Orthonectida

Gedene iku kéwan kaya cacing mikroskopis, sing lewih sekang siji lapisan sel njaba ana siliané sekitaré massa sel kelaminé. Kae rénang karo bébas ing tubuh inangé, sing kelebu platyhelminthes, cacing polychaeta, moluska bivalvia, lan echinodermata. Kae gonochoristic, karo individu lanang lan wadon misah.

Angger wis siyap kanggo réproduksi, kae lunga sekang inangé, lan sperma sekang lanang nembus awak sing wadon kanggo fertilisasi internal. Zigot sing dikasilna dadi larva ngabi silia sing lolos sekang biyungé kanggo nggolet inang anyar. Bar nemu inang, larva kelangan silia lan dadi larva plasmodium syncytial. Larva iki, gilirané, mecah dadi akèh sel-sel individual sing arep dadi génerasi selanjute.

Filum iki ana sekang 20 spésies sing dikenal, ing Rhopalura ophiocomae iku sing paling dikenal. Filum iki ora dibagi mengjero kelas utawa ordho, lan kur isi loro famili.

Awale dideskripsina déning taun 1877 kanggo kelas, lan kadang-kadang ditandai kanggo ordho ing filum Mesozoa, panalitèn anyar, orthonectids béda pisan karo rhombozoa, kelompok lain di Mesozoa.

Spesies sing wis katon:

Filum Orthonectida

• Famili Rhopaluridae Stunkard, 1937
  • Ciliocincta akkeshiensis Tajika, 1979 – Hokkaido, Japan; in flatworms (Turbellaria)
  • Ciliocincta julini (Caullery and Mesnil, 1899) – E North Atlantic, in polychaetes
  • Ciliocincta sabellariae Kozloff, 1965 – San Juan Islands, WA (USA); in polychaete (Neosabellaria cementarium)
  • Intoshia leptoplanae Giard, 1877 – E North Atlantic, in flatworms (Leptoplana)
  • Intoshia linei Giard, 1877 – E North Atlantic, in nemertines (Lineus) = Rhopalura linei
  • Intoshia major Shtein, 1953 – Arctic Ocean; in gastropods (Lepeta, Natica, Solariella) = Rhopalura major
  • Intoshia metchnikovi (Caullery & Mesnil, 1899) – E North Atlantic, in polychaetes and nemertines
  • Intoshia paraphanostomae (Westblad, 1942) – E North Atlantic, in flatworms (Acoela)
  • Intoshia variabili (Alexandrov & Sljusarev, 1992) – Arctic Ocean, in flatworms (Macrorhynchus)
  • Rhopalura elongata Shtein, 1953 – Arctic Ocean, in bivalves (Astarte)
  • Rhopalura gigas (Giard, 1877)
  • Rhopalura granosa Atkins, 1933 – E North Atlantic, in bivalves (Pododesmus)
  • Rhopalura intoshi Metchnikoff – Mediterranean, in nemertines
  • Rhopalura litoralis Shtein, 1953 – Arctic Ocean, in gastropods (Lepeta, Natica, Solariella)
  • Rhopalura major Shtein, 1953
  • Rhopalura murmanica Shtein, 1953 – Arctic Ocean, in gastropods (Rissoa, Columbella)
  • Rhopalura ophiocomae Giard, 1877 – E North Atlantic, in ophiuroids (usually Amphipholis)
  • Rhopalura pelseneeri Caullery & Mesnil, 1901 – E North Atlantic, polychaetes and nemertines
  • Rhopalura philinae Lang, 1954 – E North Atlantic, in gastropods
  • Rhopalura pterocirri de Saint-Joseph, 1896 – E North Atlantic, in polychaetes
  • Rhopalura vermiculicola
  • Stoecharthrum burresoni Kozloff, 1993
  • Stoecharthrum fosterae Kozloff, 1993
  • Stoecharthrum giardi Caullery & Mesnil, 1899 – E North Atlantic, in polychaetes
  • Stoecharthrum monnati Kozloff, 1993 – E North Atlantic, in molluscs
• Famili Pelmatosphaeridae Stunkard, 1937
  • Pelmatosphaera polycirri Caullery and Mesnil, 1904 – E North Atlantic, in polychaetes and nemertines