RAGHURAM H

@americancollege.edu.in

Assistant Professor in Zoology
The American College, Madurai

RAGHURAM H


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https://researchid.co/raghuram

EDUCATION

M.Sc. (Integrated Biology), Ph.D. (Biology)

RESEARCH INTERESTS

Behavioural Ecology, Animal Behaviour, Bioacoustics
23

Scopus Publications

590

Scholar Citations

15

Scholar h-index

18

Scholar i10-index

Scopus Publications

  • Isolation and characterization of chitinolytic bacterium, Escherichia fergusonii AMC01 from insectivorous bat, Taphozous melanopogon
    Sahayanathan Gracy Jenifer, Ganapathy Marimuthu, Hanumanthan Raghuram
    Journal of Basic Microbiology, 2021
    Chitinases are capable of hydrolyzing insoluble chitin into its oligo and monomeric parts and have received increased consideration because of their wide scope of biotechnological applications. The commercial application of microbial chitinase is appealing due to the relative ease of enormous production and to meet the current world demands. This study aimed at isolation and characterization of chitin degrading bacteria from the gut of Indian tropical insectivorous black‐bearded tomb bat, Taphozous melanopogon. The isolated bacterial strains were characterized through biochemical analysis and nucleic acid‐based approaches by 16S ribosomal RNA amplification and sequencing. The BLAST (Basic Local Alignment Search Tool) and phylogenetic analysis showed that the bacterial strain exhibited a close resemblance with Escherichia fergusonii. The chitinolytic activity of the E. fergusonii AMC01 was identified using supplemented colloidal chitin with agar medium. Compiling all, these findings would facilitate in constructing a database and presumably promote the use of E. fergusonii AMC01 as an efficient strain for the chitinase production.
  • Responses of short-nosed fruit bat, Cynopterus sphinx (Vahl 1797) towards distress calls of their conspecifics from related and unrelated sites: Implications for building a social relationship
    A. F. P. Allwin Mabes Raj, K. Emmanuvel Rajan, H. Raghuram
    Current Science, 2018
    Distress calls emitted by bats signal their conspecifics either to warn them or inform them about the situations. Conspecifics may also get attracted towards distress calls as a behaviour of cooperative mobbing or just selfishly assessing the potential source of danger. The exact functions of distress calls in bats therefore vary to a great degree and are very hard to pinpoint. We conducted playback experiments to test the response of short-nosed fruit bat, Cynopterus sphinx towards the distress calls of their conspecifics from related and unrelated sites. Bats were attracted to their conspecifics from both related and unrelated sites and in one occasion towards fruit bat (Rousettus leschenaulti) of another genus within the same family. The response towards the opposite sex was significant in most of the playback trials and the reasons remain unclear. This symmetric response towards conspecifics from related and unrelated sites suggests the possibility of fruit bats building social relationships among unrelated individuals and probably between species.
  • Geophagy by the Indian short-nosed fruit bat, Cynopterus sphinx (Pteropodidae) while foraging on Madhuca latifolia (Sapotaceae) in Tamil Nadu, South India
    Valliyappan Mahandran, Hanumanthan Raghuram, Parthasarathy Thiruchenthil Nathan
    Acta Ethologica, 2016
    Geophagy has been reported in many mammals and birds. However, in pteropodid bats, this behaviour has not been reported. Here, we document geophagy behaviour by the pteropodid bat, Cynopterus sphinx, during foraging in the fruiting trees of Madhuca latifolia (Sapotaceae). These bats removed single fruits from the foraging tree and carried it to the feeding roost for consumption. At around 1900 h, we observed three individuals of C. sphinx gleaning over the ground surface by circling flights. The bats landed with their wings spread apart and started licking the soil with head movements. Their ventral body surface rested completely on the ground while consuming the soil. A total of 91 feeding bouts of soil consumption were recorded within 1 h; however, thereafter, this behaviour was not observed. In order to understand the function of geophagy, we quantitatively analysed the composition of minerals in the soil, as well as in the M. latifolia fruits (partially ripe) along with its secondary metabolites from the study site. Our results revealed that the partially ripe fruits contained high levels of secondary metabolites (alkaloids, tannins, coumarins and saponins). The soil contained higher levels of Mg, Ca, Fe, Na and K minerals than the fruits. These findings suggest that bats may gain essential minerals that are low in their fruit diet by consuming soil. In addition, the observed minerals that play a role in detoxification of the secondary metabolites present in the partially ripe fruits that might be detrimental to the consuming bats. Frugivory, nectarivory and folivory are well understood in C. sphinx; however, geophagy behaviour has not been reported in this species so far. This may represent an ‘adaptive behavioural plasticity’ in the foraging behaviour of the observed C. sphinx population.
