浙江丽水虎纹蛙形态特征的两性异形和食性

用数显游标卡尺测量了407只2001—2003年9月下旬至10月上旬浙江丽水罚没的死亡虎纹蛙的体长等10个形态指标,结果表明:雌性成体体长(SUL)大于雄性成体,幼体形态无显著两性差异;ANCOVA去除SUL差异的影响后,雌性成体的头长和后肢长大于雄性成体,前肢长、眼径和耳径则小于雄性成体。前肢两侧对称性的偏移度成体大于幼体,雌性大于雄性;后肢两侧对称性成幼体和两性无显著差异。10个形态指标主成分分析的前三个主成分共解释64·6%的变异:第一主成分中头宽、眼径和耳径,第二主成分中后肢长,第三主成分中眼间距和鼻间距分别有较高的正负载系数。用NikonSMZ-1000解剖镜鉴别277只个体胃内容物中的食物种类,发现其秋季食物以节肢动物为主;成幼体和两性食物生态位宽度为3·42~5·25,食物生态位重叠度较高为0·93~0·98。分析表明,虎纹蛙局部形态特征的两性差异微弱,而体长两性异形差异显著;雌体具有较大的体形与食性无关,而可能与生育力选择的作用有关。     

虎纹蛙选择体温和热耐受性在个体发育过程中的变化

体温是影响变温动物表现的最重要生理学变量。检测了国家二级保护动物虎纹蛙的雌性亚成体、雄性亚成体、幼体和蝌蚪这4个发育阶段的选择体温和热耐受性。单因子方差分析表明,虎纹蛙选择体温、耐受低温、耐受高温和温度耐受范围的组间差异均显著,幼体的选择体温(24.13℃)显著低于雌性亚成体(28.06℃)、雄性亚成体(29.27℃)和蝌蚪(28.23℃),雌性亚成体、雄性亚成体和蝌蚪之间差异不显著;幼体的耐受低温(13.85℃)显著高于雌性亚成体(11.27℃)、雄性亚成体(10.84℃)和蝌蚪(10.74℃),雌性亚成体、雄性亚成体和蝌蚪之间差异不显著;幼体具有显著低的耐受高温(35.48℃)、蝌蚪具有显著高的耐受高温(43.31℃),雌性亚成体(39.55℃)和雄性亚成体(39.02℃)的耐受高温差异不显著;幼体(21.62℃)具有显著小的温度耐受范围、蝌蚪(32.58℃)具有显著大的温度耐受范围,雌性亚成体(28.28℃)和雄性亚成体(28.18℃)的温度耐受范围差异不显著。虎纹蛙幼体和亚成体体温和水温之间在降温速度和升温速度的相关关系均显著。用回归剩余值去除水温变化速度对体温变化的影响,双因子方差分析(降温和升温速度为重复检验设置)表明,幼体的体温变化速度显著大于亚成体,两性亚成体间差异不显著;温度变化类型(降温和升温)和两因子的交互作用对体温变化的影响不显著。基本热生态位分离和体温调节能力的发育限制是形成上述现象的最可能的原因。     

Choice of optimal oviposition sites by Hoplobatrachus occipitalis (Anura: Ranidae) in an unpredictable and patchy environment

 The rock pools on the river bank of the Comoé National Park (West Africa) provide a very diverse and unpredictable environment for anuran larval development. Because rock pools differ considerably in biotic and abiotic parameters, it should be adaptive for reproducing anurans to choose the most suitable oviposition sites. During the beginning of each rainy season (March to May), from 1991 to 1995, we investigated the allocation of breeding sites by Hoplobatrachus occipitalis, counted the number of eggs, and measured several biotic and abiotic factors that might influence the choice of a spawning site. The probability of predation by conspecific cannibalistic tadpoles and the water-holding capacity (WHC) of pools were the best predictor of number of eggs laid. We experimentally investigated the influence of these two parameters on egg-laying and showed that adults potentially can assess the presence, density, and size of tadpoles in pools by chemical cues. Likewise, manipulation of the water-holding capacity caused a rapid change in egg-laying behavior. To assess the risk of desiccation, frogs have to visit familiar pools repeatedly to monitor the decrease in volume over time and thus gain information about the pools’ water-holding capacity. Received: 22 April 1996 / Accepted: 17 July 1996     

虎纹蛙的含肉率及蛙肉和蛙皮氨基酸组成分析

测定了8只人工养殖虎纹蛙的含肉率及氨基酸组成。结果表明,虎纹蛙的含肉率平均为35．27％;蛙肉和蛙皮干物质中水解氨基酸总量分别为71．740％和79．084％,其中必需氨基酸分别为22．95％和15．88％,分别占氨基酸总量的32．00％和20．08％;游离氨基酸中6种呈味氨基酸含量丰富,分别占游离氨基酸总量的45．50％和60．40％;蛙肉和蛙皮限制氨基酸均为缬氨酸,必需氨基酸指数分别为43.83和27．66。认为虎纹蛙是一种营养价值和养殖价值都较高的品种。     

