http://scholars.ntou.edu.tw/handle/123456789/17231
標題: | A new internal structure of nauplius larvae: A "ghostly" support sling for cypris y left within the exuviae of nauplius y after metamorphosis (Crustacea: Thecostraca: Facetotecta) | 作者: | Grygier, Mark J. Hoeg, Jens T. Dreyer, Niklas Olesen, Jorgen |
關鍵字: | larval development;metamorphosis;naupliar morphology;y-cypris;y-nauplius | 公開日期: | 1-八月-2019 | 出版社: | WILEY | 卷: | 280 | 期: | 8 | 起(迄)頁: | 1222-1231 | 來源出版物: | JOURNAL OF MORPHOLOGY | 摘要: | Facetotecta, or crustacean "y-larvae," occur in all the world's oceans although the adult forms remain completely unknown. At the metamorphic molt from the last naupliar instar to the terminal cypris larval stage a free carapace, six pairs of natatory thoracopods, and a segmented thorax and abdomen all develop anew. Unlike in earlier molts, the cephalic shield and the so-called "faciotruncal integument" usually remain together at this last naupliar molt, and the posterior "trunk" portion of the exuviae, while hollow, is not empty. In mounted preparations examined by phase contrast or differential interference contrast (DIC) microscopy, a ghost-like image of part of the cypris thorax, particularly the thoracopods and even their setae, is commonly visible inside the naupliar exuviae, and may be universally present in the Facetotecta. To investigate this "ghost," we used DIC and digital photographic stacking, and also scanning electron microscopy, on slide or stub-mounted final naupliar exuviae of an assortment of undescribed species of Facetotecta that had been reared from planktonic lecithotropic nauplii to the cypris stage at Sesoko Island, Okinawa, Japan, and at Keelung and Green Island, Taiwan. These techniques showed that the "ghost" is a delicate, three-dimensional, fibrous structure, essentially a sling-like mold or matrix with struts attached to the outer cuticle and pairs of deep pockets that previously held the thoracopods of the developing cypris y. Whether it is endoskeletal in nature, the (partial) exuvia of an additional instar, remnants of apoptosis, or something else is currently unknown. Nothing similar has been reported in other thecostracans, or in other crustaceans that undergo a similarly abrupt metamorphosis at the last naupliar molt. |
URI: | http://scholars.ntou.edu.tw/handle/123456789/17231 | ISSN: | 0362-2525 | DOI: | 10.1002/jmor.21026 |
顯示於: | 海洋中心 |
在 IR 系統中的文件,除了特別指名其著作權條款之外,均受到著作權保護,並且保留所有的權利。