Individual experience as a key to success for the cuckoo catfish brood parasitism

Abstract

Brood parasites are involved in coevolutionary arms races with their hosts, whereby adaptations of one partner elicit the rapid evolution of counter-adaptations in the other partner. Hosts can also mitigate fitness costs of brood parasitism by learning from individual or social experience. In brood parasites, however, the role of learning can be obscured by their stealthy behaviour. Cuckoo catfish (Synodontis multipunctatus) parasitise clutches of mouthbrooding cichlids in Lake Tanganyika and are the only non-avian obligate brood parasites among vertebrates. We experimentally demonstrate that cuckoo catfish greatly enhance their efficiency in parasitising their hosts as they learn to overcome host defences. With increasing experience, cuckoo catfish increased their parasitism success by greater efficiency through improved timing and coordination of intrusions of host spawnings. Hence, within the coevolutionary arms races, brood parasites learn to overcome host defences during their lifetime.

Lack of host specialization despite selective host use in brood parasitic cuckoo catfish

“…The cuckoo catfish must acquire experience to effectively parasitize their hosts (Zimmermann et al., 2022). It opens a possibility that individual cuckoo catfish may become specialists to a particular host species as they learn to overcome their defence, but remain generalists at the population level, because different individuals learn to use different host species (cf.…”

“…The cuckoo catfish must acquire experience to effectively parasitize their hosts (Zimmermann et al, 2022). It opens a possibility that individual cuckoo catfish may become specialists to a particular host In the cuckoo catfish, this scenario may not necessarily trigger diversification, as there is no host imprinting (Zimmermann et al, 2022), no apparent host-specific mimicry (Reichard, 2019) and no behavioural parent-offspring association.…”

“…The cuckoo catfish must acquire experience to effectively parasitize their hosts (Zimmermann et al, 2022). It opens a possibility that individual cuckoo catfish may become specialists to a particular host In the cuckoo catfish, this scenario may not necessarily trigger diversification, as there is no host imprinting (Zimmermann et al, 2022), no apparent host-specific mimicry (Reichard, 2019) and no behavioural parent-offspring association. Hence, despite potential assortative mating, learned individual specialization to particular host species is reset every generation over the long juvenile period of the cuckoo catfish.…”

“…Clutch size varies from <10 to over 100 eggs, depending on cichlid species, female size and size of the eggs (Konings, 2019). The host female hastily gathers her eggs to minimize predation and, inadvertently, collects some fertilized catfish eggs (Zimmermann et al., 2022). Young catfish hatch earlier than their hosts and feed on the host embryos (Cohen et al., 2019), often resulting in complete failure of host brood (Blažek et al., 2018; Sato, 1986).…”

An Evolutionary Strategy for Spawning Habitat Selection by Pseudopungtungia tenuicorpa

“…Fish species such as Acheilognathus lanceolatus , Rhodeus sericeus , and Acheilognathus rhombeus have a habit of spawning on the bodies of freshwater clams [ 22 ], and hence, they are consistent with the distribution area of the latter [ 23 ]. Similarly, cuckoo catfish ( Synodontis multipunctatus ) is mainly distributed in Lake Tanganyika, in which cichlids are abundant, since they are known to breed via brood parasitism in the mouth-brooding cichlids [ 24 , 25 ].…”