Polygordius

Pol`y`gor´di`us


n.1.(Zool.) A genus of marine annelids, believed to be an ancient or ancestral type. It is remarkable for its simplicity of structure and want of parapodia. It is the type of the order Archiannelida, or Gymnotoma. See Loeven's larva.
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Los taxa cuya abundancia fue notablemente mayor al incluir la fraccion [mayor que o igual a] 500 [micron]m y 1 mm, respecto de la abundancia obtenida al incluir solo la fraccion de tamano [mayor que o igual a] 1 mm fueron los anelidos Aricidea catherinae (72%), Polygordius sp.
Los taxa cuya abundancia fue notablemente mayor al incluir la fraccion [mayor que o igual a] 500 [micron]m y <1 mm, respecto de la abundancia obtenida al incluir solo la fraccion de tamano [mayor que o igual a]1 mm fueron el anelido Polygordius sp.
III 410 1970 2389 (Annelida/Polychaeta) Prionospio orensanzi IV 2460 250 2710 (Annelida/Polychaeta) Polygordius sp.
In primitive annelids like Podarke (Treadwell 1901), and Polygordius (Woltereck 1904), the first two cleavages are equal, but D quadrant specification presumably does not occur by specifying 3D, but does occur one cleavage cycle later by specifying one of the fourth quartet cells.
These findings suggest that the secondary ciliated band in the veliger is not homologous to the metatroch found in the trochophore larva of other spiralians, such as the annelid Polygordius lacteits (reportedly derived from 3c and 3d; Wollereck.
For another example, the endolarva of Polygordius appendiculatus develops the segmented body as an elaborate folded pouch within the highly inflated larval hyposphere, rather than adding segments progressively to the posterior of the post-trochal region (Woltereck, 1902; Okada, 1970; ironically, this unusual larva is the original inspiration for the trochophore concept--see Rouse, 1999).
collaris after ciliation are in the range of 4-5 [micro]m, whereas those for the nemertean Carinoma tremaphoros, the polychaetes Nereis limbata and Polygordius sp.
The other extreme, with highly specialized larval types with larval organs shed during a cataclysmic metamorphosis, is well known--for example, from the nemertine pilidium larva and the larva of the annelid Polygordius.
Beitrage zur praktischen Analyse der Polygordius Entwicklung nach dem "Nordsee"-und "Mittelmeer"-Typus.
Die metamorphose yon Polygordius appendiculatus (Polychaeta, Archiannelida): Induction und ablauf.
The larval nervous system of Polygordius lacteus Scheinder, 1868 (Polygordiidae, Polychaeta): immunocytochemical data.