  • Structure of distress call: implication for specificity and activation of dopaminergic system
    Subramanian Mariappan, Wieslaw Bogdanowicz, Hanumanthan Raghuram, Ganapathy Marimuthu, Koilmani Emmanuvel Rajan
    Journal of Comparative Physiology A Neuroethology Sensory Neural and Behavioral Physiology, 2016
    We conducted a set of playback experiments aimed at understanding whether distress-call structure in the greater short-nosed fruit bat Cynopterus sphinx is specific in encoding information relating to stress that attracts conspecifics. We tested the specificity by playing their distress call and its modified version at a foraging site for free-ranging bats, as well as under captive conditions involving either a small group or individuals. In a separate playback experiment, bats showed a significantly greater response when the natural call as opposed to a modified call was played back to captive as well as free-ranging bats at the foraging site. Under captive conditions, bats showed less of a response to the playback of distress calls when in a group than when alone. We subsequently found that tyrosine hydroxylase (TH) and its transcription factor—nuclear receptor related factor 1 (Nurr-1); and the dopamine transporter (DAT) and its receptor (D1DR) were elevated significantly in the amygdala of bats both emitting and responding to a distress call, but not in the case of bats responding to the modified call. These results suggest that distress-call structure encodes information on the state of stress that is capable of being conveyed to conspecifics.
  • Silent katydid females are at higher risk of bat predation than acoustically signalling katydid males
    Hanumanthan Raghuram, Rittik Deb, Diptarup Nandi, Rohini Balakrishnan
    Proceedings of the Royal Society B Biological Sciences, 2015
    Males that produce conspicuous mate attraction signals are often at high risk of predation from eavesdropping predators. Females of such species typically search for signalling males and their higher motility may also place them at risk. The relative predation risk faced by males and females in the context of mate-finding using long-distance signals has rarely been investigated. In this study, we show, using a combination of diet analysis and behavioural experiments, that katydid females, who do not produce acoustic signals, are at higher risk of predation from a major bat predator, Megaderma spasma , than calling males. Female katydids were represented in much higher numbers than males in the culled remains beneath roosts of M. spasma . Playback experiments using katydid calls revealed that male calls were approached in only about one-third of the trials overall, whereas tethered, flying katydids were always approached and attacked. Our results question the idea that necessary costs of mate-finding, including risk of predation, are higher in signalling males than in searching females.
  • Species and acoustic diversity of bats in a palaeotropical wet evergreen forest in southern India
    Current Science, 2014
  • Effect of reproduction and nutritional qualities of fruits on food choice and voluntary food intake of indian fulvous fruit bat, rousettus leschenaulti (Desmarest 1820)
    Proceedings of the Indian National Science Academy, 2012
  • Foraging ecology of pteropodid bats: Pollination and seed dispersal
    Bats Biology Behavior and Conservation, 2011
  • Distress call-induced gene expression in the brain of the Indian short-nosed fruit bat, Cynopterus sphinx
    Ambigapathy Ganesh, Hanumanthan Raghuram, Parthasarathy T. Nathan, Ganapathy Marimuthu, Koilmani Emmanuvel Rajan
    Journal of Comparative Physiology A Neuroethology Sensory Neural and Behavioral Physiology, 2010
