[Zeitgeist]

Originariamente inviata da berto1886

per la cronaca è ermafrodita!

Diciamo che il discorso è un po' più complesso:

Quote:

The fourth category of adaptations is in the matter of sexual, or lack thereof, reproduction. Probably nowhere in nature does a single group of species possess such a diverse range of reproductive strategies. There is the obvious division of males and females with "normal" sexual reproduction in some populations. In some, such as T. granarius, sexual reproduction is obligatory. The extreme result of obligately sexual populations is that some of them have become male biased, as high as 70% males. However, most triops can reproduce by parthenogenesis. In parthenogenesis an egg develops into an embryo without having been fertilized by the spermatozoa of a male, sort of a virgin birth. This has allowed many populations to become female biased where males occur infrequently, sometimes less than one male for every one hundred females. This strategy is taken to the extreme with some populations becoming unisexual, composed entirely of females. Still other triops are hermaphroditic, possessing male and female sex organs. This is even more complex in that some are capable of fertilizing themselves, still others must cross-fertilize with another hermaphrodite, and both types may or may not be able to reproduce parthenogenetically. Some populations are technically hermaphroditic, but appear to only reproduce parthenogenetically, perhaps an evolutionary intermediate to a unisexual population. The truly bewildering thing about these markedly different strategies is that most recognized triops species utilize more than one reproductive strategy among geographically isolated populations. T. longicaudatus is particularly interesting in that it is known to exhibit all major categories: bisexual (normal distribution and both male and female biased), unisexual, and hermaphroditic. The apparent reproductive incompatibility, as well as recent genetic analysis, suggests that these differently reproducing populations will one day be recognized as subspecies of their current classification.

[fonte: http://mytriops.com/articles/triops_eggs.stm]