ACTA ICHTHYOLOGICA ET PISCATORIA (2016) 46 (3): 185–200 DOI: 10.3750/AIP2016.46.3.03 SPATIO-TEMPORAL VARIATION IN THE DIET COMPOSITION OF RED LIONFISH, PTEROIS VOLITANS (ACTINOPTERYGII: SCORPAENIFORMES: SCORPAENIDAE), IN THE MEXICAN CARIBBEAN: INSIGHTS INTO THE ECOLOGICAL EFFECT OF THE ALIEN INVASION Alfrancis Teresa ARREDONDO-CHÁVEZ1, Juan Antonio SÁNCHEZ-JIMENEZ1, Oscar Gabriel ÁVILA-MORALES2, Paola TORRES-CHÁVEZ2, Yvonne HERRERIAS-DIEGO3, Martina MEDINA-NAVA2, Xavier MADRIGAL-GURIDI2, Antonio CAMPOS-MENDOZA2, Omar DOMÍNGUEZ-DOMÍNGUEZ2, and José Adán CABALLERO-VÁZQUEZ1* 1Centro de Investigación Científi ca de Yucatán, Unidad de Ciencias del Agua, Cancún, Quintana Roo, México 2Laboratorio de Biología Acuática, Facultad de Biología, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, México 3Laboratorio de Fauna Silvestre, Facultad de Biología, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, México Arredondo-Chávez A.T., Sánchez-Jimenez J.A., Ávila-Morales O.G., Torres-Chávez P., Herrerias-Diego I., Medina-Nava M., Madrigal-Guridi X., Campos-Mendoza A., Domínguez-Domínguez O., Caballero- Vázquez J.A. 2016. Spatio-temporal variation in the diet composition of red lionfi sh, Pterois volitans (Actinopterygii: Scorpaeniformes: Scorpaenidae), in the Mexican Caribbean: Insights into the ecological effect of the alien invasion. Acta Ichthyol. Piscat. 46 (3): 185–200. Background. The observed expansion of the red lionfi sh, Pterois volitans (Linnaeus, 1758), in the Caribbean represents one of the most rapid marine fi sh invasions in the history. The invasion rate of this top predator has resulted in a marked negative effect on local fi sh populations in the Caribbean by impacting local biodiversity. The main aim of this work was to conduct the morphological identifi cation of prey items from the lionfi sh diet, and to determine the spatio-temporal variation of the lionfi sh diet composition in different sites of the Mexican Caribbean, to have a better knowledge of how this invasive species is impacting local species of commercial or ecological importance in the region. Materials and methods. The Mexican Caribbean study area was divided in three zones; North (one locality Isla Contoy), Central (three locations Xpu-Ha, Akumal and X’Cacel), and South (two locations Banco Chinchorro and Xcalak). The fi sh were collected, from different habitats, using SCUBA diving and Hawaiian harpoon. Collected fi sh were taxonomically identifi ed, measured for total length (TL) and standard length (SL), and weighed to the nearest gram. Prey items were identifi ed using a dissection microscope. After identifi cation, prey items were separated, counted, and weighted individually. Finally, statistical analyses were made for all the samples using this study database, containing predators and prey items. Results. A total of 76 prey species were identifi ed in 962 lionfi sh stomachs; 47 of them represented fi shes and 29— crustaceans. Fishes of families Pomacentridae, Labridae, and Scaridae were the most abundant diet components of lionfi sh. Rhynchocinetidae, Penaeidae, and Solenoceridae were the most representative Crustaceans families among the prey items. Molluscs were present as diet components only as incidental food. Conclusion. Red lionfi sh, known for its high competitive capacity, preyed more intensively on fi shes than on crustaceans. Therefore, it is evident that the lionfi sh presence in the Mexican Caribbean may affect mainly the local population of reef fi shes. The presently reported results contribute to a better understanding of the red lionfi sh invasion in the Caribbean. Keywords: invasive species, diet component, reef fi shes, marine protected areas, trophic ecology * Correspondence: Dr. José Adán Caballero-Vázquez, Centro de Investigación Científi ca de Yucatán, Unidad de Ciencias del Agua, Laboratorio de Ecologia y Biodiversi- dad de Organismos Acuáticos, Colonia Centro, CP 77500, Cancún, Quintana Roo, México, phone: +52 (998) 2113008, e-mail: (JACV) [email protected], (ATAC) [email protected], (JASJ) [email protected], (OGAM) [email protected], (PTC) [email protected], (IHD) [email protected], (MMN) [email protected], (XMG) [email protected], (ACM) [email protected], (ODD) [email protected]. 186 Arredondo-Chávez et al. INTRODUCTION al. 2007). This invasion is one of the main threats to the Coral reefs are one of the most productive, diverse, Caribbean coral reef ecosystems (Morris 2012). The fi rst and rich ecosystems in the world, but they are also very sighting of lionfi sh in the Mexican Caribbean was reported vulnerable to the effects of climate change, contamination, in Cozumel Island in 2009 (Schofi eld 2009). Since that and anthropogenic effects. These changes are causing a time, lionfi sh rapidly invaded the entire marine and some signifi cant decrease in species richness, and a reduction in estuarine systems in the area (Vásquez-Yeomans et al. fi sh density and biomass on coral reefs and their adjacent 2011), including deep (>75 m) waters. mangrove areas (Davis et