隆肛蛙属种群形态量度分析

对隆肛蛙属Feirana中隆肛蛙F.quadrana和太行隆肛蛙F.taihangnicus的15个种群565只标本的28项形态性状进行了测量,并运用典型判别分析法对其进行分析,分析结果表明:1)太行隆肛蛙和隆肛蛙的形态差异明显,形态度量信息支持太行隆肛蛙与隆肛蛙是不同的物种;2)原隆肛蛙河南伏牛山种群和山西中条山种群均为太行隆肛蛙的地理种群;3)隆肛蛙的种群间形态差异明显,其中四川安县种群、陕西周至种群和湖北利川种群与模式产地重庆巫山种群的差异可能达到了亚种或亚种以上分化水平.     

隆肛蛙

从2010年5月开始,对分布在甘肃省天水市利桥乡的隆肛蛙进行了包括生态习性、繁殖情况在内的调查,并了解其贸易状况及相关价值;调查发现:隆肛蛙在生态学和商业方面都具有较高的价值,应在保护的前提下进行合理的开发利用.     

隆肛蛙皮肤及其腺体的显微结构特征

观察了隆肛蛙(Paa quadranus)皮肤及其腺体的显微结构特点,主要对成体、幼蛙和蝌蚪泄殖腔上方皮肤腺进行了描述和比较。结果表明,隆肛蛙的表皮和真皮内均分布有微血管及黑色素细胞;皮肤腺为泡状腺,腺泡位于真皮浅层的疏松层内,属顶质分泌的粘液腺;雄性成体泄殖腔上方皮肤腺是隆肛蛙的特有结构,属于雄性的第二性征,本文建议称其为肛上腺(supra-anal gland)。文中对肛上腺及其机能、表皮中微血管与皮肤呼吸、黑色素细胞与体温调节等之间的关系进行了讨论。     

秦岭山区隆肛蛙胚后发育的初步观察

初步观察记录了秦岭山区隆肛蛙Feirana quadrana胚后发育过程.隆肛蛙蝌蚪的头长、体长、尾长和后肢长度随发育时间的增加而显著增长.将隆肛蛙的胚后发育过程划分为20期.其蝌蚪在发育中体色、荚膜(皮肤褶)、侧线以及唇齿式等结构都发生了相应的变化.唇齿式由以II∶ 5-5/II∶ 1-1型为主演变为以II∶ 6-6/II∶ 1-1、I∶ 6-6/II∶ 1-1和II∶ 5-5/II∶ 1-1型为主.     

叶氏隆肛蛙(无尾目,蛙科)的补充描述

对采自河南省商城县隆肛蛙标本进行了形态学研究,发现该标本在形态上与巫山隆肛蛙及太行隆肛蛙Paa(Feirana)taihangnicus存在明显差异,定为1新种,即叶氏隆肛蛙Paa(Feirana)yei.文中对该种作了详细记述.     

康县隆肛蛙的两性异形

测量和比较了采自甘肃省康县的康县隆肛蛙Feirana kangxianensis标本共计90只(雌性48只,雄性42只)。结果表明,康县隆肛蛙成体的头体长、头长、头宽、吻长、鼻间距、眼间距、眼径、鼓膜长、前臂及手长、后肢全长、手长、足长的形态特征在两性间的差异有统计学意义。以头体长为协变量的协方差分析显示,康县隆肛蛙两性的差异均有统计学意义,异形指数达到0.08,雌性与雄性的平均头体长比值为1.091。对所有测量的形态特征与头体长进行一元线性回归分析表明,雌性康县隆肛蛙局部形态特征的生长速度明显大于雄性,其中,吻长、眼间距、眼径、鼓膜长、前臂及手长、手长的两性差异最明显。生育力选择假设能解释康县隆肛蛙的两性异形现象。     

