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

Morphometric Variation ◽

Dorsal Fin ◽

Wide Range ◽

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.

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

PeerJ ◽

10.7717/peerj.3415 ◽

2017 ◽

Vol 5 ◽

pp. e3415 ◽

Cited By ~ 2

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 ◽

Morphometric Variation ◽

Dorsal Fin ◽

Wide Range ◽

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.

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

10.7287/peerj.preprints.2827v1 ◽

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 ◽

Morphometric Variation ◽

Dorsal Fin ◽

Wide Range ◽

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.

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

10.7287/peerj.preprints.2827v3 ◽

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 ◽

Morphometric Variation ◽

Dorsal Fin ◽

Wide Range ◽

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.

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

10.7287/peerj.preprints.2827v4 ◽

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 ◽

Morphometric Variation ◽

Dorsal Fin ◽

Wide Range ◽

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.

Abundance, Distribution, and Residence of Bottlenose Dolphins (Tursiops truncatus) in the Bahía San Jorge Area, Northern Gulf of California, México

Aquatic Mammals ◽

10.1578/am.32.2.2006.133 ◽

2006 ◽

Vol 32 (2) ◽

pp. 133-139 ◽

Cited By ~ 6

Author(s):

Eric Mellink ◽

Adriana Orozco-Meyer

Keyword(s):

Tursiops Truncatus ◽

Gulf Of California ◽

Bottlenose Dolphins ◽

Abundance Distribution

Persistent organic pollutants (POPs) in blood and blubber of common bottlenose dolphins (Tursiops truncatus) at three northern Gulf of Mexico sites following the Deepwater Horizon oil spill

The Science of The Total Environment ◽

10.1016/j.scitotenv.2017.11.209 ◽

2018 ◽

Vol 621 ◽

pp. 130-137 ◽

Cited By ~ 6

Author(s):

Jennifer E. Balmer ◽

Gina M. Ylitalo ◽

Teresa K. Rowles ◽

Keith D. Mullin ◽

Randall S. Wells ◽

...

Keyword(s):

Gulf Of Mexico ◽

Organic Pollutants ◽

Oil Spill ◽

Persistent Organic Pollutants ◽

Tursiops Truncatus ◽

Bottlenose Dolphins ◽

Deepwater Horizon ◽

Deepwater Horizon Oil Spill ◽

Northern Gulf Of Mexico

Effect of trophic position on mercury concentrations in bottlenose dolphins (Tursiops truncatus) from the northern Gulf of Mexico

Environmental Research ◽

10.1016/j.envres.2021.112124 ◽

2021 ◽

pp. 112124

Author(s):

Meaghan A. McCormack ◽

Weston H. Nowlin ◽

Jessica Dutton

Keyword(s):

Gulf Of Mexico ◽

Tursiops Truncatus ◽

Trophic Position ◽

Bottlenose Dolphins ◽

Northern Gulf Of Mexico

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

Journal of Experimental Biology ◽

10.1242/jeb.185.1.179 ◽

1993 ◽

Vol 185 (1) ◽

pp. 179-193 ◽

Cited By ~ 9

Author(s):

F. E. Fish

Keyword(s):

Power Output ◽

Tursiops Truncatus ◽

High Performance ◽

Bottlenose Dolphins ◽

The Body ◽

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.

Influence of artisanal fisheries on the behaviour and social structure of Tursiops truncatus in the South-western Gulf of Mexico

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s002531541900078x ◽

2019 ◽

Vol 99 (8) ◽

pp. 1841-1849

Author(s):

Nataly Morales-Rincon ◽

Eduardo Morteo ◽

Christian Alejandro Delfín-Alfonso

Keyword(s):

Gulf Of Mexico ◽

Group Size ◽

Age Structure ◽

Human Activities ◽

Tursiops Truncatus ◽

Bottlenose Dolphins ◽

Vantage Point ◽

Competitive Interactions ◽

Artisanal Fisheries ◽

Behavioural Plasticity

AbstractBehavioural plasticity in animals is tested whenever competitive interactions for space and/or food resources occur between wildlife and human activities. This study uses the concepts of operational and non-operational interactions between bottlenose dolphins (Tursiops truncatus) and artisanal fisheries in Alvarado, to search for differences in behaviour, age structure and group size. We conducted 20 surveys between 2015 and 2016, and recorded 64 groups by means of scan sampling from either a research boat or a fixed vantage point. Average dolphin group size was small (${\bar{\rm x}}$ = 3.2, SD = 2.2 individuals) and fewer individuals were commonly present when interaction with fisheries occurred. Operational interactions were defined within the first 30 m and occurred mainly with lone individuals (54% recorded from the lighthouse and 82% during surveys); this benchmark also accounted for higher frequencies in locomotion and feeding (χ2 = 83.10; df = 7; P < 0.001). We found a higher rate of new behavioural events for dolphin groups furthest from human activities, as well as a decrease in behaviours that imply greater body exposure as dolphins approach the fishing spots. Age structure and dolphin group size were not different during and in the absence of interaction with fisheries, but most interactions involved male dolphins. Behavioural variations in the dolphins' repertoire are likely a strategy to reduce the risk of injuries or death when interacting with human activities; these dolphins seem to have habituated to or at least tolerate fishing activities within the study area, possibly constituting a sex-biased pressure.