The concept of familiarity and the use of different cues in social recognition by shoaling fish species have been well researched. Recently several studies have focused on determining whether more general habitat- and diet-based odour cues can be exploited by shoaling fish species to give association preferences, rather than more specific individual recognition. In this study the effect of diet-based cues on association preferences in the guppy (Poecilia reticulata) were investigated. Firstly, fish were divided equally between two treatment groups, each being subsequently subjected to a different two-week diet treatment (either bloodworm: BW or flake food: FF).Within each treatment group sub-groups of ten were created. Binary choice tests resulted in test fish showing significant association preferences for stimulus shoals composed of BW fish, regardless of the diet treatment they had been subjected to.
In familiarity tests, where both stimulus shoals were subjected to the same diet treatment but one was composed of familiars and the other of unfamiliars, BW fish showed no significant association preference for either shoal. FF fish however showed significant association preferences for unfamiliars, contradicting previously published data. Secondly fish were tested to investigate if diet-preferences exist and therefore affect association preferences. Pairs of fish, both from the same diet treatment were subjected to a binary choice test in which odour cues from both diets were added. BW fish showed a significant preference for the BW zone, whilst FF fish showed no significant preference for either diet. Results indicate that guppies can detect odour cues and to an extent use more general diet-based cues to form association preferences for those exploiting a similar diet to themselves. This however may be overridden by an existing preference for a specific diet.
In recent years much evidence has been presented showing that the acquisition of familiarity and therefore the ability to perform detailed assessments to distinguish one individual, or group of individuals from another occurs across a wide range of taxa(Ward et al, 2005). This ability allows an informed and active decision about who to associate with to be made, and is therefore thought to play an important role in individual decision making (Griffiths, 2003). An abundance of research has been undertaken, investigating familiarity and association preferences in various species of shoaling fish, as they spend much of their lifetime closely associating with others.There is now substantial evidence proving that a wide variety of fish species have the ability to discriminate familiar from unfamiliar conspecifics (Griffiths, 2003).
Contents
1) Literature Review
2) Introduction
3) Materials and Methods
- Test Species
- Diet Treatments
- Diet Cues and Familiarity Tests
- Diet Choice Tests
- Data Analysis
4) Results
- Diet Cues and Familiarity Tests
- Diet Choice Tests
5) Discussion
6) Acknowledgments
7) References
