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Variation in dorsal fin morphology was assessed in five bottlenose dolphin (Tursiops truncatus) populations from the Southeast Pacific. We hypothesized that habitat specialization between coastal and offshore ecotypes led to differences in dorsal fin morphology. Photographs and direct measurements of dorsal fins were used to calculate three indexes: height/length base (h/b), width at half height/length base (a/b) and overhang of the dorsal fin tip/length base (falcateness) (s/b). The sample included 163 individuals (129 coastal and 34 offshore) from Ecuador, 60 individuals (9 coastal and 51 offshore) from Peru and 25 individuals of an inshore form from northcentral Chile (Pod-R). Values were logarithmically transformed to allow one-way ANOVAs and t-tests. Ontogenetic variation was found in coastal dolphins from Ecuador, with indices significantly different among age/classes. All indices ...

We succinctly summarize population ID information for common bottlenose dolphins Tursiops truncatus of the Pacific coast of South America, covering four coastal range states. Phylogenetic uncertainties relate primarily to offshore vs. coastal (inshore) ecotypes and biogeographic borders between the five proposed populations (2 offshore, 3 coastal): Colombia-Ecuador Offshore stock (probably = ETP Offshore), Peru-Chile Offshore, Ecuador Coastal, Peru Coastal and an unique community (Pod-R) on the north-central coast of Chile. Main questions concern the extent of gene flow between the offshore stocks at one hand, and with -and between- the three coastal populations at the other hand. Seven cranial characters, four non-metric (separation of occipital condyles, pterygoid bone development, exostosis of periotic) and three metric (tooth width, antorbital process length, maximum width palatines)...

A total of 308 skulls and 200 jaws from 20 species and one hybrid of odontocetes cetaceans from the Peruvian Ocean were revised for anatomical description and evaluation of bone lesions. They were grouped into 8 types, plus those at the dental alveoli and osteolitic lesions caused by the nematode Crassicauda sp. From the total bone samples, at least 31.2% showed one type of craneo-mandibular lesion whereas the bottle nosed dolphin (Tursiops truncatus) was the most affected. Dental alveoli lesions were found in 13.3% of the samples and bone lesions caused by Crassicauda sp. were in 17.3% of the skulls. The most frequent lesions were hyperostosis and osteolisis, followed by osteomyelitis, malformations and occipitoatlantoaxial ankylosed joints. Adult males showed higher frequency of bone and dental alveolar lesions and is suggested that the latter type of lesions could be associated with s...

Se revisaron 308 cráneos y 200 mandíbulas pertenecientes a 20 especies y un híbrido de cetáceos odontocetos del mar peruano a fin de realizar la descripción y evaluación anatómica de lesiones óseas. Se hallaron diversas lesiones óseas, las cuales fueron agrupadas en 8 tipos, además de las halladas a nivel de los alveolos dentarios y de las osteolíticas producidas por el nemátodo Crassicauda sp. El 31.2% de las muestras presentaron al menos un tipo de lesión cráneo-mandibular, siendo el delfín nariz de botella (Tursiops truncatus) la especie con la mayor frecuencia de lesiones. Las lesiones a nivel de los alveolos dentarios se presentaron en el 13.3% de la población mientras que las producidas por Crassicauda sp. se observó en el 17.2% de cráneos revisados. La exostosis y osteolisis fueron las lesiones con mayor frecuencia de presentación, seguido de osteomielitis, malf...