al. 2011, Green et al. 2011). Invasive species are able to produce what is called a The reefs are very important for the local communities, cascade effect through several trophic levels. For example, providing high-protein foods, areas for recreational when an “alien and exotic” fi sh enters an ecosystem and preys activities, and protection of the coastline. Moreover, on the native predator, the loss of this predator often results they are the home to nearly a third of all marine fi sh in an increase in the abundance of its prey. If the proliferation species worldwide (Pimiento et al. 2013). Coral reefs are of the latter has a negative impact on the ecosystem, then important spawning areas, and they provide protection, this outcome becomes an indirect consequence the invasive breeding and feeding grounds for many species, therefore, species occurrence in this ecosystem. Basically, invasive the conservation of the biological and genetic diversity of species causes a chain reaction in which each trophic niche the species that inhabit coral reefs is a priority for coastal in the ecosystem is affected (Green et al. 2012). Although the management and conservation (Moberg and Folke 1999). negative effects of the lionfi sh in the Caribbean ecosystems The most abundant components of coral reef seem to be obvious, the majority of the studies have focused ecosystems are corals, fi shes, and crustaceans. They in areas such as the Bahamas and Florida and little is known also play an important ecological role in the reef and about the basic aspects of the invasion in the Mexican surrounding areas, being key elements in food webs, and Caribbean. Moreover, most of the research work related to maintaining balance and dynamics in the ecosystem. As a the lionfi sh diet composition focused in the fi sh species, but result of migratory movements related to the oceanographic little is known about other groups that also serve as food and environmental conditions, changes in the abundance for the lionfi sh. Therefore, the main aims of the presently and composition are common on reef communities that reported study were: have neighbouring distribution areas (Albins and Hixon • To identify the diet composition of the lionfi sh along the 2013). In the last two decades, the structure and health Mexican Caribbean, and of many reefs in the world has diminished dramatically, • To determine the spatio-temporal variation of their diet resulting in the loss of live coral cover and biodiversity. in different sites along the Mexican Caribbean. These changes are induced by multiple factors, including pollution, sedimentation, eutrophication, overfi shing, and MATERIALS AND METHODS global warming (Moberg and Folke 1999). However, Sampling. The Caribbean region features some 26 000 these changes are not always the result of natural events, km2 of coral reefs distributed mostly in shallow areas and there are other factors that contribute to this problem with mean depths of 20 m. From these, the Mexican such as habitat destruction and introduction of not native Caribbean has a coral reef extension that covers an species that can alter dramatically the distribution and area of approximately 650 km2, constituting part of the abundance of fi sh species in these areas. Mesoamerican Barrier Reef System (MBRS). In this One of the main threats to the Caribbean fauna and work, the study site was divided in three zones identifi ed their ecosystems as a whole, is the invasion of the red as (10 km scale): lionfi sh, Pterois volitans (Linnaeus 1758). This species is a • North zone; voracious predator with a natural distribution in the Pacifi c • Central zone; and Indic Ocean, where it can be found from Australia and • South zone. Malaysia to the French Polynesia, including Japan, South For fi sh collection, zone was subdivided into localities Korea, New Zeeland, and Micronesia (Green et al. 2011). (scale of 1 to10 km); one locality from the North zone (Isla This species was reported for the fi rst time in the Atlantic Contoy), three locations for the Central zone (Xpu-Ha, in the 1980s (Betancur et al. 2010), but it was in the 1990s Akumal and X’Cacel), and two locations for the South zone when this species was systematically observed in waters (Banco Chinchorro and Xcalak). Finally, at each location of the Atlantic Ocean. It has been documented that the different collection sites were established (scale of 0.1 to lionfi sh invasion was probably the result of an accidental 1 km) (Fig.1). Of the six localities and 54 collection sites; release of only few individuals, but their potential for four were located inside Natural Protected Areas, that are expansion and colonization of local habitats, made the identifi ed as priorities by the National Commission for lionfi sh one of the most abundant species in many affected the Knowledge and Use of Biodiversity (CONABIO). areas, threatening the integrity and productivity of newly These areas are known as the National Park of Isla Contoy, colonized coastal ecosystems (Schofi eld 2009).