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Many marine fish and invertebrates show a dual life history where settled adults produce dispersing larvae. The planktonic nature of the early larval stages suggests a passive dispersal model where ocean currents would quickly cause panmixis over large spatial scales and prevent isolation of populations, a prerequisite for speciation. However, high(More)
Lobsters are capable of tracking turbulent plumes to their sources faster than can be accomplished by estimating a spatial gradient from time-averaging the concentration signal. We have used RoboLobster, a biomimetic robot lobster to investigate biologically scaled chemotaxis algorithms using two point concentration sampling to track a statistically(More)
Chemical signals connect most of life's processes, including interorganismal relationships. Detection of chemical signals involves not only recognition of a spectrum of unique compounds or mixtures of compounds but also their spatial and temporal distribution. Both spectral and temporal signal processing determine what is a signal and what is background(More)
In a previous study we showed that nocturnal piscivorous catfish track the wake left by a swimming prey fish to locate it, following past locations to detect the present location of the prey. In a wake there are hydrodynamic as well as chemical signatures that both contain information on location and suitability of the prey. In order to determine how these(More)
investigations of the kinetics of olfaction have shown that olfactory systems are capable of resolving rapid events. Second messenger production in vitro and receptor potential generation in isolated olfactory receptor neurons occur within 100 ms of stimulus onset. However, little is known about the temporal capabilities of chemoreceptor systems in situ,(More)
1. Adaptation and disadaptation rates determine the temporal response properties of sensory receptor cells. In chemoreception, temporal filter properties of receptor cells are poorly understood. We studied the time course of disadaptation in lobster antennular chemoreceptor cells by using in situ high-resolution stimulus measurement and extracellularly(More)
Previous studies suggest that urine-borne pheromones play an important role in lobster agonistic and sexual behaviour. This paper investigates the pattern of urine release in catheterised, but otherwise freely moving, adult lobsters with respect to feeding, social and non-social activities. Lobsters on average released 4.1 ml (1 % of body mass) of urine(More)
The chemical stimulus environment is pulsed in nature. Mixtures can identify an odour source with great specificity, and (hence) most chemical signals are mixtures, even when initial research may seem to indicate that single compounds are sufficient to release complete behaviour. Information currents are often necessary to receive chemical stimuli. Receptor(More)
This is the first investigation of the spectral tuning properties of single chemoreceptor cells of the third maxillipeds (mouthparts) of the lobster Homarus amer-icanus. These organs are used, among other functions, for chemical recognition of food. Based upon extracellular recordings of action potentials, we report on 53 cells identified with a 15-compound(More)
The spiny damselfish, Acanthochromis polyacanthus, is widely distributed throughout the Indo-Australian archipelago. However, this species lacks a larval dispersal stage and shows genetic differentiation between populations from closely spaced reefs. To investigate the dispersal strategy of this unique species, we used microsatellite markers to determine(More)