太行隆肛蛙的早期胚胎发育及生态适应性

报道了在自然条件下太行隆肛蛙(Feirana taihangnicus)早期胚胎发育的过程。根据胚胎外部形态变化、主要生理特征及行为的出现,其早期胚胎发育过程可划分为25个时期。在水温11.0～18.0℃下,从受精卵形成至蝌蚪两侧鳃盖完全闭合、出水管形成为止,共历时470.18 h。卵裂开始时集中在动物极顶端,直到囊胚早期植物极才出现分割线;胚体的出膜时间集中在右侧鳃盖闭合期,出膜后即具备主动取食的能力,属于晚出膜类型;隐蔽的产卵环境、特殊的卵群附着方式以及大卵径、高卵黄量,是太行隆肛蛙对低温条件下早期胚胎发育时程长的生态适应。     

太行隆肛蛙补充描述(无尾目,蛙科)

对采自我国河南济源市邵原镇太行山的隆肛蛙标本进行了形态学观察分析,发现该地标本在形态上与模式产地巫山隆肛蛙标本及其它种群存在明显差异,这表明太行山的隆肛蛙应是一独立种,即太行隆肛蛙Paa(Feirana)taihangnicus.本文对该种进行了详细的记述,并依据遗传学资料做了相应的分类讨论.     

太行隆肛蛙骨骼系统的解剖

对太行隆肛蛙的骨骼系统进行了详细的观察和描述:鼻骨较大,蝶筛骨在背而部分显露,额顶骨前后几等宽,前耳骨大.舌骨体宽明显大于长.上胸软骨小于剑胸软骨,肩胸骨基部不分叉,与中胸骨几等长,剑胸软骨呈扇形状,后端有缺刻.第8椎体为舣凹型椎体,肩带固胸型.     

叶氏肛刺蛙消化道两种内分泌细胞的研究

应用免疫组织化学方法对叶氏肛刺蛙Yerana yei胃肠道2种内分泌细胞的形态和分布进行研究.5-羟色胺(5-hydroxytryptamine,5-HT)免疫活性细胞分布于消化道各段,胃幽门分布密度最高,然后向两端递减,整个分布曲线大致呈倒"V"字型;生长抑素(somatostain,SS)细胞在消化道各段均有分布,胃幽门最高,除胃贲门处稍高于胃体处外,从幽门向两端递减.5-HT和sS细胞都形态多样,有圆形、卵圆形、锲形、梭形和长柱状等.消化道内分泌细胞的分布差异可能与其食性和生活习性有关;两栖类各物种间内分泌细胞的分布存在差异.     

Altitudinal Variation in Digestive Tract Lengh in Feirana quadranus

Selective pressures favor variation in organ size in response to environmental changes and evolutionary process. In particular, changes in environmental temperature and rainfall at different altitudes often affect food resources, thereby mediating energy intake and allocation. The digestive tract provided a functional relationship between energy intake and allocation, of which gut morphology was associated with diet changes and food quality under different environments. Here we studied altitudinal variation in the digestive tract across four Feirana quadranus populations and tested the hypothesis that relative size of digestive tract should increase with increasing altitude. The results showed that although significant variation in length of the digestive tract was observed in females among populations, altitudinal variation in relative length of digestive tract or gut was non-significant. In addition, the digestive tract length was not correlated with temperature and precipitation across the four populations. Our findings suggest that individuals living in low-temperature and-precipitation populations at high altitudes did not display longer digestive tract than high temperature and precipitation populations at low altitudes, possibly because of small populations or sample sizes.     

No Evidence for the Compensation Hypothesis in the Swelled Vent Frog(Feirana quadranus)

The compensation hypothesis predicts that if the left testis is defective e.g. due to developmental stress,the increased right testis serves a compensatory role, and thereby displaying testes asymmetry which can be a reliable indicator of male body condition. Here, to test the prediction of the compensation hypothesis, we analyzed difference in size between left testis and right testis and the relationship between testes asymmetry and male body condition in the swelled vent frog(Feirana quadranus).We found that the left testis was larger than right testis,displaying a significant directional asymmetry in testes size. Although testes mass was correlated with body condition, testes asymmetry was not correlated with body condition, which cannot provide evidence that the right testis had a compensatory function. Our findings suggest no evidence for the compensation hypothesis in this species due to lacking the compensatory function in right testis.     

