Fine structural description of the compound eye of the Madagascar ＇hissing cockroach＇ Gromphadorhinaportentosa （Dictyoptera： Blaberidae）  

作　　者：Monalisa Mishra Victor Benno Meyer-Rochow 

机构地区：[1]Faculty of Engineering and Sciences, Jacobs University (formerly known as International University Bremen), Bremen, Germany [2]Department of Biology (Elainmuseo), University of Oulu, Oulu, Finland

出　　处：《Insect Science》2008年第2期179-192,共14页昆虫科学（英文版）

摘　　要：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.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.

关 键 词：apposition BLATTODEA closed rhabdom ommatidium polarization VISION 

分 类 号：Q96[生物学—昆虫学]