scholarly journals Feeding kinematics and morphology of the alligator gar ( Atractosteus spatula , Lacépède, 1803)

2019 ◽  
Vol 280 (10) ◽  
pp. 1548-1570
Author(s):  
Justin B. Lemberg ◽  
Neil H. Shubin ◽  
Mark W. Westneat
Keyword(s):  
Alligator Gar ◽  
Feeding Kinematics ◽  
Atractosteus Spatula

scholarly journals Feeding Kinematics And Morphology Of The Alligator Gar (Atractosteus Spatula, Lacépède, 1803): Feeding Mechanics Of Atractosteus Spatula

2019 ◽  
Author(s):  
Justin B. Lemberg ◽  
Neil H. Shubin ◽  
Mark W. Westneat
Keyword(s):  
High Speed ◽  
Prey Capture ◽  
Sister Group ◽  
Rapid Expansion ◽  
Feeding System ◽  
Primary Input ◽  
Feeding Mechanism ◽  
Alligator Gar ◽  
Feeding Kinematics ◽  
Atractosteus Spatula

ABSTRACTModern (lepisosteid) gars are a small clade of seven species and two genera that occupy an important position on the actinopterygian phylogenetic tree as members of the Holostei (Amia + gars), sister-group of the teleost radiation. Often referred to as “living fossils,” these taxa preserve many plesiomorphic characteristics used to interpret and reconstruct early osteichthyan feeding conditions. Less attention, however, has been paid to the functional implications of gar-specific morphology, thought to be related to an exclusively ram-based, lateral-snapping mode of prey capture. Previous studies of feeding kinematics in gars have focused solely on members of the narrow-snouted Lepisosteus genus, and here we expand that dataset to include a member of the broad-snouted sister-genus and largest species of gar, the alligator gar (Atractosteus spatula, Lacépède, 1803). High-speed videography reveals that the feeding system of alligator gars is capable of rapid expansion from anterior-to-posterior, precisely timed in a way that appears to counteract the effects of a bow-wave during ram-feeding and generate a unidirectional flow of water through the feeding system. Reconstructed cranial anatomy based on contrast-enhanced micro-CT data show that a lateral-sliding palatoquadrate, flexible intrasuspensorial joint, pivoting interhyal, and retractable pectoral girdle are all responsible for increasing the range of motion and expansive capabilities of the gar cranial linkage system. Muscular reconstructions and manipulation experiments show that, while the sternohyoideus is the primary input to the feeding system (similar to other “basal” actinopterygians), additional input from the hyoid constrictors and hypaxials play an important role in decoupling and modulating between the dual roles of the sternohyoideus: hyoid retraction (jaw opening) and hyoid rotation (pharyngeal expansion) respectively. The data presented here demonstrate an intricate feeding mechanism, capable of precise control with plesiomorphic muscles, that represents one of the many ways the ancestral osteichthyan feeding mechanism has been modified for prey capture.RESEARCH HIGHLIGHTSAlligator gars use a surprisingly expansive cranial linkage system for prey capture that relies on specialized joints for increased mobility and is capable of precise modulation from anterior to posterior using plesiomorphic osteichthyan musculature.

Weaning of alligator gar (Atractosteus spatula) larvae to artificial diets

2008 ◽  
Vol 14 (3) ◽  
pp. 223-231 ◽  
Author(s):  
R. MENDOZA ◽  
C. AGUILERA ◽  
L. CARREÓN ◽  
J. MONTEMAYOR ◽  
M. GONZÁLEZ
Keyword(s):  
Artificial Diets ◽  
Alligator Gar ◽  
Atractosteus Spatula

Effects of Structure and Property Variations Within Hierarchal Biomineralized Composites Using Finite Element Methods

2016 ◽  
Author(s):  
Matt Nelms ◽  
Ken Livi ◽  
Bryan Crawford ◽  
A. M. Rajendran ◽  
Wayne Hodo
Keyword(s):  
Finite Element ◽  
High Strength ◽  
Elastic Response ◽  
Science And Engineering ◽  
Structure And Property ◽  
Alligator Gar ◽  
Flaw Tolerance ◽  
Delamination Resistance ◽  
Abalone Shell ◽  
Atractosteus Spatula

Biological materials (biomaterials) have had a marked increase in interest from the material science and engineering community due to unique characteristics and properties that are typically sought after in traditional engineering materials. During the last few decades, research on biomineralized composites such as abalone shell, fish armor, turtle shell, and human bone revealed that those biological systems possess a carefully arranged multilayered composite structure. Unlike metals, ceramics, and traditional composite materials; biomineralized composites often possess enhanced characteristics such as, penetration resistance high toughness, flaw tolerance energy dissipation, damage mitigation, and delamination resistance all while achieving high strength-to-weight ratios. In this research experimentally driven finite element modeling was used to investigate the elastic response for the biocomposite structure. The Atractosteus spatula (Alligator gar) was used as the model structure for determining the elastic properties.

scholarly journals First record of exotic alligator gar, Atractosteus spatula (Actinopterygii: Lepisosteiformes: Lepisosteidae), from Ganga River system, India: A possible threat to indigenous riverine fish diversity

2021 ◽  
Vol 51 (4) ◽  
pp. 385-391
Author(s):  
Ranjan Kumar Manna ◽  
Archisman Ray ◽  
Supriti Bayen ◽  
Tanushree Bera ◽  
Debashis Palui ◽  
...  
Keyword(s):  
Environmental Parameters ◽  
River System ◽  
First Record ◽  
Ganga River ◽  
Predatory Fish ◽  
Fish Diversity ◽  
Exotic Fish ◽  
Alligator Gar ◽  
Riverine Fish ◽  
Atractosteus Spatula

A new record of an exotic alligator gar, Atractosteus spatula (Lacepède, 1803), from an open wetland of the Ganga River was presented in this paper and discussed along with the environmental parameters. Entry of the exotic fish into the natural system was probably a result of uncontrolled ornamental fish trading. Considering threats of this predatory fish to become invasive and disturb riverine fish diversity, possible ways to avoid such risk have been discussed.

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