TY - JOUR
T1 - Premaxillary movements in cyprinodontiform fishes
T2 - An unusual protrusion mechanism facilitates "picking" prey capture
AU - Ferry-Graham, Lara A.
AU - Gibb, Alice C.
AU - Hernandez, L. Patricia
N1 - Funding Information:
We thank the two anonymous reviewers that commented productively and incredibly speedily on this manuscript. We gratefully acknowledge Rebecca Romansco, Tim Miller, Caley Boone, Micah Evans, Matt O’Neill, Cinnamon Pace, Jennifer Eckel, Nicole George, and Theresa Lee, all of whom assisted with data collection for this project. Comparative data were obtained from previous studies with the assistance/generosity of Peter Wainwright, Dylan Wainwright, David Bellwood, Mark Westneat, Brooke Flammang, Chris Rinewalt, Daniele Ardizone, Chante Davis, and Tonatiuh Trejo. We also thank Daphne Gehringer, Phil Motta, Lynn Parenti, and Dave Catania who provided some of the necessary specimens. Live specimens were obtained from commercial suppliers and filmed and sacrificed according to approved protocols NAU IACUC # 04-007 and SJSU/MLML IACUC #814. This work was supported by NSF MRI-0320972 to LFG and Science Foundation Arizona CAA 0057-07 to ACG.
PY - 2008/10/1
Y1 - 2008/10/1
N2 - Premaxillary protrusion is hypothesized to confer a number of feeding advantages to teleost fishes; however, most proposed advantages relate to enhanced stealth or suction production during prey capture. Cyprinodontiformes exhibit an unusual form of premaxillary protrusion where the descending process of the premaxilla does not rotate anteriorly to occlude the sides of the open mouth during prey capture. Instead, the premaxilla is protruded such that it gives the impression of a beak during prey capture. We quantified premaxillary kinematics during feeding in four cyprinodontiform taxa and compared them with three percomorph taxa to identify any performance consequences of this protrusion mechanism. Individual prey capture events were recorded using digital high-speed video at 250-500 frames per second (n≥4 individuals, ≥4 strikes per individual). Species differed in the timing of movement and the maximum displacement of the premaxilla during the gape cycle and in the contribution of the premaxilla to jaw closing. Cyprinodontiform taxa produced less premaxillary protrusion than the percomorph taxa, and were consistently slower in the time to maximum gape. Further, it appears cyprinodontiforms can alter the contribution of the premaxilla to mouth closure on an event-specific basis. We were able to demonstrate that, within at least one species, this variability is associated with the location of the prey (bottom vs. water column). Cyprinodontiform upper jaw movements likely reflect increased dexterity associated with a foraging ecology where prey items are "picked" from a variety of locations: the bottom, water column, or surface. We postulate that dexterity requires slow, precisely controlled jaw movements; thus, may be traded off for some aspects of suction-feeding performance, such as protrusion distance and speed.
AB - Premaxillary protrusion is hypothesized to confer a number of feeding advantages to teleost fishes; however, most proposed advantages relate to enhanced stealth or suction production during prey capture. Cyprinodontiformes exhibit an unusual form of premaxillary protrusion where the descending process of the premaxilla does not rotate anteriorly to occlude the sides of the open mouth during prey capture. Instead, the premaxilla is protruded such that it gives the impression of a beak during prey capture. We quantified premaxillary kinematics during feeding in four cyprinodontiform taxa and compared them with three percomorph taxa to identify any performance consequences of this protrusion mechanism. Individual prey capture events were recorded using digital high-speed video at 250-500 frames per second (n≥4 individuals, ≥4 strikes per individual). Species differed in the timing of movement and the maximum displacement of the premaxilla during the gape cycle and in the contribution of the premaxilla to jaw closing. Cyprinodontiform taxa produced less premaxillary protrusion than the percomorph taxa, and were consistently slower in the time to maximum gape. Further, it appears cyprinodontiforms can alter the contribution of the premaxilla to mouth closure on an event-specific basis. We were able to demonstrate that, within at least one species, this variability is associated with the location of the prey (bottom vs. water column). Cyprinodontiform upper jaw movements likely reflect increased dexterity associated with a foraging ecology where prey items are "picked" from a variety of locations: the bottom, water column, or surface. We postulate that dexterity requires slow, precisely controlled jaw movements; thus, may be traded off for some aspects of suction-feeding performance, such as protrusion distance and speed.
KW - Atherinomorpha
KW - Feeding kinematics
KW - Percomorpha
KW - Teleost fishes
UR - http://www.scopus.com/inward/record.url?scp=50149109177&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=50149109177&partnerID=8YFLogxK
U2 - 10.1016/j.zool.2007.11.003
DO - 10.1016/j.zool.2007.11.003
M3 - Article
C2 - 18619823
AN - SCOPUS:50149109177
SN - 0944-2006
VL - 111
SP - 455
EP - 466
JO - Zoology
JF - Zoology
IS - 6
ER -