Research Article

Effects of vertebrate and invertebrate predators on the life history of Daphnia similis and Moina macrocopa (Crustacea: Cladocera)

¹ Universidade Federal Rural do Rio de Janeiro (UFRRJ), Departamento de Ciências Ambientais, Rodovia BR 465 Km 07, CEP 23890-000, Seropédica, RJ, Brazil
² Universidade Federal de Minas Gerais (UFMG). Av. Antônio Carlos, 6627, Pampulha, CEP 31270-901, Belo Horizonte, MG, Brazil
³ Animal Ecology, Evolution and Biodiversity, Ruhr-Universität Bochum, Universitätsstr 150, 44780 Bochum, Germany
⁴ Universidade Federal do Rio de Janeiro (UFRJ), Av. Carlos Chagas Filho 373, CEP 21941-902, PO Box 68020, Rio de Janeiro, RJ, Brazil

^* Corresponding author: jaymems@gmail.com

Received: 16 November 2017
Accepted: 7 May 2018

Abstract

Cladocerans serve as prey for several aquatic predators like fish and Chaoborus larvae. However, because different predators consume different sized prey, cladocerans may display differing life-history responses depending on predator type. Although most studies use the genus Daphnia to evaluate phenotypic plasticity in cladocerans, other genera might also respond to predator infochemicals. In this study, we compared life-history responses of Daphnia similis and Moina macrocopa to infochemicals released by a vertebrate (fish) and an invertebrate (Chaoborus) predator. As expected, some life-history parameters were altered depending on the type of predator. Overall, fish infochemicals increased the size at primipara, clutch size, net reproductive rate and longevity in both cladocerans. We argue that increased body lengths in the presence of fish promote bigger clutch sizes. Conversely, responses to Chaoborus were weaker, affecting only the net reproductive rates and longevity. Non-daphniid cladocerans may display similar responses to Daphnia when exposed to predators. However, as Daphnia is usually underrepresented in tropical lakes, studying other genera might offer new insights into predator-prey relationships and food webs in lake ecosystems.