A preliminary overview of skin and skeletal diseases and traumata in small cetaceans from South American waters

We succinctly review and document new cases of diseases of the skin and the skeletal system and external traumata in cetaceans from Ecuador, Colombia, Peru, Chile, Argentina, Uruguay, Brazil, and Venezuela. The survey revealed 590 cases diagnosed with a significant pathology, injury or malformation on a total of 7635 specimens of 12 odontocete species examined or observed in 1984-2007. Tattoo skin disease (TSD), lobomycosis-like disease (LLD) and cutaneous diseases of unknown aetiology seem to be emerging in several populations. TSD was confirmed in eight species from the SE Pacific and SW Atlantic. LLD affected only inshore Tursiops truncatus but was found in four tropical countries, namely Colombia, Ecuador, Peru and Brazil. Lobomycosis was confirmed by histology in one male from the Tramandaí estuary, southern Brazil. All LLD-affected specimens were encountered in the vicinity of major ports and cities and a possible association with chemical or organic water pollution is suspected. Whitish velvety cutaneous marks associated with scars occurred in inshore T. truncatus, Sotalia guianensis and Pseudorca crassidens. Large, rounded lesions were seen in a Cephalorhynchus eutropia calf and a C. commersonii. Cutaneous wounds and scars as well as body traumata possibly related to net entanglements and boat collisions were observed in 73 delphinids and Phocoena spinipinnis. Traumatic injuries resulted in the partial or complete amputation and other disfiguring scars of appendages in 17 cases. Fractures of the skull, ribs and vertebrae thought to be caused by fisheries-related interactions or boat collisions were seen in single individuals of Delphinus capensis, Lagenorhynchus obscurus, T. truncatus, S. guianensis and Ziphius cavirostris. Prevalence of osteopathology in small cetaceans from Peru, Brazil and Venezuela ranged widely, from 5.4% to 69.1%. In four species from Peru, lytic cranial lesions were the most frequently observed disease (5.4%-42.9%), followed by hyperostosis and ankylosing spondylitis in offshore (31%, n=42) and inshore (15.4%, n=26) T. truncatus. Fractures and other bone traumata were present in 47.2% of 53 axial skeletons of S. guianensis from the northern Rio de Janeiro state (Brazil) in 1987-1998. A high prevalence (48.4%, n=31) of, apparently congenital, malformations of cervical vertebrae, observed in a 2001-2006 sample, may be explained by a hypothetical genetic bottleneck in this population. Malformations with deficient ossification would clearly increase susceptibility for fractures. This study demonstrates the utility of a continent-wide analysis to discern epizootiological trends more readily than any local study could provide. Secondly, it underscores the need for focussed research on the effects of human activities on the spread of diseases in cetaceans, particularly in near-shore populations that utilize highly degraded coastal habitats

Cervical ribs and cleft arches in Brazilian Sotalia guianensis: contribution to comparative studies of skeletal morphology in northern and southeastern specimens

The Guiana dolphin, Sotalia guianensis (Van Bénéden, 1864), is a delphinid species found along the Brazilian coast. Morphological and genetic data point to the existence of different biological populations of the species within this portion of the range. The present paper compares the frequencies of developmental anomalies in two skeletal collections from geographically distant areas. The vertebral column of 43 specimens from Marajó Bay, located on the Pará State coast, and 20 specimens from the central-north coast of the Rio de Janeiro State were analyzed. The only anomalies found were cervical ribs and cleft neural arches, both located on the seventh cervical (C7) vertebra. Cervical ribs were found in 12% of the Pará specimens and in 45% of the Rio de Janeiro specimens; according to the Fisher’s Exact Test the difference was significant at a confidence level of α = 0.01, thus confirming that the series belong to different populations. The frequencies of cervical ribs observed in the present study were also compared to the frequencies of the same anomaly found in S. guianensis from the Ceará and Santa Catarina states, Brazil, and in tucuxi (S. fluviatilis) from the Brazilian Amazon. Although the results can be partially explained by demographic and evolutionary models for Sotalia, they may be affected by differences in the composition of the collections and in diagnostic methods/criteria used by different authors. Regarding the presence of cervical ribs, Amazon tucuxi were significantly different from the Rio de Janeiro and Pará series, as well as other marine series, as previously stated in the literature. The difference in the frequency of cleft neural arches in specimens from Rio de Janeiro and Pará was also significant, but no comparison could be conducted with other series due to lack of published material. A metric technique to discriminate transverse processes with and without fused cervical ribs is proposed as a methodological contribution for diagnosing the described anomaly

Natural history of dolphins of the genus Sotalia

General biology, including food habits, reproduction, age and health of the dolphins of the genus Sotalia, are reviewed according to current scientific knowledge. At least 25 teleost fish families, 5 cephalopod families and 1 crustacean family are included in the diet of the Guiana dolphin (S. guianensis), while up to 13 fish families were identified in the stomachs of the tucuxi (S. fluviatilis). Among the fish consumed by Sotalia spp., the schooling fish are the most common ones and both dolphin species use similar foraging strategies. However, due to the completely different ecosystems used by them, prey species consumed by these dolphins are also different. The maximum age of incidentally caught Guiana dolphin was 30yr and the maximum age estimated in the tucuxi was 43yr. The maximum total body length and weight reached by S. guianensis was 222cm and 121kg, respectively, and for S. fluviatilis 152cm and 53kg, respectively. Sexual maturity in the Guiana dolphin was estimated to occur at 170-180 cm in males, and 160-169 cm in females, while onset maturity in the tucuxi occurs at around 140cm in males and 132-137 cm in females. Ovulation apparently occurs only in the left ovary of the tucuxi, while both ovaries of the Guiana dolphins are functional. The proportion of testes mass in relation to total body mass in adult males can reach up to 5% in the tucuxi, and 3.3% in the Guiana dolphin, suggesting a promiscuous mating system with sperm competition in both species. Although seasonal birth peaks can occur in Guiana dolphins, they seem to reproduce throughout the year. However, the tucuxi presents defined birth seasonality, with most females giving birth during the low-water season in the Amazon. We suggest maintaining S. fluviatilis in the ‘Data Deficient’ category of the IUCN Red Data Book. Nevertheless, due to the recent recognition of S. guianensis as a species, its conservation status has not been assessed yet. This species, however, deserves special attention as it is strongly subjected to anthropogenic pressures throughout its distribution

Ophyra capensis(Wiedemann) (Diptera, Muscidae) found inside the esophagus of a mummy in Lisbon (Portugal)

The present paper aims to describe the material (puparia and adult fragments) of Ophyra capensis (Wiedemann, 1818) (Diptera, Muscidae) recently found inside the esophagus of a mummified body from the XIX century, in Lisbon (Portugal). Illustrations of the material and a brief discussion are presented. Third larvar stadium, pupa and adult of O. capensis and O. ignava are presented.<br>O presente trabalho tem o objetivo de descrever fragmentos de pupário e adultos de Ophyra capensis (Wiedemann, 1818) (Diptera, Muscidae) recentemente encontrados no interior do esôfago de um corpo mumificado do século XIX em Lisboa (Portugal). Ilustrações do material e uma breve discussão são apresentados