Functional morphology of the feeding apparatus, feeding constraints, and suction performance in the nurse sharkGinglymostoma cirratum

2008 ◽  
Vol 269 (9) ◽  
pp. 1041-1055 ◽  
Author(s):  
Philip J. Motta ◽  
Robert E. Hueter ◽  
Timothy C. Tricas ◽  
Adam P. Summers ◽  
Daniel R. Huber ◽  
...  
1997 ◽  
Vol 352 (1361) ◽  
pp. 1545-1564 ◽  
Author(s):  
Mark A. Purnell ◽  
Philip C. J. Donoghue

Ozarkodinid conodonts were one of the most successful groups of agnathan vertebrates. Only the oropharyngeal feeding apparatus of conodonts was mineralized, and the skeletal elements were generally disarticulated on the death and decay of the body. Occasionally, however, they were preserved in association as ‘natural assemblages’, fossilized in situ after post–mortem collapse of the apparatus. From analysis of element arrangement in natural assemblages of Idiognathodus from the Pennsylvanian of Illinois we have produced a precise scale model of the feeding apparatus of ozarkodinid conodonts. At the front lay an axial Sa element, flanked by two groups of four close-set elongate Sb and Sc elements which were inclined obliquely inwards and forwards; above these elements lay a pair of arched and inward pointing M elements. Behind the S-M array lay transversely oriented and bilaterally opposed Pb and Pa elements. Our model sheds new light on food acquisition in conodonts. We propose that the anterior S and M elements of ozarkodinid conodonts were attached to cartilaginous plates. In order for the animal to feed, these plates were first everted, and then drawn back and upward over the anterior edge of an underlying cartilage. These movements produced a highly effective grasping action, the cusps and denticles of the elements converging to grab and impale any food item that lay anterior to the open array. According to this hypothesis, the anterior part of the conodont apparatus is comparable to, and possibly homologous with, the lingual apparatus of extant agnathans; the elements themselves, however, have no direct homologues.


2003 ◽  
Vol 60 (6) ◽  
pp. 700-709 ◽  
Author(s):  
Joakim Hjelm ◽  
Gerco H van de Weerd ◽  
Ferdinand A Sibbing

This study explores how feeding performance (size-dependent attack rate) and the diet shift from zooplankton to benthic macroinvertebrates in the fish species roach (Rutilus rutilus L.) is related to changes in functional morphology over ontogeny. The morphological changes included overall body shape and structures of the feeding apparatus. The foraging performance of roach on zooplankton, as a function of size, was hump-shaped with a maximum of ~160 mm, and the diet shift took place around 150 mm. Over ontogeny, roach body shape gradually changed from fusiform into high-bodied. The second principal component (PC2) of the feeding apparatus had a U-shaped relationship with body size, with a minimum at 140-mm total length, which is the inverse of that found for the foraging performance on zooplankton. We suggest that changes of the feeding apparatus affect prey intake during the early zooplanktivorous phases and at the final benthivorous feeding stage, whereas prey retention ability limits the maximum intake rate at a later phase of the zooplanktivorous feeding stage. Our results also suggest the presence of both positive and negative correlations in morphology between the feeding niches, which point to the occurrence of morphological trade-offs within ontogenetic niches.


2013 ◽  
Vol 110 (2) ◽  
pp. 291-304 ◽  
Author(s):  
Julia Anne-Sophie Bauder ◽  
Stephan Handschuh ◽  
Brian Douglas Metscher ◽  
Harald Wolfgang Krenn

2006 ◽  
Vol 305A (12) ◽  
pp. 974-985 ◽  
Author(s):  
Kevin D. Friedland ◽  
Dean W. Ahrenholz ◽  
Joseph W. Smith ◽  
Maureen Manning ◽  
Julia Ryan

2012 ◽  
Vol 279 (1739) ◽  
pp. 2849-2854 ◽  
Author(s):  
David Jones ◽  
Alistair R. Evans ◽  
Karen K. W. Siu ◽  
Emily J. Rayfield ◽  
Philip C. J. Donoghue

Conodonts have been considered the earliest skeletonizing vertebrates and their mineralized feeding apparatus interpreted as having performed a tooth function. However, the absence of jaws in conodonts and the small size of their oropharyngeal musculature limits the force available for fracturing food items, presenting a challenge to this interpretation. We address this issue quantitatively using engineering approaches previously applied to mammalian dentitions. We show that the morphology of conodont food-processing elements was adapted to overcome size limitations through developing dental tools of unparalleled sharpness that maximize applied pressure. Combined with observations of wear, we also show how this morphology was employed, demonstrating how Wurmiella excavata used rotational kinematics similar to other conodonts, suggesting that this occlusal style is typical for the clade. Our work places conodont elements within a broader dental framework, providing a phylogenetically independent system for examining convergence and scaling in dental tools.


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