Page 1 - Bracciali_2016

Marine Environmental Research 113 (2016) 116e123

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Marine Environmental Research

journal homepage: www.elsevier.com/locate/marenvrev

Fish functional traits are affected by hydrodynamics at small spatial
scale

c
b
a
C. Bracciali a, b , G. Guzzo , C. Giacoma , J.M. Dean , G. Sar a a, d, *
a
Dipartimento di Scienze della Terra e del Mare, University of Palermo, Viale delle Scienze Ed. 16, 90128 Palermo, Italy
b
Department of Life Sciences and Systems Biology, University of Turin, Via Accademia Albertina 13, 10123 Turin, Italy
c Baruch Institute for Marine and Coastal Sciences, University of South Carolina, Columbia, SC 29208, USA
d
CoNISMa, UO-Palermo, Via Archirafi, 18, 90123 Palermo, Italy
article i nf o abstract
Article history: The Mediterranean damselfish Chromis chromis is a species with a broad distribution found both in the
Received 17 October 2015 Mediterranean Sea and Eastern Atlantic as far south as the coast of Angola. We hypothesized that the
Received in revised form
species may have significant functional morphological plasticity to adapt along a gradient of environ-
28 November 2015 mental conditions. It is a non-migratory zooplanktivorous species and spends the daytime searching for
Accepted 1 December 2015
Available online 11 December 2015 food in the middle of the water column. Therefore, local hydrodynamics could be one of the environ-
mental factors affecting traits of C. chromis with repercussions at the population level. We compared the
body condition, individual growth and body shapes of damselfish collected under two different hydro-
Keywords:
dynamic conditions (low ~10 cm s 1 vs. high ~20 cm s 1 ). Specimens showed higher body condition
Mediterranean damselfish
Morphometry under high-hydrodynamics, where conditions offered greater amounts of food, which were able to
Body condition state support larger individuals. Individuals smaller than 60-mm were more abundant under low-
Growth hydrodynamics. Morphometric analysis revealed that high-hydrodynamics were favored by fish with a
Hydrodynamic variability more fusiform body shape and body traits developed for propellant swimming.
Egadi marine protected area © 2015 Elsevier Ltd. All rights reserved.
Mediterranean Sea

1. Introduction requirements through the impairment of feeding behaviors (Stoll
and Fisher, 2010). The search for food in particular is an impor-
Hydrodynamics affects many ecological aspects of aquatic tant functional trait (Shoener, 1986; Sar a et al., 2014) whose effects
habitats, such as seagrass landscapes (Robbins and Bell, 2000; have rebounds in terms of the energy budget of any fish. The
Gaylord et al., 2002), larvae dispersal (Eckman, 1990; Crimaldi amount of energy spent for searching is usually paid on food
et al., 2002) and plankton distribution (George and Edwards, through a major quota of energy spent for food searching due to
1976). Hydrodynamics can make the availability of food unpre- environmental changing conditions affecting in ultimis somatic
dictably variable in abundance and patchily distributed challenging maintenance and fish life history traits such as growth and repro-
the ability of secondary consumers to get sufficient food to permit duction (sensu Kooijman, 2010). To live under unpredictable
the overtime persistence of local populations (Frechette et al.,1989; changing environmental conditions, fish have to optimize the en-
Beaulieu, 2003; Sar a, 2006). However, high hydrodynamics can ergetic ratio between income and costs; a phenotypic response to
increase the prey encounter rate (Rothschild and Osborn, 1988; hydrodynamic variability may be a solution (Sfakiotakis et al.,1999;
Gabel et al., 2008) and provide ephemeral patches of increased Lauder and Drucker, 2004) as when fish adapt their body shape to
food availability although at some point, the conditions become too the hydrodynamics of sites in which they live (Cakic et al., 2002).
high-energy and make feeding functional traits such as food Santos et al. (2011) found morphological divergences at the intra-
searching and manipulation more difficult. Thus, hydrodynamics specific level between individuals living in river channels and la-
can modify the fish activity costs due to swimming performance goons. Under quicker currents (i.e. river), individuals are more
fusiform, reflecting a functional (behavioral and morphological)
plasticity (Cunico and Agostinho, 2006; Pulcini et al., 2008;
Borazjani and Sotiropoulos, 2010). Thus, it is reasonable to as-
* Corresponding author. Dipartimento di Scienze della Terra e del Mare, Uni-
versity of Palermo, Viale delle Scienze Ed. 16, 90128 Palermo, Italy. sume that broadly-distributed species living under changing en-
E-mail address: gianluca.sara@unipa.it (G. Sar a). vironments can adapt some traits (i.e. have phenotypic plasticity;
http://dx.doi.org/10.1016/j.marenvres.2015.12.002
0141-1136/© 2015 Elsevier Ltd. All rights reserved.