Tactical Tentacles: New Insights on the Processes of Sexual Selection among the Cephalopoda
- 1Australian Institute of Marine Science (AIMS), Australia
- 2James Cook University, Australia
- 3Monterey Bay Aquarium Research Institute (MBARI), United States
- 4California Academy of Sciences, United States
The cephalopods (Mollusca: Cephalopoda) are an exceptional class among the invertebrates, characterised by the advanced development of their conditional learning abilities, long-term memories, capacity for rapid colour change and extremely adaptable hydrostatic skeletons. These traits enable cephalopods to occupy diverse marine ecological niches, become successful predators, employ sophisticated predator avoidance behaviours and have complex intraspecific interactions. Where studied, observations of cephalopod mating systems have revealed detailed insights to the life histories and behavioural ecologies of these animals. The reproductive biology of cephalopods is typified by high levels of both male and female promiscuity, alternative mating tactics, long-term sperm storage prior to spawning and the capacity for intricate visual displays and/or use of a distinct sensory ecology. This review summarises the current understanding of cephalopod reproductive biology, and where investigated, how both precopulatory behaviours and postcopulatory fertilisation patterns can influence the processes of sexual selection. Overall, it is concluded that sperm competition and possibly cryptic female choice are likely to be critical determinants of which individuals’ alleles get transferred to subsequent generations in cephalopod mating systems. Additionally, it is emphasised that the optimisation of offspring quality and/or fertilisation bias to genetically compatible males are necessary drivers for the proliferation of polyandry observed among cephalopods, and potential methods for testing these hypotheses are proposed within the conclusion of this review. Further gaps within the current knowledge of how sexual selection operates in this group are also highlighted, in the hopes of prompting new directions for research of the distinctive mating systems in this unique lineage.
Keywords: Courtship, Cryptic female choice, cuttlefish, mate choice, octopus, polyandry, promiscuity, sperm competition, Squid, Reproduction
Received: 25 Mar 2019;
Accepted: 29 Jul 2019.
Edited by:Graziano Fiorito, Stazione Zoologica Anton Dohrn, Italy
Reviewed by:Gustavo B. Rivas, Texas A&M University, United States
Andrea Tarallo, Department of Sciences and Technologies, University of Sannio, Italy
Copyright: © 2019 Morse and Huffard. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Dr. Peter Morse, Australian Institute of Marine Science (AIMS), Crawley, Western Australia, Australia, Peter.Morse@my.jcu.edu.au