The pineal gland of insectivorous microchiroptern – Rhinopoma kinneari subserves dual function photosensory and endocrine. Its secretions play a pivotal role in complex reproductive processes and functions. Using normal light as control for the basis for comparison, groups of bats were exposed to cotinuous blue, green, yellow red light and total darkness for eighteen day to assess their impact on pineal gland testicular morphology and histologicaly of sexually mature male bats. Blue and green light induced significant increase in the length and cross section area of pineal gland. This inverse trend was not discerned in bats exposed to yellow and red colour light; or total darkness. The results indicate that the observed changes in pineal gland are probably mediated via the optic pathway, while the alterations in the testes and seminiferous tubules are due to modulation in the secretory functions of the pineal gland.

doi: 10.5214/ans.0972.7531.2005.120303