Minnow alarm pheromone

Wisenden, B. D., Chivers, D. P., Brown, G. E., and Smith, R. J. F., 1995, The role of experience in risk assessment Avoidance of areas chemically labelled with fathead minnow alarm pheromone by conspecifics and heterospecifics, Geoscience 2 116-122. 

FIGURE 7.9 A field experiment to test alarm pheromone in minnows. The minnows were attracted to a feeding table and worms were fed through the tube. When minnows were feeding, macerated minnow skin, containing alarm pheromone, was dropped through the pipe. (From von Frisch, 1941.)... 

European minnow phoxinus Both sexes Alarm pheromone Bradycardia Pfeiffer and Lamour, 1976... 

In minnows, taste is not sufficient for predator recognition. Anosmic fathead minnows, P. pmmelas, did not show the flight reaction to the odor of northern pike, Esox lucius (Chivers and Smith, 1993). Naive European minnows, Phoxinus phoxinus, do not exhibit a fright reaction when first exposed to a predator odor, such as that of pike, E. lucius. They develop a conditioned fright response only after experiencing the predator odor in dangerous circumstances, such as when accompanied by schreckstoff (alarm pheromone) of conspecifics. Responses to the odor of non-piscivorous fishes such as tilapia, Tilapia mariae, can also be conditioned in this fashion but the responses are much weaker (Magurran, 1989). 

Mathias, A. and Smith, R. J. F., Chemical labeling of northern pike (Esox lucias) by the alarm pheromone of fathead minnows (Pimpromelas sp.), J. Chem. Ecol., 19, 1967, 1993. 

Rehnberg, B.G., E.H. Bates, R.J. Smith, B.D. Sloley and J.S. Richardson. Brain benzodiazepine receptors in fathead minnows and the behavioral response to alarm pheromone. Pharmacol. Biochem. Behav. 33 435-442, 1989. 

Brown, G. E., Adrian, J. C. Jr., Patton, T., and Chivers, D. P., 2001c, Fathead minnows learn to recognize predator odour when exposed to concentrations of artificial alarm pheromones below their behavioural response thresholds. Can. J. Tool. 79 2239-2245. 

In most families of the Superorder Ostariophysi (e.g., minnows, suckers, catfish, characins and loaches), individuals show antipredator responses when they detect chemicals released from injured conspecifics. This response is absent in some armoured catfish, pencilfishes and ostariophysans with electric organs (Pfeiffer 1977). In ostariophysan fishes the alarm pheromone is contained in epidermal club cells, or alarm substance cells, that have no pores to the exterior, and have no proven function except the production and storage of the alarm substance that triggers antipredator behavior in conspecific receivers. 

The effectiveness of the overt fright reaction as defense has been demonstrated in fathead minnows Pimephales promelas) where the overt responses decrease an individual s vulnerability to predation by pike in laboratory tanks (Mathis Smith 1993b). There is also evidence that the overt responses are often contingent on other variables. For example, both Iowa darters (Etheostoma exile) (Smith 1981), which are not ostariophysans, and fathead minnows, which are, (Brown Smith 1996) show a reduction or absence of overt responses when foraging tradeoffs are increased by 48 hours of food deprivation. Common shiners Luxilus cornutus) vary their responses to alarm pheromones according to whether they detect an aquatic or avian predator in the vicinity (Heczko 1980). 

Brown, G.E., Chivers, D.P. Smith, R.J.F. 1995b. Fathead minnows avoid conspecific and heterospecific alarm pheromones in the faeces of northern pike. J. Fish Biol., 47, 387—393. 

Other published statements about the chemical nature of alarm pheromone are not sufficiently precise to provide information on potential non-alarm functions. These include the statement by Ahsan and Prasad (1982) that the alarm pheromone is a polypeptide or protein molecule and the suggestion by Tucker and Suzuki (1972) that the alarm pheromone may be a mixture of peptides, amino acids and derivatives. Similarly Lebedeva et al. (1975) isolated active fractions from minnow skin (Phoxinus phoxinus) but did not identify specific compounds although they found the molecular weight of their active components to be over 950, well above the molecular weight of hypoxanthine-3-oxide. Kasumyan and Lebedeva (1977, 1979) similarly do not provide sufficient detail about the fractions isolated to allow conclusions about other functions for alarm substance. 

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