scholarly journals POWER OUTPUT AND PROPULSIVE EFFICIENCY OF SWIMMING BOTTLENOSE DOLPHINS (TURSIOPS TRUNCATUS)

1993 ◽  
Vol 185 (1) ◽  
pp. 179-193 ◽  
Author(s):  
F. E. Fish
Keyword(s):  
Power Output ◽  
Tursiops Truncatus ◽  
High Performance ◽  
Bottlenose Dolphins ◽  
The Body ◽  
Hydrodynamic Performance ◽  
Propulsive Efficiency ◽  
Velocity Amplitude ◽  
Swimming Depth ◽  
Maximum Angle

The power output and propulsive efficiency of swimming bottlenose dolphins (Tursiops truncatus) were determined from a hydromechanical model. The propulsive movements were filmed as dolphins swam in large pools. Dolphins swam at velocities of 1.2-6.0 m s-1. Propulsion was provided by dorsoventral oscillations of the posterior body and flukes. The maximum angle of attack of the flukes showed a linear decrease with velocity, whereas the frequency of the propulsive cycle increased linearly with increasing velocity. Amplitude was 20 % of body length and remained constant with velocity. Propulsive efficiency was 0.81. The thrust power computed was within physiological limits. After correction for effects due to swimming depth, the coefficient of drag was found to be 3.2 times higher than the theoretical minimum assuming turbulent boundary conditions. The motions of the body and flukes are primarily responsible for the increased drag. This analysis supports other studies that indicate that bottlenose dolphins, although well adapted for efficient high- performance swimming, show no unusual hydrodynamic performance.

HIGH PERFORMANCE TURNING CAPABILITIES DURING FORAGING BY BOTTLENOSE DOLPHINS (TURSIOPS TRUNCATUS)

2004 ◽  
Vol 20 (3) ◽  
pp. 498-509 ◽  
Author(s):  
Jennifer L. Maresh ◽  
Frank E. Fish ◽  
Douglas P. Nowacek ◽  
Stephanie M. Nowacek ◽  
Randall S. Wells
Keyword(s):  
Tursiops Truncatus ◽  
High Performance ◽  
Bottlenose Dolphins

scholarly journals Phenotypic variation in dorsal fin morphology of coastal bottlenose dolphins (Tursiops truncatus) off Mexico

2017 ◽  
Author(s):  
Eduardo Morteo ◽  
Axayácatl Rocha-Olivares ◽  
Rodrigo Morteo ◽  
David W Weller
Keyword(s):  
Gulf Of Mexico ◽  
Tursiops Truncatus ◽  
Gulf Of California ◽  
Function Analysis ◽  
Bottlenose Dolphins ◽  
Hydrodynamic Performance ◽  
Morphometric Variation ◽  
Dorsal Fin ◽  
Wide Range ◽  
Fin Shape

Geographic variation in external morphology is thought to reflect an interplay between genotype and the environment. Morphological variation has been well-described for a number of cetacean species, including the bottlenose dolphin (Tursiops truncatus). In this study we analyzed dorsal fin morphometric variation in coastal bottlenose dolphins to search for geographic patterns at different spatial scales. A total of 533 dorsal fin images from 19 available photo-identification catalogs across the three Mexican oceanic regions (Pacific Ocean n=6, Gulf of California n=6 and, Gulf of Mexico n=7) were used in the analysis. Eleven fin shape measurements were analyzed to evaluate fin polymorphism through multivariate tests. Principal Component Analysis on log-transformed standardized ratios explained 94% of the variance. Canonical Discriminant Function Analysis on factor scores showed separation among most study areas (p<0.05) with exception of the Gulf of Mexico where a strong morphometric cline was found. Possible explanations for the observed differences are related to environmental, biological and evolutionary processes. Shape distinction between dorsal fins from the Pacific and those from the Gulf of California were consistent with previously reported differences in skull morphometrics and genetics. Although the functional advantages of dorsal fin shape remains to be assessed, it is not unlikely that over a wide range of environments, fin shape may represent a trade-off among thermoregulatory capacity, hydrodynamic performance and the swimming/hunting behavior of the species.

