A laboratory study of host use by the cuckoo catfish Synodontis multipunctatus

• Published in: Environmental biology of fishes 2018-09, Vol.101 (9), p.1417-1425
• Main Authors: Cohen, Marcus S., Hawkins, M. Brent, Knox-Hayes, Janelle, Vinton, Anna C., Cruz, Alexander
• Format: Article
• Language: English
• Subjects: Acuity; Adaptation; Aggressive behavior; Aggressive behaviour; Albinism; Allopatry; Animal Systematics/Taxonomy/Biogeography; Biomedical and Life Sciences; Brood parasitism; Catfish; Cichlidae; Cichlids; Ctenochromis horei; Eggs; Endemic species; Environment; Freshwater & Marine Ecology; Freshwater fishes; Haplochromis latifasciatus; Haplochromis nubilus; Laboratories; Lakes; Life Sciences; Metriaclima estherae; Model testing; Nature Conservation; Oviposition; Parasites; Parasitism; Reproductive behaviour; Rift valleys; Spawning; Synodontis multipunctatus; Visual acuity; Zoology
• ISSN: 0378-1909; 1573-5133
• DOI: 10.1007/s10641-018-0788-1

The only known non-avian vertebrate obligate brood parasite is the cuckoo catfish ( Synodontis multipunctatus ), a Lake Tanganyikan endemic. The cuckoo catfish parasitizes Tanganyikan mouthbrooding cichlids, and under captive conditions, will also parasitize cichlids from other Rift Valley lakes. Here we examine the frequency of parasitism by the cuckoo catfish of Ctenochromis horei from Lake Tanganyika and three species from Lake Malawi and the greater Lake Victorian system in a laboratory setting. C. horei was parasitized significantly less (17%) than the allopatric species Haplochromis latifasciatus , Haplochromis nubilus , and Metriaclima estherae (combined parasitism rate of 28%). The lower rates of parasitism in C. horei may be due to differences in the mating ritual, oviposition (e.g., long periods of pseudo-spawning before actual oviposition), and behavioral adaptations (e.g., increased aggression towards the cuckoo catfish). The number of catfish eggs per parasitized brood was similar between C. horei, H. latifasciatus, H. nubilus, and M. estherae . Our results are comparable to findings from the field for C. horei parasitism frequency and number of cuckoo catfish per brood. We also analyzed the parasitism rate of the albino morph of Metriaclima zebra , a domestic strain. Parasitism rates and number of catfish per brood were the highest in the albino morphotype suggesting that the higher levels of parasitism may be related to lower aggressive behavior, lower visual acuity, or captive influence. Cuckoo catfish and mouthbrooding cichlids provide a model system for testing brood parasitism in a laboratory setting.