“吸血鬼鱼”身长0.6英寸(约合17毫米)
“吸血鬼鱼”的獠牙
这条鱼是过去几十年来发现的最非比寻常的脊椎动物之一
英国动物学家3月11日表示，他们在缅甸北部河流中发现了一条长着“吸血鬼一般牙齿”的小鱼。
这条学名为“Danionella dracula”(达尼埃拉·德拉库拉，西方传说中吸血鬼的名字)的小鱼身长0.6英寸(约合17毫米)，属于鲤形目(Cypriniform)家族，这个家族的成员长得都像鲤鱼。据悉，“吸血鬼鱼”是在2007年4月发现的，但直到现在才被正式命名为一个新鱼种。英国伦敦自然历史博物馆动物学家拉尔夫·布里茨(Ralf Britz)博士称这条通体透明的小鱼“非比寻常”。
布里茨说：“这条鱼是过去几十年来发现的最非比寻常的脊椎动物之一。Danionella dracula长有牙齿确实让我们大吃一惊，因为在鲤形目家族的其它3700个种类中，颌部都没有长牙齿。事实上，它们在大约5000万年前始新世早期便失去了牙齿。然而，Danionella dracula却进化出自己的像吸血鬼一样的牙齿结构，它们的牙齿是从颌骨长出来的，不是不断进化的颌牙。”
伦敦自然历史博物馆宣称，尽管这条鱼体型小的令人惊异，但Danionella dracula并不是世界上最小的鱼——这一头衔属于只有0.3英寸(约合7.6毫米)长的Paedocypris progenetica，这种鱼同样属于鲤形目家属。这项发现刊登在最新一期国际生物研究期刊英国《皇家学会学报B》（Proceedings of the Royal Society B）上。（生物谷Bioon.com）
生物谷推荐原始出处：
Spectacular morphological novelty in a miniature cyprinid fish, Danionella dracula n. sp.
Ralf Britz1,*, Kevin W Conway2 and Lukas Rüber1
1Department of Zoology, The Natural History Museum Cromwell Road, London SW7 5BD, UK
2Department of Biology, Saint Louis University 3507 Laclede Avenue, St Louis, MO 63103-2010, USA
Abstract
Danionella dracula is a new species of sexually dimorphic, miniature and highly developmentally truncated cyprinid fish. Compared with its close relative, the zebrafish Danio rerio, it lacks 44 bones or parts thereof and represents one of the most developmentally truncated vertebrates. Absence of the majority of bones appears to be due to developmental truncation via terminal deletion. In contrast to these larval-like features, D. dracula also shows several hyperossifications. Uniquely, among carp-like fishes, male D. dracula have a series of long, pointed odontoid processes on the jaws greatly resembling the jaw dentition of teleosts with true teeth. The anterior-most process in each jaw is extended as a canine-like fang projecting through the epithelium. True jaw teeth are absent from all 3700 species of cypriniforms and were lost at least in the Upper Eocene. It remains to be investigated, however, whether the conserved pathways to regulate tooth development in cypriniforms have been used in D. dracula to form and pattern the odontoid processes. This new species represents a remarkable example linking progenetic paedomorphosis via heterochronic change in developmental timing to the evolution of morphological novelties.
