Made available in DSpace on 2014-06-11T19:30:15Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-08-12Bitstream added on 2014-06-13T21:00:38Z : No. of bitstreams: 1 silva_df_me_rcla.pdf: 1778952 bytes, checksum: a376ba77746867b99630c47a08cee512 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A biologia reprodutiva de toninhas, Pontoporia blainvillei, capturadas acidentalmente em redes de pesca entre abril de 2005 e agosto de 2007 do sul do estado de São Paulo (24º24’S, 46°57’W) ao norte do Paraná (25º22’S, 48º09’W) foi estudada. Os testículos de 57 machos e os ovários de 35 fêmeas foram analisados macro e microscopicamente para determinação da maturidade sexual. As presenças de leite nas glândulas mamárias e de feto no útero foram avaliadas para determinação de lactação e de prenhez das fêmeas, respectivamente. A proporção apresentada entre machos e fêmeas capturados acidentalmente foi de 1,6:1. As idades de 86 indivíduos foram estimadas a partir da contagem do número de grupos de linhas de crescimento presentes nas camadas de dentina e de cemento dos dentes. As idades variaram de zero a 18 anos para machos e de zero a 12 anos para fêmeas. A mediana das idades foi de um ano e 75 indivíduos (87,2%) tinham até três anos de idade. A análise histológica revelou que 21 dos 57 machos analisados (36,8%) estavam sexualmente maduros. Os testículos apresentaram simetria lateral e baixo peso testicular relativo em relação ao peso corporal, sendo em média de 0,031% em machos maduros sexualmente. O peso testicular combinado (soma dos pesos de ambos os testículos), a largura testicular média, o comprimento testicular médio e o índice de maturidade testicular (razão entre o peso e o comprimento dos testículos) se demonstraram como potenciais ferramentas macroscópicas para auxiliar na identificação de indivíduos maduros, mas a análise histológica ainda é necessária para confirmação dos estágios de maturidade em machos / The reproductive biology of franciscana dolphins, Pontoporia blainvillei, incidentally caught by gillnets between 2005 and 2007 from southern São Paulo (24°24’S, 46°57’W) to northern Paraná (25º22’S, 48°09’W) States was studied. The testes of 57 males and the ovaries of 35 females were macroscopically and microscopically analyzed to determine the sexual maturity. The presence of milk in the mammary glands and of fetus in the uterus was evaluated to determine lactating and pregnant females, respectively. The ratio between males and females incidentally caught was 1.6:1. The age (n=86) was estimated through growth layer groups in dentine and cementum using longitudinal sections of teeth. The ages ranged from zero to 18 years for males and from zero to 12 years for females. The median of age was one year and 75 individuals (87.2%) were three years old or less when captured. Histological analysis revealed that 21 of the 57 males analyzed (36.8%) were sexually mature. The testes showed lateral symmetry and low testicular weight relative to body weight, with an average of 0.031% in sexually mature males. The combined testicular weight (sum of weights of both testes), the average testicular width, the average testicular length and testicular maturity index (ratio of testicular weight per testicular length) were considered as potential macroscopic tools to classify mature individuals, but histological confirmation is still required to confirm the sexual maturity condition

The main aim of this work was to determine the past, present and future conservation status of the bottlenose dolphin population inhabiting the Sado estuary region, Portugal, using a long term (photo ID) data set. Resident animals, identified from their strong resighting pattern, were confined to the estuary region. There is little evidence of social interchange with other coastal bottlenose dolphins and the role of emigration and immigration is unclear. This is a very small population. Numbers of animals have decreased in the past but now seem to be increasing. A mark-recapture analysis of individual capture histories showed that time changes in age-specific survival explained the observed changes in number of animals. Survival was lower, particularly in young animals, in earlier years which have resulted in a long period of lack of recruitment to adulthood. In the most recent years survival has increased, especially for calves in their second and third years. Fecundity has also been higher. Protected areas and proposed marine SACs reflect the importance of the Sado estuary region; this is also an area of intense anthropogenic activities that threaten the dolphin population. Population viability analysis was conducted using the software VORTEX incorporating estimates of past or current vital rates. The likely future of the resident population is for it to decline, especially during the next few decades. A viable population was only predicted if maximum values of vital rates were used or if regular immigration occurred. A number of proposals for management action are discussed. This work constitutes an example in conservation biology where life history parameters were estimated, and used to predict future viability and thus to indicate management actions that could increase the chance of saving a very small marine mammal population.

