DOI: 10.5061/dryad.djh9w0w1z
title: Kinematic and morphological data from: Trophic guilds of suction-feeding fish are distinguished by their characteristic hydrodynamics of swimming and feeding

description: Suction-feeding in fish is a ubiquitous form of prey capture whose outcome
 depends both on the movements of the predator and the prey, and on the
 dynamics of the surrounding fluid, which exerts forces on the two
 organisms. The inherent complexity of suction-feeding has challenged
 previous efforts to understand how the feeding strikes are modified when
 species evolve to feed on different prey types. Here, we utilize the
 concept of dynamic similarity, commonly applied to understanding the
 mechanisms of swimming, flying, walking, and aquatic feeding. We
 characterize the hydrodynamic regimes pertaining to 1) the forward
 movement of the fish (ram), and 2) the suction flows for feeding strikes
 of 71 species of acanthomorph fish. A discriminant function analysis
 revealed that feeding strikes of zooplanktivores, generalists, and
 piscivores could be distinguished based on their hydrodynamic regimes.
 Furthermore, a phylogenetic comparative analysis revealed that there are
 distinctive hydrodynamic adaptive peaks associated with zooplanktivores,
 generalists, and piscivores. The scaling of dynamic similarity across
 species, body sizes, and feeding guilds in fish indicates that elementary
 hydrodynamic principles govern the trophic evolution of suction-feeding in
 fish.
description: Data on fish feeding kinematics were obtained from previously
 published studies. These encompassed feeding strikes of 15 species of
 Centrarchidae (Holzman et al. 2012), 27 species of Serranidae (Oufiero et
 al. 2012), and 21 species of Cichlidae (Hulsey et al. 2010). Original
 movies from the cichlid study (Hulsey et al. 2010) were
 reanalyzed<br> to extract all the kinematic variables relevant to
 this study (ESM 1. Data collection). These data were supplemented with
 unpublished data on two species of Antennariidae, two species of
 Centrarchidae, four species of Cichlidae, four species of Pomacentridae,
 and six species of Serranidae. All data were collected
 in a similar way, with fish being filmed from a lateral view at 500 fps
 (Hulsey et al., 2010; Holzman et al., 2012; Oufiero et al., 2012, using
 NAC Memrecam Ci Tokyo Japan), or 1000 fps (Oufiero et al., 2012, using
 Fastec HiSpec 1 San Diego CA USA), while striking an evasive prey (small
 guppies Poecilia reticulata in Hulsey et al., 2010; ghost shrimp in
 Holzman et al., 2012; and zebrafish Danio rerio and mosquitofish Gambusia
 sp. in Oufiero et al., 2012). After each trial, a ruler was filmed to
 enable scaling. For each recorded strike, landmarks on the fish were
 tracked in space and time using the DLTdv package for MATLAB (Hedrick,
 2008) or a similar digitizing software. Specifically, gape size was
 measured as the distance between the anterior tips of the premaxilla and
 the lower jaw. Because gape expansion is typically asymptotic at onset and
 end of a strike, the mouth opening phase was demarcated by the point where
 gape is 20% of maximum gape and the point where gape is 95% of maximum
 gape (Oufiero et al., 2012). The time to peak gape (TTPG) was measured as
 the duration of the mouth opening phase. Ram speed was measured as the
 slope of the linear regression of the forward cumulative displacement of
 the body during the mouth opening phase as a function of time, measured by
 tracking a landmark on the body. We used published
 literature to determine feeding guild, and prioritized sources that
 reported primary data (stomach content analysis). We classified fish as
 herbivores, detritivores, molluskivores, generalists, zooplanktivores, or
 piscivores. When primary data were available, species were classified
 according to the dominant food type, recognizing that many fish are
 opportunistic and may consume any food item that is readily available,
 irrespective of feeding specializations, in which case we also
 acknowledged a feeding guild designation given by the authors, if backed
 up by data (for example Lepomis microlophus is a molluskivore specialist,
 but stomach content depends on both season and fish body size (Desselle et
 al., 1978)). Fish that were primarily recorded as feeding on zooplankton,
 copepods and calanoids were classified as zooplanktivores and fish that
 primarily fed on other fish were classified as piscivores. Fish that were
 recorded as feeding on a variety of prey, such as gastropods, decapod
 crustaceans, mollusks, and plants were classified as generalists. Fish
 that were recorded as specializing on mollusks, plants, or detritus were
 classified as molluskivores, herbivores and detritivores,
 respectively.
description: Original data sometimes contained multiple recordings from each
 fish, or used several individual fish from each species. To avoid bias, we
 calculated the average value for each individual and the the average value
 for the species. The total number of fish and the average number of
 strikes from each fish are listed in columns No. fish and No. strikes,
 respectively.