江西赣江源区域两栖动物的群落组成和物种多样性特征

赣江发源于武夷山脉南段西麓的高山岭间,该区域独特的地理环境和气候特征蕴育了丰富的生物多样性。然而关于该区域两栖动物群落组成和物种多样性调查非常匮乏,不利于赣江源头两栖动物物种多样性的保护。于2016年4-9月期间在江西赣江源区域采用样线法调查了两栖动物的资源状况、群落组成及物种多样性特征,比较了它们在山地森林区、丘陵森林与农田区和盆地农田区3类栖息地之间的差异性。结果表明：赣江源区域分布有8科23种两栖动物,新增记录3个物种,包括尖舌浮蛙、寒露林蛙和九龙棘蛙,泽陆蛙和饰纹姬蛙为优势种。赣江源区域的两栖动物群落组成和物种多样性存在显著的季节间差异和栖息地间差异;两栖动物季节性繁殖是造成前者差异的主要因素,而土地利用类型、栖息地特征、空间距离、生活习性的物种特性等因素成就了后者差异的出现。因此,春、夏季一般有比秋季见到更高的两栖动物物种丰富度和多样性;山地森林区的两栖动物物种丰富度和多样性最高,盆地农田区次之,丘陵森林与农田区的最低。山地森林区应成为赣江源区域两栖动物多样性保护的优先区域。国家Ⅱ级重点保护野生动物虎纹蛙,在3类栖息地中均有分布,且在盆地农田区和山地森林区能见到更多个体,但农田区分布的虎纹蛙遭受到更大的威胁,建议加强对农田区虎纹蛙及其栖息地的保护。     

杀虫剂硫丹对中国虎纹蛙的毒性效应： 存活率、红细胞核异常及酶活性

农药的使用对水生动物有直接和间接的影响。本文研究了有机氯杀虫剂硫丹对中国虎纹蛙（Hoplobatrachus chinensis）蝌蚪的毒性效应。具体而言,首先检测了硫丹的安全浓度（SC）,并在急性毒性实验中评估了硫丹的毒性等级。然后检测了外周血液中红细胞核形态异常,并在慢性毒性实验中测定了酸性磷酸酶（ACP）、碱性磷酸酶（AKP）和乳酸脱氢酶（LDH）的活性。结果表明,在急性毒性中,随着硫丹溶液浓度的增加和染毒时间的延长,蝌蚪的平均死亡率显著增加,即蝌蚪存活率取决于农药剂量和染毒的时长。硫丹对中国虎纹蛙蝌蚪的96 h半致死浓度LC50值为23.38 μg/L,安全浓度为2.34 μg/L,为剧毒性农药。在血液红细胞核异常实验中,观察到5种不同类型的细胞核异常：核碎裂、双核、不等分裂、核凹陷和核空洞。血液红细胞核异常率与农药浓度呈正相关。在酶活性检测中,三种酶的活性均受硫丹浓度的影响。与对照组相比,酸性磷酸酶（ACP）和碱性磷酸酶（AKP）活性随硫丹浓度的增加而降低,乳酸脱氢酶（LDH）活性随着硫丹浓度的增加呈先升高后降低。研究结果表明,硫丹对中国虎纹蛙蝌蚪具有很高的毒性,并证明了血液红细胞核异常和特定的代谢酶可以作为环境监测的生物标志物。     

Out of Asia: Mitochondrial DNA Evidence for an Oriental Origin of Tiger Frogs, Genus Hoplobatrachus

Most examples of intercontinental dispersal events after the Miocene contact between Africa and Asia involve mammal lineages. Among amphibians, a number of probably related groups are known from both continents, but their phylogenies are so far largely unresolved. To test the hypothesis of Miocene dispersal against a Mesozoic vicariance scenario in the context of Gondwana fragmentation, we analyzed fragments of the mitochondrial 16S rRNA gene (572 bp) in 40 specimens of 34 species of the anuran family Ranidae. Results corroborated the monophyly of tiger frogs (genus Hoplobatrachus), a genus with representatives in Africa and Asia. The African H. occipitalis was the sister group of the Asian H. crassus, H. chinensis, and H. tigerinus. Hoplobatrachus was placed in a clade also containing the Asian genera Euphlyctis and Nannophrys. Combined analysis of sequences of 16S and 12S rRNA genes (total 903 bp) in a reduced set of taxa corroborated the monophyly of the lineage containing these three genera and identified the Asian genus Fejervarya as its possible sister group. The fact that the African H. occipitalis is nested within an otherwise exclusively Asian clade indicates its probable Oriental origin. Rough molecular clock estimates did not contradict the assumption that the dispersal event took place in the Miocene. Our data further identified a similar molecular divergence between closely related Asian and African species of Rana (belonging to the section Hylarana), indicating that Neogene intercontinental dispersal also may have taken place in this group and possibly in rhacophorid treefrogs.     