Coastal dolphin populations are indicators of environmental health and may be sensitive to anthropogenic influences. An observed increase in lesions during routine necropsies of dolphins prompted the first systematic health assessment of dolphins incidentally caught in shark nets off the KwaZulu-Natal coast. A detailed standard dissecting and sampling protocol for small cetaceans was developed for use in South Africa. Thirty five Indian Ocean bottlenose dolphins (Tursiops aduncus) and five Indo-Pacific humpback dolphins (Sousa chinensis), incidentally caught between 2010 and 2012, were subsequently evaluated by full necropsy and sampling using this protocol. All animals were considered to be in good nutritional condition, based on blubber thickness measurements and muscle condition. A large proportion of dolphins had lesions with parasitic aetiology, including pneumonia (34/40), bronchiolar epithelial mineralisation (33/40), gastroenteritis (28/40), hepatitis (24/39); endometritis (11/26), capsular inflammation of various abdominal and thoracic organs (30/40), and splenic capsular tags (18/40). Four parasite species (Halocercus sp., Crassicauda sp., Brachycladiinae, and Xenobalanus globicipitis) were recovered from six animals. Non-specific encephalomeningitis was found in 7/18 animals. Adrenal cortical hyperplasia (18/37,) possibly related to chronic stress, was also found, as well as myocardial fibrosis (10/39). Pulmonary pneumoconiosis and lymph node foreign material accumulation, possibly indicating exposure to polluted air, was seen in three animals. Lesions suggestive of morbillivirus, Toxoplasma gondii, or Brucella spp. tested negative on immunohistochemistry. The first confirmed cases of lobomycosis and sarcocystosis in South Africa were found. Most lesions were mild, although their high and apparently increasing prevalence may indicate a change in the host/parasite interface. This may be attributed to anthropogenic factors, such as stress or environmental pollution, suggesting degradation of the marine environment. This could also negatively impact human populations associated with the marine environment. The results indicate a need for continued health monitoring of coastal dolphin populations and for further research into disease pathophysiology and anthropogenic factors affecting these populations. This standard necropsy protocol will encourage a more complete health investigation of incidentally caught and stranded cetaceans in the region and will assist in expanding the current knowledge of diseases affecting dolphin populations in southern Africa. Furthermore, we provide valuable information regarding the baseline of disease affecting these populations, which may be used to determine and monitor temporal trends. / Dissertation (MSc)--University of Pretoria, 2013. / gm2014 / Production Animal Studies / unrestricted

