Ontogeny of the skull of Sotalia guianensis (Cetartiodactyla: Delphinidae) on the Northern coast of Brazil

This study aimed to investigate the ontogenetic development of the skull in the Guiana dolphin (Sotalia guianensis Van Bénéden, 1864 ) through the comparison of 29 morphological non-metrical characters together with the estimated age of 54 specimens derived from four areas on the northern coast of Brazil. The state of each character was associated with the age of each specimen to assess the formation of bone structures, and the degree of fusion of the sutures in each state of the character studied. Nineteen qualitative morphological characters presenting state ontogenetic variations have been analyzed statistically. The analysis depicted that the characters associated with the parietal-frontal suture, parietosupraoccipital, parietoexoccipital, supraoccipital-exoccipital and basioccipital-pterygoid varied according with the age. The results suggest that the physical maturity of the cranium was more premature in the specimens from the Northern Coast, suggesting a geographical adjustment of the species, or a biological response to an intense pressure of by-catch in fisheries over decades on the populations.(AU)

O objetivo do estudo foi investigar o desenvolvimento ontogenético craniano do boto-cinza (Sotalia guianensis Van Bénéden, 1864), comparando 29 caracteres morfológicos não métricos aliados às estimativas de idade de 54 espécimes provenientes de quatro áreas da Costa Norte do Brasil. Cada estado de caráter foi associado à idade de cada espécime para avaliar a formação de estruturas ósseas e o grau de fusionamento das suturas em cada estado de caráter analisado. Foram analisados estatisticamente 19 caracteres morfológicos qualitativos que apresentaram variação nos estados de caráter. A análise revelou que os caracteres que diferiram de acordo com a idade foram aqueles ligados à sutura parietal-frontal, parietal-supraoccipital, parietal-exoccipital, supraoccipital-exoccipital e basioccipital-pterigóide. Os resultados indicaram que a maturidade física do crânio foi mais precoce nos espécimes da Costa Norte, sugerindo uma estruturação geográfica da espécie ou uma resposta biológica a uma intensa pressão de captura acidental em redes de pesca sobre as populações.(AU)

Ontogeny of the skull of Sotalia guianensis (Cetartiodactyla: Delphinidae) on the Northern coast of Brazil

This study aimed to investigate the ontogenetic development of the skull in the Guiana dolphin (Sotalia guianensis Van Bénéden, 1864 ) through the comparison of 29 morphological non-metrical characters together with the estimated age of 54 specimens derived from four areas on the northern coast of Brazil. The state of each character was associated with the age of each specimen to assess the formation of bone structures, and the degree of fusion of the sutures in each state of the character studied. Nineteen qualitative morphological characters presenting state ontogenetic variations have been analyzed statistically. The analysis depicted that the characters associated with the parietal-frontal suture, parietosupraoccipital, parietoexoccipital, supraoccipital-exoccipital and basioccipital-pterygoid varied according with the age. The results suggest that the physical maturity of the cranium was more premature in the specimens from the Northern Coast, suggesting a geographical adjustment of the species, or a biological response to an intense pressure of by-catch in fisheries over decades on the populations.

O objetivo do estudo foi investigar o desenvolvimento ontogenético craniano do boto-cinza (Sotalia guianensis Van Bénéden, 1864), comparando 29 caracteres morfológicos não métricos aliados às estimativas de idade de 54 espécimes provenientes de quatro áreas da Costa Norte do Brasil. Cada estado de caráter foi associado à idade de cada espécime para avaliar a formação de estruturas ósseas e o grau de fusionamento das suturas em cada estado de caráter analisado. Foram analisados estatisticamente 19 caracteres morfológicos qualitativos que apresentaram variação nos estados de caráter. A análise revelou que os caracteres que diferiram de acordo com a idade foram aqueles ligados à sutura parietal-frontal, parietal-supraoccipital, parietal-exoccipital, supraoccipital-exoccipital e basioccipital-pterigóide. Os resultados indicaram que a maturidade física do crânio foi mais precoce nos espécimes da Costa Norte, sugerindo uma estruturação geográfica da espécie ou uma resposta biológica a uma intensa pressão de captura acidental em redes de pesca sobre as populações.

Lectin spatial immunolocalization during in vitro capacitation in Tursiops truncatus spermatozoa

Spermatozoa interactions with the female reproductive tract and oocyte are regulated by surface molecules such as glycocalyx. The capacitation process comprises molecular and structural modifications which increase zona pellucida binding affinity. Lectins allowed us to describe glycocalyx changes during maturation, capacitation and acrosome reaction. This study had as its aim to identify lectin binding patterns using four lectins with different carbohydrate affinity in bottlenose dolphin (Tursiops truncatus) spermatozoa both before and after in vitro capacitation. Two semen samples from the same dolphin obtained on consecutive days were used, with four different lectin binding patterns becoming visible in both samples before and after capacitation. A highly stained equatorial segment with prolongations at the edges appeared as the most frequent pattern with Wheat germ agglutinin (WGA) in uncapacitated spermatozoa. However, it was homogeneously distributed over the acrosomal region after capacitation. Instead, the use of Peanut agglutinin (PNA) resulted in most spermatozoa showing high labelling in the acrosomal periphery region before capacitation and a homogeneous staining in the acrosomal region within the population of capacitated spermatozoa. Nevertheless, the most representative patterns with Concavalin A (ConA) and Aleuria aurantia agglutinin (AAA) lectins did not change before and after capacitation, labelling the acrosomal region periphery. These findings could contribute to the understanding of the reproductive biology of cetaceans and the improvement of sperm selection techniques.(AU)

