hypostome


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Related to hypostome: basal disc

hypostome

[′hī·pə‚stōm]
(invertebrate zoology)
Projection surrounding the oral aperture in many cnidarian polyps.
Anteroventral part of the head in Diptera.
Median ventral mouthpart in ticks.
Raised area on the posterior oral margin in crustaceans.
References in periodicals archive ?
The alimentary canal is visible on the occipital ring, but its anterior continuation on the glabella is not known, as the axial part of the cephalon shows only the lower ventral surface of the hypostome (Hy in Fig.
Mae'r hypostome yma wedi'i wneud o galch ac yn hynod o galed.
Key to the sub orders, families and genera: 1 With dentate faces of cheliceral digits directed externally (laterally), presence of a well developed hypostome provided ventrally with re-curved teeth; with lateral stigmatal openings behind coxae-IV or laterally above coxae II-III; prosoma completely fused; no trace of segmentation to the abdominal section; behind the legs size large, possession of true Haller's organ on the I pair of legs.
The mouthparts consist of a pair of segmented palps (feelers), a pair of sharp-bladed chelicerae (pincers) that slice the skin, and a needlelike hypostome through which blood is sucked.
Inserting a syringelike hypostome, which is lined with backward-pointing teeth to lock it in place, they begin their feast.
b, c a Euglena a a Netrium a a (Phacus) a (Peridinium) a Scenedesmus d a, c a a a Staurastrum a a Herbivores Brachionus c a a Frontonia d a Hypostome sp.
Ontogeny, hypostome attachment and trilobite classification.
The associated hypostome has a subtriangular outline, an almost transverse anterior margin very gently curved distally, a rounded posterior margin and an elongate, suboval middle body.
Hypostome subrectangular in shape and cone shaped distally, with 4 pairs simple hypognathal setae (hg1-hg4) and 2 pairs adoral setae, with dot like lobes (Fig.
The repeated injection of saliva into bite wound incites a host reaction forming a straw-like hollow tube, the hypostome or stylostome, which extends downwards into the host's skin firmly anchoring the mite.
Its longitudinally conducted impulses are thought to be generated in a circumferential nerve ring located just below the hypostome (Passano and McCullough, 1963; Kass-Simon, 1972; Kass-Simon and Passano, 1978; Kinnamon and Westfall, 1981; Koizumi et al, 1992), but may also originate elsewhere in the ectoderm of the body column (Kass-Simon, 1970).