Dissertation Research: Scorpionfish (Telostei: Scorpaenoidei) Phylogenetics and the Evolution of Venom in Fishes

毒液和毒液输送系统在从水母到蝎子、蜘蛛、蜥蜴、蛇甚至灵长类动物的动物群体中进化。令人惊讶的是，蛇并不是种类最多、数量最多的有毒脊椎动物，因为有1400多种有毒鱼类，占所有带刺有毒动物的70%以上。也许同样令人惊讶的是，直到现在，科学家们才开始进行第一次详细的研究，以检验毒液作为鱼类的一种防御性特化的进化。在十类有毒鱼类中，蝎子鱼是本研究的重点。这是因为这一类是有毒海洋鱼类中最多样化的一类。它还包括一些世界上最常见的有毒鱼类(狮子鱼和火鸡鱼，它们很受水族学家的欢迎)以及最致命的(石鱼，它可以杀死不幸踩到一条鱼的成年人)。蝎鱼之间的进化关系一直存在争议，但严格的系谱是更广泛地研究它们的毒液和毒液输送系统的关键第一步。为了建造这样一棵树，这项研究将利用幼体和成体解剖学以及线粒体和核DNA序列的证据，对100多种蝎鱼及其相关群体进行比较研究。由此产生的树不仅将被用来检验关于毒液进化的相互竞争的假说，还将被用来研究解剖多样性和蝎鱼活产的进化。这项研究有三个具体的更广泛的影响：1)解剖学和分子生物学方面的博士生培训；2)关于许多商业捕捞的蝎鱼物种水平关系的详细信息，如加州石斑鱼；这是一个重要的目标，因为蝎鱼占美国捕捞鱼类的9%以上，正变得越来越濒危或受到世界各地的威胁；3)为在筛选毒液时做出知情选择提供一个框架；其他动物的毒液已被证明具有突出的药用价值，但对鱼类的这种调查还处于幼年阶段，一棵蝎鱼树可以迅速启动对其毒液的有前途的生物勘探。

Venom and venom delivery systems have evolved in animal groups ranging from jellyfishes to scorpions, spiders, lizards, snakes and even primates. Surprisingly, snakes are neither the most diverse or most abundant group of venomous vertebrates, for there are more than 1,400 species of venomous fishes, which account for more than 70% of all venomous animals with backbones. It is perhaps equally surprising that only now are scientists undertaking the first detailed studies to examine the evolution of venom as a defensive specialization in fishes. Among the ten groups of venomous fishes, scorpionfishes are the focus of the present study. This is because this group is the most diverse group of venomous marine fishes. It also includes some of the world's most familiar venomous fishes (lionfishes and turkeyfishes, which are very popular with aquarists) as well as the most deadly (stonefishes, which can kill an adult human unfortunate enough to step on one). Evolutionary relationships within scorpionfishes have been contentious, yet a rigorous family tree is the critical first step to broader study of their venom and venom delivery systems. To build such a tree, this study will undertake a comparative study of more than 100 species of scorpionfishes and related groups using evidence from larval and adult anatomy and mitochondrial and nuclear DNA sequences. The resulting tree will be used not only to test competing hypotheses about the evolution of venom, but will also examine anatomical diversification and the evolution of live birth in scorpionfishes. This study has three specific broader impacts: 1) training of a doctoral student in anatomy and molecular biology; 2) detailed information on species-level relationships of the many commercially harvested species of scorpionfishes such as California rockfishes; this is an important goal given that scorpionfishes represent more than 9% of harvested fish in the Unites States and are becoming increasingly endangered or threatened worldwide; 3) provision of a framework for making informed choices of species when screening venoms for potential pharmaceutical applications; venoms of other animals have proven to be of outstanding pharmaceutical importance, yet such investigations of fishes are in their infancy and a tree of scorpionfishes could jump-start promising bioprospecting of their venoms.