4/28/2023 0 Comments Scorpion optical isolator![]() Their phylogenetic position within the Arthropoda also provides a critical opportunity for deepening our understanding of the conservation and/or retooling of ancient developmental pathways. ![]() This is unfortunate, because spider visual systems are highly diverse and hence present many useful opportunities to probe the genetic bases of visual specializations. Others, such as the orb weavers (Araneidae), rely less on their eyes for prey capture yet still retain visual functions that play an important role in their daily lives (Foelix, 2011).ĭespite their taxonomic diversity and often-visual habits, our understanding of the molecular and genetic basis of spider visual systems lags significantly behind that of other major animal groups. Several large families of hunting spiders are also highly visual (Land, 1985 Foelix, 2011), including the wolf spiders (Lycosidae), lynx spiders (Oxyopidae), and jumping spiders (Salticidae). ![]() They are voracious predators (Jackson and Pollard, 1996), often playing a role in the control of prey populations (Riechert and Lockley, 1984) and the dynamics of trophic cascades (Schmitz et al., 1997 Schmitz, 2008). These diverse animals are found in every biome and on every continent, save Antarctica (Turnbull, 1973). The earliest spiders may have arisen as early as the Devonian (~400 million years ago Foelix, 2011), and since that time, their numbers have grown to an estimated 80,000 extant species (Raven and Yeates, 2007), with only a little over half of these species described (46,433 species described to date Platnick, 2017). ![]() Spiders are a large and ancient group of animals. We therefore discuss what some of these first steps might be in the hopes of convincing others to join us in studying the vision of these fascinating creatures. This deep homology provides a number of useful footholds into new work on spider vision and the molecular basis of its extant variety. Similarly, our analyses of opsins and related phototransduction genes suggest that spider photoreceptors employ many of the same genes and molecular mechanisms known from other arthropods, with a hypothesized ancestral spider set of four visual and four nonvisual opsins. For example, many (but not all) of the genes that appear important for early eye development in spiders are familiar players known from the developmental networks of other model systems ( e.g., Drosophila). Our efforts highlight that there are many new things to discover from spider eyes, and yet these opportunities are set against a backdrop of deep homology with other arthropod lineages. Here, we review the current literature, analyze publicly available transcriptomic data, and discuss hypotheses about the origins and development of spider eyes. However, despite this conspicuous diversity, our understanding of the genetic underpinnings of these visual systems remains shallow. These modular visual systems, composed of four pairs of image-forming “camera” eyes, have taken on a huge variety of forms, exhibiting variation in eye size, eye placement, image resolution, and field of view, as well as sensitivity to color, polarization, light levels, and motion cues. Spiders are among the world’s most species-rich animal lineages, and their visual systems are likewise highly diverse.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |