Orthonectida

Orthonectids
Orthonetida dict flat and cylinder.png
Two different female Orthonectids
Scientific classification
Kingdom:Animalia
(unranked):Bilateria
Phylum:Orthonectida
Giard, 1877
Families
  • Pelmatosphaeridae
  • Rhopaluridae

Orthonectida is a small phylum of poorly-known parasites of marine invertebrates. They are among the simplest of multi-cellular organisms.[1]

Biology

The adults are microscopic wormlike animals. They have a single layer of outer cells surrounding a mass of sex cells. They swim freely within the bodies of their hosts, which include flatworms, polychaete worms, bivalve molluscs, and echinoderms. They have separate male and female individuals.[2]

Reproduction

When they are ready to reproduce, the adults are released from the host, and sperm from the males penetrates the bodies of the females to achieve fertilisation. The resulting zygote develops into a ciliated larva that escapes from the mother to seek out new hosts. Once it finds a host, the larva loses its cilia and develops into a syncytial plasmodium larva. This, in turn, breaks up into numerous individual cells that become the next generation of adults.[2]

The resulting zygote develops into a ciliated larva that escapes from the mother to seek out new hosts. Once it finds a host, the larva loses its cilia and develops into a syncytial plasmodium larva.

Other Languages
azərbaycanca: Ortonektidlər
български: Ортонектиди
català: Ortonèctids
Cebuano: Ortonektida
čeština: Plazmodiovky
Deutsch: Orthonectida
English: Orthonectida
español: Orthonectida
Esperanto: Ortonektidoj
euskara: Orthonectida
français: Orthonectida
한국어: 직유동물
hrvatski: Orthonectida
Bahasa Indonesia: Orthonectida
interlingua: Orthonectida
italiano: Orthonectida
Basa Jawa: Orthonectida
Nederlands: Orthonectida
日本語: 直泳動物門
Nordfriisk: Orthonectida
occitan: Orthonectida
português: Orthonectida
română: Ortonectide
русский: Ортонектиды
slovenčina: Orthonectia
српски / srpski: Orthonectida
svenska: Stavsimmare
Tagalog: Orthonectida
українська: Прямоплави
Winaray: Orthonectida