    Individuals in distress emit audible vocalizations to either warn or inform conspecifics. The Indian short-nosed fruit bat, Cynopterus sphinx, emits distress calls soon after becoming entangled in mist nets, which appear to attract conspecifics. Phase I of these distress calls is longer and louder, and includes a secondary peak, compared to phase II. Activity-dependent expression of egr-1 was examined in free-ranging C. sphinx following the emissions and responses to a distress call. We found that the level of expression of egr-1 was higher in bats that emitted a distress call, in adults that responded, and in pups than in silent bats. Up-regulated cDNA was amplified to identify the target gene (TOE1) of the protein Egr-1. The observed expression pattern Toe1 was similar to that of egr-1. These findings suggest that the neuronal activity related to recognition of a distress call and an auditory feedback mechanism induces the expression of Egr-1. Co-expression of egr-1 with Toe1 may play a role in initial triggering of the genetic mechanism that could be involved in the consolidation or stabilization of distress call memories.
  • Bat foraging strategies and pollination of Madhuca latifolia (Sapotaceae) in southern India
    Parthasarathy Thiruchenthil Nathan, Thangavel Karuppudurai, Hanumanthan Raghuram, Ganapathy Marimuthu
    Acta Chiropterologica, 2009
    The sympatrically occurring Indian short-nosed fruit bat Cynopterus sphinx and Indian flying fox Pteropus giganteus visit Madhuca latifolia (Sapotaceae), which offers fleshy corollas (≈ 300 mg) to pollinating bats. The flowers are white, tiny and in dense fascicles. The foraging activities of the two bat species were segregated in space and time. Cynopterus sphinx fed on resources at lower heights in the trees than P. giganteus and its peak foraging activity occurred at 19:30 h, before that of P. giganteus. Foraging activities involved short searching flights followed by landing and removal of the corolla by mouth. Cynopterus sphinx detached single corollas from fascicles and carried them to nearby feeding roosts, where it sucked the juice and spat out the fibrous remains. Pteropus giganteus landed on top of the trees and fed on the corollas in situ; its peak activity occurred at 20:30 h. This species glided and crawled between the branches and held the branches with claws and forearms when removing fleshy corollas with its mouth. Both C. sphinx and P. giganteus consumed fleshy corollas with attached stamens and left the gynoecium intact. Bagging experiments showed that fruit-set in bat-visited flowers was significantly higher (P < 0.001) than in self-pollinated flowers.
  • The role of olfaction and vision in the foraging behaviour of an echolocating megachiropteran fruit bat, Rousettus leschenaulti (Pteropodidae)
    Hanumanthan Raghuram, Chinnathambi Thangadurai, Nagappan Gopukumar, Kulam Nathar, Kandula Sripathi
    Mammalian Biology, 2009
  • Maternal feeding of offspring with vertebrate prey in captive Indian false vampire bat, Megaderma lyra
    Hanumanthan Raghuram, Ganapathy Marimuthu
    Acta Chiropterologica, 2007
  • Wing morphology and flight development in the short-nosed fruit bat Cynopterus sphinx
    Vadamalai Elangovan, Elangovan Yuvana Satya Priya, Hanumanth Raghuram, Ganapathy Marimuthu
    Zoology, 2007
  • Development of prey capture in the Indian false vampire bat Megaderma lyra
    Hanumanthan Raghuram, Granapathy Marimuthu
    Ethology, 2007
  • Presence of single as well as double clicks in the echolocation signals of a fruit bat, Rousettus leschenaulti (Chiroptera: Pteropodidae)
    Folia Zoologica, 2007
  • Echolocation sounds of the painted bat Kerivoula picta (Vespertilionidae)
    Current Science, 2006
  • Sex ratio, population structure and roost fidelity in a free-ranging colony of Indian false vampire bat, Megaderma lyra
    Current Science, 2006
  • Hunting in unfamiliar space: Echolocation in the Indian false vampire bat, Megaderma lyra, when gleaning prey
    John M. Ratcliffe, Hanumanthan Raghuram, Ganapathy Marimuthu, James H. Fullard, M. Brock Fenton
    Behavioral Ecology and Sociobiology, 2005
  • Bat pollination of kapok tree, Ceiba pentandra
    Current Science, 2005
  • Wing morphology and flight performance in Rousettus leschenaulti
    V. Elangovan, H. Raghuram, E. Yuvana Satya Priya, G. Marimuthu
    Journal of Mammalogy, 2004
  • Population size and survival in the Indian false vampire bat Megaderma lyra
    Kandula Sripathi, Hanumanthan Raghuram, Raman Rajasekar, Thangavel Karuppudurai, Suba Gnana Abraham
    Acta Chiropterologica, 2004
  • Postnatal development in the Indian short-nosed fruit bat Cynopterus sphinx: Growth rate and age estimation
    Vadamalai Elangovan, Elangovan Yuvana Satya Priya, Hanumanthan Raghuram, Ganapathy Marimuthu
    Acta Chiropterologica, 2003
  • Postnatal growth, age estimation and development of foraging behaviour in the fulvous fruit bat Rousettus leschenaulti
    V. Elangovan, H. Raghuram, E. Yuvana Satya Priya, G. Marimuthu
    Journal of Biosciences, 2002

