"Ino" colour aberration in gentoo penguin (Pygoscelis papua) in Antarctica

Two main types of pigments, carotenoids and melanin, primarily determine plumage colouration in birds. Carotenoids are obtained from food, while melanin formation involves metabolic processes and is genetically determined. Melanin pigments comprise pheomelanin (red/brown) and eumelanin (brown/black). Any change in the formation processes of these types of pigments may lead to abnormal colouration of an individual For example, a strong qualitative reduction of both types of melanin defines a colour mutation called "ino". On 15 Dec 2003, an ino chick of a gentoo penguin (Pygoscelis papua); was observed at Stranger Point, 25 de Mayo/King George I, South Shetland (62° 16´ S, 58° 37´ W). The following year, on 5 Dec 2004, an ino prebreeder gentoo penguin was seen at the same locality. During 2006/07 breeding season an ino adult of the same species successfully reared 2 normally coloured chicks. The ino penguin we observed showed pale brown colour in the normally dark areas of the plumage in this species. It had reddish eyes and grey claws. The beak remained orange but the normally dark culmen was grey. In summary, the ino penguin showed a clear reduction of the darkest areas of the body changing from black to pale brown in plumage and from black to grey in other tissues such as beak and claws. Nevertheless, the distinctive colour pattern of a gentoo penguin was still recognisable. To our knowledge this is the 1st report of an ino gentoo penguin, following van Grouwes (2006) classification.Fil: Juares, Mariana Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; ArgentinaFil: Negrete, Javier. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; ArgentinaFil: Mennucci, Jorge Augusto. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; ArgentinaFil: Longarzo, Mria Lucrecia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; ArgentinaFil: Coria, Néstor Rubén. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; Argentin

"Ino" colour aberration in gentoo penguin (Pygoscelis papua) in Antarctica

Two main types of pigments, carotenoids and melanin, primarily determine plumage colouration in birds. Carotenoids are obtained from food, while melanin formation involves metabolic processes and is genetically determined. Melanin pigments comprise pheomelanin (red/brown) and eumelanin (brown/black). Any change in the formation processes of these types of pigments may lead to abnormal colouration of an individual For example, a strong qualitative reduction of both types of melanin defines a colour mutation called "ino". On 15 Dec 2003, an ino chick of a gentoo penguin (Pygoscelis papua); was observed at Stranger Point, 25 de Mayo/King George I, South Shetland (62° 16´ S, 58° 37´ W). The following year, on 5 Dec 2004, an ino prebreeder gentoo penguin was seen at the same locality. During 2006/07 breeding season an ino adult of the same species successfully reared 2 normally coloured chicks. The ino penguin we observed showed pale brown colour in the normally dark areas of the plumage in this species. It had reddish eyes and grey claws. The beak remained orange but the normally dark culmen was grey. In summary, the ino penguin showed a clear reduction of the darkest areas of the body changing from black to pale brown in plumage and from black to grey in other tissues such as beak and claws. Nevertheless, the distinctive colour pattern of a gentoo penguin was still recognisable. To our knowledge this is the 1st report of an ino gentoo penguin, following van Grouwes (2006) classification.Fil: Juares, Mariana Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; ArgentinaFil: Negrete, Javier. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; ArgentinaFil: Mennucci, Jorge Augusto. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; ArgentinaFil: Longarzo, Mria Lucrecia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; ArgentinaFil: Coria, Néstor Rubén. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; Argentin

Relato de deformidade no bico de um ninhego do pinguim-gentoo Pygoscelis papua (Spheniscidae)

Neste artigo reportamos sobre um filhote de pinguim-gentoo com uma deformidade na maxila, encontrado numa colônia das ilhas Shetland do sul. Embora a prevalência deste tipo de anomalia esteja aumentando, as razões para sua explicação não são tão simples de determinar. Contudo, como uma das causas conhecidas de indução à anomalias de formação á a deterioração de condições ambientais, consideramos importantes relatos como o feito nesta publicação.Fil: Juares, Mariana Alejandra. Ministerio de Relaciones Exteriores y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino. Departamento de Biología de Predadores Tope; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Santos, Maria Mercedes. Ministerio de Relaciones Exteriores y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino. Departamento de Biología de Predadores Tope; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mennucci, Jorge Augusto. Ministerio de Relaciones Exteriores y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino. Departamento de Biología de Predadores Tope; ArgentinaFil: Longarzo, Mria Lucrecia. Ministerio de Relaciones Exteriores y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino. Departamento de Biología de Predadores Tope; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Coria, Néstor Rubén. Ministerio de Relaciones Exteriores y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino. Departamento de Biología de Predadores Tope; Argentin

Relato de deformidade no bico de um ninhego do pinguim-gentoo Pygoscelis papua (Spheniscidae)

Neste artigo reportamos sobre um filhote de pinguim-gentoo com uma deformidade na maxila, encontrado numa colônia das ilhas Shetland do sul. Embora a prevalência deste tipo de anomalia esteja aumentando, as razões para sua explicação não são tão simples de determinar. Contudo, como uma das causas conhecidas de indução à anomalias de formação á a deterioração de condições ambientais, consideramos importantes relatos como o feito nesta publicação.Fil: Juares, Mariana Alejandra. Ministerio de Relaciones Exteriores y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino. Departamento de Biología de Predadores Tope; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Santos, Maria Mercedes. Ministerio de Relaciones Exteriores y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino. Departamento de Biología de Predadores Tope; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mennucci, Jorge Augusto. Ministerio de Relaciones Exteriores y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino. Departamento de Biología de Predadores Tope; ArgentinaFil: Longarzo, Mria Lucrecia. Ministerio de Relaciones Exteriores y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino. Departamento de Biología de Predadores Tope; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Coria, Néstor Rubén. Ministerio de Relaciones Exteriores y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino. Departamento de Biología de Predadores Tope; Argentin

