02155nas a2200169   4500008004100000245005400041210005400095300001400149490000800163520166700171100002001838700002301858700002001881700001501901700001701916856005201933       2011                        eng d00aMating behavior and the evolution of sperm design0 aMating behavior and the evolution of sperm design  a1490-14950 v1083 aSperm are the most diverse of all animal cell types, and much of the diversity in sperm design is thought to reflect adaptations to the highly variable conditions under which sperm function and compete to achieve fertilization. Recent work has shown that these conditions often evolve rapidly as a consequence of multiple mating, suggesting a role for sexual selection and sexual conflict in the evolution of sperm design. However, very little of the striking diversity in sperm design is understood functionally, particularly in internally fertilizing organisms. We use phylogenetic comparative analyses covering 16 species of the hermaphroditic flatworm genus Macrostomum to show that a complex sperm design is associated with reciprocal mating and that this complexity is lost secondarily when hypodermic insemination—sperm injection through the epidermis—evolves. Specifically, the complex sperm design, which includes stiff lateral bristles, is likely a male persistence trait associated with sexual conflicts over the fate of received ejaculates and linked to female resistance traits, namely an intriguing postcopulatory sucking behavior and a thickened epithelium of the sperm-receiving organ. Our results suggest that the interactions between sperm donor, sperm, and sperm recipient can change drastically when hypodermic insemination evolves, involving convergent evolution of a needle-like copulatory organ, a simpler sperm design, and a simpler female genital morphology. Our study documents that a shift in the mating behavior may alter fundamentally the conditions under which sperm compete and thereby lead to a drastic change in sperm design.1 aSchärer, Lukas1 aLittlewood, D, T J1 aWaeschenbach, A1 aYoshida, W1 aVizoso, D, B  uhttps://macrostomorpha.myspecies.info/node/470101640nas a2200169   4500008004100000245017100041210006900212300001000281490000700291520103500298653001601333653001601349100001901365700001701384700001701401856005201418       2011                        eng d00aResearch on taxonomic characters and one new recorded species of genus <i>Macrostomum</i> (Platyhelminthes, Macrostomida) from China [In Chinese with English summary]0 aResearch on taxonomic characters and one new recorded species of  a39-440 v303 aMacrostomum saifunicum Nasonov, 1929, a species belonging to the family Macrostomidae of the Order Macrostomida, was reported in China for the first time. The relationship between ontogenesis and penis development of M. saifunicum was studied in detail. The results indicated that: 1) The tip structure of the penis stylet of M. saifunicum formed and stabilized at 9 days old and was a reliable morphological characteristic. 2) The length of the individual penis stylet reached 140 µm after 20 days' growth, and increased to more than 160 µm after 40 days of growth when the individual reached senescent stage, showing that the length of the penis stylet was not a stable taxonomic characteristic. 3) M. saifunicum had been found in Beijing, Anhui, Hunan, Jiangxi, and Guangdong based on the author's collections for many years, indicating that M. saifunicum was a common and widespread species in China. The study also showed that Macrostomum was an ideal experimental animal in the fields of education and scientific research.10aMacrostomum10aSystematics1 aZhao, Peng-fei1 aLuo, Hui-lin1 aWang, An-Tai  uhttps://macrostomorpha.myspecies.info/node/4332