scholarly journals Phenotypic variation in dorsal fin morphology of coastal bottlenose dolphins (Tursiops truncatus) off Mexico

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3415 ◽  
Author(s):  
Eduardo Morteo ◽  
Axayácatl Rocha-Olivares ◽  
Rodrigo Morteo ◽  
David W. Weller
Keyword(s):  
Gulf Of Mexico ◽  
Tursiops Truncatus ◽  
Gulf Of California ◽  
Function Analysis ◽  
Bottlenose Dolphins ◽  
Hydrodynamic Performance ◽  
Morphometric Variation ◽  
Dorsal Fin ◽  
Wide Range ◽  
Fin Shape

Geographic variation in external morphology is thought to reflect an interplay between genotype and the environment. Morphological variation has been well-described for a number of cetacean species, including the bottlenose dolphin (Tursiops truncatus). In this study we analyzed dorsal fin morphometric variation in coastal bottlenose dolphins to search for geographic patterns at different spatial scales. A total of 533 dorsal fin images from 19 available photo-identification catalogs across the three Mexican oceanic regions (Pacific Oceann = 6, Gulf of Californian = 6 and, Gulf of Mexicon = 7) were used in the analysis. Eleven fin shape measurements were analyzed to evaluate fin polymorphism through multivariate tests. Principal Component Analysis on log-transformed standardized ratios explained 94% of the variance. Canonical Discriminant Function Analysis on factor scores showed separation among most study areas (p < 0.05) with exception of the Gulf of Mexico where a strong morphometric cline was found. Possible explanations for the observed differences are related to environmental, biological and evolutionary processes. Shape distinction between dorsal fins from the Pacific and those from the Gulf of California were consistent with previously reported differences in skull morphometrics and genetics. Although the functional advantages of dorsal fin shape remains to be assessed, it is not unlikely that over a wide range of environments, fin shape may represent a trade-off among thermoregulatory capacity, hydrodynamic performance and the swimming/hunting behavior of the species.

scholarly journals Phenotypic variation in dorsal fin morphology of coastal bottlenose dolphins (Tursiops truncatus) off Mexico

2017 ◽  
Author(s):  
Eduardo Morteo ◽  
Axayácatl Rocha-Olivares ◽  
Rodrigo Morteo ◽  
David W Weller
Keyword(s):  
Gulf Of Mexico ◽  
Tursiops Truncatus ◽  
Gulf Of California ◽  
Function Analysis ◽  
Bottlenose Dolphins ◽  
Hydrodynamic Performance ◽  
Morphometric Variation ◽  
Dorsal Fin ◽  
Wide Range ◽  
Fin Shape

Geographic variation in external morphology is thought to reflect an interplay between genotype and the environment. Morphological variation has been well-described for a number of cetacean species, including the bottlenose dolphin (Tursiops truncatus). In this study we analyzed dorsal fin morphometric variation in coastal bottlenose dolphins to search for geographic patterns at different spatial scales. A total of 533 dorsal fin images from 19 available photo-identification catalogs across the three Mexican oceanic regions (Pacific Ocean n=6, Gulf of California n=6 and, Gulf of Mexico n=7) were used in the analysis. Eleven fin shape measurements were analyzed to evaluate fin polymorphism through multivariate tests. Principal Component Analysis on log-transformed standardized ratios explained 94% of the variance. Canonical Discriminant Function Analysis on factor scores showed separation among most study areas (p<0.05) with exception of the Gulf of Mexico where a strong morphometric cline was found. Possible explanations for the observed differences are related to environmental, biological and evolutionary processes. Shape distinction between dorsal fins from the Pacific and those from the Gulf of California were consistent with previously reported differences in skull morphometrics and genetics. Although the functional advantages of dorsal fin shape remains to be assessed, it is not unlikely that over a wide range of environments, fin shape may represent a trade-off among thermoregulatory capacity, hydrodynamic performance and the swimming/hunting behavior of the species.

