Behavioral Asymmetries of Pectoral Fin Use During Social Interactions of Bottlenose Dolphins (Tursiops truncatus)

The preference for utilizing certain appendages (handedness) has been explored in human and nonhuman primates. Similarly to primates, dolphins possess hemispheres that allow an individual to present behaviorally dominant features as well as appendages (i.e., pectoral fins) that are utilized both as social facilitators as well as means to interact with objects. Thus, the possibility of handedness in a captive population of 27 bottlenose dolphins (Tursiops truncatus) was explored. Dolphins in a mother-offspring relationship made significantly more pectoral fin contacts than in the absence of this relationship (p < 0.001). No significant difference was observed between maternal siblings and non-maternal siblings in overall pectoral fin contact. Handedness indexes were calculated for 26 individuals that initiated pectoral fin contact with both conspecifics and flora (i.e., seagrass) in their habitat. No significant differences were observed between the sexes in handedness indexes, however calves displayed a significant right-fin handedness compared to both sub-adults and adults (p < 0.05). Both sub-adults and adults showed a left-fin handedness indexes, but no significant difference in the strength of this relationship among these two age classes was observed. Individual variation in handedness indexes was noted. These results suggest that handedness may be present in Atlantic bottlenose dolphins with regards to social contact, and a larger and more diverse sample size may provide a better understanding in why handedness may change across development.

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Osteological variation and taxonomic affinities of bottlenose dolphins, Tursiops spp., from South Australia

Australian Journal of Zoology ◽

10.1071/zo03026 ◽

2004 ◽

Vol 52 (1) ◽

pp. 29 ◽

Cited By ~ 29

Author(s):

Catherine M. Kemper

Keyword(s):

Bone Resorption ◽

Cancellous Bone ◽

Tursiops Truncatus ◽

Bottlenose Dolphins ◽

South Australia ◽

Wide Band ◽

Categorical Variables ◽

Significant Difference ◽

Partial Correlations ◽

Skull Measurements

Skulls and skeletons of 84 cranially mature bottlenose dolphins collected from South Australia were studied to distinguish morphological groups. The dataset comprised 38 skull measurements, 5 tooth counts/measurements, 6 coded skull features and 2 vertebral counts. There was no significant difference between sexes. Agglomerative, heirarchical cluster analyses performed on all variables and a dataset refined by eliminating those with high partial correlations produced two clear groups of skulls but with some differences in group membership between the statistical treatments. Size was an important factor in distinguishing groups, especially when categorical variables were excluded. Groups produced by cluster analysis of all variables were aligned with Tursiops truncatus and T. aduncus. In general, Tursiops truncatus was distinguished by a wide band (3-9 mm) of cancellous bone on the premaxillae, a distinct supraoccipital crest, raised naso-frontal complex, the almost complete lack of bone resorption on the pterygoid bones, a relatively wider rostrum, generally larger skull size (condylobasal length >465 mm versus <476 mm, except two skulls of 445 and 448 mm), and more than 60 vertebrae. This species was collected from open ocean coasts and sometimes stranded in groups. Tursiops aduncus generally had a narrow or no band of cancellous bone (0-5 mm), an indistinct or no supraoccipital crest, a naso-frontal complex that was not markedly raised, moderate to extensive bone resorption on the pterygoids, relatively narrow rostrum, fewer than 63 vertebrae and was collected mainly from the large gulfs. There was no significant difference between tooth diameter of T. aduncus and T. truncatus from South Australia.

