Infrared antenna-like structures in mammalian fur

Many small animals, including shrews, most rodents and some marsupials, have fur composed of at least four types of hair, all with distinctive and complex anatomy. A ubiquitous and unexplained feature is periodic, internal banding with spacing in the 6–12 µm range that hints at an underlying infrared function. One bristle-like form, called guard hair, has the correct shape and internal periodic patterns to function as an infrared antenna. Optical analysis of guard hair from a wide range of species shows precise tuning to the optimum wavelength for thermal imaging. For heavily predated, nocturnal animals the ability to sense local infrared sources has a clear survival advantage. The tuned antennae, spectral filters and waveguides present in guard hair, all operating at a scale similar to the infrared wavelength, could be a rich source of bio-inspiration in the field of photonics. The tools developed in this work may enable us to understand the other hair types and their evolution.

Morphometric variation in wolves and golden jackal in India (Mammalia, Carnivora)

Species of Canis (Carnivora, Canidae) have similar morphology and distinguishing sympatric species is challenging. We present data on morphometry of skull, body and hair of three wild Canis species that occur in India, which include two wolves (Indian wolf, Canis lupus pallipes; and Himalayan wolf, Canis himalayensis) and the golden jackal (Canis aureus). A total of 20 cranial and six body measurements and microscopic characteristics of guard hair were analysed, using multivariate ordination to differentiate between species. Cranial measures of the Himalayan wolves were found to be the largest followed by Indian wolves and golden jackals. However, many measures overlapped amongst the three species. Two Principal Components each, for body measures and cranial measures, explained 86 and 91% of the variation in the data, respectively. These Components discriminated the two wolves from golden jackals, but could not distinguish between wolves. Hair medullary patterns were simple and wide type, whereas hair cuticular patterns showed crenate scale margins, near scale distance and irregular wavey scale patterns for all Canis taxa and were not useful to distinguish species. Data reported in this study further contribute to the existing global data on wild canids for a holistic understanding of the variation within the genus and show that distinguishing between all sympatric species from morphology alone may not be possible.

METHODOLOGICAL FEATURES OF RESEARCH ON A DOMESTIC DOG INTERMEDIATE HAIR

Currently, offenses against animals, in particular, dogs are often committed. Many scientists developed theory and methodology to study animal hair. However, today there remained certain difficulties in establishing genus assignment and species of hair. It is noted that animal hair that belong to related genera is the most difficult to differentiate. The Article purpose is to establish diagnostic features of an intermediate type of hair of an animal in order to trace its origin from a domestic dog. Micro-objects similar to hair have been received for study. Objects were examined macroscopically and microscopically. The length was measured with a metal ruler, thickness was determined using an ocular screw micrometer MOV 1-16x on the “MIKMED-2-20” microscope with a binocular body. A cuticle imprint was obtained on the “BF-6” glue; thermochemical treatment (alkaline hydrolysis) was carried out in a 20% sodium hydroxide solution. The established morphological structure of the objects under study confirms the fact that intermediate hair is somewhere in the middle between down and guard hairs with a different number of features specific to mentioned categories. Objects have features attributed to animal hair of the Canidae family: complex cuticle pattern, medulla begins at some distance from the root end, medulla thickness and the shape of medulla cells. Thus, one feature that is characteristic of guard hairs, namely a complex cuticle pattern in the form of various cones can give a forensic expert a reason to state that objects under study can originate from a domestic dog. It can be concluded that in order to establish taxonomic identity of an intermediate hair in a domestic dog, it is necessary: 1) to determine features of guard hairs and signs of down hair in an object under study; 2) to identify and evaluate signs of guard hair (in this case, a specific cuticle pattern, medulla thickness) 3) to compare the information obtained while research with literature data and make a positive or negative conclusion.

