棘胸蛙

棘胸蛙（学名："Quasipaa spinosa"），又名石蛤、石鸡、山鸡、石冻、飞鱼、石鳞、石蛙、石蛤蟆、石虾蟆、石坑蛙等，是两栖纲无尾目叉舌蛙科的一种动物。其肉可食用。本物种的中文名称及学名均源于其雄蛙胸前的大型胸棘。其体型在蛙类来说算是大型，因为已知可长至超过，使牠们赢得香港体型最大蛙类的美誉。
分类学.
近年的分子系统发生学分析认为本物种事实上由三条不同的组成。因此，名义上的"Quasipaa spinosa"可能代表一个隐藏物种复合体。谱系在地理上是不同的；在云南省找到一个谱系, 中国东南部（安徽省、 浙江省、福建省北部和江西省)还有一个谱系, 第三个谱系位于中国中南部（南部福建省、江西省、湖南省、广东省和广西壮族自治区）。在该分析中，小棘蛙位于"Quasipaa spinosa"内。。它的复合种是越南的""。
The complete 线粒体DNA (18,012 base pairs in length) of "Quasipaa spinosa" has been sequenced, helping to shed light into the 系统发生树 of "Quasipaa" and related frogs.
分布、栖息地及习性.
本物种栖息于中华人民共和国长江以南（包括香港）地域的山溪水坑内或石洞岩隙中。由于水体相通，估计亦同时分布于越南、老挝及缅甸三国的淡水水域，但缺乏相关文献报告的支持。
习性昼伏夜出，主要食物为昆虫及其幼体。每年11月-翌年4月冬眠。
No certain records exist from Vietnam, earlier records may refer to "" described in 2009 as a new species from that country. It may also have been mixed with "多疣棘蛙" and "双团棘胸蛙".
"Quasipaa spinosa" is associated with rocky streams in evergreen forests and open countryside on hills and mountains. Its altitude range is about above sea level.
形态特征及生命周期.
成年个体体长8-20cm，体重200-350g。背面黑灰色、浅棕色或黄褐色。背面、侧面和四肢皮肤上生有肉疣，有的时候疣上生黑色角质刺。
The most distinctive characteristic of "Quasipaa spinosa" are the keratinized skin spines in the chest of males. It is dark brown in colour, interspersed with dense, yellowish mottling.
"Quasipaa spinosa" are moderately large frogs: males grow to a snout–vent length of about and females to or more, up to in snout–vent length. It is the largest frog in 香港. Later studies has shown that usually males are larger than females, but with considerable overlap between sexes. Body size is positively correlated with maximum temperature and rainfall. Mean body weight among males may reach at least .
"Quasipaa spinosa" breeds in streams, laying the eggs in water under stones. Reproduction takes place in April–October. Male frogs call near slow-flowing sections of streams or around pools adjacent to streams. The advertisement call consists of three to seven notes, the last being the longest. Pairs in are found within the chorus area.
Population demography of "Quasipaa spinosa" has been studied for two populations in the 大帽山 in Hong Kong. These populations exhibit high site fidelity. Populations have low densities (13–42 frogs per 100 m of stream) and female-biased sex ratio. Each female produced an average 1.26 juveniles that survived until the age of 2 years. Annual survival was low, 38–65%.
用途.
因为肉味鲜美，生长速度快而且个大，是主要的食用蛙类之一。
"Quasipaa spinosa" is an important food and medicinal resource in China and considered as a delicacy. Populations are heavily harvested, and overcollection is implicated in population declines. In 江西省 province alone, the value of production of "Quasipaa spinosa" for domestic consumption is of the same magnitude as global trade of frog meat. "Quasipaa spinosa" are also farmed, but farming operations are likely based on tadpoles or juveniles sourced from wild population, instead of captive breeding. Thus, farming may not reduce the pressure on wild populations.
保育.
过往本物种的数量曾经有大量，但由于遭到大量捕杀，目前已被国际自然保护联盟列为易危物种，因为在最近期的三代，其数量已下跌了超过三成。捕杀主要还是被捕获与人类食用；其次是因为农业及水坝的兴建导致的栖息地破坏。当物种的数量变得愈来愈少，即使是中等数量的下跌亦已足以令物种的灭绝风险提过。在中国，棘胸蛙是江西省和安徽省的重点保护野生动物之一。另外自20世纪80年代起，棘胸蛙也被广泛养殖用作食品，以避免野外再有人去捕捉棘胸蛙作食用。
棘胸蛙在中国已被列为国家二级保护野生动物。
寄生虫.
棘胸蛙体内的寄生虫均为纤毛虫，计有多粒韦氏肠肾虫（"Sicuophora multigranularis"，旧作"Wichtermania multigranularis" Xiao et al., 2002）。Wichtherman 根据 Cheng 在福建采集的棘腹蛙体内的标本, 发现棘蛙韦氏肠肾虫（"Wichtermania (Nyctotherus) cheni"）。