nephridium

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Related to nephridia: Malpighian tubules, parapodia

ne·phrid·i·um

, pl.

ne·phrid·i·a

(ne-frid'ē-ŭm, -ă),
One of the paired, segmentally arranged excretory tubules of invertebrates such as the annelids.
[G. nephros, kidney, + Mod. L. -idium, dim. suffix, fr. G. -idion]

nephridium

(nə-frĭd′ē-əm)
n. pl. nephrid·ia (-ē-ə)
1. A tubular excretory organ in many invertebrates, such as mollusks and earthworms.
2. The excretory organ of a vertebrate embryo from which the kidney develops.

ne·phrid′i·al adj.

nephridium

(pl. nephridia) a primitive excretory organ present in many invertebrates (e.g. the earthworm) in the form of a tube which opens at one end to the exterior. The other end may open into the COELOM or may terminate in a FLAME CELL.

nephridium

pl. nephridia [L.]
1. either of the paired excretory organs in each body segment of certain invertebrates, having the inner end of the tubule opening into the coelomic cavity.
2. various excretory structures such as the nephron of the embryo.
References in periodicals archive ?
Both authors indicated a proandric condition (later not confirmed) and did not observe nephridia.
Michaelsen (1918: 332), in synonymizing the genus Brachydrilus under Tritogenia, accepted duplication of nephridia as the exclusive generic character for this genus, and wrote '.
Michaelsen (1928a: 7) described Microchaetus melmothanus, with the gizzard in segments 6-7 (characteristic for Tritogenia), although not observing nephridia.
more than one pair of nephridia small and fairly simple in constitution .
Excretory system meroic; two or more small nephridia per segment (except in some anterior segments, sometimes also absent from a few posterior segments).
Diagnosis: Two or more small nephridia per segment (except for three anterior segments, sometimes also missing in a few posterior segments).
Two pairs of nephridia per segment, noticeable in posterior segments; dorsal pairs with long thin tubes; ventral pairs close to median body line, with shorter tubes.
Excretory system holoic; one pair of nephridia per segment (except for three anterior segments); large or medium-sized, tightly coiled loops with elongated nephridial bladders, V-shaped or J-shaped at the ectal end.