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Vocalizations associated with pectoral fin contact in bottlenose dolphins (Tursiops truncatus)

Behavioural Processes ◽

10.1016/j.beproc.2013.07.025 ◽

2013 ◽

Vol 100 ◽

pp. 74-81 ◽

Cited By ~ 4

Author(s):

J. Evans-Wilent ◽

K.M. Dudzinski

Keyword(s):

Tursiops Truncatus ◽

Bottlenose Dolphins ◽

Pectoral Fin

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Aspectos etnoecológicos e implicações para a conservação de Tursiops truncatus (Cetartiodactyla: Delphinidae) no Arquipélago das Cagarras, Rio de Janeiro, Brasil

SITIENTIBUS série Ciências Biológicas ◽

10.13102/scb200 ◽

2013 ◽

Vol 13 ◽

Author(s):

Liliane Lodi ◽

Camilah Antunes Zappes ◽

Álvaro Samuel Guimarães dos Santos

Keyword(s):

Tursiops Truncatus ◽

Rio De Janeiro ◽

Anthropogenic Impacts ◽

Participant Observation ◽

Bottlenose Dolphins ◽

Morphological Characteristics ◽

Small Scale ◽

Common Bottlenose Dolphin ◽

Significant Difference ◽

The Common

The objectives of this study were to understand the ecological aspects of the common bottlenose dolphin (Tursiops truncatus) in the Cagarras Archipelago, Rio de Janeiro, Brazil, and possible anthropogenic impacts by comparing the knowledge of local small-scale fishermen (GA) and the regulars in the archipelago (GB). The data obtained were compared with those available in the literature to propose strategies for monitoring and preservation. Between August and December 2010, we applied the methods of participant observation, interviews-questionnaires and use of illustrative posters. Sixty-one interviews were conducted, from which 83.6% were selected by considering correct answers about the identification of the species on posters (morphological characteristics) and description of time of occurrence in the archipelago (July to December) as reported for the species in the literature. Regarding the seven questions analyzed statistically, a significant difference was found between the accounts of the two groups with respect to anthropic threats to T. truncatus. Gill-nets and the decrease of fishing resources were the main causes identified by the GA group whereas the GB group pointed to the disorganized use of space, pollution and predatory fishing as the factors that have threatened the common bottlenose dolphins. The use of ethnobiological data in conservation programs brings opportunities for the collaboration and participation of the community that is directly inserted into the ecosystem as well as a chance for locals to get involved in issues concerning the sustainability of the archipelago.

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The Effect of Feeding Frequency on the Fin Condition in Rainbow Trout (Oncorhynchus mykiss)

Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis ◽

10.11118/actaun201866030669 ◽

2018 ◽

Vol 66 (3) ◽

pp. 669-675 ◽

Cited By ~ 1

Author(s):

Ondřej Klíma ◽

Lukáš Kohút ◽

Jan Mareš ◽

Radovan Kopp

Keyword(s):

Rainbow Trout ◽

Oncorhynchus Mykiss ◽

Flow Direction ◽

Feeding Frequency ◽

Pectoral Fin ◽

Fish Welfare ◽

Pectoral Fins ◽

Rainbow Trout Oncorhynchus Mykiss ◽

Significant Difference ◽

The Right

Fin condition was assessed in the rainbow trout (Oncorhynchus mykiss) at an experimental recirculating facility using manual feeding 2 and 3 meals per day. Fin Index (FI) was used as an indicator of the find condition. Comparing the feeding frequencies 2 and 3 meals per day, a statistically significant difference was found (p < 0.05) for the FI of the pectoral, pelvic, anal, and caudal fins. For the 3 meals per day feeding frequency, a greater decrease of the FI was found compared to the feeding frequency 2 meals per day. In both pelvic fins the FI decreased by 53 %, in the caudal fins the FI decreased by 18 % and by 11 % in the anal fins, in the left pectoral fin the FI decreased by 6 % and by 12 % in the right one. Statistically significant difference was found between both pectoral fins for the feeding frequency of 3 meals per day. The left pectoral fin showed a FI higher by 8 % compared to the right one; the reason for the asymmetry being the water flow direction in the circular tanks. It follows from the results that in terms of fish welfare, it is more advisable to administer the feed 2 meals per day at maximum, in order to lower the risk of random biting by other individuals and to obtain a better fin condition.

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Sex differences in the epidemiology of tattoo skin disease in captive common bottlenose dolphins (Tursiops truncatus): are males more vulnerable than females?

