The Effects of Acute Temperature Change on Prey Capture Kinematics in Largemouth Bass, Micropterus Salmoides

We present the first analysis of scaling effects on the motor pattern of a feeding vertebrate. Data are presented for the effects of body size on the pattern of activity in four head muscles during prey capture in the largemouth bass, Micropterus salmoides. Electromyographic (EMG) recordings were made from three expansive-phase muscles (the epaxialis, the sternohyoideus and the levator arcus palatini) and one compressive-phase muscle (the adductor mandibulae), during the capture of small fish prey. Recordings were made of 181 prey-capture events from 19 bass that ranged in size from 83 to 289 mm standard length. We measured seven variables from the myogram of each capture to quantify the temporal pattern of muscle activation, including the duration of activity in each muscle and the onset time of each muscle, relative to the onset of the sternohyoideus muscle. Regressions of the mean value of each variable for the 19 individuals on standard length revealed that only the onset time of the adductor mandibulae changed with fish body size. The increase in onset time of the adductor muscle appears to reflect the longer time taken to open the mouth fully in larger fish. Other research shows that the kinematics of the strike in this species slows significantly with increasing body size. The combined results indicate that the duration of the EMG signal is not directly correlated with the duration of force production in muscles when compared between fish of different sizes. The lack of scaling of burst duration variables suggests that the reduced speeds of prey-capture motion are explained not by changes in the envelope of muscle activity, but rather by the effects of scale on muscle contractile kinetics. These scaling effects may include changes in the relative resistance of the jaw and head structures to movement through water and changes in the intrinsic contractile properties of the muscles of the feeding apparatus.

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Use of sonomicrometry demonstrates the link between prey capture kinematics and suction pressure in largemouth bass

Journal of Experimental Biology ◽

10.1242/jeb.205.22.3445 ◽

2002 ◽

Vol 205 (22) ◽

pp. 3445-3457 ◽

Cited By ~ 21

Author(s):

Christopher P. J. Sanford ◽

Peter C. Wainwright

Keyword(s):

Largemouth Bass ◽

High Speed ◽

Prey Capture ◽

Buccal Cavity ◽

Micropterus Salmoides ◽

Sampling Rate ◽

Great Promise ◽

Suction Pressure ◽

Video Recordings ◽

Explosive Expansion

SUMMARYSuction feeding in fishes is the result of a highly coordinated explosive expansion of the buccal cavity that results in a rapid drop in pressure. Prey are drawn into the mouth by a flow of water that is generated by this expansion. At a gross level it is clear that the expansion of the buccal cavity is responsible for the drop in pressure. However, attempts using high-speed video recordings to demonstrate a tight link between prey capture kinematics and suction pressure have met with limited success. In a study with largemouth bass Micropterus salmoides, we adopted a new technique for studying kinematics, sonomicrometry, to transduce the movement of skeletal elements of the head during feeding, and synchronized pressure recordings at a sampling rate of 500 Hz. From the positional relationships of six piezoelectric crystals we monitored the internal movements of the buccal cavity and mouth in both mid-sagittal and transverse planes. We found that peak subambient pressure was reached very early in the kinematic expansion of the buccal cavity, occurring at the time when the rate of percentage change in buccal volume was at its peak. Using multiple regression analyses we were consistently able to account for over 90%, and in the best model 99%, of the variation in buccal pressure among strikes using kinematic variables. Sonomicrometry shows great promise as a method for documenting movements of biological structures that are not clearly visible in the external view provided by film and video recordings.

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Morphological basis of kinematic diversity in feeding sunfishes

Journal of Experimental Biology ◽

10.1242/jeb.202.22.3101 ◽

1999 ◽

Vol 202 (22) ◽

pp. 3101-3110 ◽

Cited By ~ 12

Author(s):

P.C. Wainwright ◽

S.S. Shaw

Keyword(s):

Largemouth Bass ◽

Prey Capture ◽

Micropterus Salmoides ◽

General Pattern ◽

Lepomis Macrochirus ◽

Scaling Exponents ◽

Interspecific Differences ◽

Evolutionary Changes ◽

Predicted Values ◽

Centrarchid Fishes

The effects of differences among species in the scaling of lower jaw levers on the scaling of prey-capture kinematics are explored in three species of centrarchid fishes. We consider the jaw opening and closing lever systems and calculate the consequences of differences in the scaling of the in-levers for the scaling of the time taken to open the mouth (T(o)) and the time taken to close the mouth (T(c)) during prey capture. Predictions of T(o) and T(c), based on differences in the scaling of jaw in-levers, are compared with the observed scaling of T(o) and T(c) in three centrarchid fishes. Video recordings (200 and 400 images s(−)(1)) were made of prey capture in largemouth bass Micropterus salmoides (33–206 mm standard length, SL), spotted sunfish Lepomis punctatus (24–145 mm SL) and bluegill sunfish Lepomis macrochirus (24–220 mm SL), and the fastest values of T(o) and T(c) were taken from the fastest recorded feeding event for each fish. The scaling exponents of T(o) and T(c) regressed on fish SL for largemouth bass were 0.592 and 0.572, respectively. Exponents observed for sunfishes were not significantly different from predicted values, based on scaling exponents in largemouth bass and interspecific differences in jaw lever proportions. Two conclusions are emphasized. First, between 25 and 220 mm SL, the time taken to open and close the mouth during the strike increases with body size in all three species, suggesting a general pattern for this family. Second, evolutionary changes in jaw lever mechanics are a major determinant of the diversity of prey-capture kinematics in this sample of centrarchid fishes.

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Scaling the feeding mechanism of largemouth bass (Micropterus salmoides): kinematics of prey capture

Journal of Experimental Biology ◽

10.1242/jeb.198.2.419 ◽

1995 ◽

Vol 198 (2) ◽

pp. 419-433 ◽

Cited By ~ 25

Author(s):

B Richard ◽

P Wainwright

Keyword(s):

Body Size ◽

Largemouth Bass ◽

High Speed ◽

Time Course ◽

Prey Capture ◽

Micropterus Salmoides ◽

Feeding Mechanism ◽

Functional Changes ◽

Lower Jaw ◽

Feeding Kinematics

We present the first analysis of scaling effects on prey capture kinematics of a feeding vertebrate. The scaling of feeding kinematics of largemouth bass (Micropterus salmoides) was investigated using high-speed video (200 fields s-1) to determine what functional changes occur in the feeding mechanism as a consequence of body size. A size series of ten bass ranging from 32 to 210 mm standard length was used for the study and ten feeding sequences from each individual were analyzed to quantify movements of the feeding apparatus during prey capture. Maximal linear and angular displacements of the strike scaled isometrically. The time course of the strike was longer in larger fish. Maximal velocities of displacement were more rapid in larger fish, but their scaling exponents indicated that the intrinsic rate of muscle shortening decreased with fish size. Morphological measurements of the lever arms of the lower jaw and of the two major muscles that drive the feeding mechanism were made to relate possible biomechanical changes in the feeding mechanism to the observed kinematic relationships. The lever arms of the lower jaw and the muscles scaled isometrically; hence, the relative slowing of movements with increasing body size cannot be attributed to changes in mechanical advantage with change in body size. The scaling of feeding kinematics in the largemouth bass is in accord with the scaling of rates of muscle contraction found in other lower vertebrates. These findings demonstrate that body size can have major effects on feeding kinematics and that future comparative studies of feeding kinematics should use empirical data on size effects in kinematic comparisons between taxa.

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