scholarly journals Acquired predator recognition in juvenile rainbow trout (Oncorhynchus mykiss): conditioning hatchery-reared fish to recognize chemical cues of a predator

1998 ◽  
Vol 55 (3) ◽  
pp. 611-617 ◽  
Author(s):  
Grant E Brown ◽  
R Jan F. Smith

In this study, we exposed predator-naive, hatchery-reared juvenile rainbow trout (Oncorhynchus mykiss) to the chemical stimuli from northern pike (Esox lucius) and either trout skin extract (a chemical alarm signal) or a distilled water control to test for acquired recognition of a novel predator. Trout exposed to conspecific skin extract and pike odour significantly increased antipredator behaviour (i.e., decreased foraging and area use and increased shoaling and freezing), while those exposed to distilled water and pike odour did not. Conditioned trout were exposed to pike odour alone (versus a distilled water control) either 4 or 21 days later. When presented with pike odour 4 days postconditioning, trout significantly increased antipredator behaviour (i.e., decreased foraging and area use and increased time under cover and freezing). Trout tested 21 days postconditioning still exhibited a significant increase in antipredator behaviours when presented with pike odour alone (i.e., decreased foraging and increased freezing). These data are the first to demonstrate that hatchery-reared trout can be conditioned to recognize the chemical cues of a predator and suggest that this may serve as a strategy to train hatchery-reared fish to recognize predators prior to stocking into natural waterways.

1997 ◽  
Vol 75 (11) ◽  
pp. 1916-1922 ◽  
Author(s):  
Grant E. Brown ◽  
R. Jan F. Smith

We investigated, under laboratory conditions, the presence of chemical alarm signals in juvenile rainbow trout (Oncorhynchus mykiss). In an initial experiment, we exposed trout to a whole-body extract from conspecifics or a distilled-water control. When exposed to whole-body extract, trout significantly (i) decreased time spent swimming, (ii) increased time taken to resume foraging, and (iii) decreased the number of food items eaten. These data indicate a significant chemically mediated antipredator response. A second experiment was conducted to determine (i) if this is a generalized response to injured fish or a specific response to injured conspecifics, and (ii) if the chemical signal is localized in the skin. We exposed juvenile trout to one of three chemical stimuli: (1) trout skin extract, (2) trout body extract, or (3) swordtail (Xiphophorus helleri) skin extract. Significant antipredator responses were observed in trout exposed to conspecific skin extract, but responses of those exposed to conspecific body extract or swordtail skin extract did not differ from those of distilled-water controls. These data strongly suggest that juvenile rainbow trout possess a chemical alarm signal, localized in the skin, that elicits antipredator behaviour when detected.by conspecifics.


Animals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 187 ◽  
Author(s):  
Paulo Rema ◽  
Subramanian Saravanan ◽  
Benjamin Armenjon ◽  
Constant Motte ◽  
Jorge Dias

Insects are emerging as a sustainable alternative to fishmeal and fish oil in aquafeeds. This study assessed the effect of graded incorporation levels of defatted yellow mealworm (Tenebrio molitor) protein meal on juvenile rainbow trout (Oncorhynchus mykiss) growth performance, body composition, and apparent nutrient digestibility. The trial comprised five dietary treatments: control diet with 25% fishmeal, and four experimental diets with yellow mealworm protein meal at 5%, 7.5%, 15%, or 25%, which corresponded to a fishmeal replacement of 20%, 30%, 60%, or 100%, respectively. After 90 days, the graded incorporation of insect protein meal led to a significant stepwise increase in final body weight, and a significant improvement of specific growth rate, feed conversion ratio, and protein efficiency ratio compared to the control treatment. Regardless of the incorporation level, the insect protein meal had no effects on fish whole-body composition and apparent digestibility coefficients of dry matter, protein, fat, phosphorus, and energy. Protein, phosphorus, and energy retention significantly increased in fish fed the diets with an insect protein meal. In conclusion, the yellow mealworm protein meal could effectively replace 100% of fishmeal in the diet of juvenile rainbow trout with positive effects on its overall zootechnical performance.


