Other arachnids may reproduce asexually or sexually. Most trematodes are monoecious and alternately reproduce sexually and asexually. Meiosis does not occur in archaea or bacteria, which generally reproduce asexually via binary fission. Colonial ascidians reproduce both asexually and sexually. "Phytophthora" species may reproduce sexually or asexually. Females of many species are known to be capable of reproducing asexually through thelytokous parthenogenesis. They can reproduce both sexually and asexually. Phylogenetic classification of asexually reproducing fungi now commonly uses molecular systematics. The species is perennial and reproduces asexually. Siphonophores are colonial hydrozoans that reproduce asexually through a budding process. The larvae released from the female settle as benthic polyps that reproduce asexually. They are filamentous, heterotrophic, and can reproduce both sexually and asexually. These disperse to infest other plants, where they continue to reproduce asexually. Females are also capable of reproducing asexually. A few species within Squamata have the ability to reproduce asexually.