The identification of pika and hare through tricho-taxonomy (Mammalia: Lagomorpha)

The macroscopic and microscopic characters of dorsal guard hairs of Indian lagomorphs (four species of pikas and three species of hare) are described; the cuticular and medullary characters are similar between the species studied. The cuticular and medullary characters, however, are dissimilar between the family Ochotonidae and Leporidae. The cross-section of hair of the species had shown two identical shapes between the family Ochotonidae and Leporidae. The cross-section was observed as an oval shape in all the four ochotonid species, whereas there was a dumb-bell shape in all three leporid species. The hair of the Indian lagomorphs can easily be differentiated up to the family level on the basis of their unique cuticula, medulla and cross-section of the dorsal guard hair. The high-resolution microphotographs and key characteristics of hair that are presented here can be used as an appropriate reference for family-level identification of Indian lagomorphs.

Cuticular and Medullary Structure of Some Wild Herbivoresof India

The dorsal guard hair is considered as a mammalian exoskeleton. The anatomical feature of the three concentric layers of the mammalian hair, viz., medulla, cortex, and cuticle vary considerably with different species. The characteristics features of cuticular scales and medullary pattern can be used as an important tool for species identification by using various methods for hair analysis. The morphological features of cuticle and medulla of dorsal guard hair samples of Sambar (Rusa unicolor), Nilgai/blue bull (Boselaphus tragocamelus) and Spotted deer (Axix axis), six each, were studied during post-mortem examination. The microscopic studies showed a difference in some of the cuticular scale and medullar cells among three species. Hence, a single morphological feature of hair may not be a confirmative tool for species identification but multiple morphological features can be used as a confirmative tool of species identification. This study provides pictographic details in eead of some wild species which can be used to curb criminal acts against wild animals.

Activated carbon powder derived from cashmere guard hair

Converting waste fiber to high value-added carbonaceous materials has been considered as an effective and affordable route in response to the increasing volume of waste fiber in recent year. In this study, we are the first to prepare activated carbon powder derived from cashmere guard hair as a renewable waste protein fiber, using a chemical activation method at different impregnation ratios of K2CO3/cashmere guard hair char and activation temperatures ranging from 400℃ to 600℃. Characterization of the activated carbon powder was carried out by morphology study, specific surface area study, and adsorption study. Results have shown that the increase of the impregnation ratio and the activation temperature created more microporous structure in the activated carbon powder, and then increased the specific surface area of the activated carbon powder as well as the amount of methylene blue adsorbed. However, the carbon yield increases with the increase in the impregnation ratio of K2CO3/cashmere guard hair char and decreases with the increase in the activation temperature. The activated carbon powder, activated by the condition of 1:2 K2CO3/cashmere guard hair char impregnation ratio and 600℃ activation temperature, has a specific surface area of 764.86 m2g−1 and a carbon yield of 14.07 wt%. Compared to the activated carbon powder derived from fine merino wool fibers, the activated carbon powder derived from cashmere guard hair has higher carbon yield, surface area, and total pore volume, showing a superior adsorption performance.

Characterization of dorsal guard hair of the wild goats and sheep (Bovidae: Caprinae) occurring in the Himalaya and Western Ghats of India

The morphological and microscopic characteristics of dorsal guard hair of six species of the Indian goat-antelopes are described. Although the cuticular characteristics of hair of all the six species studied are similar, the morphological, medulla and transverse section characteristics of hair are varied between the species. The hair of Indian caprines can easily be identified on the basis of their unique medulla and transverse section. The high-resolution microphotographs and key characteristics of hair are presented here and can be used as an appropriate reference for species identification of the wild goats and sheep occurring in the Himalaya and Western Ghats of India.

The identification of Takin Budorcas taxicolor (Mammalia: Bovidae) through dorsal guard hair

The dorsal guard hairs of Takin Budorcas taxicolor was examined using the optical light and scanning electron microscopes for species identification. It is found that the dorsal guard hair of B. taxicolor is possessed a completely unique microscopic characteristic especially the medullary character-uniserial ladder structure, which differs from other species of mammals. The ‘irregular wave’ of scale patterns and ‘rippled’ scale margins of cuticular, and the ‘circular’ shape of a transverse section of hair also determines the species identity of B. taxicolor, because these characteristics are infrequent in other species of mammals. The micro-photographs and characters of hairs are presented here can be used in the forensic science, as an appropriate reference for species identification of B. taxicolor.