
Author(s):  
Mallary Clay ◽  
Jim Stoeckel ◽  
Brian Helms

Environmental cues contain critical information for individuals while searching for mates and suitable habitat. Crayfish have well-developed chemosensory abilities for detecting environmental cues in water; much less is known about these abilities on land. The Devil crayfish (Cambarus diogenes) is a burrowing crayfish often found in dense floodplain colonies as adults. Juveniles however are released in surface water and must navigate overland to burrow. Previous work demonstrates juveniles use cues from conspecific adults, and to a lesser extent, soil cues, for burrow site selection. Using mesocosms, we build on this by examining burrowing cues associated with (1) congeneric adults, (2) excavated burrow material and (3) other juveniles. In contrast to conspecific adults, cues provided by congeneric adults did not override cues associated with soil type. Similarly, juveniles burrowed closer to conspecific adult burrow mounds than to congeneric and human-built mounds. Juveniles also showed significant grouping behaviour in the absence of all other cues. These results suggest juvenile crayfish integrate multiple terrestrial cues for burrow site selection.

2021 ◽  
pp. 109634802110115
Author(s):  
Seonjeong (Ally) Lee ◽  
Ning-Kuang Chuang

The physical environment plays an essential role in customers’ hotel stay experiences. Hotels offer a differentiated atmosphere that creates favorable customers’ evaluations. Based on the significant role of environmental cues, this study investigates the effects of an expanded servicescape on customers’ evaluations, including customer satisfaction, quality of life, and customer loyalty, in the context of the hotel industry. To test the proposed research framework, this study collects data from previous hotel customers and conducts a self-administered, online survey. Findings identified ambience, interactions with employees, authenticity, and fascination positively influenced customers’ satisfaction, which further influenced customer loyalty. Only ambience and fascination positively influenced quality of life, which in turn influenced customer loyalty. Results contributed to the application of expanded servicescape in the hotel context. Results also suggested practical implications of the holistic approach of servicescape in the hotel industry.


2021 ◽  
Vol 640 ◽  
pp. 119740
Author(s):  
Li Zhang ◽  
Nigel Graham ◽  
Nicolas Derlon ◽  
Youneng Tang ◽  
Muhammad Saboor Siddique ◽  
...  

Behaviour ◽  
1996 ◽  
Vol 133 (15-16) ◽  
pp. 1265-1279 ◽  
Author(s):  
Cliff H. Summers ◽  
Thomas J. Andrews

AbstractFemale green anoles, Anolis carolinensis, were paired in terraria to investigate behavioral components of social interaction. Resources (perching sites, prey, and males as potential mates) were limited to assess their importance to cohabiting females. During interaction, paired females exhibited aggressive social behavior which contributed to the development of dominant-subordinate relationships. Dominant status and its relationship to differential resource acquisition was defined primarily by frequency of displacement of another female. Along with displacement, dominant females also had increased frequency of assertion displays, challenge displays, attacks and biting (Figs 1 & 2). Subordinate females were displaced more often and assumed submissive postures. No differences were found between dominant and subordinate females for perch site selection, body color or in prey capturing latency or success (Figs 3 & 4). Perch site elevation was not different between dominant and subordinate females, but was significantly lower than males. The color of paired females was not different unless males were present, in which case dominant females were darker. Paired females also respond differently to courtship display (Fig. 5). Dominant females responded with displays significantly more often than subordinate females to male courtship, indicating receptivity. The role of dominant-subordinate relationships among female A. carolinensis may include courtship and reproductive success as an important component, with consequences for the outcome of aggressive and reproductive social interactions with males.


2021 ◽  
Author(s):  
Melanie Münch ◽  
Rianne van Kaam ◽  
Karel As ◽  
Stefan Peiffer ◽  
Gerard ter Heerdt ◽  
...  

<p>The decline of surface water quality due to excess phosphorus (P) input is a global problem of increasing urgency. Finding sustainable measures to restore the surface water quality of eutrophic lakes with respect to P, other than by decreasing P inputs, remains a challenge. The addition of iron (Fe) salts has been shown to be effective in removing dissolved phosphate from the water column of eutrophic lakes. However, the resulting changes in biogeochemical processes in sediments as well as the long-term effects of Fe additions on P dynamics in both sediments and the water column are not well understood.</p><p>In this study, we assess the impact of past Fe additions on the sediment P biogeochemistry of Lake Terra Nova, a well-mixed shallow peat lake in the Netherlands. The Fe-treatment in 2010 efficiently reduced P release from the sediments to the surface waters for 6 years. Since then, the internal sediment P source in the lake has been increasing again with a growing trend over the years.</p><p>In 2020, we sampled sediments at three locations in Terra Nova, of which one received two times more Fe during treatment than the other two. Sediment cores from all sites were sectioned under oxygen-free conditions. Both the porewaters and sediments were analysed for their chemical composition, with sequential extractions providing insight into the sediment forms of P and Fe. Additional sediment cores were incubated under oxic and anoxic conditions and the respective fluxes of P and Fe across the sediment water interface were measured.</p><p>The results suggest that Fe and P dynamics in the lake sediments are strongly coupled. We also find that the P dynamics are sensitive to the amount of Fe supplied, even though enhanced burial of P in the sediment was not detected. The results of the sequential extraction procedure for P, which distinguishes P associated with humic acids and Fe oxides, as well as reduced flux of Fe(II) across the sediment water interface in the anoxic incubations, suggest a major role of organic matter in the interaction of Fe and P in these sediments.</p><p>Further research will include investigations of the role of organic matter and sulphur in determining the success of Fe-treatment in sequestering P in lake sediments. Based on these data in combination with reactive transport modelling we aim to constrain conditions for successful lake restoration through Fe addition.</p>


1994 ◽  
Vol 188 (1) ◽  
pp. 89-101 ◽  
Author(s):  
T Teyke ◽  
S Schaerer

In apparatus for measuring optomotor behaviour, blind Mexican cave fish, Astyanax hubbsi, increase their swimming velocity upon rotation of a striped cylinder, i.e. in response to a solely visual stimulus. The fish follow the movements of the stripes at (i) rotation velocities between 60 degrees s-1 and 80 degrees s-1, (ii) light intensities of less than 20 lx and, (iii) stimulus widths subtending an angle of less than 1 °. Extirpation of the vestigial eye structures does not affect the response to the moving visual stimulus, which indicates that the response is mediated by extra-ocular photoreceptors. An optomotor response can be reliably evoked in a round test aquarium. Fish do not respond when the test aquarium contains environmental cues, such as bars on the wall or when a section of the round aquarium is divided off. This indicates that the fish obtain information about their environment from different sensory sources and that the visual stimulus is effective only when no other means of orientation are available. We suggest a modified theory of the optomotor response, which emphasizes the crucial role of the environment in eliciting the response and which permits behaviours more complex than just following the stimulus.


Author(s):  
Faisal B A Zaidi ◽  
Salma Ahmed ◽  
Munish Makkad

ABSTRACTPharmaceuticals are passing through the difficult phase due to increasing numbers of patents expiry along with increasing cost of drug development.Protocol design, regulatory cycle time, site selection, patient enrollment and monitoring are some of the cost contributing elements for late phaseclinical trials. This paper applies the principles of project management and suggests means to reduce the cost of late phase drug development. It alsothrows light on the critical role that a project manager can play in overall drug development process.Keywords: Cost of drug development, Effective project management, Reduction in cost of drug development.


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