10.1101/101915 ◽

2017 ◽

Author(s):

Marie-Françoise Van Bressem ◽

Koen Van Waerebeek ◽

Pádraig J. Duignan

Keyword(s):

Gender Bias ◽

Skin Disease ◽

Tursiops Truncatus ◽

Bottlenose Dolphins ◽

Biological Data ◽

Age Classes ◽

Epidemiological Features ◽

The Usa ◽

Related Stress ◽

Free Ranging

AbstractThe clinical and epidemiological features of tattoo skin disease (TSD), caused by cetacean poxviruses, are reported in 257 common bottlenose dolphins (Tursiops truncatus) held in 31 facilities in the USA and Europe. Photographs and biological data of 146 females and 111 males were analyzed. Dolphins were classified into three age classes (0-3; 4-8; over 9 years), approximating the life stages of ‘calves and young juveniles’, ‘juveniles and sub-adults’ and ‘adults’. The youngest dolphins with tattoos were 14 and 15 months old. Minimal TSD persistence varied between 4 and 65 months in 30 dolphins and was over 22 months in those with very large lesions (> 115 mm). In 2012-2014, 20.6% of the 257 dolphins had TSD. Prevalence varied between facilities from 5.6% (n= 18) to 60% (n= 20), possibly reflecting variation in environmental conditions. Prevalence was significantly higher in males (31.5%) than in females (12.3%), a pattern which departs from that observed in free-ranging Delphinidae where there is no gender bias. As with free-ranging Delphinidae, TSD prevalence in captive females varied with age category, being the highest in the 4 to 8 year old. By contrast, prevalence levels in males were high in all age classes. Prevalence of very large tattoos was also higher in males (28.6%, n= 35) than in females (11.1%, n= 18). Combined, these data suggest that captive male T. truncatus are more vulnerable to TSD than females possibly because of differences in immune response and because males may be more susceptible to captivity-related stress than females.

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Cranial crassicaudiasis in two coastal dolphin species from South Africa is predominantly a disease of immature individuals

Diseases of Aquatic Organisms ◽

10.3354/dao03468 ◽

2020 ◽

Vol 139 ◽

pp. 93-102 ◽

Cited By ~ 3

Author(s):

MF Van Bressem ◽

P Duignan ◽

JA Raga ◽

K Van Waerebeek ◽

N Fraijia-Fernández ◽

...

Keyword(s):

South Africa ◽

Bone Development ◽

Bottlenose Dolphins ◽

Fatal Outcome ◽

Population Level ◽

Cape Coast ◽

Osteolytic Lesions ◽

Immune Mediated ◽

Significant Difference ◽

The Difference

Crassicauda spp. (Nematoda) infest the cranial sinuses of several odontocetes, causing diagnostic trabecular osteolytic lesions. We examined skulls of 77 Indian Ocean humpback dolphins Sousa plumbea and 69 Indo-Pacific bottlenose dolphins Tursiops aduncus, caught in bather-protecting nets off KwaZulu-Natal (KZN) from 1970-2017, and skulls of 6 S. plumbea stranded along the southern Cape coast in South Africa from 1963-2002. Prevalence of cranial crassicaudiasis was evaluated according to sex and cranial maturity. Overall, prevalence in S. plumbea and T. aduncus taken off KZN was 13 and 31.9%, respectively. Parasitosis variably affected 1 or more cranial bones (frontal, pterygoid, maxillary and sphenoid). No significant difference was found by gender for either species, allowing sexes to be pooled. However, there was a significant difference in lesion prevalence by age, with immature T. aduncus 4.6 times more likely affected than adults, while for S. plumbea, the difference was 6.5-fold. As severe osteolytic lesions are unlikely to heal without trace, we propose that infection is more likely to have a fatal outcome for immature dolphins, possibly because of incomplete bone development, lower immune competence in clearing parasites or an over-exuberant inflammatory response in concert with parasitic enzymatic erosion. Cranial osteolysis was not observed in mature males (18 S. plumbea, 21 T. aduncus), suggesting potential cohort-linked immune-mediated resistance to infestation. Crassicauda spp. may play a role in the natural mortality of S. plumbea and T. aduncus, but the pathogenesis and population level impact remain unknown.

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