scholarly journals Preliminary Evaluation of Potential Impacts Associated with Small Cetacean Remote Biopsy Sampling by Controlled Testing on Stranded Common Bottlenose Dolphins (Tursiops truncatus)

2021 ◽  
Vol 2 (4) ◽  
pp. 544-558
Author(s):  
Errol I. Ronje ◽  
Casey Brechtel
Keyword(s):  
Tursiops Truncatus ◽  
Bottlenose Dolphins ◽  
The Body ◽  
Preliminary Evaluation ◽  
Target Area ◽  
Sample Length ◽  
Adult Age ◽  
The Individual ◽  
Tools And Techniques ◽  
Body Condition Scores

To explore the potential macroscopic tissue effects of select remote biopsy tools to common bottlenose dolphins (Tursiops truncatus), carcasses were darted and their traumatic effects on the anatomy in target and non-target areas of the body were described. In total, 87 samples were collected (target area, n = 19; non-target area, n = 68) within standardized grid partitions from five carcasses of sub-adult to adult age classes with a range of body condition scores. We broadly classified impacts penetrating completely through the blubber into muscle or deeper internal tissues as over-penetrations (n = 51/87, 59%). For samples collected in the defined target area, there was a low number of over-penetrations (n = 5/51; 10%). However, for samples collected in the defined, non-target areas, a much higher number of over-penetrations occurred (n = 45/51 88%). A visual examination of some samples indicated that sample length and appearance may not be reliable guides to assess the penetration depth of the wounds. These preliminary results suggest samples collected in non-targeted areas could pose much higher risk to the individual. We encourage other researchers considering the use of remote biopsy tools to conduct similar assessments prior to field sampling to better understand the potential consequences of misplaced samples with a view towards continually improving remote biopsy tools and techniques for the benefit of cetacean welfare.

scholarly journals Phenotypic variation in dorsal fin morphology of coastal bottlenose dolphins (Tursiops truncatus) off Mexico

2017 ◽  
Author(s):  
Eduardo Morteo ◽  
Axayácatl Rocha-Olivares ◽  
Rodrigo Morteo ◽  
David W Weller
Keyword(s):  
Gulf Of Mexico ◽  
Tursiops Truncatus ◽  
Gulf Of California ◽  
Function Analysis ◽  
Bottlenose Dolphins ◽  
Hydrodynamic Performance ◽  
Morphometric Variation ◽  
Dorsal Fin ◽  
Wide Range ◽  
Fin Shape

Geographic variation in external morphology is thought to reflect an interplay between genotype and the environment. Morphological variation has been well-described for a number of cetacean species, including the bottlenose dolphin (Tursiops truncatus). In this study we analyzed dorsal fin morphometric variation in coastal bottlenose dolphins to search for geographic patterns at different spatial scales. A total of 533 dorsal fin images from 19 available photo-identification catalogs across the three Mexican oceanic regions (Pacific Ocean n=6, Gulf of California n=6 and, Gulf of Mexico n=7) were used in the analysis. Eleven fin shape measurements were analyzed to evaluate fin polymorphism through multivariate tests. Principal Component Analysis on log-transformed standardized ratios explained 94% of the variance. Canonical Discriminant Function Analysis on factor scores showed separation among most study areas (p<0.05) with exception of the Gulf of Mexico where a strong morphometric cline was found. Possible explanations for the observed differences are related to environmental, biological and evolutionary processes. Shape distinction between dorsal fins from the Pacific and those from the Gulf of California were consistent with previously reported differences in skull morphometrics and genetics. Although the functional advantages of dorsal fin shape remains to be assessed, it is not unlikely that over a wide range of environments, fin shape may represent a trade-off among thermoregulatory capacity, hydrodynamic performance and the swimming/hunting behavior of the species.

scholarly journals Bottlenose dolphins (Tursiops truncatus, Montagu 1821) in central-northern coast of Rio de Janeiro State, Brazil: stranding patterns and insights into feeding habits

