Somaye Vaissi

    Climate change is one of the most important threats to biodiversity. During recent years, much attention has been focused on declining amphibians. Alien species including hunting fish, and global warming are the important factors of decline amphibians. One of the consequences of global warming is the early droughts of the ponds. On the other hand, amphibian densities in ponds are also affected by changes in water levels. In this study, the interaction effects of three factors including temperature, water level and density were investigated on snout-vent length (SVL), SVL at metamorphosis, time at metamorphosis, percentage of metamorphosis, cannibalism and survival of larvae of Pelophylax bedriagae which was previously known as Pelophylax ridibundus, carried out within 10 months. We designed a 2×2×3 factorial experiment, crossing two levels of temperature ( high =22.5 and low=18.5 ), two levels of density (low, n =5 and high, n =25) and three level of water (low: 300 cc, high 1400 cc, and decreasing 150 cc of water, Once a week). Results of experiment showed the highest survival rate in was observed in the low density / low water / low temperature with 73.33% ±5.77 and the lowest survival rate was observed in the high density / low water / low temperature with 13.31 % ±2.54. The highest hatching percentage was observed in the low temperature×   decreasing water level × low density (93.3 mm±11.54) and the lowest hatching percentage was observed in high temperature× high water level × low density (56.6 mm±15.27). Results of ANOVA showed that three temperature, density, and water level had not significant independent effects on the hatching but   interaction of three factors included temperature, water level and density had a significant effect on the hatching (P=0.05). The highest size at metamorphosis (SVL) was observed in high temperature × decreasing water level × high density (16.21 mm±1.89) and the lowest was observed in low temperature× decreasing water level × high density (10.33 mm±8.95(.Results of ANOVA showed that   temperature had significant independent effects on the size at metamorphosis (SVL)   ut water level and density had not significant independent effects on the size at metamorphosis (SVL). Interaction of three factors included temperature, water level and density had a significant effect on the size at metamorphosis (P=0.008).. Interaction of three factors included temperature, water level and density had a significant effect on the percentage of metamorphosis (P=0.05).  

  Amphibians are an indicator of environmental health their population is decreasing around the world at a significant rate. The climate change, chemical pollutants, increased ultraviolet radiation, habitat changes, exotic species, and pathogens are some of the causes of amphibian decline. The aim of this study was to investigate the interaction effects of density, water level and predator cues factors on the growth rate, metamorphosis, survival and cannibalism in marsh frog Pelophylax ridibundus. In this study, an experiment was carried out with 2 × 3 × 2 factors consisted of two levels of density (low density (n: 5) and high density (n: 25)), three levels of water level (low water level (400 cc), high water level (1400 cc) and decreasing water level (100 cc each week)) and two levels of predator (presence (as indirect) or absence of predator (Gambusia holbrooki). The results of our experiment showed the highest growth rate was observed in low-density treatment/ predator presence/high water level with 0.144 mm/day, maximum snout-vent length during metamorphosis (SVL) in low-density treatment/predator presence/low water level (17/006 mm ± 1/07), and the highest mean of head width (HW) was recorded in the low-density/predator presence/ decreasing water level (7/853 mm ± 1/755) during 201 days. Also, the highest mean age of metamorphosis in high-density of treatment/absence of predator/low water level (134/415 days ± 26/99), highest percentage of metamorphosis in low-density of treatment/ predator presence/decreasing water level (86/66% ± 23/094), highest survival rate in low-density of treatment/predator/high water level (86/666% ± 11/547), and highest overall cannibalism (head + tail + full) was recorded in the high-density of treatment/absence of predator/low water level (3/522% ± 5/994). The ANOVA results showed that density factor independently had a significant effect on SVL, HW, age and percentage of metamorphosis but had no effect on survival rate over time. The water level had no significant effect on total cannibalism percentage, metamorphosis time, metamorphosis percentage and survival percentage but had a significant effect on head width. Also, the interactive effect of three factors had no significant on SVL, head width, metamorphosis time, percentage of metamorphosis, total cannibalism percentage and survival rate.

  During recent years, much attention has been focused on declining amphibians. Alien species including mosquitofish, and global warming are the important factors of decline amphibians. One of the consequences of global warming is the early droughts of the ponds. On the other hand, amphibian densities in ponds are also affected by changes in water levels. In this study, the interaction effects of three factors including predatory cues (Gambusia halbrooki), water level and density were investigated on snout-vent length (SVL), SVL at metamorphosis, time at metamorphosis, percentage of metamorphosis and survival of larvae of Bufotes variabilis that carried out within 60 days. We designed a 2×2×3 factorial experiment, crossing two levels of predatory (present of predatory cues and without of predatory cues), two levels of density (low, n =5 and high, n =25) and three level of water (low: 400 cc, high 1400 cc, and decreasing 150 cc of water, Once a week). Result of experiment showed, larval growth rate was highest at the both of present of predator × high water level × high density and present of predator × decreasing water level × low density (0.30 mm/day). The highest size at metamorphosis (SVL) was observed in without of predator × high water level × low density (14.42 mm±0.43). The slowest development time (34.41 days±3.82), the lowest percentage of metamorphosis (18.66%±8.33) and the highest survival rate (32%±10.58) were observed at the present of predator × high water level × high density treatment. Except for the significant impact of present of predator on SVL and density on survival over time, B. variabilis was tolerant and there was no interaction between predator cues, water level and density in term of growth and survival rates.

