Foraging behavior interactions between the invasive Nile Tilapia (Cichliformes: Cichlidae) and three large native predators

Neotropical Ichthyology, 17(3): e180116, 2019 DOI: 10.1590/1982-0224-20180116 Copyright © 2019 Sociedade Brasileira de Ictiologia Journal homepage: www.scielo.br/ni Published online: 30 September 2019 (ISSN 1982-0224) Printed: 30 September 2019 (ISSN 1679-6225) Original article Foraging behavior interactions between the invasive Nile Tilapia (Cichliformes: Cichlidae) and three large native predators Tiago Birck1, Hugo José Message1,2, Gilmar Baumgartner2,3, Nyamien Yahaut Sebastien1,2 and Dirceu Baumgartner1,2 The predator-prey relationships between juvenile Nile Tilapia Oreochromis niloticus and native fish species of the Paraná River basin, Brazil, were experimentally examined. Juveniles of O. niloticus were offered to three native predator species (Salminus brasiliensis, Pseudoplatystoma corruscans, and Brycon orbignyanus) in 2,000-L tanks with four levels of habitat complexity (0%, 50%, 100% and RD (rocks and driftwood)). Predator efficiency was more variable among species (S. brasiliensis consumed 86.6% of the prey, P. corruscans 22.5% and B. orbignyanus 18.3%) than among levels of habitat complexity, and S. brasiliensis was faster than the others in detecting and consuming the prey. The higher predatory efficiency observed for S. brasiliensis can be partially explained by its more aggressive behavior (it fed earlier and for longer) and its presence in the surface layer. Here, the presence of predators led to O. niloticus juveniles spending more time at the surface or remaining in schools to coexist at the bottom with the predators, as expected for cichlids under predatory pressure in natural environments. Our results suggest that preserving and restoring populations of S. brasiliensis (and also to some extent P. corruscans and B. orbignyanus) might help to control O. niloticus in the Paraná River basin. Keywords: Invasion, Management, Oreochromis niloticus, Predation, Prey. As relações predador-presa entre alevinos de Tilápia-do-Nilo Oreochromis niloticus e espécies de peixes nativos da bacia do rio Paraná, Brasil, foram examinadas experimentalmente. Dez alevinos de O. niloticus foram oferecidos a três espécies nativas de predadores (Salminus brasiliensis, Pseudoplatystoma corruscans e Brycon orbignyanus) em tanques de 2000L com quatro níveis de complexidade ambiental (0%, 50%, 100% e RD (rochas e galhos)). A eficiência predatória foi mais variável entre espécies (S. brasiliensis consumiu 86,6%, P. corruscans 22,5% e B. orbignyanus 18,3% dos alevinos) do que para complexidade ambiental, e S. brasiliensis foi mais rápido do que os outros em detectar e consumir a presa. A eficiência predatória de S. brasiliensis pode ser parcialmente explicada pelo seu comportamento mais agressivo (alimentou-se mais cedo e por mais tempo de experimento) e pela presença na área de superfície. A presença de predadores levou os alevinos de O. niloticus a passar mais tempo na superfície ou formar cardume para coexistir no fundo com os predadores, como o esperado para ciclídeos sob pressão predatória no campo. Nossos resultados sugerem que preservar e restaurar as populações de S. brasiliensis (principalmente, mas também P. corruscans e B. orbignyanus) podem ajudar no controle de O. niloticus na bacia do rio Paraná. Palavras-chave: Invasão, Manejo, Oreochromis niloticus, Predação, Presa. Introduction Aquaculture is an important economic activity; however, it is also a major pathway for the introduction of aquatic non-native species (Naylor et al., 2001; Ortega et al., 2015; Padial et al., 2017; Alves et al., 2018). Escapes from fish farms and invasions of non-native aquatic species into the wild are frequently associated with ecological and economic damages (Chandra, Gerhardt, 2008; Leprieur et al., 2008; Daga et al., 2016; Agostinho et al., 2018) and, against this backdrop, there is the paradigmatic issue that biological invasions are a major cause of biodiversity loss (Dirzo et al., 2014). Non-native species may prey upon native species or compete with them, catalyze ecosystem alteration and biotic homogenization (Olden, Poff, 2004), spread diseases, cause reductions in wild stocks, (e.g., Latini, Petrere Júnior, 2004) and decrease the economic value of rivers and lakes (Pimentel et al., 2005; Ellender, Weyl, 2014; Lima et al., 2018). 1 Programa de Pós-Graduação em Ciências Ambientais, Universidade Estadual do Oeste do Paraná, R. da Faculdade, 645 - Jardim La Salle, 85903-000 Toledo, PR, Brazil. (TB) , https://orcid.org/0000-0002-1042-4697; (HJM) , https://orcid.org/0000-0002-6031-8577 (corresponding author). 2 Grupo de Pesquisas em Recursos Pesqueiros e Limnologia (Gerpel), Universidade Estadual do Oeste do Paraná, Toledo, Paraná, Brazil. (NYS) , https://orcid.org/0000-0002-5288-7593; (DB) , https://orcid.org/0000-0001-9943-6290. 3 Programa de Pós-Graduação em Recursos Pesqueiros e Engenharia de Pesca, Universidade Estadual do Oeste do Paraná, Toledo, Paraná, Brazil. (GB) , https://orcid.org/0000-0003-0912-482X. e180116[1] Neotropical Ichthyology, 17(3): e180116, 2019 2 Oreochromis niloticus versus native predators There is some evidence that the Nile Tilapia Oreochromis niloticus (Linnaeus, 1758), introduced for aquaculture purposes, has established populations worldwide outside its native ranges and become invasive (Lowe et al., 2000; Naylor et al., 2001; Vicente, FonsecaAlves, 2013; Padial et al., 2017). The negative effects of Nile Tilapia invasions on native biodiversity (OgutuOhwayo, 1990; Canonico et al., 2005), on the ecosystem services (Vitule, 2009; Vitule et al., 2009; Njiru et al., 2010) and on ecosystem features (Zaret, Paine, 1973; Attayde et al., 2007), are well documented, and follow expected patterns of biological invasions in aquatic ecosystems (Mollot et al., 2017; Agostinho et al., 2018). However, whereas we know that the Nile Tilapia is a very invasive species, the interaction with native predators, which may possibly feed on Nile Tilapia, remains unknown. In summary, the following questions remain unanswered: whether native predators consume Nile Tilapia, under what environmental conditions this occurs and, finally, whether native predators are capable of reducing the effects of Nile Tilapia invasion. Our study aimed to answer these questions. The Nile Tilapia, Oreochromis niloticus, is an omnivorous species native to northern and eastern Africa. Oreochromis niloticus is one of the top ten species in the world (Lowe et al., 2000; Picker, Griffiths, 2011) most frequently introduced through aquaculture. The rearing of Nile Tilapia can be traced back to ancient Egyptian times (4,000 years ago), and the species was first introduced to African countries in the 1940s and 1950s and to Asian and South, Central and North American countries in the 1960s and 1970s. Market development and processing advances have led to a rapid expansion of the cultured Nile Tilapia since the mid-1980s. Oreochromis niloticus is the most cultivated fish species in the world (FAO, (...truncated)