10.5597/00228 ◽  
2017 ◽  
Vol 11 (1-2) ◽  
pp. 191-198 ◽  
Author(s):  
Jailson Moura ◽  
Davi Castro Tavares ◽  
Helio K.C. Secco ◽  
Salvatore Siciliano
Keyword(s):  
Body Length ◽  
Bottlenose Dolphin ◽  
Tursiops Truncatus ◽  
Rio De Janeiro ◽  
Prey Species ◽  
Bottlenose Dolphins ◽  
Stomach Contents ◽  
The Body ◽  
Northern Coast ◽  
Janeiro State

The bottlenose dolphin (Tursiops truncatus) may be one of the best known dolphin species worldwide, principally due to its coastal distribution in many regions. However, few studies about ecology, biology and threats have been conducted on the Brazilian coast. The aim of the present work is to analyze the stranding pattern and stomach contents of bottlenose dolphins in the central-north coast of the Rio de Janeiro State, from Saquarema to São Francisco de Itabapoana (~300km of coast line). Forty nine stranding events were recorded through regular beach surveys from 1999 to 2012 and also through access to previous published studies conducted since 1984. The strandings were distributed throughout the study area, but there was a trend of occurrence in the extreme southern and northern regions. Nine specimens showed evidence of accidental mortality in fishing nets. The strandings were more frequently recorded during autumn and winter (χ2; p < 0.05). Male bottlenose dolphins stranded more often than females, showing significant differences in this relationship (χ2; p < 0.05). Most stranded dolphins were classified as adults (> 230cm of body length) (χ2; p < 0.05). The body length varied from 106 to 335cm. Four prey species were found in the stomach contents from the three specimens of bottlenose dolphin analyzed. The most representative prey species was the cutlassfish (Trichiurus lepturus). This study showed that bottlenose dolphins are frequently found dead along the Rio de Janeiro State where they feed mainly on coastal fish. Future studies need to be conducted to improve the knowledge on this poorly known cetacean in Brazil.

scholarly journals Phenotypic variation in dorsal fin morphology of coastal bottlenose dolphins (Tursiops truncatus) off Mexico

2017 ◽  
Author(s):  
Eduardo Morteo ◽  
Axayácatl Rocha-Olivares ◽  
Rodrigo Morteo ◽  
David W Weller
Keyword(s):  
Gulf Of Mexico ◽  
Tursiops Truncatus ◽  
Gulf Of California ◽  
Function Analysis ◽  
Bottlenose Dolphins ◽  
Hydrodynamic Performance ◽  
Morphometric Variation ◽  
Dorsal Fin ◽  
Wide Range ◽  
Fin Shape

Geographic variation in external morphology is thought to reflect an interplay between genotype and the environment. Morphological variation has been well-described for a number of cetacean species, including the bottlenose dolphin (Tursiops truncatus). In this study we analyzed dorsal fin morphometric variation in coastal bottlenose dolphins to search for geographic patterns at different spatial scales. A total of 533 dorsal fin images from 19 available photo-identification catalogs across the three Mexican oceanic regions (Pacific Ocean n=6, Gulf of California n=6 and, Gulf of Mexico n=7) were used in the analysis. Eleven fin shape measurements were analyzed to evaluate fin polymorphism through multivariate tests. Principal Component Analysis on log-transformed standardized ratios explained 94% of the variance. Canonical Discriminant Function Analysis on factor scores showed separation among most study areas (p<0.05) with exception of the Gulf of Mexico where a strong morphometric cline was found. Possible explanations for the observed differences are related to environmental, biological and evolutionary processes. Shape distinction between dorsal fins from the Pacific and those from the Gulf of California were consistent with previously reported differences in skull morphometrics and genetics. Although the functional advantages of dorsal fin shape remains to be assessed, it is not unlikely that over a wide range of environments, fin shape may represent a trade-off among thermoregulatory capacity, hydrodynamic performance and the swimming/hunting behavior of the species.