Extinción local de tiburones del género Carcharias Rafinesque, 1810 (Elasmobranchii, Odontaspididae) en el Océano Pacífico oriental

Fossil record has shown that the genus Carcharias and probably species C. taurus Rafinesque, 1810 occupied the western coast of South America during the Miocene and part of the Pliocene. The genus is absent in the area today. It is suggested that its local extinction was the consequence of a drop of global temperatures during the middle Pliocene and Pleistocene and the coeval lowering of sea level that shrinked the area of distribution to the northern areas and provoked the disappearance of suitable environments when the shelf area became extremely reduced. After approximately 3 Ma it would have not been possible for the species to migrate from the north to the region due to the establishment of the Panamanian isthmus.El estudio del registro paleontológico indica que la distribución de Carcharias y posiblemente C. taurus Rafinesque, 1810, durante el Mioceno y parte del Plioceno, habría incluido la costa oeste de Sudamérica, donde hoy se encuentra ausente. Se propone que su extirpación de esta zona habría sido provocada por el abrupto descenso de las temperaturas durante el Plioceno medio y Pleistoceno y la consiguiente caída del nivel del mar, lo que habría reducido notablemente el ambiente de plataforma, hábitat natural de este taxón. Posteriormente a los 3 Ma aproximadamente, al restablecerse el nivel del mar, la recolonización desde el norte no habría sido posible debido al establecimiento del istmo de Panamá.Facultad de Ciencias Naturales y Muse

Better late than never? Interannual and seasonal variability in breeding chronology of gentoo penguins at stranger point, Antarctica

Rapid climate change recorded in the western Antarctic Peninsula confronts species with less predictable conditions in the marine and terrestrial environments. We analysed the breeding chronology and nesting site selection of gentoo penguins (Pygoscelis papua) at King George Island (Isla 25 de Mayo), Antarctica, during four seasons in which differences in snow presence and persistence on the ground were observed. We recorded an overall delay as well as seasonal asynchrony at the beginning of reproduction for those years with higher snow deposition. A redistribution of breeding groups was also observed. Nevertheless, the population breeding success and chicks' weight at fledging remained relatively constant, despite the delay in breeding chronology, the increased duration of foraging trips during the guard stage and the decreased weight of stomach contents during the cre'che stage. We suggest that the plasticity of their trophic biology, along with the flexibility of their breeding phenology and relocation of breeding groups, may be complementary reasons why gentoo penguin populations in the region have remained stable in spite of the changing conditions currently registered.Facultad de Ciencias Naturales y MuseoInstituto Multidisciplinario de Biología Celula

Jóvenes investigadores argentinos : Una experiencia en Escuelas de Educación Media de adultos

Mediante esta actividad buscamos dar a conocer qué es un científico, cómo se llega a serlo y cuales son los principales aspectos de su actividad profesional. Asimismo, intentamos mostrar las diferentes líneas de trabajo que se desarrollan en el seno de las ciencias naturales, en general, y en el Museo de La Plata, en particular. Como destinatarios de la propuesta elegimos dos escuelas de adultos, basando tal selección en que generalmente no suelen tener acceso a encuentros de este tipo, por la poca disponibilidad de tiempo para la realización de actividades extracurriculares. En cada una de las escuelas, los resultados fueron diferentes, reflejando expectativas e intereses totalmente distintos.Through this activity we try to make known what is a scientist, how people become in it and what are the main aspects of his work. Also, we try to show the different lines of research that are developed within the natural sciences in general and at the Museo de La Plata in particular. As recipients of the proposal, we selected two adult schools, basing our selection in that these students do not have usually access to such information due to the little time available for their extracurricular activities. In each school, the results were different, reflecting totally different expectations and interests.Facultad de Ciencias Naturales y Muse

Better late than never? Interannual and seasonal variability in breeding chronology of gentoo penguins at Stranger Point, Antarctica

Rapid climate change recorded in the western Antarctic Peninsula confronts species with less predictable conditions in the marine and terrestrial environments. We analysed the breeding chronology and nesting site selection of gentoo penguins (Pygoscelis papua) at King George Island (Isla 25 de Mayo), Antarctica, during four seasons in which differences in snow presence and persistence on the ground were observed. We recorded an overall delay as well as seasonal asynchrony at the beginning of reproduction for those years with higher snow deposition. A redistribution of breeding groups was also observed. Nevertheless, the population breeding success and chicks' weight at fledging remained relatively constant, despite the delay in breeding chronology, the increased duration of foraging trips during the guard stage and the decreased weight of stomach contents during the cre'che stage. We suggest that the plasticity of their trophic biology, along with the flexibility of their breeding phenology and relocation of breeding groups, may be complementary reasons why gentoo penguin populations in the region have remained stable in spite of the changing conditions currently registered.Facultad de Ciencias Naturales y MuseoInstituto Multidisciplinario de Biología Celula

Good Computational Practice in the Assignment of Absolute Configurations by TDDFT Calculations of ECD Spectra

Quantum-mechanical calculations of chiroptical properties have rapidly become the most popular method for assigning absolute configurations (AC) of organic compounds, including natural products. Black-box time-dependent Density Functional Theory (TDDFT) calculations of electronic circular dichroism (ECD) spectra are nowadays readily accessible to nonexperts. However, an uncritical attitude may easily deliver a wrong answer. We present to the Chirality Forum a discussion on what can be called good computational practice in running TDDFT ECD calculations, highlighting the most crucial points with several examples from the recent literature