Aneesh P. H. Bose, PhD

Alternative mating tactics… Sneaking, deceit, and cuckoldry

As the adage goes, “there’s more than one way to peel an orange” (or use your own preferred vernacular), and nature has found this to be true for animal reproduction as well. In many species, same-sex individuals can adopt different tactics to achieve reproduction. For example, sometimes males may seek to reproduce by courting females or providing them with nuptial gifts, while at other times males may choose to avoid this hassle and attempt to reproduce coercively or surreptitiously. In some species, individuals may even express specialized morphology and physiology allowing them to maximize the benefits they get by pursuing one mating tactic (e.g., through sneak fertilizations as opposed to mate attraction and courtship). This can lead to two or more ‘morphs’ coexisting, and competing, with each other in the same population. For example, males of one of my study species, the plainfin midshipman fish, Porichthys notatus, adopt one of two tactics that are fixed for life, either a ‘guarder male’, which fights for nesting sites, sings to females, and cares for offspring, or a ‘sneaker male’, which stealthily tries to cuckold guarder males while they are spawning with females. I am interested in how ecological and social circumstances shape the costs and benefits of different alternative mating tactics, and what morphological and physiological specializations they express.

Example publications:

• Zimmermann H, Bose APH, Eisner H, Henshaw JM, Ziegelbecker A, Richter F, Bračun S, Katongo C, Fritzsche K, Sefc KM (2023). Seasonal variation in cuckoldry rates in the socially monogamous cichlid fish Variabilichromis moorii. Hydrobiologia 1-13. [paper]

• Bose APH, Henshaw JM, Zimmermann H, Fritzsche K, Sefc KM (2019). Inclusive fitness benefits mitigate costs of cuckoldry to socially paired males. BMC Biology 17(2). [paper]

• Miller JS, Bose APH, Fitzpatrick JL, Balshine S (2019). Sperm maturation and male tactic-specific differences in ejaculates in the plainfin midshipman fish Porichthys notatus. Journal of Fish Biology 2019:1-12. [paper]

• McCallum ES*, Bose APH*, Lobban N, Marentette J, Pettitt-Wade H, Koops M, Fisk A, Balshine S (2019). Alternative reproductive tactics, an overlooked source of life history variation in the invasive Round Goby. Canadian Journal of Fisheries and Aquatic Sciences 76(9), 1562-1570. *Co-first authors [paper]

• Bose APH, Zimmermann H, Henshaw JM, Fritzsche K, Sefc KM (2018). Brood-tending males in a biparental fish suffer high paternity losses but rarely cuckold. Molecular Ecology 27(21): 4309-4321. [paper]

Parentage… Brothers (or sisters) from another mother (or father)

Understanding parentage, i.e., which adults have sired or produced which offspring in a population, is integral for understanding patterns of (sexual) selection. Reproductive competition and alternative mating tactics can often result in broods being comprised of full-siblings, half-siblings, or even non-kin. This can affect the levels of parental care that these broods receive, the levels of mate guarding that individuals engage in, and the trade-offs between providing care at home and seeking extra reproduction elsewhere. This can also affect the frequency that individuals encounter kin as they navigate their environments during various life stages, which has important consequences for the degree of competitiveness or cooperativeness they ought to express. Parentage variation and its ramifications are therefore thought to be central for many aspects of reproductive behaviour and social behaviour more generally.

