scholarly journals Effect of nearshore surface slicks on meroplankton distribution: role of larval behaviour

2014 ◽  
Vol 506 ◽  
pp. 15-30 ◽  
Author(s):  
N Weidberg ◽  
C Lobón ◽  
E López ◽  
L García Flórez ◽  
MdP Fernández Rueda ◽  
...  
Keyword(s):  
Larval Behaviour

Movement patterns and rheoreaction of larvae of a fluvial specialist (nase, Chondrostoma nasus): the role of active versus passive components of behaviour in dispersal

2018 ◽  
Vol 75 (2) ◽  
pp. 193-200 ◽  
Author(s):  
Bernhard Zens ◽  
Martin Glas ◽  
Michael Tritthart ◽  
Helmut Habersack ◽  
Hubert Keckeis
Keyword(s):  
Current Velocity ◽  
Water Movement ◽  
Fish Larvae ◽  
Movement Patterns ◽  
Swimming Activity ◽  
Natural Habitats ◽  
Larval Stages ◽  
Larval Behaviour ◽  
Upstream Direction

The dispersal of fish larvae in rivers might result from water movement but also from larval behaviour. Although potentially crucial for dispersion, knowledge of the role of behaviour is still fragmentary. This study intends to contribute to the question of how riverine fish larvae drift or move. All dispersal-relevant movement patterns of larvae of a characteristic rheophilic species were analyzed based on the parameters (i) swimming activity, (ii) direction of movement, and (iii) the orientation towards the current vector. Experiments were conducted in a novel flume mesocosm at three different flow scenarios covering the current velocity range of natural habitats. Mean current velocities in these scenarios were under, near, and over the “critical current velocity”, above which fish larvae are not able to constantly hold their position in the water column. Three consecutive larval stages were tested to account for possible ontogenetic shifts in movement behaviour, both during the day and at night. Our results strongly suggest that the assumption of mainly passively drifting larvae has to be refused; in total, 92.6% of all observed movement events were characterized by swimming activity and directed orientation, whereas only 7.4% could be assigned to passive drift. During downstream movement, a significant portion of movement events (57.1%) was attributed to larvae that orientated in an upstream direction and performed active swimming movements.

scholarly journals An ancient FMRFamide-related peptide–receptor pair induces defence behaviour in a brachiopod larva

Open Biology ◽  
2017 ◽  
Vol 7 (8) ◽  
pp. 170136 ◽  
Author(s):  
Daniel Thiel ◽  
Philipp Bauknecht ◽  
Gáspár Jékely ◽  
Andreas Hejnol
Keyword(s):  
Nervous System ◽  
Animal Behaviour ◽  
Peptide Receptor ◽  
Behavioural Responses ◽  
Related Peptide ◽  
Larval Behaviour ◽  
Apical Lobe ◽  
Defence Behaviour ◽  
Trunk Musculature

Animal behaviour often comprises spatially separated sub-reactions and even ciliated larvae are able to coordinate sub-reactions of complex behaviours (metamorphosis, feeding). How these sub-reactions are coordinated is currently not well understood. Neuropeptides are potential candidates for triggering larval behaviour. However, although their immunoreactivity has been widely analysed, their function in trochozoan larvae has only been studied for a few cases. Here, we investigate the role of neuropeptides in the defence behaviour of brachiopod larvae. When mechanically disturbed, the planktonic larvae of Terebratalia transversa protrude their stiff chaetae and sink down slowly. We identified endogenous FLRFamide-type neuropeptides (AFLRFamide and DFLRFamide) in T. transversa larvae and show that the protrusion of the chaetae as well as the sinking reaction can both be induced by each of these peptides. This also correlates with the presence of FLRFamidergic neurons in the apical lobe and adjacent to the trunk musculature. We deorphanized the AFLRFamide/DFLRFamide receptor and detected its expression in the same tissues. Furthermore, the ability of native and modified FLRFamide-type peptides to activate this receptor was found to correspond with their ability to trigger behavioural responses. Our results show how FLRFamide-type neuropeptides can induce two coherent sub-reactions in a larva with a simple nervous system.

Environmental factors affecting reproduction and development in ascidians and other protochordates

2005 ◽  
Vol 83 (1) ◽  
pp. 51-61 ◽  
Author(s):  
William R Bates
Keyword(s):  
Environmental Factors ◽  
Environmental Regulation ◽  
Larval Settlement ◽  
Multiple Roles ◽  
Factors Affecting ◽  
Nitric Oxide Signaling ◽  
Larval Behaviour ◽  
Sexual And Asexual Reproduction ◽  
Cell Signaling Pathways

Protochordate reproduction and development are influenced by many kinds of environmental factors. For example, spawning, sexual and asexual reproduction, larval behaviour, and life-cycle transitions (metamorphosis) are key processes known to be affected by environmental factors. This review must be restricted primarily to only one group of protochordates, the ascidians or "sea squirts", because information on the reproductive ecology of hemichordates and cephalochordates is limited to only a few studies. Topics discussed in the present review include (i) environmental factors that regulate larval settlement, (ii) how pelagic embryos avoid damage to DNA caused by UV radiation, (iii) the effect of water temperature and food availability on sexual reproduction in colonial ascidians, (iv) environmental regulation of asexual budding, (v) environmental regulation of metamorphosis, and (vi) the possible role of the environment in the evolution of direct-developing ascidians. A novel role for HSP90 and nitric oxide signaling in the integration of environmental factors with cell signaling pathways in ascidians is discussed near the end of this review. Throughout this review, the multiple roles of environmental stress on ascidian reproduction and development are emphasized.

Role of dactinomycin in the improved survival of children with Wilms' tumor

JAMA ◽  
1966 ◽  
Vol 195 (12) ◽  
pp. 1005-1009 ◽  
Author(s):  
D. J. Fernbach
Keyword(s):  
Wilms Tumor

Role of the allergist in diagnosis and management of patients with uveitis

JAMA ◽  
1966 ◽  
Vol 195 (3) ◽  
pp. 167-172 ◽  
Author(s):  
T. E. Van Metre
Keyword(s):  
Diagnosis And Management

The power of norms to sway fused group members

2018 ◽  
Vol 41 ◽  
Author(s):  
Winnifred R. Louis ◽  
Craig McGarty ◽  
Emma F. Thomas ◽  
Catherine E. Amiot ◽  
Fathali M. Moghaddam
Keyword(s):  
Evolutionary Anthropology ◽  
Normative Systems ◽  
Violent Extremism ◽  
Identity Fusion ◽  
Group Members

AbstractWhitehouse adapts insights from evolutionary anthropology to interpret extreme self-sacrifice through the concept of identity fusion. The model neglects the role of normative systems in shaping behaviors, especially in relation to violent extremism. In peaceful groups, increasing fusion will actually decrease extremism. Groups collectively appraise threats and opportunities, actively debate action options, and rarely choose violence toward self or others.

Elaborating the role of reflection and individual differences in the study of folk-economic beliefs

2018 ◽  
Vol 41 ◽  
Author(s):  
Kevin Arceneaux
Keyword(s):  
Decision Making ◽  
Individual Differences ◽  
Cognitive Processes ◽  
Evolutionary History ◽  
Behavioral Responses ◽  
History Of ◽  
Economic Beliefs

AbstractIntuitions guide decision-making, and looking to the evolutionary history of humans illuminates why some behavioral responses are more intuitive than others. Yet a place remains for cognitive processes to second-guess intuitive responses – that is, to be reflective – and individual differences abound in automatic, intuitive processing as well.

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