Morphological variation does not influence locomotor performance within a cohort of hatchling lizards (Amphibolurus muricatus, Agamidae)

A causal link between morphology and performance is a central tenet of ecomorphological analyses, but there are few detailed analyses of exactly how morphological variation within a hatchling cohort maps onto locomotor performance, and especially whether or not different tasks favour different morphologies (or vice versa). We measured morphological traits (including body length, mass, head size, limb proportions and fluctuating asymmetry [FA]) on a large sample of laboratory-incubated hatchling lizards ( Amphibolurus muricatus , Agamidae), and used principal component analysis to reduce this data set to four major axes of variation (size, shape and two FA axes). Running speeds of each lizard were measured on raceways at four inclines, from level (0°) through to steep (45°). Unsurprisingly, steeper inclines reduced locomotor speeds. Absolute body size was the only morphological trait that was consistently related to sprinting performance, and the relationships were similar at each incline. Within-cohort variation in body shape and FA among this large sample was unrelated to locomotor speeds, thus challenging the common assumption of a causal link between these variables. The only exception was a weak trend for greater hind limb length to enhance locomotor performance more at steep inclines than at shallower angles. In general, our data suggest that different morphological traits do not differentially maximize locomotor performance up variable inclines. Overall, our data provide a cautionary note about the generality of causal connections between within-cohort morphological variation and locomotor performance under different environmental contexts.     

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.     

大蹼铃蟾的两性异形

2018年6—8月,测量采自云南省昆明市金殿水库后山的71只(47♂,24♀)大蹼铃蟾Bombina maxima成体的体长、头长、头宽等15项形态特征指标并检验该物种的两性异形。结果表明:雄性平均体长为53.54 mm±1.14 mm,雌性平均体长为52.74 mm±1.45 mm,雄性与雌性平均体长比为1.015,两性异性指数为0.01;大蹼铃蟾的体长、体质量与性别之间的差异无统计学意义;除了雌性的眼间距外,其余13项形态特征与体长均有极显著相关性;以体长为协变量的协方差分析结果显示,大蹼铃蟾的头长、吻长、前臂宽、腿或后肢全长、胫长、胫宽和跗足长在两性间的差异有高度统计学意义;雄性的这7项形态特征随体长的生长速率大于雌性。性选择假说能解释大蹼铃蟾的两性异形现象。     

两种穿山甲外形量衡度的测定及比较

There are 7 species of pangolin in the world. This paper deah with the measurement of some morphology indices in Manis petadactyla and Mania javanica. Measured variables included the body weight, the total body length, the length of head and body, the length of tail,the length of protruding rim of external ear, the length of hind feet, the length of middle claws of fore feet, the length of middle claws of hind feet, the number of rows of scales round mid-body, the number of single flank scales of edge tail. All variables measured were compared respectively between this 2 species. The results indicated that: ( 1 ) there were no signifieant differences in body weight and length of hind feet between this 2 species, but differences in the other variables were extremely significant. (21 The ratio of the length of middle claws of hind feet and fore feet in Mania pentadactyla was less than 1/2 ( n = 48 ), while Mania jaw, nica was more than 1/2 ( n = 15 ) ; the length of protruding rim of external ear in Mania pentadactyla was over 10 mm { n = 38 ), whereas Manis javanica was under 10 mm { n = 13 ) ; the number of single flank scales of edge tail in Mania pentadactyla was not beyond 21 (n = 65), and Mania javanica exeeeded 21 (n = 14) . So the ratio of the length of middle claws of hind feet and fore feet, the length of protruding rim of external ear, arid the ntunber of single flank scales of edge tail should be regard as distinctive features and taxonomic indices between this 2 species. (3) The relationships between body weight ( Y) and the total body length, the length of head and body, the length of tail {X) were positive correlation, and satisfied relation equation Y= aX^b.     

粤北山区饰纹姬蛙胚后发育的初步观察

初步观察记录了饰纹姬蛙Microhyla ornata胚后发育过程。饰纹姬蛙的卵采于广东韶关小坑国家森林公园,置于人工实验缸中自然孵化,在23.0～28.7℃水温条件下观察饰纹姬蛙蝌蚪胚后发育的过程。该蛙的胚后发育可以分为19期,历时31.1d,对其后肢芽、趾、前肢的发育,以及肛管及尾的变化等方面做了系统的描述,饰纹姬蛙蝌蚪的头长、体长、尾长和后肢长度随发育时间的增加而显著增长。     

Analysis of tadpole growth following gamma-ray irradiation

This investigation reports observations on the growth of Rana cyanophlyctis tadpoles following a whole body gamma-ray exposure. The effect on the body and hind limb size is perhaps the most significant of the period of latency. A dose of 2,000 R serves as a stressor and activates ACTH secretion in the tadpoles. The resultant somatotrophic hormone (STH) inhibition and subsequent recovery during the following days seem an integral part of the radiation syndrome.     

