Eggcases of eight rajiform skates (Dipturus nidarosiensis, D. oxyrinchus, Leucoraja melitensis, Raja asterias, R. brachyura, R. clavata, R. miraletus and R. polystigma) present in the central-western Mediterranean are described, based on specimens obtained from fishery surveys. Eggcase features such as dimensions, horns and apron lengths, and presence/absence of lateral keels were crucial to discriminate the eggcases of the various species. Morphological and morphometric data, confirmed by the multivariate analysis, indicated that the eggcase of R. miraletus and L. melitensis were distinct from those of the other species for being unkeeled. Within the species having keeled eggcases, those of the genus Dipturus and R. brachyura were discriminated from the remaining group by having the largest dimensions and aprons. Sandy bottoms (<100–150 m depth) were identified as egg-laying sites (i.e. sites with females bearing eggcases in uteri) for many species belonging to genus Raja Raja asterias, R. brachyura, R. miraletus and R. polystigma). The finding of R. asterias and R. miraletus carrying eggcases yearly on the same sites, seems to confirm the theory that many rajid species demonstrate site fidelity, returning to the same depositional area on an annual basis. Some remarks on reproductive biology of these skates are also provided. The eggcase identification key reported here represents the first for the Mediterranean and may be useful, in the future, to identify egg-laying grounds of skates with a nonlethal method.

中文翻译：

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地中海中西部地区冰鞋（Rajidae）蛋壳的形态学描述，并注明其分布

根据从标本获得的标本，描述了地中海中部地区存在的八种rajiform滑冰鞋（Dipturus nidarosiensis，D。oxyrinchus，Leucoraja melitensis，Raja asterias，R。brachyura，R。clavata，R。miraletus和R. polystigma）的蛋箱。渔业调查。蛋箱的特征，例如尺寸，角和围裙的长度以及侧龙骨的存在/不存在对于区分不同种类的蛋箱至关重要。通过多变量分析证实的形态学和形态计量学数据表明，米勒罗非鱼和melitensis的蛋壳与其他物种的蛋壳是不带龙骨的。在具有龙骨蛋壳的物种中，Dipturus和R. brachyura属的那些具有最大的尺寸和围裙，与其余的族群区分开。桑迪底部（< 100-150 m深度）被确定为许多属于Raja Raja asterias属，R。brachyura，R。miraletus和R. polystigma的物种的产卵位点（即，雌性在子宫中带有蛋壳的位点）。每年在同一地点发现带壳蛋壳的天体小食蟹和miraletus的事实，似乎证实了许多拉吉德物种表现出地点保真度的理论，并每年返回相同的沉积区域。还提供了有关这些溜冰鞋生殖生物学的一些评论。此处报告的蛋盒识别码代表了地中海地区的第一个，将来可能会用非致命方法识别溜冰鞋的产卵场。miraletus和R. polystigma）。每年在同一地点发现带壳蛋壳的天体小食蟹和miraletus的事实，似乎证实了许多拉吉德物种表现出地点保真度的理论，并每年返回相同的沉积区域。还提供了有关这些溜冰鞋生殖生物学的一些评论。此处报告的蛋盒识别码代表了地中海地区的第一个蛋盒识别码，将来可能会用非致命方法识别溜冰鞋的产卵场。miraletus和R. polystigma）。每年在同一地点发现带壳蛋壳的天体小食蟹和miraletus的事实，似乎证实了许多拉吉德物种表现出地点保真度的理论，并每年返回相同的沉积区域。还提供了有关这些溜冰鞋生殖生物学的一些评论。此处报告的蛋盒识别码代表了地中海地区的第一个蛋盒识别码，将来可能会用非致命方法识别溜冰鞋的产卵场。