Alternative mating tactics and tactical deception: Is the common cuttlefish (Sepia officinalis) nothing but a common cheat?

Abstract

6Alternative mating tactics (AMTs) are common in the animal kingdom, yet much work 7 remains before their evolution and role in driving sexual selection is fully understood. 8 Utilizing features of citizen science, we present compelling evidence that a third species in 9 the cuttlefish genus Sepia (Cephalopoda) possess males who use sneaky mating and female 10 mimicry as alternative strategies to conspicuous signalling and fighting.. We also present new 11 evidence of large aggregations (n~30) in this species that possibly drive alternative mating 12 strategies. Lastly, we provide footage of an opportunistic sneaky copulation in this species. 13 We believe that alternative mating tactics may be more common in this genus than previously 14 recorded (based on observations presented here and a search of the literature for similar life 15 history, environmental and behavioural factors found in other species within the Sepia 16 genus), and as much of their captive husbandry is well known, they could an ideal system for 17 studying the evolution of alternative reproductive strategies. 18 20 21 22 23 24 25 65 1991), however, a signal may also be received by eavesdroppers who may be able to gain 66 information about the signaller (McGregor, 1993) and their intentions (e.g. court/copulate 67 with a female). A signaller may try and reduce the cost of eavesdropping through tactical 68 deception (Kuczai et al. 2001) i.e. signals may not consistently reveal the genuine status or 69 intentions of the signaller. To be a genuine a case of deception, the receiver of the deception 70 must pay a cost (e.g. Kuczai et al. 2001) and the deceiver must benefit (Byrne and Whitton 71 1992; Hauser 1997).72 73 Another important influence on AMTs is the operational sex ratio (OSR: the ratio of sexually 74 mature males to fertilisable females -Mills and Reynolds, 2003) within a breeding 75 population. If the OSR is skewed towards more males, then this increased competition for 76 females can further drive sexual selection, including AMTs. OSRs are variable between 77 species and even within them from population to population. This variation in the distribution 78 of sexually mature adults may arise from environmental influences on the potential 79 reproductive rates of the sexes (Kvarnemo 1994; Reynolds et al.1986).80 81 1.1 AMTs and cuttlefish 82 Brown et al. (2012) reported an AMT using tactical deception in Sepia plangon (a cuttlefish 83 of the Class Cephalopoda) where males use a 'split' signal. The split signal includes male 84 mating signals (zebra patterning; see Hanlon and Messenger, 1996) on one side of the body 85 (the side towards a female) and a female pattern (e.g. blotched) on the other sidewhich is 86 directed towards a rival male. In certain circumstances, this could allow males to mate with 87 females without alerting other males i.e. a sneak AMT. The authors suggest this strategy 88 deceives a conspecific whilst simultaneously attracting a female (see figure 1, Brown et al. 89 2012). Alternatively, two further studies ...