Morphological correlates of locomotor performance in hatchling Amblyrhynchus cristatus

Previous studies of locomotor performance from a variety of perspectives often assumed that speed and limb length were strongly correlated. Despite support of this assumption from biomechanical models, few empirical studies have demonstrated a significant relationship between measures of locomotor capacity, such as maximum velocity, and length of the hindlimb at either the inter- or intra-specific level. We examined whether one measure of locomotor performance, maximum velocity, correlates with body size and elements of the hindlimb in hatchling marine iguanas (Amblyrhynchus cristatus). Larger hatchlings ran faster. Removing the effects of body size revealed that relative lengths of the tibia and hindfoot correlated with size-adjusted maximum velocity. Individuals with relatively long tibia and short pes were relatively faster than individuals with short tibia and long pes. Functional morphological analyses predict that femur length should correlate with maximum velocity. However, our analyses failed to support this prediction. Because hatchling marine iguanas exploit relatively open habitats, the relationship between maximum velocity and limb morphology may be interpreted as an adaptation enhancing escape from predators.     

Simultaneous induction of ectopic pelvic zone and duplication of regenerated limbs in tadpoles of Polypedates maculatus by vitamin A

With a view to determine ectopic limb developing capacity along with normal hind limb regeneration in response to vitamin A palmitate in well-differentiated hind limb stage tadpoles of P. maculatus, higher doses of vitamin A (30 IU/ml and 20 IU/ml) were administered for a longer period (120 hr) to the tadpoles following tail amputation through middle and hind limb amputation through middle of thigh. Simultaneous development of ectopic pelvic zone was observed along with hind limbs from the cut end of tail and duplication of regenerated hind limbs in the same tadpole for the first time. Besides, development of double ectopic pelvic girdle was also reported in one case. Results also indicate that induction of pelvic zone and duplication of regenerated limbs are concentration dependent.     

Parthenogenetic reproduction in the neotropical unisexual lizard,Gymnophthalmus underwoodi (Reptilia: Teiidae)

All adult specimens known for Gymnophthalmus underwoodi are females, and their mode of reproduction has been a mystery. In order to rule out the possibility of a bisexual mode of reproduction by means of mating with undiscovered males, hermaphroditism, or sex reversal during ontogeny, we examined hundreds of serial histological sections of complete reproductive tracts from juveniles and adults representing two generations of a lineage raised in captivity. In addition, comparative dissections were performed on other individuals and other species, and reproduction to the F₅ generation was documented in laboratory colonies of G. underwoodi established from Trinidad and Surinam stocks. A lineage of three successive generations was produced entirely by individuals that were maintained in isolation from the moment of hatching. All specimens of G. underwoodi proved to be female, with reproductive anatomy identical to that of females of closely related, bisexual species of Gymnophthalmus: G. pleei and G. speciosus. Thus, G. underwoodi is an all-female species that reproduces by means of strict parthenogenesis, in the absence of sperm. As in the macroteiids of the genus Cnemidophorus studied previously, Gymnophthalmus has functional mesonephric kidneys throughout life. G. underwoodi ranks among the smallest amniotes, adults weighing about 1.2 gm and having a body length of 36–43 mm. Data from the laboratory colonies indicate the following: clutch size, 1–4 (X = 2); mean egg size about 9.4 × 6.5 mm (weight, 0.23 gm); development time, up to 61 days or more; hatchling body length, 16–19 mm (X = 18); hatchling tail length, 18–25 mm (X = 22); hatchling weight, 0.09–0.14 gm (X = 0.115); reproduction continuous year round with individuals able to produce successive clutches in less than a month but quiescent periods following reproductive sessions; maturity attainable seven mo after hatching; longevity at least 4 yr and 5 mo; and a dramatic decline occurred in egg viability in successive generations in the laboratory.     

Does metatarsal/femur ratio predict maximal running speed in cursorial mammals?

