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Anim Cogn (2012) 15:745762 DOI 10.1007/s10071-012-0513-y
REVIEW
Revisiting social recognition systems in invertebrates
Francesca Gherardi Laura Aquiloni
Elena Tricarico
Received: 14 December 2011 / Revised: 1 May 2012 / Accepted: 1 May 2012 / Published online: 26 May 2012 Springer-Verlag 2012
Abstract Since the 1970s, the ability of some invertebrate species to recognize individual conspecics has attracted increased scientic interest. However, there is still confusion in the literature, possibly due to the lack of unambiguous criteria for classifying social recognition in its different forms. Here, we synthesize the results of studies on invertebrates and provide a framework with the purpose of identifying research needs and directions for future investigations. Following in part Sherman et al.s (Behavioural ecology: an evolutionary approach. Blackwell Science, Oxford, pp 6996, 1997) denition of recognition systems and Tibbetts and Dales (Trends Ecol Evol 22:529537, 2007) classication of individual recognition, we rst discuss different case studies that exemplify the categories of familiar recognition and class-level recognition. Then, through the analysis of the invertebrate literature, we illustrate eight key properties that characterize true individual recognition systems. We are condent that the proposed framework will provide opportunities for exciting discoveries of the cognitive abilities in invertebrates.
Keywords True individual recognition
Kin recognition Familiar recognition
Class-level recognition Invertebrates
Introduction
Individual recognition in non-human vertebrates has attracted increased scientic interest over the past 50 years (Halpin 1986; Fig. 1a). In some model organisms within birds (Kroodsma and Miller 1996), rodents (Johnston 2003), and non-human primates (Rendall et al. 1996), abundant information has been gathered about the adaptive functions of this ability and the senses adopted (Colgan 1983). Research has focused on auditory and olfactory media (Thom and Hurst 2004; Brennan and Kendrick 2006; Shapiro 2009), but vision (Gothard et al. 2009; Lea 2010) and even the electric sense (Hagedorn 1986) have been also investigated.
Due to the apparent complexity of the phenomenon, individual recognition has been regarded as a sophisticated skill present only in vertebrates with a well-developed neural machinery. A paper by Hazlett (1969) on hermit crabs awakened the interest in individual recognition of invertebrates, particularly arthropods. However, this interest seems to have grown relatively slowly over the years: The number of papers on individual recognition in vertebrates has increased much more rapidly than those...