Although scorpions are an ancient group their method of reproduction is rather complex and poorly studied. This review aims at clarifying some of the aspects of their reproduction that are important for understanding the reproductive ecology of other arthropods, including insects. The following aspects of scorpion reproduction are discussed and reviewed: mating, insemination, fertilization, gestation, parturition and birth. The onset of gestation and its duration are difficult to determine as both depend on the time of fertilization, for which there are no accurate estimates. There are only a few records of the time between birth and emergence of a larva from the maternal envelope in apoikogenic scorpions, which is important for a better understanding of ovoviviparity. All these questions are important as the answers will greatly enhance our understanding of the population ecology of scorpions in terms of the recruitment rates of cohorts and their chances of survival., Michael R. Warburg., and Obsahuje seznam literatury
The levels of four pregnanolone isomers and their polar conjugates and pregnenolone sulfate were measured in the plasma of 13 and 7 women at delivery with subarachnoidal and epidural analgesia, respectively, and in corresponding samples of umbilical plasma using a simple quadrupole GC/MS system with electron impact ionization (pregnenolone isomers), RIA following HPLC separation (pregnenolone) and specific RIA (pregnanolone sulfate). The concentration of epipregnanolone (3b-hydroxy-5b-pregnan-20-one) in both maternal and umbilical plasma was much lower than that of other pregnanolone isomers. The levels of 3b-hydroxy-pregnanolone isomers were significantly higher in the umbilical plasma than in the maternal, while the differences in 3a-hydroxy-isomers were insignificant. The differences in conjugates were insignificant with the exception of allopregnanolone, the levels of which were lower in umbilical plasma. In all the pregnanolone isomers, a significantly lower conjugated/unconjugated steroid ratio was found in the umbilical plasma than in the maternal plasma. In addition, time profiles of the steroids were measured around parturition and in the postpartum period in the maternal serum. Similarly, the levels of polar conjugates of all pregnanolone isomers were followed during parturition. Changes in concentrations of free steroids exhibited a similar pattern, with a fall primarily within the first hour after delivery. The decrease in conjugated steroids was shifted to the interval within the first hour and first day after delivery, and the changes were more pronounced. The time profiles of the conjugated/free steroid ratio exhibited a significant decrease within the first hour and the first day after delivery in all of the isomers investigated. A decrease was also observed in the ratio of 3a/3b- isomers and 5a/5b- isomers around parturition.The possible physiological consequences of the findings are indicated., J. Klak, M. Hill, A. Pařízek, H. Havlíková, M. Bičíková, R. Hampl T. Fait, J. Šulcová V. Pouzar, R. Kancheva, L. Stárka., and Obsahuje bibliografii
Between 1997 and 2001, the birth dates of free living and captive Alpine musk deer were examined to determine fawning patterns, and discuss potential influencing factors. In the wild, parturition shows strong seasonality, and occurred in three months from May to July, most of the births (75%) occurring within a 27 day period. Environmental seasonality, including the climate and forage availability, plays the major role in determining the timing of births in wild musk deer. Similarly, fawning in captivity shows constancy between years and seasonality, although with later initiation and a longer season than in the wild, influenced by an environmental seasonality of relatively lower intensity. More detailed differences in fawning patterns were observed in different rows of enclosures, resulting from differences in human care, and intensified by the social interaction among individuals within a row of enclosures. Although the fawning pattern is not strongly related to age of the captives, an individual’s reproductive history seemed to influence fawning timing and synchrony, and the birth date is not strongly related to the survival of the newborn.