We tested the hypothesis that hind limb proportions may be used to predict locomotor performance in a sample of 49 species of primarily cursorial mamals. Data on maximal sprint running speeds taken from published sources were related to measurements of hind limb lengths. To control for statistical complications due to the hierarchical nature of phylogenetic relationships, we used Felsenstein's (1985) independent contrasts method for analysing comparative data, and a composite phylogeny for all 49 species, based on a variety of published sources. The independent contrasts method indicates that maximal running speed does not covary significantly with body mass for this sample of mammals (mass range= 2.5–2,000 kg). Even though quality of the available speed data is highly variable, both metatarsal/femur ratio—the traditional index of 'cursoriality' in mammals—and hind limb length (corrected for body size) are significant predictors of maximal running speed. When only fully curorial species are included in the analyses (n = 32), hind limb length still significantly predicts speed (r²= 16%), but MT/F ratio does not. Although ungulates tend to have larger MT/F ratios than do Carnivora, they are not generally faster; relatonships between speed and limb proportions within the two clades show no significant differences. These and previous results suggest that hind limb proportions and maximal running speed may not have evolved in a tightly coupled fashion. Prediction of locomotor performance of extinct forms, based solely on their limb proportions, should be undertaken with caution.     

Increased SCE levels in Mediterranean Italian buffaloes affected by limb malformation (transversal hemimelia)

In recent years some buffalo farms in Campania have reported the birth of calves with limb malformation, especially with transversal hemimelia. We investigated 20 Mediterranean Italian buffaloes (8 males and 12 females) from one day to six months of age, of which 10 were affected by transversal hemimelia (group 1) and 10 were healthy controls (group 2). The following clinical and radiological patterns were observed in the malformed animals: hind limbs amputated, the right amputated off the second tarsus bones and the left amputated off the proximal epiphysis metatarsus, and the right thoracic limb hypoplasic (1 female); left hind limb amputated off the proximal epiphysis metatarsus (2 females and 1 male); left hind limb amputated off the third tarsus bones (1 female); left hind limb amputated off the tibia (1 female and 1 male); left hind limb amputated off the distal epiphysis metatarsus (1 female); left hind limb amputated off the first phalanx (1 male); right hind limb amputated off the proximal epiphysis metatarsus (1 male). In their malformed limbs all the animals presented more or less developed outlines of claws. The mean rate of SCE/cell in animals with transversal hemimelia was 8.80 +/- 3.19, that of the controls 6.61 +/- 2.73. The difference was statistically significant (P < 0.001).     

中国林蛙生长发育参数与产油量关系的研究

为了能够直接通过外部形态特征判断中国林蛙的产油量,本文采用单因素回归和逐步回归分析方法,初步研究了黑龙江省中部地区中国林蛙(Raaa chensinensis David)雌体的体重、体长、前后肢长、卵重、年龄与产油量(左右输卵管重量之和)之间的关系。结果表明：产油量与体重、体长、前肢长、后肢长、卵重、年龄均存在正相关;产油量与体重和体长具有显著的正相关(r=0．930),其回归方程：Y=-0．566 0．016x1 0．072x2。因此,体重和体长可以作为判断产油量多少的重要指标。     

Reevaluation of the effects of growth hormone and prolactin on anuran tadpole growth and development

The effects of ovine prolactin (oPRL) and ovine (o) or porcine (p) growth hormone (GH) on growth of anuran larvae were compared. In grass frog tadpoles (Rana pipiens), injections of oPRL (10 micrograms/gm/day) increased tail growth and body weight but had no effect on hindlimb growth or development. The same dose of oGH did not significantly affect the tail or body weight but it caused a striking increase in limb length and development. In bullfrog tadpoles (Rana catesbeiana) given an ergot drug (bromocriptine) to induce metamorphic changes, significant tail regression and loss of body weight occurred. Treatment with oPRL reversed these effects but had no effect on hindlimb growth or development. The pGH was much less effective than the oPRL in blocking tail regression and body weight loss but it significantly increased limb growth and development. These results show that GH and PRL can differentially regulate growth and development of structures in larval anurans. The effects of GH on limb growth and development can not be explained simply by a thyrotropic effect.     

桓仁林蛙与东北林蛙蝌蚪的形态特征及比较

桓仁林蛙（Rana huanrenensis Liu,Zhang,＆ Liu,1993）为一种与东北林蛙（Rana dybowskii）同域分布的林蛙,但其分布区域较狭窄.通过对其蝌蚪的形态特征描述及测量相关的形态学量度并和东北林蛙比较,发现在体色、体型、尾部形态以及身体各部位量度比值等方面存在显著性差异.桓仁林蛙的蝌蚪外形与流水型的蝌蚪相类似,而东北林蛙的蝌蚪则属于典型的静水型蝌蚪.     

