52221. |
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52222. |
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52223. |
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52224. |
- Jack, JE, et al.
(författare)
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The eyes of Macrosoma sp. (Lepidoptera: Hedyloidea): a nocturnal butterfly with superposition optics.
- 2007
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Ingår i: Arthropod Structure & Development. - : Elsevier BV. - 1467-8039. ; 36:1, s. 11-22
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Tidskriftsartikel (refereegranskat)abstract
- The visual system of nocturnal Hedyloidea butterflies was investigated for the first time, using light and electron microscopy. This study was undertaken to determine whether hedylids possess the classic superposition eye design characteristic of most moths, or apposition eyes of true butterflies (Papilionoidea), and, to gain insights into the sensory ecology of the Hedyloidea. We show that Macrosoma heliconiaria possesses a superposition-type visual mechanism, characterized by long cylindrical crystalline cones, a lack of corneal processes, 8 constricted retinular sense cells, rhabdoms separated from the crystalline cones forming a translucent ‘clear zone’, and tight networks of trachea that form a tapetum proximal to the retina and which also surround the rhabdoms to form a tracheal sheath. Dark-adapted individuals of M. heliconiaria, M. conifera, and M. rubidinarea exhibited distal retinular pigment migration, forming an eye glow. Correspondingly, light-exposure induced pigment to migrate proximally, causing the eye glow to be replaced by a dark pseudopupil. Other characteristics of the visual system, including relative eye size, facet size, and external morphology of the optic lobes, are mostly ‘moth like’ and correlate with an active, nocturnal lifestyle. The results are discussed in relation to the evolution of lepidopteran eyes, and the sensory ecology of this poorly understood butterfly superfamily.
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52225. |
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52226. |
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52227. |
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52228. |
- Jacobson, Anders, et al.
(författare)
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Phylogenetic relationships in Alisma (Alismataceae) based on RAPDs, and sequence data from ITS and trnL
- 2007
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Ingår i: Plant Systematics and Evolution. - : Springer Science and Business Media LLC. - 1615-6110 .- 0378-2697. ; 265:1-2, s. 27-44
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Tidskriftsartikel (refereegranskat)abstract
- The phylogeny of Alisma (Alismataceae), a genus of approximately nine species of aquatic plants mainly distributed in the Northern Hemisphere, was reconstructed with parsimony analysis on RAPD data and sequences of the nuclear ITS and chloroplast trnL regions, and with MDS on RAPD data. Separate analyses were performed on each data set. Butomus umbellatus was used as outgroup in the analysis of sequence data, and Luronium and Baldellia in the analyses of RAPD data. Among diploid Alisma, two major groups were found: (i) the gramineum group consisting of A. gramineum and A. wahlenbergii, and (ii) the plantago-aquatica group with A. plantago-aquatica, A. orientale, A. subcordatum, A. juzepczukii and A. "bottnicum". Taxa within the groups were poorly separated. The Baltic endemics A. wahlenbergii, A. juzepczukii and A. "bottnicum" have probably originated relatively recently from local populations of A. gramineum (i.e. A. wahlenbergii) and A. plantago-aquatica (i.e. A. juzepczukii and A. "bottnicum"). The exact origin of the polyploid taxa, i.e. A. lanceolatum, A. triviale, A. canaliculatum and A. rariflorum, is still unclear.
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52229. |
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52230. |
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