Geerinckx Tom, Brunain Marleen, Adriaens Dominique
Evolutionary Morphology of Vertebrates, Ghent University, Belgium.
J Morphol. 2005 Dec;266(3):331-55. doi: 10.1002/jmor.10381.
The chondrocranium of the suckermouth armored catfish Ancistrus cf. triradiatus was studied. Its development is described based on specimens ranging from small prehatching stages with no cartilage visible, to larger posthatching stages where the chondrocranium is reducing. Cleared and stained specimens, as well as serial sections, revealed a cartilaginous skeleton with many features common for Siluriformes, yet several aspects of A. cf. triradiatus are not seen as such in other catfishes, or to a lesser extent. The skull is platybasic, but the acrochordal cartilage is very small and variably present, leaving the notochord protruding into the hypophyseal fenestra in the earlier stages. The ethmoid region is slender, with a rudimentary solum nasi. A lateral commissure and myodomes are present. The larger posterior myodome is roofed by a prootic bridge. The maxillary barbel is supported by a conspicuous cartilaginous rod from early prehatching stages. The ceratohyal has four prominent lateral processes. Infrapharyngobranchials I-II do not develop. During ontogeny, the skull lengthens, with an elongated ethmoid, pointing ventrally, and a long and bar-shaped hyosymplectic-pterygoquadrate plate. Meckel's cartilages point medially instead of rostrally.
对吸口甲鲶属近似三棘吸口鲶（Ancistrus cf. triradiatus）的软骨颅进行了研究。根据标本描述了其发育过程，这些标本涵盖了从孵化前软骨不可见的小阶段到软骨颅正在退化的较大孵化后阶段。透明和染色标本以及连续切片显示出一个具有许多鲶形目常见特征的软骨骨骼，但近似三棘吸口鲶的几个方面在其他鲶鱼中未见，或程度较轻。头骨为平颅底型，但软颅底软骨非常小且存在变异，在早期阶段脊索突入垂体窗。筛骨区域细长，有一个鼻基板雏形。存在外侧连合和肌窝。较大的后肌窝由前耳桥覆盖。从孵化前早期阶段开始，上颌须就由一根明显的软骨棒支撑。角舌骨有四个突出的外侧突起。下咽骨I-II不发育。在个体发育过程中，头骨变长，筛骨拉长并指向腹侧，舌颌骨 - 翼方骨板长且呈棒状。梅克尔软骨指向内侧而非吻侧。
