title: Molecular evidence for high frequency of multiple paternity in a freshwater shrimp species Caridina ensifera.
abstract: BACKGROUND
  Molecular genetic analyses of parentage provide insights into mating systems. Although there are 22,000 members in Malacostraca, not much has been known about mating systems in Malacostraca. The freshwater shrimp Caridina ensifera blue, is a new species belonging to Malacostraca which was discovered recently in Sulawesi, Indonesia. Due to its small body size and low fecundity, this species is an ideal species to study the occurrence and frequency of multiple paternity and to understand of how the low fecundity species persist and evolve.
  
  
  RESULTS
  In this study, we developed four polymorphic microsatellites from C. ensifera and applied them to investigate the occurrence and frequency of multiple paternity in 20 C. ensifera broods caught from Lake Matano, Sulawesi. By genotyping the mother and all offspring from each brood we discovered multiple paternity in all 20 broods. In most of the 20 broods, fathers contributed skewed numbers of offspring and there was an apparent inverse correlation between reproductive success of sires and their relatedness to mothers.
  
  
  CONCLUSIONS
  Our results in combination with recent reports on multiple paternity in crayfish, crab and lobster species suggests that multiple paternity is common in Malacostraca. Skewed contribution of fathers to the numbers of offspring and inverse correlation between reproductive success of sires and their relatedness to mothers suggest that sperm competition occurred and/or pre- and postcopulatory female choice happen, which may be important for avoiding the occurrence of inbreeding and optimize genetic variation in offspring and for persistence and evolution of low fecundity species.
authors.affiliation: Molecular Population Genetics Group, Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore. genhua@tll.org.sg
authors.forename: Gen Hua
authors.initials: GH
authors.lastname: Yue
authors.forename: Alex
authors.initials: A
authors.lastname: Chang
mesh_terms: D000818:Animals; D033364:Decapoda / Q000235:genetics* / Q000502:physiology; D005260:Female; D005838:Genotype; D008297:Male; D052586:Mating Preference, Animal; D018895:Microsatellite Repeats; D012726:Sexual Behavior, Animal