RECENT SCHOLAR PUBLICATIONS

  • REVIEWERS OF ARTICLES SUBMITTED TO VOLUME 27
    AM Adams, MM Andrews, E Arias, A Arias-Aguilar, JA Cabrales, ...
    Acta Chiropterologica 27 (2), 329 , 2025
    2025
  • Isolation and characterization of chitinolytic bacterium, Escherichia fergusonii AMC01 from insectivorous bat, Taphozous melanopogon
    S Gracy Jenifer, G Marimuthu, H Raghuram
    Journal of basic microbiology 61 (10), 940-946 , 2021
    2021
    Citations: 5
  • Responses of short-nosed fruit bat, Cynopterus sphinx (Vahl 1797) towards distress calls of their conspecifics from related and unrelated sites: implications for building a …
    AFP Allwin Mabes Raj, K Emmanuvel Rajan, H Raghuram
    Current Science (00113891) , 2018
    2018
  • Postnatal growth and age estimation in a tropical insectivorous bat, Hipposideros speoris
    DPS Doss, H Raghuran, S Muthuselvan, MR Sudhakaran, SS Isaac
    International Journal of Zoology and Applied Biosciences 3, 34-40 , 2018
    2018
    Citations: 2
  • Geophagy by the Indian short-nosed fruit bat, Cynopterus sphinx (Pteropodidae) while foraging on Madhuca latifolia (Sapotaceae) in Tamil Nadu, South India
    V Mahandran, H Raghuram, PT Nathan
    Acta ethologica 19 (1), 95-99 , 2016
    2016
    Citations: 17
  • Structure of distress call: implication for specificity and activation of dopaminergic system
    S Mariappan, W Bogdanowicz, H Raghuram, G Marimuthu, KE Rajan
    Journal of Comparative Physiology A 202 (1), 55-65 , 2016
    2016
    Citations: 19
  • Silent katydid females are at higher risk of bat predation than acoustically signalling katydid males
    H Raghuram, R Deb, D Nandi, R Balakrishnan
    Proceedings of the Royal Society B: Biological Sciences 282 (1798) , 2015
    2015
    Citations: 51
  • Species and acoustic diversity of bats in a palaeotropical wet evergreen forest in southern India
    H Raghuram, M Jain, R Balakrishnan
    Current Science, 631-641 , 2014
    2014
    Citations: 50
  • Effect of Reproduction and Nutritional Qualities of Fruits on Food Choice and Voluntary Food Intake of Indian Fulvous Fruit bat, Rousettus leschenaulti (Desmarest 1820)
    H RAGHURAM, YS PRIYA, G MARIMUTHU
    Proc Indian natn Sci Acad 78 (1), 1-7 , 2012
    2012
  • Bats: biology, behavior and conservation
    H Raghuram, N Singaravelan, PT Nathan, KE Rajan, G Marimuthu, ...
