scholarly journals A novel intramandibular joint facilitates feeding versatility in the sixbar distichodus

Author(s):  
Christopher M. Martinez ◽  
Angelly J. Tovar ◽  
Peter C. Wainwright

The intramandibular joint (IMJ) is a secondary point of movement between the two major bones of the lower jaw. It has independently evolved in several groups of teleost fishes, each time representing a departure from related species in which the mandible functions as a single structure rotating only at the quadratomandibular joint (QMJ). In this study, we examine kinematic consequences of the IMJ novelty in a freshwater characiform fish, the herbivorous Distichodus sexfasciatus. We combine traditional kinematic approaches with trajectory-based analysis of motion shapes to compare patterns of prey capture movements during substrate biting, the fish's native feeding mode, and suction of prey from the water column. We find that the IMJ enables complex jaw motions and contributes to feeding versatility by allowing the fish to modulate its kinematics in response to different prey and to various scenarios of jaw-substrate interaction. Implications of the IMJ include context-dependent movements of lower versus upper jaws, enhanced lower jaw protrusion, and the ability to maintain contact between the teeth and substrate throughout the jaw closing or biting phase of the motion. The IMJ in D. sexfasciatus appears to be an adaptation for removing attached benthic prey, consistent with its function in other groups that have evolved the joint. This study builds on our understanding of the role of the IMJ during prey capture and provides insights into broader implications of the innovative trait.

2008 ◽  
Vol 5 (29) ◽  
pp. 1445-1457 ◽  
Author(s):  
Roi Holzman ◽  
Steven W Day ◽  
Rita S Mehta ◽  
Peter C Wainwright

The ability to protrude the jaws during prey capture is a hallmark of teleost fishes, widely recognized as one of the most significant innovations in their diverse and mechanically complex skull. An elaborated jaw protrusion mechanism has independently evolved multiple times in bony fishes, and is a conspicuous feature in several of their most spectacular radiations, ultimately being found in about half of the approximately 30 000 living species. Variation in jaw protrusion distance and speed is thought to have facilitated the remarkable trophic diversity found across fish groups, although the mechanical consequences of jaw protrusion for aquatic feeding performance remain unclear. Using a hydrodynamic approach, we show that rapid protrusion of the jaws towards the prey, coupled with the spatial pattern of the flow in front of the mouth, accelerates the water around the prey. Jaw protrusion provides an independent source of acceleration from that induced by the unsteady flow at the mouth aperture, increasing by up to 35% the total force exerted on attached, escaping and free-floating passive prey. Despite initiating the strike further away, fishes can increase peak force on their prey by protruding their jaws towards it, compared with a ‘non-protruding’ state, where the distance to prey remains constant throughout the strike. The force requirements for capturing aquatic prey might have served as a selective factor for the evolution of jaw protrusion in modern fishes.


2011 ◽  
Vol 4 (2) ◽  
pp. 120-127 ◽  
Author(s):  
Nikolai N. Iordansky

The cranial kinesis and movements of the lower jaw in Typhlops are analyzed, with special emphasis placed on the functions of the jugomandibular ligament. The musculature of the Typhlops jaw apparatus is described. The role of movements of the quadrato-mandibular and palato-maxillary systems in feeding mechanics and functioning of the jaw apparatus muscles is discussed.


2001 ◽  
Vol 204 (17) ◽  
pp. 3039-3051 ◽  
Author(s):  
Peter C. Wainwright ◽  
Lara A. Ferry-Graham ◽  
Thomas B. Waltzek ◽  
Andrew M. Carroll ◽  
C. Darrin Hulsey ◽  
...  

SUMMARYWe characterized prey-capture strategies in seven species of cichlid fishes representing diverse trophic habits and anticipated feeding abilities. The species examined were Petenia splendida, Cichla ocellaris, Cichlasoma minckleyi, Astronotus ocellatus, Crenicichla geayi, Heros severus (formerly Cichlasoma severum) and Cyprichromis leptosoma. Three individuals per species were filmed with video at 500Hz as they captured live adult Artemia sp. and Poecilia reticulata. For each feeding sequence, we measured the contribution of predator movement towards the prey (i.e. ram) and the movement of prey towards the predator due to suction. The use of ram differed significantly among prey types and predator species, varying as much as sixfold across predator species. High values of ram resulted in high attack velocities. Jaw protrusion contributed as much as 50% to overall ram values in some species, verifying its role in enhancing attack velocity. Suction distance did not vary significantly among species. Diversity in prey-capture behavior was therefore found to reflect differences among species in the strategy used to approach prey. Limited variation in the distance from which prey were sucked into the mouth is interpreted as the result of an expected exponential decline in water velocity with distance from the mouth of the suction-feeding predator. We propose that this relationship represents a major constraint on the distance over which suction feeding is effective for all aquatic-feeding predators.


2012 ◽  
Vol 215 (9) ◽  
pp. 1456-1463 ◽  
Author(s):  
K. L. Staab ◽  
R. Holzman ◽  
L. P. Hernandez ◽  
P. C. Wainwright

2018 ◽  
Vol 17 (3) ◽  
pp. 433-437 ◽  
Author(s):  
Jenna Annis ◽  
Janice Coons ◽  
Charles Helm ◽  
Brenda Molano-Flores
Keyword(s):  

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