Critique of the Article; Predator Recognition of Chemical Cues in Crayfish: Diet and Experience Influence the Ability to Detect Predation Threats

Critique of the Article; Predator Recognition of Chemical Cues in Crayfish: Diet and Experience Influence the Ability to Detect Predation Threats

Article Critique

Summary

There is no enough knowledge on whether chemical cues influence the diet of the predator, and if they alter their morphological characteristics, their features and behaviours. In the article, Beattie & Moore (2018) tested the ability of diet and experience on the strength of prey to detect predation. In carrying this experiment, the authors used crayfish as the prey. They carried out tests to determine if its diet and experience influence its ability to detect threats from the predator. Various specimens comprising of the prey, which was the crayfish, the predator identified as largemouth bass, and the diet were collected for the study. The results showed that in the presence of a predator odour, a crayfish altered its behavior (Beattie & Moore, 2018). It was therefore concluded that the crayfish was the best organism to test predator recognition of chemical cues. Even though the article has produced significant results regarding the ability of prey to detect predation threats, some limitations are related to methods and sampling.

Introduction

It is evident from the abstract that this is not a simple issue. Information provided in the study is confusing, and it requires one to be keen to understand the whole research. There has been a high need and interest to learn and understand how aquatic animals can communicate through the use of non-visual signals. Many studies have concluded that aquatic animals such as crayfish use chemical cues to survive in their habitat, for example, detecting predators and locating food (Ferrari, Wisenden & Chivers, 2010). The latter is, however, the main interest of the article, which has provided enough basis for conclusions to be made. The authors have moved around and touched many things which seem irrelevant before landing on the main subject. The introduction of the article is too complicated because it appears to address a wide range of issues which are far much related to the main theme of the study. It is thus forcing me to internalize everything from it just to seek understanding. Out of the much information provided, the only main idea that I have got is, chemoreception in aquatic animals such as crayfish is probably one of the common types of perception that animals use to exploit valuable resources and detect danger (Beattie & Moore, 2018). One challenging thing about the article is that the authors have explained how the process occurs through complicated experimental analyses that are not easily understandable. Some of the behavioural processes that are altered by chemical cues like reproduction, foraging, and other anti-predator responses haven’t been explained in details.

In coming up with concise results, it is always important to carry out tests on various animals to determine if they show similar behaviours (Gherardi et al., 2011). Different organisms such as snail, crucian carp crabs have been mentioned in the study, but I think the authors have slowly moved out of the main organism of research, which the crayfish. It would have been better if the authors just dwelt on crayfish to avoid confusion and match the study with the topic. In the aquatic ecosystem, one factor that determines if an animal will survive in their habitat is its ability to detect the smell of a predator even before seeing it (Large & Smee, 2010). Those able to identify the scent like crayfish and snails will be able to survive, while those unable to detect it will perish. It seems that predator detection and the strength of the response of the animal depends on the chemical cues of the prey (Beattie & Moore, 2018). Nevertheless, the author has not informed us if the animals can notice the direction of the predator because, in my opinion, the prey can escape in the direction of the predator. However, the introduction of the article has provided enough back information and thus has established the importance of the study.

Research Methods

Most of the terms used in the methodology section are a bit technical to understand. I feel that the authors have gone too much to details because even the calculations are given on average. Too many species of aquatic animals have been introduced, although they should have dwelt only on a specific predator and prey. The largemouth bass is significant predators of these two types of crayfish, and by occupying the same ecosystem, we expect to meet the results of the research (Beattie & Moore, 2018). To ensure validity in the results, the containers which contained the organisms were correctly measured, but the simulations are very technical because they are very procedural (Reynolds, 2011). To avoid errors in the results, distressed crayfish were removed from the experimental tanks.

Most of the methods used in the study were appropriate because they were all aimed at answering the research questions. One disadvantage of the method section of the study is that we haven’t been informed of the sample size and the only figure that we have been given here is very small. Such a sample size will affect the reliability of the results of the survey. The sample size also leads to a higher variability, which is likely to create biasness. When some subjects mentioned in the introduction part do not get the opportunity to participate in the survey, there is no likelihood of response occurring (Gherardi et al., 2011).

Research design has, however, also been identified, and all the data gathering instruments have been well described. We can know which kind of crayfish is in which device, and this has helped in the avoidance of confusion. (Lucon-Xiccato et al., 2018).

The methodology still makes a significant contribution to the existing knowledge about the research topic.

