madreporite

(redirected from madreporites)
Also found in: Dictionary, Encyclopedia.

madreporite

the porous opening to the hydrocoel in ECHINODERMS.
References in periodicals archive ?
Their study led Ellers and Telford (1992) to question Fechter's argument that the madreporite is primarily involved in acute pressure equalization.
Fechter's contention is, furthermore, not consistent with the anatomy of the madreporite and its associated stone canal.
Thus, the functions of the prominent madreporite system of sea urchins remain unknown, and the normal osmotic differences that might exist between their various body fluids and the media have not been accurately measured.
Influxes of seawater through the madreporite and into the water vascular system were demonstrated as follows.
An effort was made to quantify the influx of seawater through the madreporite with the soluble, high molecular weight tracer, fluorescein isothiocyanate dextran (FID), as was previously done with asteroids (Ferguson, 1989, 1994).
Two sets of experiments tested the effect of long-term obstruction of the madreporite on behavior, tube feet activity, and maintenance of body fluid volume.
Its madreporite cannot be seen externally, and the structure of its water vascular system must be inferred from old descriptions of other ophiuroid species (cf.
To locate the site of the madreporite and examine the organization of the entire system, two small specimens (6-7 mm disk diameter) were fixed in Helly's fixative and decalcified for one week in changes of cold (4 [degrees] C) 5% disodium EDTA.
The extent of seawater entry through the madreporite was evaluated in two sets of experiments.
Further tests were conducted to see if madreporite oblation would lead to diminished functions.
Both pores lead to a discrete lobe of the madreporite "ampulla." This spacious chamber lies just under the surface of the oral shield.
Weight variations (g) of Ophioderma appressum following destruction of the madreporite area, and control animals with a comparable injury to another site