1993 ◽  
Vol 50 (10) ◽  
pp. 2119-2128 ◽  
Author(s):  
Michael D. Riehle ◽  
J. S. Griffith

We assessed changes in density, distribution, and microhabitat of age-0 rainbow trout (Oncorhynchus mykiss) in Silver Creek, a partially spring-fed stream, by periodic snorkeling in August 1987 through January 1988. We examined trout stomach contents and invertebrate drift samples in diel collections in August, September, October, and January to test if the period of feeding shifted from daytime to nighttime, concurrent with a transition to day concealment. In late September, fish aggregated briefly during the day and then began to conceal themselves in macrophyte beds, undercut banks, and submerged sedges and grasses along streambanks as temperature dropped below 8 °C in early October. Fish emerged from concealment at night, and numbers of trout visible were greatest 30–60 min after sunset and about 30 min before sunrise. Periods of peak feeding changed from afternoon and evening in August and September, when fish were day active, to mainly at night in October after the initiation of day concealment. Trout did not feed upon abundant chironomids in the daytime drift in October. In January, fish fed at 1–4 °C on mayflies, and stomachs were fullest in the early morning. Observations suggest that Silver Creek trout experienced a metabolic deficit that began in September.


2021 ◽  
Vol 221 ◽  
pp. 112454
Author(s):  
Mahaut Beghin ◽  
Mélodie Schmitz ◽  
Stéphane Betoulle ◽  
Olivier Palluel ◽  
Sébastien Baekelandt ◽  
...  

Chemosphere ◽  
2017 ◽  
Vol 188 ◽  
pp. 548-556 ◽  
Author(s):  
Gillian McEneff ◽  
Brian Quinn ◽  
Matthew Bennion ◽  
Sorcha Dolan ◽  
Kathleen O'Rourke ◽  
...  

2020 ◽  
Vol 142 ◽  
pp. 105836
Author(s):  
Kristina Rehberger ◽  
Elena Wernicke von Siebenthal ◽  
Christyn Bailey ◽  
Patrick Bregy ◽  
Melanie Fasel ◽  
...  

Behaviour ◽  
1998 ◽  
Vol 135 (8) ◽  
pp. 1213-1228 ◽  
Author(s):  
Renée Godard ◽  
Catherine Wannamaker ◽  
Bonnie Bowers

AbstractStudies of a limited number of species of fish in the superorder Ostariophysi have shown they they exhibit strong antipredator behaviour to conserved alarm substance in feces and in other byproducts from predatory fish that have consumed ostariophysans. Our experiments examined the ability of a previously untested ostariophysan to recognize chemical cues from two species of snake predators. In Experiment 1, shoals of golden shiners (Notemigonus chrysoleucas) exhibited strong shelter-seeking responses to water which contained waste byproducts from either a sympatric snake or an allopatric snake which had been fed golden shiners but not to a distilled water control. There was no difference in response to the sympatrie snake predator, northern water snakes (Nerodia sipedon), compared to the allopatric snake predator, black-bellied garter snakes (Thamnophis melanogaster). In Experiment 2, individual shiners exhibited vigourous dashing when presented with water which contained waste byproducts from N. sipedon fed golden shiners but exhibited a much weaker response to water which contained waste byproducts from N. sipedon fed green swordtails (Xiphophorus helleri, a non-ostariophysan) or to a water control. These results suggest that the alarm substance produced in the epidermis of the golden shiners is conserved in snake waste byproducts. Experiment 3 showed that there was little difference in shelter-seeking behaviour by shoals of shiners when presented with water in which N. sipedon had soaked, water in which T. melanogaster had soaked, or a distilled water control. Thus it appears that secretions from the skin of these predators may not be chemically labelled.


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