Study Results

Study results suggest that the overall model of interaction between the prey and the predator in the study area were influenced by the chemoreception ability of the organisms (Beattie & Moore, 2018). We realize that the focus of the data analysis was on the most frequently observed activities that involved the movement of the organisms. The results also indicate that the walking speed of the crayfish depended on the direction of the predator. If the odour was felt in the self side of the study area, the movement speed of the crayfish was higher towards the right side of the study area, and the converse is also true (Lucon-Xiccato et al., 2018). This was advantageous to the prey because it could escape from the predator.

The results of the study are understandable because they show how the behavior of the crayfish was monitored. There is a bit of information that seems to be reported out of the research; for example, the worms have been included in the measurement of the working speed of the study organisms. (Weissburg et al., 2016). Since the study is descriptive in design, it has only used descriptive statistics, and this is my rule of thumb as far as this section is concerned. As mentioned above, inferential statics have been used to identify the statistical significance of the relationship or mismatch between the variables (Beattie & Moore, 2018). The statistical significance of the study has helped the researcher to point out the threat that would be posed by crayfishes, which are distressed. The results of the research are, therefore, transparent and appropriate because they have discussed all the findings.

Discussion, Conclusion and Recommendation

The results of the study indicate two significant findings, which have also been mentioned in the research results section. First, the diet of the predator greatly influenced the behavior of crayfish, whether it was familiar with the predator or not (Beattie & Moore, 2018). Secondly, how the crayfish responded to the predator depended on their familiarity with the odour of the donor. I indeed agree with this because, in the methodology section of the research, the movement of the crayfish depended on the direction of the donor. The discussion of the findings of the study also flows logically from data collection to the results. In the introduction section of the research, it was hypothesized that crayfish would fear the predator based on the diet of the conspecific crayfish, heterospecific crayfish, and the diet of the vegetarian alone (Beattie & Moore, 2018). However, that was not the case since the findings have not fully supported the hypothesis.

There is no theoretical framework evident in the study, and this is the reason why major findings haven’t been explored. The only thing mentioned about the literature is; “There is still debate among the literature of whether these kairomones are continually produced or only produced during the consumption of prey (Beattie & Moore, 2018)”. For a study to achieve originality and relevance, it should be related to prior research statistics, but that is not the case with the article. The overall strengths and limitations of the study haven’t been developed since the significance of the findings hasn’t been well stated in the research. The key factors that affect predator recognition of chemical cues in crayfish have been assessed correctly in the sampling, analysis, and design sections of the article (Lucon-Xiccato et al., 2018). My recommendation is that further research on the topic should be made to support the existing knowledge.

References

Beattie, M. C., & Moore, P. A. (2018). Predator recognition of chemical cues in crayfish: diet and experience influence the ability to detect predation threats. Behaviour, 155(6), 505- 530.

Ferrari, M.C.O., Wisenden, B.D. & Chivers, D.P. (2010). Chemical ecology of predator-prey interactions in aquatic ecosystems: a review and prospectus. — Can. J. Zool. 88: 698-724

Gherardi, F., Mavuti, K.M., Pacini, N., Tricario, E. & Harper, D.M. (2011). The smell of danger: chemical recognition of fish predators by the invasive crayfish Procambarus clarkii. — Freshw. Biol. 56: 1567-1578.

Large, S.I. & Smee, D.L. (2010). Type and nature of cues used by Nucella lapillus to evaluate predation risk. — J. Exp. Mar. Biol. Ecol. 396: 10-17

Lucon-Xiccato, T., Ferrari, M. C., Chivers, D. P., & Bisazza, A. (2018). Odour recognition learning of multiple predators by amphibian larvae. Animal behaviour, 140, 199-205.

Nunes, A.L., Richter-Biox, A., Laurila, A. & Rebelo, R. (2012). Do anuran larvae respond behaviourally to chemical cues from an invasive crayfish predator? A community-wide study. — Oecology 171: 115-127

Reynolds, J.D. (2011). A review of ecological interactions between crayfish and fish, indigenous and introduced. — Knowl. Manage. Aquat. Ecosyst. 401: 10

Schoeppner, N.M. & Relyea, R.A. (2005). Damage, digestion, and defence: the roles of alarm cues and kairomones for inducing prey defences. — Ecol. Lett. 8: 505-512.

Weissburg, M., Poulin, R.X. & Kubanek, J. (2016). You are what you eat: a metabolomics approach to understanding prey responses to diet-dependent chemical cues by predators. — J. Chem. Ecol. 42: 1037-104