Lectin spatial immunolocalization during in vitro capacitation in Tursiops truncatus spermatozoa

Spermatozoa interactions with the female reproductive tract and oocyte are regulated by surface molecules such as glycocalyx. The capacitation process comprises molecular and structural modifications which increase zona pellucida binding affinity. Lectins allowed us to describe glycocalyx changes during maturation, capacitation and acrosome reaction. This study had as its aim to identify lectin binding patterns using four lectins with different carbohydrate affinity in bottlenose dolphin (Tursiops truncatus) spermatozoa both before and after in vitro capacitation. Two semen samples from the same dolphin obtained on consecutive days were used, with four different lectin binding patterns becoming visible in both samples before and after capacitation. A highly stained equatorial segment with prolongations at the edges appeared as the most frequent pattern with Wheat germ agglutinin (WGA) in uncapacitated spermatozoa. However, it was homogeneously distributed over the acrosomal region after capacitation. Instead, the use of Peanut agglutinin (PNA) resulted in most spermatozoa showing high labelling in the acrosomal periphery region before capacitation and a homogeneous staining in the acrosomal region within the population of capacitated spermatozoa. Nevertheless, the most representative patterns with Concavalin A (ConA) and Aleuria aurantia agglutinin (AAA) lectins did not change before and after capacitation, labelling the acrosomal region periphery. These findings could contribute to the understanding of the reproductive biology of cetaceans and the improvement of sperm selection techniques.

Comparative anatomical description of brain hemisphere surfaces in toninha dolphin and humans

Pontoporia blainvillei (cetacean order and odontoceti suborder), popularly known in Brazil as Toninha, is a small dolphin with a long, thin beak found on the southern shore waters of the western Atlantic. The brain development of dolphins (expressed by the encephalization coefficient) in relation to body size is quite high, and is second only to humans. This high correlation in brain development between dolphins and humans was targeted in this research to describe and compare the morphology of cerebral hemisphere surfaces of these two species. Five brains of Pontoporia blainvillei donated by the BioPesca Project (a non-governmental organization) were analyzed. The brains were fixed in 20% formaldehyde solution for further description and comparison to human brains described in books of neuroanatomy. The telencephalon of Pontoporia blainvillei is rostrally tapered and expanded at the caudal end and it has a greater number of folds/gyrus when compared to human species. Some encephalic grooves/sulcus are similar to grooves found in the human species, such as the cruciate sulcus (central sulcus), lateral fissure (Sylvian cleft), cingulate sulcus and calcarine sulcus. The same encephalic lobes are seen in both species; however the parietal and temporal lobes are highly developed in the Pontoporia blainvillei. These differences are associated with specific function of the species, as the presence of the an efficient auditive system in dolphins.

Comparative anatomical description of brain hemisphere surfaces in toninha dolphin and humans

Pontoporia blainvillei (cetacean order and odontoceti suborder), popularly known in Brazil as Toninha, is a small dolphin with a long, thin beak found on the southern shore waters of the western Atlantic. The brain development of dolphins (expressed by the encephalization coefficient) in relation to body size is quite high, and is second only to humans. This high correlation in brain development between dolphins and humans was targeted in this research to describe and compare the morphology of cerebral hemisphere surfaces of these two species. Five brains of Pontoporia blainvillei donated by the BioPesca Project (a non-governmental organization) were analyzed. The brains were fixed in 20% formaldehyde solution for further description and comparison to human brains described in books of neuroanatomy. The telencephalon of Pontoporia blainvillei is rostrally tapered and expanded at the caudal end and it has a greater number of folds/gyrus when compared to human species. Some encephalic grooves/sulcus are similar to grooves found in the human species, such as the cruciate sulcus (central sulcus), lateral fissure (Sylvian cleft), cingulate sulcus and calcarine sulcus. The same encephalic lobes are seen in both species; however the parietal and temporal lobes are highly developed in the Pontoporia blainvillei. These differences are associated with specific function of the species, as the presence of the an efficient auditive system in dolphins.(AU)

First description of corpus luteum with central cavity during pregnancy in Sotaia guianensis (Van Bénéden, 1864) - Case report / Primeira descrição de corpo lúteo cavitário gestacional em Sotalia guianensis (Van Bénéden, 1864) - Relato de Caso

