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, pl.


(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]
Farlex Partner Medical Dictionary © Farlex 2012


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.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.


(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.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005
References in periodicals archive ?
Last, there is the uterine apex, a looped projection of the reproductive tract that extends into the internal viscera and is incorporated beneath the kidney and nephridial gland.
A comprehensive assessment includes these organs as well as foot and columellar muscle, nephridial gland, esophagus, stomach, small intestine, rectum, and anus.
Briefly, 10 mg of nephridial tissue was homogenized at 4[degrees]C in PBS, and then the mixture was further treated by ultrasonication.
As described for the species by Londono-Mesa (2009) nephridial papillae occur on setigers 3, 4 and 6 and 7.
tanae leech, Tan describes its features (without using epididymal or nephridial even once).
Initially, nephridial pair 4 resides roughly at the ankle of the sock, where it is folded over, and the larval esophagus and mid-gut reside entirely outside the sock; nephridial pairs 1-4 hang into the blastocoelic space from the unrolled leg, whereas pairs 5-7 reside inside the foot of the sock along with the larval hindgut (Fig.
(D-F) late-stage mitraria with fully formed juvenile rudiment surrounding the larval mid-gut (mg) and hindgut (hg) with nephridial pairs, juvenile chaetal muscles (outlined arrows), and juvenile buccal organ (bu).
Relevant taxonomic characteristics in the holotype description: "Diagnosis: In fourth and fifth legs, nephridial tubercle free from third sole and only partially surrounded by the fourth arc.
Nephridial tubercle: Present in the 4th and 5th oncopod pairs, anteriorly displaced and opening between the 3rd and 4th creeping pads, free from the 3rd and indenting the proximal margin of 4th pad, which is crescent-shaped around it.
Ultrastructure of the crayfish kidney - coelomosae, labyrinth, and nephridial canal.
Nephridial pores: Begin on segment 2, somewhat dorsal to setal line ab.