Acute and joint toxicity of three agrochemicals to Chinese tiger frog(Hoplobatrachus chinensis) tadpoles

We studied acute and joint toxicity of three different agrochemicals(chlorantraniliprole, flubendiamide-abamectin and penoxsulam) to Chinese tiger frog(Hoplobatrachus chinensis) tadpoles with the method of stability water tests. Results showed that the three agrochemicals increased tadpole mortality. For acute toxicity, the LC50 values after 24, 48 and 72 h of chlorantraniliprole, flubendiamide-abamectin and penoxsulam exposure were 5.37, 4.90 and 4.68 mg/L; 0.035, 0.025 and 0.021 mg/L; 1.74, 1.45 and 1.29 mg/L, respectively. The safety concentrations(SC) of chlorantraniliprole, flubendiamide-abamectin and penoxsulam to the tadpoles were 1.23, 0.30 and 0.003 mg/L, respectively. Based on these findings, chlorantraniliprole and penoxsulam were moderately toxic, while flubendiamide-abamectin was highly toxic. All pairwise joint toxicity tests showed moderate toxicity. The LC50 values after 24, 48 and 72 h of exposure were 7.08, 6.61 and 6.03 mg/L for chlorantraniliprole+penoxsulam, with corresponding values of 2.455, 2.328 and 2.183 mg/L for chlorantraniliprole+flubendiamide-abamectin, and 1.132, 1.084 and 1.050 mg/L for penoxsulam+flubendiamide-abamectin, with safe concentrations of 1.73, 0.63 and 0.30 mg/L, respectively. For toxic evaluations of pairwise combinations of the three agrochemicals, only the joint toxicity of chlorantraniliprole and flubendiamide-abamectin after 24 h was found to be synergistic, whereas all other tests were antagonistic. Our findings provide valuable information on the toxic effects of agrochemicals on amphibians and how various types of agrochemicals can be reasonably used in agricultural areas.     

低温胁迫下虎纹蛙的生存力及免疫和抗氧化能力

全球气候变化是造成世界范围内两栖类种群衰退和灭绝的重要因素之一。随着极端天气出现变得日趋频繁,非季节性的、短期且剧烈的气温变化可能会严重干扰两栖类动物的生存与种群稳定。监测了浙江省金华市南山野生虎纹蛙(Hoplobatrachus rugulosus)分布区冬季的环境气温,并参考监测数据在实验室条件下研究了虎纹蛙在短期梯度降温(2℃/24 h)和急性冷暴露(即冷休克)(2℃)下的生存力及冷休克对机体免疫功能和抗氧化能力的影响。结果表明,虎纹蛙在冬季(2009-12-01—2010-03-31)经历的温度范围普遍在0—14℃之间,主要遭遇的低温区间在0—4℃,主要高温区间在10—14℃。通过梯度降温实验,发现温度降至12℃累积死亡率约为28.1%,10℃为87.5%,8℃为100%。在一定温度范围内,虎纹蛙死亡率与环境温度呈显著负相关(Pearson test,r=-0.952,P<0.05)。经曲线拟合,回归方程计算可得半数致死温度为11.5℃。虎纹蛙在冷休克处理下,在第6 h累积死亡率为45%,12 h为80%,24 h达到100%。虎纹蛙死亡率与冷休克时间呈显著正相关(Pearson test,r=0.91,P<0.05),半数致死时间为7.6 h。此外,冷休克(2℃,6 h)显著抑制了虎纹蛙脾脏巨噬细胞呼吸爆发强度(t=3.827,df=6,P<0.05)、全血吞噬活性(t=5.388,df=3.037,P<0.05)及胃溶菌酶活力(t=6.37,df=6,P<0.05);肝脏(t=0.773,df=8,P>0.05)和肾脏(t=0.164,df=4.542,P>0.05)组织脂质过氧化物产物丙二醛(MDA)的含量虽无明显变化,但肝脏(t=-2.817,df=6,P<0.05)和肾脏(t=-11.302,df=6,P<0.05)组织抗氧化物谷胱甘肽(GSH)含量及肝脏(t=-3.3,df=6,P<0.05)超氧化物歧化酶(SOD)活性均显著升高。上述结果表明虎纹蛙对低温较为敏感,冷休克能够诱导机体的免疫抑制,并导致机体对抗氧化物质需求的增加。可以推测,当遭遇极端低温天气时,低温胁迫可能会严重干扰虎纹蛙生理机能,加大种群的生存压力和疾病感染的风险。     

虎纹蛙繁殖季节的求偶鸣叫特征(英文)

对交配季节虎纹蛙求偶鸣叫进行录制和特征分析。分析结果表明,虎纹蛙求偶鸣叫主要集中在晚上,求偶鸣叫声音主要含有3个鸣叫谐波,鸣叫主频率共有4种类型,即在第一谐波上有3个主频率段,分别为500、700和800Hz段,在第二谐波上有1个主频率段,即1800Hz段。鸣叫时程(call duration)、能环率(call dutycycle)、声强(call intensity)和鸣叫脉冲率(pulse rate)在4种主频率中变化很大。这些鸣叫参数特征的分析将对虎纹蛙生理生态学的进一步研究提供有价值的基础数据。