Click
here to close Hello! We notice that
you are using Internet Explorer, which is not supported by Echinobase
and may cause the site to display incorrectly. We suggest using a
current version of Chrome,
FireFox,
or Safari.
J Exp Biol
2024 Oct 01;22719:. doi: 10.1242/jeb.247523.
Show Gene links
Show Anatomy links
Finding food: how generalist predators use contact-chemosensory information to guide prey preferences.
Zimmer RK
,
Ferrier GA
,
Zimmer CA
.
???displayArticle.abstract???
Understanding the processes that guide carnivores in finding and selecting prey is a fundamental, unresolved challenge in sensory biology. To our knowledge, no published work has yet revealed the complete structural identities of compounds that cue preferences by generalist predators for different prey species. With this research imperative in mind, we determined the chemistry driving consumer preferences for live intact prey using two generalist predatory species (sea stars, Pisaster ochraceus; whelks, Acanthinucella spirata), along with two foundation prey species (mussels, Mytilus californianus; barnacles, Balanus glandula), inhabiting rocky, wave-swept shores. Each prey species is known to secrete either a 29.6 kDa (named 'KEYSTONEin') or a 199.6 kDa (named 'MULTIFUNCin') glycoprotein as a contact-chemical cue. Here, experimental manipulations utilized faux prey consisting of cleaned barnacle or mussel shells infused with KEYSTONEin, MULTIFUNCin or seawater (control) gels. Whelks exhibited a strong penchant for MULTIFUNCin over KEYSTONEin, irrespective of shell type. In contrast, sea stars generally preferred KEYSTONEin over MULTIFUNCin, but this preference shifted depending on the experimental context in which they encountered physical (shell) and chemical (glycoprotein) stimuli. This study ultimately demonstrates clear and contrasting chemical preferences between sea stars and whelks. It highlights the importance of experimental setting in determining chemical preferences. Finally, it shows that prey preferences by these predators hinge only on one or two contact-protein cues, without the need for quality coding via fluid-borne compounds, low-molecular-weight substances or mixture blends.
Fig. 1. A schematic depicting set 1, 2, 3 and 4 experiments. Images are not drawn to scale. Each picture of a single barnacle (Balanus glandula) or mussel (Mytilus californianus) represents a clean, empty shell with either MULTIFUNCin (M), KEYSTONEin (K) or filtered seawater (FSW) infused gel. Two similar experiments were performed in each set for whelks (Acanthinucella spirata) and sea stars (Pisaster ochraceus). Only one predator (P) was placed per trial into an arena, and never reused. Faux prey were positioned equidistantly from one another, surrounding the centrally located predator. The exact position of each faux prey treatment within a group was chosen using a random numbers table, and the randomized order changed from trial to trial. A trial began when a predator was first introduced, and was stopped when this consumer ate a single faux prey, or after 1 h without feeding. To compensate for size differences in sets 1 and 4, we placed 4–7 faux barnacles for each faux mussel. This procedure ensured that both prey types covered approximately the same bottom surface area of each arena. A minimum of 16 trials was conducted per experiment. Each trial employed one group with four faux-prey treatments in sets 1 and 4; four groups, each with three treatments in set 2; and two groups, each with three treatments in set 3. All other details pertaining to experimental trials and treatments are provided in the text (see Materials and Methods, Preference tests).
Fig. 2. Feeding preferences of whelks and sea stars in set 1 experiments. (A) Whelks; (B) sea stars. Here, we matched shell type with gel chemistry for each faux prey species. Each predator was allowed to consume no more than one faux prey per trial. As shown in A, there are 18 total replicate trials (N); a whelk ate one of the four faux prey treatments (10+1+0+0) in 11 trials, and a whelk failed to feed in 18–11=7 trials. For each experiment, a bar depicts the total number of replicate trials in which a given faux prey treatment was eaten. MULTI, MULTIFUNCin-infused gels; KEY, KEYSTONEin-infused gels; FSW, 0.45 µm-filtered seawater infused gels.
Fig. 3. Feeding preferences of whelks and sea stars in set 2 experiments. (A) Whelks; (B) sea stars. Here, we presented only protein- or seawater-laced gels within cleaned barnacle shells. All other conditions are as described in the Fig. 2 legend.
Fig. 4. Feeding preferences of whelks and sea stars in set 3 experiments. (A) Whelks; (B) sea stars. Here, we presented only protein- or seawater-laced gels within cleaned mussel shells. All other conditions are as described in the Fig. 2 and 3 legends.
Fig. 5. Feeding preferences of whelks and sea stars in set 4 experiments. (A) Whelks; (B) sea stars. Here, we deliberately mismatched shell type with gel chemistry for each faux prey. All other conditions are as described in the Fig. 2 and 3 legends.