  The yellow-spotted mountain newt Neurergus derjugini is listed as Endangered by the International Union for Conservation ofNature (IUCN). In spite of its conservation status and laws protecting it, thespecies continues to decline in the wild. A captive breeding program wassuccessfully established to provide information to support the species’recovery.We designed a   2 ×2 × 2 factorial experiment with two high (N = 14) and low (N = 4) densities,two levels offood (high and low) and the present and absence of spatial complexity (refugia)including (LD/LF/R), (LD/HF/R), (HD/LF/R), (HD/HF/R),(LD/LF/NR), (LD/HF/NR), (HD/LF/NR), (HD/HF/NR).The resultsof the experiment in 10 months showed that the growth, development and survivalrate in larval of N. derjugini is influenced by the amount of availablefood, so that larvae grown in high levels of food have a faster metamorphosistime (P?0.01), larger size (P?0.01) and highersurvival rate (P?0.0001) compared to reared at low levels of food. On the otherhand, the density (P?0.04) and the presence of refugia (P?0.03) showed a significanteffect on survival over time. Also, the interactive effect of these threefactors showed a significant effect on the ageof metamorphosis (P?0.05) and survival rate (P?0.04) over time. In this study, also, the level of cannibalistic behaviour (including the loss of fore and hind limbs, missing toes, tail, and gills, body damage, andwhole body consumption) was investigated. According to the results cannibalism changed as the larvaegrew, from a low level during the first five weeks, peaking from weeks 5–15,and then dropped during weeks 15–37. The results of thisstudy showed that the presence of sufficient food (P?0.002) significantly reducedthe rate of cannibalism over time but interaction it with density and refugiashowednon significant effect. Information obtained from the current experiment could improve the productivity of captive breeding facilities toensure the release of adequate numbers of individuals for reintroductionprograms.

  The time inwhich a young mammal develops appropriate sensory and locomotors skillsnecessary to become independent from its mother is defined as the postnatalgrowth period. Postnatal changes are very important in peculiarities ofphysiology, physiology and behavior for bats, and during this period they gainabilities such as flight, nutrition and ecolocation. The bats are distinctamong mammals because of their flight. This study documents the postnatal growth of body mass, forearm and the epiphyseal phalangeal gap in a free rangingpopulation of the Rhinolophus ferrumequinum  in a maternity roostin Kerned   cave in western Iran. The pups at   irth had a meanbirth body mass of 5/69   ±   0/3 grm and forearm length of 25/64   ± 1/23mm. The length of forearm and body massincreased linearly during first 3 weeks, and thereafter maintained an apparentstability. The epiphyseal gap of the fourth metacarpal phalangeal jointincreased until 12 days, then decreased linearly until 80 days and thereafterfused. The rate of body mass gain and forearm growth during the first 21 dayswas 0.35 g/d and 1.38 mm/d respectively. Initiation of flight occurred 3 weeksafter birth. Also in thisstudy, wing morphology including wingspan, wing area, handwing length, handwingarea, armwing length, armwing area, aspect ratio and wing loading were studied.The wingspan in 30 and wing area increased linearly until 21 days of age bywhich time the young bats exhibited clumsy flight with gentle turns. Analysisof changes occurring on wing morphology indicates that seven wing characteristicsperform a rapid growth rate at “pre-flight” and second slower growth rate at“post-flight” periods. Wingspan, handwing, length and area, armwing length andarea, and total wing area increased linearly until the age of first flight,after which the growth rates decreased significantly (all P<0. 000). Wingloading decreased until 50 days of age and thereafter increased to 9/62 Nm_2at 80 days of age. The aspect ratio showed a high degree of scatter at earlystages of life which decreased at the later period of growth. In this study,four nonlinear growth models including Logistic, Gompertz , Von Bertalanffy andModified von Bertalanffy for length was investigated. Accordingly, the mostsuitable model for Forearmlength   was Gompertz, the most suitablemodel for Body ma   was Von Bertalanffy and the most suitablemodel for Wingspan was Gompertz .Additionally, linear regression equations, confidenceintervals and prediction intervals used for age estimation based on dataavailable for the forearm, body mass, the total gap of the 4th metacarpal-phalangealjoint, wing area , handwinglength and wingspan.

Neurergus derjugini