    Nova Science Publishers, Hauppauge, NY , 2011
    2011
    Citations: 4
  • Foraging ecology of pteropodid bats: pollination and seed dispersal
    H Raghuram, N Singaravelan, PT Nathan, KE Rajan, G Marimuthu
    Bats: biology, behavior and conservation, 177-188 , 2011
    2011
    Citations: 19
  • Distress call-induced gene expression in the brain of the Indian short-nosed fruit bat, Cynopterus sphinx
    A Ganesh, H Raghuram, PT Nathan, G Marimuthu, KE Rajan
    Journal of Comparative Physiology A 196 (2), 155-164 , 2010
    2010
    Citations: 14
  • Bat foraging strategies and pollination of Madhuca latifolia (Sapotaceae) in southern India
    PT Nathan, T Karuppudurai, H Raghuram, G Marimuthu
    Acta chiropterologica 11 (2), 435-441 , 2009
    2009
    Citations: 37
  • The role of olfaction and vision in the foraging behaviour of an echolocating megachiropteran fruit bat, Rousettus leschenaulti (Pteropodidae)
    H Raghuram, C Thangadurai, N Gopukumar, K Nathar, K Sripathi
    Mammalian Biology 74 (1), 9-14 , 2009
    2009
    Citations: 51
  • Maternal feeding of offspring with vertebrate prey in captive Indian false vampire bat, Megaderma lyra
    H Raghuram, G Marimuthu
    Acta Chiropterologica 9 (2), 437-443 , 2007
    2007
    Citations: 15
  • Wing morphology and flight development in the short-nosed fruit bat Cynopterus sphinx
    V Elangovan, EYS Priya, H Raghuram, G Marimuthu
    Zoology 110 (3), 189-196 , 2007
    2007
    Citations: 38
  • Development of Prey Capture in the Indian False Vampire Bat Megaderma Lyra
    H Raghuram, G Marimuthu
    Ethology 113 (6), 555-561 , 2007
    2007
    Citations: 4
  • Presence of single as well as double clicks in the echolocation signals of a fruit bat, Rousettus leschenaulti (Chiroptera: Pteropodidae)
    H Raghuram, N Gopukumar, K Sripathi
    Folia zoologica 56 (1), 33 , 2007
    2007
    Citations: 26
  • Sex ratio, population structure and roost fidelity in a free-ranging colony of Indian false vampire bat, Megaderma lyra
    H Raghuram, B Chattopadhyay, PT Nathan, K Sripathi
    Current science, 965-968 , 2006
    2006
    Citations: 8
  • Echolocation sounds of the painted bat Kerivoula picta (Vespertilionidae)
    S Kandula, H Raghuram, Thiruchenthil Nathan, Parthasarathy
    Current Science 91 (9), 1145-1147 , 2006
    2006
    Citations: 7

