a-modified-mirror-test-as-visual-guide-for-self-awareness-trait-wild

A Modified Mirror Test as a Visual Guide for the Self-awareness Trait in Wild Antarctica Penguins, <em>Pygoscelis adeliae</em>

In this study, the self-awareness trait was tested in Adelie penguins living on a remote island in Antarctica. Four experimental paradigms were designed ...

Government of India

The prevalence of microplastics (MPs, <5 mm) in natural environments presents a formidable global environmental threat MPs can be found from the Arctic to Antarctica, including glaciers. Despite their widespread distribution, studies on MP accumulation in apex predators inhabiting Polar Regions remain limited. The objective of this study was to conduct a comprehensive examination, for the first time, of MP bioaccumulation in various organs and tissue of Adélie penguins. This investigation comprehends the gastrointestinal tract (GIT), scat, internal organ (lung, trachea, spleen, and liver) and tissue (muscle) samples collected from Svenner Island, Antarctica during the 39th Indian expedition to Antarctica in 2019-2020. Our analyses revealed the presence of 34 MPs across the GIT, scat, lung, and trachea samples, with no MPs detected in muscle, spleen, or liver tissues. Blue-colored microfibers (>50 %) and MPs smaller than 1 mm (38 %) in size were prominently observed. Polymer characterization utilizing μ-FTIR spectroscopy identified low-density polyethylene (LDPE) (~63 %) as the predominant polymer type. The accumulation of MP fibers in the gastrointestinal tract and scat of Adélie penguins may originate from marine ambient media and prey organisms. Furthermore, the presence of LDPE fibers in the trachea and lungs likely occurred through inhalation and subsequent deposition of MPs originating from both local and long-range airborne sources. The identification of fibers ranging between 20 and 100 μm within the trachea suggests a plausible chance of cellular deposition of MPs. Overall our findings provide valuable insights into the organ-specific accumulation of MPs in apex predators. Adélie penguins emerge as promising environmental bio-monitoring species, offering insights into the potential trophic transfer of MPs within frigid environments.

Do microplastics accumulate in penguin internal organs? Evidence from Svenner island, Antarctica.

The morphology and molecular study of the penguin brain are crucial to define its survival in the extreme conditions of Antarctica. The present study focusses on extracting different optical parameters of the penguin brain using label-free optical imaging and spectroscopic techniques. In label-free optical imaging, we have used quantitative phase imaging, which provides morphological information about the neurons in brain tissue, giving the quantitative phase value of 5 to 20 radians corresponding to the 8 µm tissue section. In label-free spectroscopic techniques, we have used autofluorescence and Raman spectroscopy. Autofluorescence spectroscopy provides molecular information about nicotinamide dinucleotide, flavins, lipofuscins, and porphyrins in the brain's spectral range of 420 nm to 700 nm. Raman spectroscopy provides multiple peaks associated with different molecules in the brain; among them, few signals are observed at approximately 1305 cm, 1448 cm, and 1661 cm, which correspond to vibrational modes indicative of vibrational features within lipids and protein structures, as well as the presence of amide groups within brain tissue constituents. All these techniques provide the microscopic and molecular fingerprint of the penguin brain, which can be useful for understanding penguin's anatomical, physiological, and social behavior.

Article	Year
Do microplastics accumulate in penguin internal organs? Evidence from Svenner island, Antarctica. The Science of the total environment\| PubMed ID: 39117209	2024
Investigation on morphological and molecular fingerprints of penguin brain using label-free optical imaging and spectroscopic techniques. Scientific reports\| PubMed ID: 39929855	2025

Prabir G Dastidar

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