Example publications:

• Bose APH, Dabernig-Heinz J, Oberkofler J, Koch L, Grimm J, Sefc KM, Jordan A (2023). Aggression and spatial positioning of kin and non-kin fish in social groups. Behavioral Ecology 34(4): 673-681. [paper]

• Bose APH, Dabernig-Heinz J, Koch L, Grimm J, Lang S, Hegedűs B, Banda T, Makasa L, Jordan A, Sefc KM (2022). Parentage analysis across age cohorts reveals sex differences in reproductive skew in a group-living cichlid fish, Neolamprologus multifasciatus. Molecular Ecology 31:2418-2434. [paper]

• Zimmermann H, Fritzsche K, Henshaw JM, Katongo C, Banda T, Makasa L, Sefc KM, Bose APH (2019). Nest defense in the face of cuckoldry: Evolutionary rather than facultative adaptation to chronic paternity loss. BMC Evolutionary Biology 19: 200. [paper]

Parental care… Sometimes kids are worth the effort, but other times not

Animals display an amazing diversity of parental care strategies – while some animals do not care at all for their young, others are prepared to care for and protect their offspring with their lives. Furthermore, while some parents care for all their offspring equally, others pick favourites and may even abandon, kill, or cannibalise some of their young. What drives such variation within and among species? My research program strives to understand the ecological, physiological, and social factors that explain how much a parent should care for their babies, and why some parents engage in rather surprising parental behaviours.

Example publications:

• Bose APH (2022) Parent-offspring cannibalism throughout the animal kingdom: A review of adaptive hypotheses. Biological Reviews 97(5), 1868-1885. [paper]

• Bose APH, Lau M, Cogliati KM, Neff B, Balshine S. (2019). Cannibalism of young is related to low paternity and nest takeovers in an intertidal fish. Animal Behaviour 153: 41-48. [paper]

• Zimmermann H, Bose APH, Ziegelbecker A, Richter F, Bracun S, Natmessnig H, Katongo C, Banda T, Makasa L, Henshaw JM, Fritzsche K, Sefc KM (2021). Is biparental defence driven by territory protection, offspring protection, or both? Animal Behaviour 176: 43-56. [paper]

• Bose APH, Houpt N, Rawlins M, Miller JS, Juanes F, Balshine S (2020). Indirect cue of paternity uncertainty does not affect nest site selection or parental care in a Pacific toadfish. Behavioral Ecology and Sociobiology 74: 1-10. [paper]

• Jindal S*, Bose APH*, O'Connor CM, Balshine S (2017). A test of male infanticide as a reproductive tactic in a cichlid fish. Royal Society Open Science 4(3): 160891. *Co-first authors [paper]

Comprehending man-made horrors… How is anthropogenic change impacting social and reproductive evolution?

Chemical contaminants in nature represent a novel selective regime for wild animals, especially since many chemical pollutants have the potential to alter animal physiology and behaviour. Gaining a deeper understanding of how such chemicals affect the survival and reproduction of exposed animals is a daunting task, but one that is imperative for grappling with the magnitude of change that humans are imposing on nature. In collaboration with ecotoxicologists I am aiming to understand how exposure to chemical contaminants can alter the strengths and mechanisms of natural and sexual selection.

Example publications:

• McCallum ES, Cerveny D, Bose APH, Fick J, Brodin T (2023). Cost-effective pharmaceutical implants in fish: validating the performance of slow-release implants for the antidepressant fluoxetine. Environmental Toxicology and Chemistry 42(6): 1326-1336. [paper]

• Bose APH, McCallum ES, Avramović M, Bertram MG, Blom E, Cerveny D, Grønlund SN, Leander J, Lundberg P, Martin JM, Michelangeli M, Persson L, Brodin T (2022). Pharmaceutical pollution disrupts the behaviour and predator–prey interactions of two widespread aquatic insects. iScience 25(12): 105672. [paper]

• McCallum ES, Dey CJ, Cerveny D, Bose APH, Brodin T (2021). Social status modulates the behavioural and physiological consequences of a chemical pollutant in animal groups. Ecological Applications 31(8), e02454. [paper]

• McCallum ES, Bose APH, Warriner TR, Balshine S (2017). An evaluation of behavioural endpoints: The pharmaceutical pollutant fluoxetine decreases aggression across multiple contexts in round goby (Neogobius melanostomus). Chemosphere 175: 401-410. [paper]