Postglacial Colonization of the Qinling Mountains: Phylogeography of the Swelled Vent Frog (Feirana quadranus)

Background

The influence of Pleistocene climatic fluctuations on intraspecific diversification in the Qinling–Daba Mountains of East Asia remains poorly investigated. We tested hypotheses concerning refugia during the last glacial maximum (LGM) in this region by examining the phylogeography of the swelled vent frog (Feirana quadranus; Dicroglossidae, Anura, Amphibia).

Methodology/Principal Findings

We obtained complete mitochondrial ND2 gene sequences of 224 individuals from 34 populations of Feirana quadranus for phylogeographic analyses. Additionally, we obtained nuclear tyrosinase gene sequences of 68 F. quadranus, one F. kangxianensis and three F. taihangnica samples to test for mitochondrial introgression among them. Phylogenetic analyses based on all genes revealed no introgression among them. Phylogenetic analyses based on ND2 datasets revealed that F. quadranus was comprised of six lineages which were separated by deep valleys; the sole exception is that the Main Qinling and Micang–Western Qinling lineages overlap in distribution. Analyses of population structure indicated restricted gene flow among lineages. Coalescent simulations and divergence dating indicated that the basal diversification within F. quadranus may be associated with the dramatic uplifts of the Tibetan Plateau during the Pliocene. Coalescent simulations indicated that Wuling, Daba, and Western Qinling–Micang–Longmen Mountains were refugia for F. quadranus during the LGM. Demographic analyses indicated that the Daba lineage experienced population size increase prior to the LGM but the Main Qinling and the Micang–Western Qinling lineages expanded in population size and range after the LGM, and the other lineages almost have stable population size or slight slow population size decline.

Conclusions/Significance

The Qinling–Daba Mountains hosted three refugia for F. quadranus during the LGM. Populations that originated in the Daba Mountains colonized the Main Qinling Mountains after the LGM. Recent sharp expansion of the Micang–Western Qinling and Main Qinling lineages probably contribute to their present-day secondary contact.     

Role of CDMP-1 in Skeletal Morphogenesis: Promotion of Mesenchymal Cell Recruitment and Chondrocyte Differentiation

Cartilage provides the template for endochondral ossification and is crucial for determining the length and width of the skeleton. Transgenic mice with targeted expression of recombinant cartilage-derived morphogenetic protein-1 (CDMP-1), a member of the bone morphogenetic protein family, were created to investigate the role of CDMP-1 in skeletal formation. The mice exhibited chondrodysplasia with expanded cartilage, which consists of the enlarged hypertrophic zone and the reduced proliferating chondrocyte zone. Histologically, CDMP-1 increased the number of chondroprogenitor cells and accelerated chondrocyte differentiation to hypertrophy. Expression of CDMP-1 in the notochord inhibited vertebral body formation by blocking migration of sclerotome cells to the notochord. These results indicate that CDMP-1 antagonizes the ventralization signals from the notochord. Our study suggests a molecular mechanism by which CDMP-1 regulates the formation, growth, and differentiation of the skeletal elements.     

Morphogenesis of the Acanthocephala

Postzygotic development of acanthocephalans is described. The major conclusion that can be drawn is that there has been a great deal of speculation, and that there are still many questions left unanswered. For example, exactly when does the acanthor become a complete syncytium? Is the formulation of the central nuclear mass really homologous to gastrulation, and does this mass really represent endoderm? What is endoderm in an animal with no trace of a digestive system? What is the significance, if any, of the 90 degree change in polarity from the acanthor to the adult? How do a few giant nuclei determine the fate and function of a massive synctial body? These and other questions continue to intrigue and perplex the investigator. Perhaps by the time of ICOPA-VII we will have some of the answers.