Britz Ralf, Hoffmann Matthias
Department of Zoology, The Natural History Museum, London, UK.
J Morphol. 2006 Aug;267(8):909-23. doi: 10.1002/jmor.10447.
We studied the ontogeny of the claustrum comparatively in representatives of all otophysan subgroups. The claustrum of cypriniforms has a cartilaginous precursor, the claustral cartilage, which subsequently ossifies perichondrally at its anterior face and develops an extensive lamina of membrane bone. The membrane bone component of the claustrum and its close association with the atrium sinus imparis, a perilymphatic space of the Weberian apparatus, are both synapomorphies of cypriniforms. The characiform claustrum is not preformed in cartilage and originates as a membrane bone ossification, a putative synapomorphy of that taxon. Among siluriforms, the claustrum is present only in more basal groups and originates as an elongate cartilage that ossifies in a characteristic ventrodorsal direction, possibly a synapomorphy of catfishes. Gymnotiforms lack the claustral cartilage and claustrum. We review all previous hypothesis of claustrum homology in light of the above findings and conclude that the most plausible hypothesis is the one originally proposed by Bloch ([1900] Jen Z Naturw 34:1-64) that claustra are homologs of the supradorsals of the first vertebra.
我们对硬骨鱼亚纲所有亚群的代表动物进行了比较，研究了屏状核的个体发育。鲤形目鱼类的屏状核有一个软骨前体，即屏状软骨，随后它在其前表面通过软骨膜骨化，并形成一个广泛的膜性骨板。屏状核的膜性骨成分及其与奇静脉心房（韦氏器的一个外淋巴间隙）的紧密联系，都是鲤形目的共有衍征。脂鲤目的屏状核并非由软骨预先形成，而是起源于膜性骨的骨化，这可能是该分类单元的共有衍征。在鲇形目中，屏状核仅存在于更基部的类群中，起源于一块细长的软骨，并沿特征性的腹背方向骨化，这可能是鲇形目的共有衍征。裸背电鳗目鱼类没有屏状软骨和屏状核。我们根据上述发现重新审视了以往所有关于屏状核同源性的假说，并得出结论，最合理的假说是布洛赫（[1900]《耶拿自然科学杂志》34:1 - 64）最初提出的，即屏状核与第一椎骨的上背片是同源的。