Hydrodynamic Analysis of Flapping Foils for Propulsion of Shallow-Water and Near-Surface Underwater Vehicles

2014 ◽  
Author(s):  
Palaniswamy Ananthakrishnan
Keyword(s):  
Free Surface ◽  
Critical Frequency ◽  
Underwater Vehicles ◽  
The Body ◽  
Hydrodynamic Performance ◽  
Propulsive Efficiency ◽  
Near Surface ◽  
Generating Capacity ◽  
Low Efficiency ◽  
Flapping Foils

Hydrodynamic performance of flapping foils for the propulsion or station keeping of near-surface underwater vehicles is examined numerically. The objective of the project is to determine effects of momentum fluxes associated with the vortex wake, radiating waves and their interactions on the thrust and efficiency of the flapping foils. The fully nonlinear viscous flow problem is solved using a finite difference method based on boundary-fitted coordinates. Various flapping foil mechanisms, such as of a single foil, twin foil and hinge-connected double foil, are considered. Results are obtained for a range of key variables such as the Strouhal and Froude numbers, unsteady parameter, and the depth of foil submergence. New results obtained in this work reveal complex interactions between the flap-motion generated waves and vortices, in particular, how the deforming free surface above the vehicle and radiating surface waves could affect the generation and evolution of shed vortices and the thrust-generating capacity of flapping foils. Necessary conditions for high propulsive efficiency are found to be (i) Strouhal number between 0.25 and 0.35 and (ii) oscillation at supercritical frequency, i.e., τ > 0.25. At the critical frequency τ = 0.25 the efficiency is found to be low particularly when the body is very to the free surface. Upstream wave propagation at sub-critical frequency τ < 0.25 results in the loss of propulsive efficiency. Mechanisms affecting the efficiency are amplified by the foil proximity to the surface. In the case of flapping hinged double foil, in-phase oscillation of the foils results in high thrust while out-of phase flapping produces nearly null mean thrust. Flapping of twin foil in the “clapping mode” results in a pulsating wake jet yielding a large thrust but requiring large torque and hence at low efficiency. Efficiencies upto 80% are found in the simulations with single foil.

scholarly journals Phenotypic variation in dorsal fin morphology of coastal bottlenose dolphins (Tursiops truncatus) off Mexico

2017 ◽  
Author(s):  
Eduardo Morteo ◽  
Axayácatl Rocha-Olivares ◽  
Rodrigo Morteo ◽  
David W Weller
Keyword(s):  
Gulf Of Mexico ◽  
Tursiops Truncatus ◽  
Gulf Of California ◽  
Function Analysis ◽  
Bottlenose Dolphins ◽  
Hydrodynamic Performance ◽  
Morphometric Variation ◽  
Dorsal Fin ◽  
Wide Range ◽  
Fin Shape

Geographic variation in external morphology is thought to reflect an interplay between genotype and the environment. Morphological variation has been well-described for a number of cetacean species, including the bottlenose dolphin (Tursiops truncatus). In this study we analyzed dorsal fin morphometric variation in coastal bottlenose dolphins to search for geographic patterns at different spatial scales. A total of 533 dorsal fin images from 19 available photo-identification catalogs across the three Mexican oceanic regions (Pacific Ocean n=6, Gulf of California n=6 and, Gulf of Mexico n=7) were used in the analysis. Eleven fin shape measurements were analyzed to evaluate fin polymorphism through multivariate tests. Principal Component Analysis on log-transformed standardized ratios explained 94% of the variance. Canonical Discriminant Function Analysis on factor scores showed separation among most study areas (p<0.05) with exception of the Gulf of Mexico where a strong morphometric cline was found. Possible explanations for the observed differences are related to environmental, biological and evolutionary processes. Shape distinction between dorsal fins from the Pacific and those from the Gulf of California were consistent with previously reported differences in skull morphometrics and genetics. Although the functional advantages of dorsal fin shape remains to be assessed, it is not unlikely that over a wide range of environments, fin shape may represent a trade-off among thermoregulatory capacity, hydrodynamic performance and the swimming/hunting behavior of the species.

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