The whitespotted bamboo shark is being utilized as a representative of the suction mechanism used by sharks to capture prey.  These animals are endemic to the Indo-west Pacific region, and inhabit inshore reef systems.  Mechanical models of cranial design, including theoretical estimates of the forces generated by the cranial musculature, are being designed to identify attributes of their cranial morphology suited to the unique loading regimes associated with prey capture utilizing a suction feeding mechanism.  These estimates will be compared to bite force measurements taken on free-swimming animals at the University of South Florida in Tampa, FL and at SeaWorld in Orlando, FL using a custom designed bite force transducer.  Comparison of these theoretical and in situ bite force measurements will allow us to evaluate differences between the prey these animals are capable of consuming and that which they actually consume.  The mechanical models of prey capture will be supplemented by kinematic analyses of prey capture performed with a Redlake Motionscope high-speed digital video system, and compared to similar models generated for prey capture by the horn shark Heterodontus francisci and the lemon shark Negaprion brevirostris.  Having designed mechanical models of each of these feeding mechanisms, I will then be applying these models to both extant and extinct sharks to identify how shark feeding mechanisms have evolved to handle the stresses associated with prey capture and to generate inferences about the feeding ecology of extinct taxa based on the properties of extant feeding mechanisms.

To see video, click here

Although ontogenetic changes in the feeding kinematics of various teleost fishes and amphibians have been well studied, a paucity of comparable studies have focused on elasmobranchs.  The limited research that has dealt with elasmobranchs suggests that substantial changes in feeding may be present that correlate with absolute consequences of predator size, ability to generate appreciable suction, and/or predator experience.  Identification and quantification of these correlations is necessary to provide a clear understanding of early postnatal development associated with the feeding ecology of elasmobranchs.  The goals of this research are to quantify ontogenetic changes in the kinematics of cephalic components, shape and extent of water flow patterns, and pressure generated by buccal expansion during feeding in the whitespotted bambooshark.  This research employs high-speed videography techniques, partical image velocimetry, and pressure change measurements during repeated feeding trials to achieve its goals.  Sampling has been performed at weekly intervals for one year with five individuals.  Prey items presented to the individuals during each sampling session consisted of small live shrimp (Paleomonetes sp.) and small (0.5 mouth width) and large (1.0 mouth width) pieces of krill and clam.  This collection of prey items is intended to allow distinction between situational capture modulation as a result of prey type and systematic modulation rooted in ontogeny.  Thus far, the whitespotted bambooshark appears to switch from a ram-dominated to a suction-dominated feeding modality as predator experience and size increases, although analysis is presently incomplete.  With this modality switch, an increase in the degree of overall capture bite stereotypy appears to occur.  The protocols described above are also being used to investigate changes in prey capture through ontogeny in the leopard shark Triakis semifasciata, about which more can be found on the appropriate species page.

To see video, click here