The striped dolphin, Stenella coeruleoalba, is an oceanic dolphin found worldwide in tropical to warm temperate waters. Globally populations are threatened through direct fishing, bycatch and pollution. Little is known about the life history of this species in South African waters and it is currently listed as ‘Data Deficient’ by the International Union for Conservation of Nature (IUCN). Critical to the conservation and management of this species is an understanding of basic life history parameters. For the present study, metadata and tissues from 101 stranded S. coeruleoalba along the south-east coast of southern Africa between 1969 and 2012 were analyzed to examine age and growth, male and female reproduction and sexual dimorphism. Age and growth were determined by counting the number of growth layer groups (GLG’s) present in their teeth. A von Bertalanffy growth curve gave the best fit to the data and indicated that physical maturity was reached around 21 years in males and 18 years in females. Additionally, asymptotic lengths were reached at 231cm and 224cm in males and females, respectively. The maximum ages obtained were 21 years for males and 20 years for females. Length at birth was estimated to be between 116cm and 119cm for males and between 112cm and 114cm for females. The reproductive status of the adult dolphins was assessed by histological and macroscopic analyses of gonadal tissue. Sexual maturity was attained before physical maturity in both sexes. The males reached sexual maturity between 8 and 12 years of age and between 209 and 224cm in total body length. The maximum combined testis weight comprised about 0.24% of the total body weight and sexual maturity was reached between a combined testis weight of 16 and 41g, a mean testis length of 8 and 10cm, and a mean seminiferous tubule diameter of 44 and 70μm. Females attained sexual maturity between 7 and 8 years of age and between 213 and 216 cm in total body length. The ovulation rate was 0.32 per year and the majority of ovulations occurred in the left ovary, with ovulations occurring in the right ovary only in individuals older than 10 years of age. The annual pregnancy rate was calculated to be 26%. Reproductive seasonality could not be established due to the small sample size and the absence of samples throughout the year. However, both conceptions and births appear to occur in both August and December/January. Additionally, testis weight and seminiferous tubule diameters appear to fluctuate throughout the year, which could suggest reproductive seasonality in this species. Sexual size dimorphism in mature adults was evident for a number of external measurements, however, sexual shape dimorphism was not present in this species. Mature males had significantly longer and wider pectoral fins, dorsal fins and flukes than females (p<0.05 in all cases). It was suggested that the larger appendages are required for male on male combat during intraspecific competition for females. Additionally, larger appendages aid in thermoregulation, propulsion and maneuverability. Females had a significantly greater distance between the tip upper jaw and the genital aperture and anus, which was expected due to differences in anatomy between male and female genital openings. Overall, S. coeruleoalba did not exhibit distinct sexual dimorphism and together with the relatively small testes in relation to the total body weight (0.24%) it was proposed that this species demonstrates a less extreme form of polygyny. Additionaly, the results of this study are important to the understanding of the basic biology of the species.

Consistent leadership of group travel by specific individuals has been documented in many animals. Most species exhibiting this type of leadership have relatively stable group membership. Animals using fission-fusion grouping are not expected to use specific leaders because associations would not be frequent. Certain conditions, however, may allow this type of control over group travel to occur. First, a population would need to be small enough to allow regular associations between individuals. Second, leadership may be useful if the environment where the population in question lives is complex and requires learning to access the resources efficiently. To determine whether fission-fusion species existing under these conditions utilize specific individual leadership, I examined a small residential population of bottlenose dolphins (Tursiops truncatus) in the Lower Florida Keys (LFK) where the benthic habitat is highly complex. My goals were to 1) determine whether specific individuals in this population led group travel more often than expected; 2) determine whether certain factors predicted which animals would lead most often and 3) investigate the benefits of leading to leaders and to followers in a fission-fusion society. Multiple types of data were collected to answer questions posed including dolphin behavior (for leadership analyses), fish sampling (to examine dolphin habitat use under leadership), and dolphin biopsy sampling (for genetic analyses). Results of analyses provided strong evidence for consistent leadership in this population. Leaders were female, most were mothers and on average they had larger measures of centrality within the LFK population. Leaders benefited by leading individuals who were more closely related than expected. Followers benefited from efficient access to profitable habitat. Results build on previous leadership research by expanding our knowledge about the type of species in which specific individuals lead and predictors for what types of individuals may lead. Additionally, results provide the first detailed information about benefits group members obtain by both leading and following.