MOST CITED SCHOLAR PUBLICATIONS

  • Hunting in unfamiliar space: echolocation in the Indian false vampire bat, Megaderma lyra , when gleaning prey
    JM Ratcliffe, H Raghuram, G Marimuthu, JH Fullard, MB Fenton
    Behavioral Ecology and Sociobiology 58 (2), 157-164 , 2005
    2005
    Citations: 56
  • Silent katydid females are at higher risk of bat predation than acoustically signalling katydid males
    H Raghuram, R Deb, D Nandi, R Balakrishnan
    Proceedings of the Royal Society B: Biological Sciences 282 (1798) , 2015
    2015
    Citations: 51
  • The role of olfaction and vision in the foraging behaviour of an echolocating megachiropteran fruit bat, Rousettus leschenaulti (Pteropodidae)
    H Raghuram, C Thangadurai, N Gopukumar, K Nathar, K Sripathi
    Mammalian Biology 74 (1), 9-14 , 2009
    2009
    Citations: 51
  • Species and acoustic diversity of bats in a palaeotropical wet evergreen forest in southern India
    H Raghuram, M Jain, R Balakrishnan
    Current Science, 631-641 , 2014
    2014
    Citations: 50
  • Bat pollination of kapok tree, Ceiba pentandra
    PT Nathan, H Raghuram, V Elangovan, T Karuppudurai, G Marimuthu
    Current Science, 1679-1681 , 2005
    2005
    Citations: 49
  • Wing morphology and flight development in the short-nosed fruit bat Cynopterus sphinx
    V Elangovan, EYS Priya, H Raghuram, G Marimuthu
    Zoology 110 (3), 189-196 , 2007
    2007
    Citations: 38
  • Postnatal growth, age estimation and development of foraging behaviour in the fulvous fruit bat Rousettus leschenaulti
    V Elangovan, H Raghuram, E Yuvana Satya Priya, G Marimuthu
    Journal of Biosciences 27 (7), 695-702 , 2002
    2002
    Citations: 38
  • Bat foraging strategies and pollination of Madhuca latifolia (Sapotaceae) in southern India
    PT Nathan, T Karuppudurai, H Raghuram, G Marimuthu
    Acta chiropterologica 11 (2), 435-441 , 2009
    2009
    Citations: 37
  • Postnatal development in the Indian short-nosed fruit bat Cynopterus sphinx: growth rate and age estimation
    V Elangovan, EYS Priya, H Raghuram, G Marimuthu
    Acta Chiropterologica 5 (1), 107-116 , 2003
    2003
    Citations: 31
  • Presence of single as well as double clicks in the echolocation signals of a fruit bat, Rousettus leschenaulti (Chiroptera: Pteropodidae)
    H Raghuram, N Gopukumar, K Sripathi
    Folia zoologica 56 (1), 33 , 2007
    2007
    Citations: 26
  • Wing Morphology and Flight Performance in Rousettus leschenaulti
    V Elangovan, H Raghuram, EY Satya Priya, G Marimuthu
    Journal of Mammalogy 85 (4), 806-812 , 2004
    2004
    Citations: 25
  • Structure of distress call: implication for specificity and activation of dopaminergic system
    S Mariappan, W Bogdanowicz, H Raghuram, G Marimuthu, KE Rajan
    Journal of Comparative Physiology A 202 (1), 55-65 , 2016
    2016
    Citations: 19
  • Foraging ecology of pteropodid bats: pollination and seed dispersal
    H Raghuram, N Singaravelan, PT Nathan, KE Rajan, G Marimuthu
    Bats: biology, behavior and conservation, 177-188 , 2011
    2011
    Citations: 19
  • Geophagy by the Indian short-nosed fruit bat, Cynopterus sphinx (Pteropodidae) while foraging on Madhuca latifolia (Sapotaceae) in Tamil Nadu, South India
    V Mahandran, H Raghuram, PT Nathan
    Acta ethologica 19 (1), 95-99 , 2016
    2016
    Citations: 17
  • Maternal feeding of offspring with vertebrate prey in captive Indian false vampire bat, Megaderma lyra
    H Raghuram, G Marimuthu
    Acta Chiropterologica 9 (2), 437-443 , 2007
    2007
    Citations: 15
  • Distress call-induced gene expression in the brain of the Indian short-nosed fruit bat, Cynopterus sphinx
    A Ganesh, H Raghuram, PT Nathan, G Marimuthu, KE Rajan
    Journal of Comparative Physiology A 196 (2), 155-164 , 2010
    2010
    Citations: 14
  • Donald redfield griffin: The discovery of echolocation
    H Raghuram, G Marimuthu
    Resonance 10 (2), 20-32 , 2005
    2005
    Citations: 13
  • Population size and survival in the Indian false vampire bat Megaderma lyra
    K Sripathi, H Raghuram, R Rajasekar, T Karuppudurai, SG Abraham
    Acta Chiropterologica 6 (1), 145-154 , 2004
    2004
    Citations: 11
  • Sex ratio, population structure and roost fidelity in a free-ranging colony of Indian false vampire bat, Megaderma lyra
    H Raghuram, B Chattopadhyay, PT Nathan, K Sripathi
    Current science, 965-968 , 2006
    2006
    Citations: 8
  • Echolocation sounds of the painted bat Kerivoula picta (Vespertilionidae)
    S Kandula, H Raghuram, Thiruchenthil Nathan, Parthasarathy
    Current Science 91 (9), 1145-1147 , 2006
    2006
    Citations: 7