O objetivo foi descrever pela primeira vez o corpo lúteo cavitário gestacional em Sotalia guianensis, espécie de golfinhocosteiro que se distribui ao longo da costa Atlântica Ocidental. Os ovários de um espécime com 196cm de comprimentocorporal, com 9,2 meses de gestação, capturado acidentalmente durante atividade pesqueira na costa norte do estado doRio de Janeiro. O material foi avaliado morfologicamente e processado para cortes em parafina, corado pela hematoxilina eeosina para microscopia. O ovário direito apresentava forma amendoada, com sulcos em uma lateral, três folículos e umcorpo lúteo polar em involução. O ovário esquerdo pesava sete vezes mais que o direito. A superfície era enrugada, com umfolículo, seis corpos lúteos e quatro albicans. O maior corpo lúteo era protruso, com diâmetro médio de 3cm e uma cavidadecentral de 1cm de diâmetro, revestida por paredes regulares e espessas, sugerindo ser um corpo lúteo em desenvolvimento.Os outros corpos lúteos eram maciços e estavam em regressão. A microscopia do corpo lúteo não demonstrou envolvimentopatológico. Esta descrição, ímpar na espécie, representa uma contribuição ao conhecimento da biologia (reprodutiva) da S.guianensis, que consta como "Dados Deficientes" na lista vermelha da União Internacional para Conservação da Natureza.(AU)

This is the first study to describe the corpus luteum with central cavity during pregnancy in Sotalia guianensis, a coastal dolphin species distributed along the Atlantic Ocean coast. The material analyzed was a pair of ovaries of a 196-cm-long female was 9.2 months pregnant, accidentally captured on the north coast of the state of Rio de Janeiro, Brazil. Both ovaries were measured and inspected for anatomic structures. After, ovaries were process in paraffin-embedded and stained with hematoxylin and eosin for microscopy. The left ovary had a wrinkled outside, one follicle, six corpora lutea and four corpora albicans. The largest corpus luteum was protruded, 3 cm long in mean diameter with one central cavity. It was lined by uniform thick walls and peripheral vascularization, which suggests that the corpus luteum is under development. The left ovary was deformed due to the presence of corpus luteum, which accounted for the seven-fold higher weight as compared to the right ovary. The histology of the corpus luteum did not evince any pathologic status of the material. This description, the first ever made for the species, offers a contribution to the existing knowledge about the reproduction biology of S. guianensis, which is a member of the "Insufficient Data" Red List prepared by the World Conservation Union.(AU)

First description of corpus luteum with central cavity during pregnancy in Sotaia guianensis (Van Bénéden, 1864) - Case report / Primeira descrição de corpo lúteo cavitário gestacional em Sotalia guianensis (Van Bénéden, 1864) - Relato de Caso

O objetivo foi descrever pela primeira vez o corpo lúteo cavitário gestacional em Sotalia guianensis, espécie de golfinhocosteiro que se distribui ao longo da costa Atlântica Ocidental. Os ovários de um espécime com 196cm de comprimentocorporal, com 9,2 meses de gestação, capturado acidentalmente durante atividade pesqueira na costa norte do estado doRio de Janeiro. O material foi avaliado morfologicamente e processado para cortes em parafina, corado pela hematoxilina eeosina para microscopia. O ovário direito apresentava forma amendoada, com sulcos em uma lateral, três folículos e umcorpo lúteo polar em involução. O ovário esquerdo pesava sete vezes mais que o direito. A superfície era enrugada, com umfolículo, seis corpos lúteos e quatro albicans. O maior corpo lúteo era protruso, com diâmetro médio de 3cm e uma cavidadecentral de 1cm de diâmetro, revestida por paredes regulares e espessas, sugerindo ser um corpo lúteo em desenvolvimento.Os outros corpos lúteos eram maciços e estavam em regressão. A microscopia do corpo lúteo não demonstrou envolvimentopatológico. Esta descrição, ímpar na espécie, representa uma contribuição ao conhecimento da biologia (reprodutiva) da S.guianensis, que consta como "Dados Deficientes" na lista vermelha da União Internacional para Conservação da Natureza.

This is the first study to describe the corpus luteum with central cavity during pregnancy in Sotalia guianensis, a coastal dolphin species distributed along the Atlantic Ocean coast. The material analyzed was a pair of ovaries of a 196-cm-long female was 9.2 months pregnant, accidentally captured on the north coast of the state of Rio de Janeiro, Brazil. Both ovaries were measured and inspected for anatomic structures. After, ovaries were process in paraffin-embedded and stained with hematoxylin and eosin for microscopy. The left ovary had a wrinkled outside, one follicle, six corpora lutea and four corpora albicans. The largest corpus luteum was protruded, 3 cm long in mean diameter with one central cavity. It was lined by uniform thick walls and peripheral vascularization, which suggests that the corpus luteum is under development. The left ovary was deformed due to the presence of corpus luteum, which accounted for the seven-fold higher weight as compared to the right ovary. The histology of the corpus luteum did not evince any pathologic status of the material. This description, the first ever made for the species, offers a contribution to the existing knowledge about the reproduction biology of S. guianensis, which is a member of the "Insufficient Data" Red List prepared by the World Conservation Union.