The compound eyes of the wingless adults of the Madagascar ＇hissing cockroach＇ Gromphadorhinaportentosa Sachum, 1853 were examined by light and electron microscopy. Each eye contains 2 400-2 500 mostly hexagonal fac...The compound eyes of the wingless adults of the Madagascar ＇hissing cockroach＇ Gromphadorhinaportentosa Sachum, 1853 were examined by light and electron microscopy. Each eye contains 2 400-2 500 mostly hexagonal facets. However, irregularities affecting both shape and size of the ommatidia are relatively common, especially towards the margins of the eye. An individual ommatidium of this eucone type of apposition eye contains eight retinula cells, which give rise to a centrally-fused, tiered rhabdom. The distal end of the latter is funnel-shaped and accommodates the proximal end of the cone in its midst, Further below, the rhabdom （then formed by the rhabdomeres of four retinula cells） assumes a squarish profile with microvilli aligned in two directions at right-angle to each other. Cross sections through the proximal regions of the rhabdom display triangular rhabdom outlines and microvilli （belonging to 3-4 retinula cells different from those involved in the squarish more distal rhabdom） that run in three directions inclined to one another by 120°. Overall the organization of the eye conforms to the orthopteroid pattern and particularly closely resembles that of the American cockroach Periplaneta americana. However, since G. portentosa possesses fewer ommatidia, this could be a consequence of its inability to fly. On the other hand, the large size of the facets and the voluminous rhabdoms suggest considerable absolute sensitivity and an ability to detect the plane of linearly polarized light. Based on the pattern of microvillus orientations in combination with the crepuscular lifestyle G. portentosa leads and the habitat it occurs in, the prediction is made that this insect uses its green receptors for e-vector discrimination in the environment of down-welling light that reaches the forest floor.展开更多
Light polarization is the phenomenon that describes the oscillations and orientations of the light waves.Polarized light is a source of substantial cue for navigation in many marine and land-dwelling animals.This work...Light polarization is the phenomenon that describes the oscillations and orientations of the light waves.Polarized light is a source of substantial cue for navigation in many marine and land-dwelling animals.This work investigates the challenges of obtaining information regarding polarization under various conditions by observing the phenomenology of the ommatidium in many insects.Noisy conditions can be because of haze or the presence of clouds in the atmosphere.Aerosol molecules are greater in volume and scale in such atmospheric conditions.When sunlight crosses through these molecules of aerosol,its polarization information is distorted.The distorted pattern has a little or no information on neutral points of light polarization.On the basis of the relationship bet ween wavelength of sunlight and polarization,we propose a novel hue based color mixing(HBCM)model to calculate the polarization information and orientation information more accurately and robustly.This method improves the symmetries of polarization patterns and eliminates the effect of noises.Symmetries of polarization patterns are compared with red,green and blue(RGB)spectrum and these differences are quantified and compared especially under high noisy weather conditions.展开更多
文摘The compound eyes of the wingless adults of the Madagascar ＇hissing cockroach＇ Gromphadorhinaportentosa Sachum, 1853 were examined by light and electron microscopy. Each eye contains 2 400-2 500 mostly hexagonal facets. However, irregularities affecting both shape and size of the ommatidia are relatively common, especially towards the margins of the eye. An individual ommatidium of this eucone type of apposition eye contains eight retinula cells, which give rise to a centrally-fused, tiered rhabdom. The distal end of the latter is funnel-shaped and accommodates the proximal end of the cone in its midst, Further below, the rhabdom （then formed by the rhabdomeres of four retinula cells） assumes a squarish profile with microvilli aligned in two directions at right-angle to each other. Cross sections through the proximal regions of the rhabdom display triangular rhabdom outlines and microvilli （belonging to 3-4 retinula cells different from those involved in the squarish more distal rhabdom） that run in three directions inclined to one another by 120°. Overall the organization of the eye conforms to the orthopteroid pattern and particularly closely resembles that of the American cockroach Periplaneta americana. However, since G. portentosa possesses fewer ommatidia, this could be a consequence of its inability to fly. On the other hand, the large size of the facets and the voluminous rhabdoms suggest considerable absolute sensitivity and an ability to detect the plane of linearly polarized light. Based on the pattern of microvillus orientations in combination with the crepuscular lifestyle G. portentosa leads and the habitat it occurs in, the prediction is made that this insect uses its green receptors for e-vector discrimination in the environment of down-welling light that reaches the forest floor.
基金the National Natural Science Foundation of China(No.61627810)the Joint Fund of Advanced Aerospace Manufacturing Technology Research of China(No.USCAST2016)。
文摘Light polarization is the phenomenon that describes the oscillations and orientations of the light waves.Polarized light is a source of substantial cue for navigation in many marine and land-dwelling animals.This work investigates the challenges of obtaining information regarding polarization under various conditions by observing the phenomenology of the ommatidium in many insects.Noisy conditions can be because of haze or the presence of clouds in the atmosphere.Aerosol molecules are greater in volume and scale in such atmospheric conditions.When sunlight crosses through these molecules of aerosol,its polarization information is distorted.The distorted pattern has a little or no information on neutral points of light polarization.On the basis of the relationship bet ween wavelength of sunlight and polarization,we propose a novel hue based color mixing(HBCM)model to calculate the polarization information and orientation information more accurately and robustly.This method improves the symmetries of polarization patterns and eliminates the effect of noises.Symmetries of polarization patterns are compared with red,green and blue(RGB)spectrum and these differences are quantified and compared especially under high noisy weather conditions.
