Suction Feeding Strategies of Two Species of Mediterranean Serranidae (Serranus Cabrilla and Serranus Scriba)

Abstract

A comparative study of the suction feeding strategies in Serranus cabrilla and Serranus scriba was carried out. Several specimens from both species were filmed at high speed. From these films, kinetics of the suction movements and dynamic parameters, such as volume increase/time, were calculated. A simulation model of the hydrodynamics of suction feeding was used to calculate velocities, accelerations and pressure waves. Simulation results are within the range of those previously found with experimental methods for other species. The results showed that feeding strategies are different. S. cabrilla is feeding as from an ambush, with a sudden big head expansion whereas S. scriba expands its head more gradually. The graudal increase could be related to a feeding mode in which an important component of the feeding flow is contributed to swimming. These differences are discussed in the context of the ecology of the species.

Strike mechanics of an ambush predator: the spearing mantis shrimp

“…Thus, one would predict that ambush predators should require strikes of the greatest speed and shortest duration to give an element of surprise, compared with foragers of sedentary prey which should not need strikes of high speed and short duration (Cooper et al, 1985;Viladiu et al, 1999;Webb, 1984;Wilga et al, 2007). Support for this prediction is provided by several groups of small aquatic ambush predators, such as odonate larvae, hemipterans and juvenile guppies (Gambusia affinis).…”

“…The piscivorous garter snake, T. rufipunctatus, an ambush predator, achieves peak mouth-opening speeds of 0.82ms −1 in ~30-35ms (Alfaro, 2002) and another ambush predator, a suction-feeding wrasse, S. cabrilla, has an average time to peak gape of 43ms (Viladiu et al, 1999). Teleosts such as the largemouth bass, blue gill sunfish, midas cichlids and eels reach peak gape in ~22-38ms (deVries and Wainwright, 2006;Higham et al, 2006), 32ms (Higham et al, 2005), 30ms (Mehta and Wainwright, 2007) and even 347ms (Mehta and Wainwright, 2007), respectively.…”

“…The garter snake, Thamnophis rufipunctatus, ambushes prey from a hiding place by producing a rapid scissor strike that may drive water into the mouth and increase the chances of capturing prey (Alfaro, 2002). The wrasse, Serrranus cabrilla, which uses the power of suction feeding to capture evasive fish prey, produces higher flow velocities in the buccal cavity compared with the widely foraging species Serrranus scriba, when the two species are given the same prey items (Viladiu et al, 1999).…”

Multidimensional analysis of suction feeding performance in fishes: fluid speed, acceleration, strike accuracy and the ingested volume of water

“…For example, although it is clear that an increase in swimming speed will result in a narrower and more elongate ingested volume of water (Weihs, 1980;Higham et al, 2005a), it is not clear how ram speed influences the total volume of ingested water or the flow rate of this volume. Most studies have either measured volume indirectly from morphology (Cook, 1996;De Visser and Barel, 1998;Viladiu et al, 1999;Van Wassenbergh et al, 2005) or from geometric estimates of volume change of the head during the strike (Van Leeuwen, 1984). With fishes, these methods underestimate the total volume of water ingested during the strike, because while fish ingest water through their buccal cavity they expel water out a caudal valve located at the posterior end of the opercular cavity.…”