Background: Maximal muscle strength and body proportions are some of the key attributes to be a fast swimmer. Even though dolphin kick (DK) has become essential to be a fast swimmer little is known of its associations to muscle strength and body proportions. Moreover, the effect of feet size has been stated to be a primary contributor to dolphin kick thrust production, but scientific evidence is still scarce. Aim: The aim of this study was to examine the correlation between lower extremity muscle strength, abdominal strength and feet length with dolphin kick performance over 15 meters in active competitive swimmers 15-20 years old Method: Twelve Test subjects (six male and six female) participated. Test subjects performed four 15 meters dolphin kick trials. Lower extremity muscle strength was tested with a three repetition maximum strength test and abdominal strength with brutal bench test. The muscles tested were rectus femoris, biceps femoris and rectus abdominis. Feet length was measured with a measuring tape. The correlations between lower extremity strength, abdominal strength and feet length with dolphin kick performance were calculated with spearman’s correlation. Results: Twelve test subjects between ages 15-20 years old participated. Spearman correlation test showed that lower extremity strength (rectus femoris: rs=-0.57 and biceps femoris: rs=-0.66) had a large association with dolphin kick performance. Abdominal strength (rs=-0.46) and feet length (rs=-0.35) had a moderate association with dolphin kick performance. Conclusion: The present study conclude that lower extremity strength is important for DK performance over 15 meters and that abdominal strength and feet length also is important but is less associated to it. The finding from this study can be used for making training programs for improving DK performance and for scouting swimmers with beneficial traits for specific swimming technique.

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第18846号 / 理博第4104号 / 新制||理||1590(附属図書館) / 31797 / 京都大学大学院理学研究科生物科学専攻 / (主査)教授 幸島 司郎, 教授 伊谷 原一, 教授 村山 美穂 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

Dolphins at Kolmården dolphinarium were given a set of 20 floating fish hides, in order to simulate aforaging situation. The idea was to motivate the dolphins to use echolocation, in order to differentiatebetween hides which contained fish and hides that were empty. The dolphins would access the fish hidesfor 20-minute sessions five days per week, during a total period of five weeks. The results indicated thattheir interest in the fish hides was maintained over the entire study period for all individuals, and thisinterest did not correlate with age. However, older dolphins seemed more prone to solely inspect, possiblyby using echolocation aimed towards the fish hides than to physically interact with them. Neither was theirinterest affected by the dolphins’ pre-session activities. However, not all dolphins seemed interested in fishunless given to them by care takers. Thus, some dolphins were likely less motivated in solving theecholocation task. As a pod, the dolphins’ interest in this innovative enrichment was maintained over time,and the plasticity of these fish hides would suggest a range of different setups for the future. However,when analysing the potential use of echolocation cues, theoretical calculations of the target strengthdifferences between filled and empty fish hides, together with data on the physical interactions with them,suggested that the dolphins did not use sonar cues, but resorted to more or less random manipulation of thefish hides in order to eject the fish.

Age determination of bottlenose dolphins (Tursiops truncatus) is a critical tool in understanding their health. There are many methods of aging dolphins including morphometrics, counting growth layer groups (GLGs) of teeth, comparing dentin to pulp cavity ratio on dental radiographs, analysis of the pectoral flipper radiographs, and epigenetic testing. The most common method for aging toothed cetaceans is the counting of GLGs in the teeth. Since there are many challenges associated with aging dolphins based on the counting of GLGs, a processing technique that results in better resolution of GLGs is needed. This is a two-part study that first compares different decalcification and staining techniques that results in the process that best highlights GLGs. Secondly, this study compares the results of aging via GLGs and pectoral flipper radiographs in 47 bottlenose dolphins. This study suggests aging by pectoral flipper radiograph assessment can more accurately classify dolphins by age class.

Bottlenose dolprlin (Tursiops trunratus) whistles are currently studied by subjective visual comparison of whistle spectrograms. This thesis describes the novel use of stochastic modeling to automate the comparison of dolphin whistles and to yield an objective, quantitative measure of whistle similarity. The relationship of bottlenose dolphin whistle production to a model of human speech production is discussed, providing a basis for the use of human speech recognition techniques for creating whistle models. Discrete hidden Markov models based on vector quantization of linear prediction coefficients are used to create whistle models based on statistical information derived from a sample set of dolphin whistles. Whistle model comparison results are presented indicating that evaluation of bottlenose dolphin whistles via hidden Markov modeling provides an objective measure of similarity between whistles. The results also demonstrate that hidden Markov models provide robustness against the effects of temporal and frequency variance in the comparison of whistles. The extensibility of stochastic modeling techniques to other animal vocalizations is discussed and possibilities for further work in areas such as the determination of possible structural components, similar to phonemes in human speech, is provided. / Master of Science