Sex Ratio and Sexual Size Dimorphism in a Toad-headed Lizard,Phrynocephalus guinanensis

Phrynocephalus guinanensis has sexual dimorphism in abdominal coloration, but its ontogenetic development of sexual size dimorphism(SSD) is unknown. Using mark-recapture data during four days each year from August from 2014 to 2016, we investigated the development of sex ratios, SSD, sex-specific survivorship and growth rates in a population of P. guinanensis. Our results indicated that the sex ratio of males to females was 1:2.8. Males had a lower survival rate(6%) than females(14%) across the age range from hatchling to adult, which supported the discovered female-biased sex ratio potentially associated with the low survival rate of males between hatchlings and juveniles. Male-biased SSD in tail length and head width existed in adults rather than in hatchling or juvenile lizards. The growth rates in body dimensions were undistinguishable between the sexes during the age from hatchling to juvenile, but the growth rate in head length from juvenile to adult was significantly larger in males than females. Average growth rate of all morphological measurements from hatchling to juvenile were larger compared with corresponding measurements from juvenile to adult, but only being significant in tail length, head width, abdomen length in females and snout-vent length in males. We provided a case study to strengthen our understanding of the important life history traits on how a viviparous lizard population can survive and develop their morphology in cold climates.     

贵州省鼠耳蝠属一新纪录——狭耳鼠耳蝠

2010年10月在贵州省荔波县进行翼手目动物调查过程中,于荔波县洞塘乡捕获14只鼠耳蝠,经鉴定为狭耳鼠耳蝠Myotisblythii。主要鉴别特征:体型中等,前臂长64.60(60.78～67.72)mm(n=14,SD=1.71);耳狭长;耳屏直而细长,顶端尖锐;第三指最长、第五指最短;后足长约为胫长之半;无距缘膜;尾长67.99(60.56～73.82)mm(n=14,SD=3.7);雄性个体无阴茎骨,阴茎长12.58(8.42～15.72)mm(n=5,SD=2.86);颅全长24.09(23.48～24.72)mm(n=6,SD=0.55);头骨窄长;听泡发达;矢状脊较低;上颌内门齿有1个主尖和1个小附尖,外门齿小,与上犬齿分离;第2上前臼齿(P3)稍位于齿列内侧。此种鼠耳蝠为贵州省翼手目新纪录。     

新疆敏麻蜥3个地理种群趾长及趾长比的两性异形

趾长比是指动物不同趾长的比值,常被认为是早期雄激素或雌激素暴露的标记物之一.本文通过测量新疆敏麻蜥Eremias arguta 3个地理种群的雌雄成体各趾长并计算趾长比,探究不同地理种群趾长及趾长比的两性差异.结果表明,伊犁地区雄性后肢的第2趾显著大于雌性(P<0.05);富蕴县雄性前肢、后肢的第2、3、4、5趾长均显...     

A steady efflux of ionic current predicts hind limb development in the axolotl

For more than a week prior to the emergence of a hind limb, a steady electric current is driven out of the ventrolateral flank in the immature axolotl, returning through the integument in adjacent regions of the body. A marked peak in the density of this outcurrent could be observed over the exact area of hind limb formation 4 to 6 days prior to its appearance. After a bud projected from the flank, current densities were observed to decrease in magnitude yet localize about the early limb. In about one-half of the animals observed, current reversed its polarity and entered the apex of large buds, 0.4 to 0.5 mm in length. We discuss the possible role such endogenous currents and their associated fields may play in limb development and compare it to similar current flow associated with the regeneration of amphibian limbs.     

Heterochronic differences of Hoxa-11 expression in Xenopus fore- and hind limb development: Evidence for lower limb identity of the anuran ankle bones

 The wrist (carpus) and ankle (tarsus) of most tetrapods, as well as the wrist of anurans, contains relatively small nodular skeletal elements. The anuran tarsus, however, comprises a pair of long bones, the proximal tarsals tibiale and fibulare, which resemble the lower leg bones, tibia and fibula (zeugopodium). In this paper we investigate whether the proximal tarsals of Xenopus are of zeugopodial character identity, i.e. whether they develop under the influence of the same genes that pattern the lower limb. We compare Hoxa-11 expression in the forelimb bud with that in the hind limb bud by whole-mount in situ hybridization. Hoxa-11 has been implicated in the development of the lower limb. In Xenopus we note three differences between Hoxa-11 expression in fore- and hind limb buds: (1) Hoxa-11 expression is maintained until the hind limb bud reaches a larger size (2 mm) than that of the forelimb bud (1.5 mm); (2) Hoxa-11 expression is maintained over larger spatial domains than in the forelimb; and (3) Hoxa-11 expression has a pronounced posterior polarity in the hind limb, but not in the forelimb. Hind limb expression of Hoxa-11 can be understood as a heterochronic prolonging of the expression dynamic in the forelimb. Finally we found that the proximal tarsals start to develop within the expression domain of Hoxa-11, while in the forelimb the lower arm elements reach the distal expression limit of Hoxa-11. The gene expression data presented here support the notion of a zeugopodial identity of the proximal tarsal elements in Xenopus. Received: 20 January 1998 / Accepted: 27 March 1998