WebThe next segment, the peristome, surrounds the mouth and is followed by a series of segments, the total number of which may be limited or unlimited. The parapodia, fleshy outgrowths on each segment following the peristome, contain bundles of setae (movable bristles), which differ in structure and function among species and thus provide a key to ... WebThe mouth lies in the centre of the oral surface in regular urchins, or towards one end in irregular urchins. It is surrounded by lips of softer tissue, with numerous small, embedded bony pieces. This area, called the peristome, …
Peristome - Wikipedia
In mosses [ edit] The first is termed haplolepidous and consists of a single circle of 16 peristome teeth. The second type is the diplolepidous peristome found in subclass Bryidae. In this type, there are two rings of peristome... See more Peristome (from the Greek peri, meaning 'around' or 'about', and stoma, 'mouth') is an anatomical feature that surrounds an opening to an organ or structure. Some plants, fungi, and shelled gastropods have peristomes. See more In pitcher plants, the peristome is a reflexed ring (or partial ring) of tissue that surrounds the entrance to the digestive tube in these plants. It often (for example in Cephalotus and Nepenthes) possesses sharp, overhanging 'teeth' which aid in prey retention. It is often … See more The peristome is the margin of the aperture of a gastropod shell. It is the edge of the lip of the shell. This part is sometimes reflected (turned back) or thickened once the … See more In mosses, the peristome is a specialized structure in the sporangium that allows for gradual spore discharge, instead of releasing them all at once. Most mosses produce a capsule with a lid (the operculum) which falls off when the spores inside … See more The basidiocarps of some gasteroid fungi - such as puffballs and earthstars - release spores through an apical opening that is termed a peristome and is variously delimited, its … See more The peristome is any of the structures or sets of parts that surround the mouth or invertebrates such as echinoderms or earthworms See more • Dictionary definition See more Web…opening by apical cap (operculum); peristome teeth usually surrounding the sporangium mouth and influencing spore release; columella usually present, encircled or overarched … flowers in the attic jason priestley
Peristome definition and meaning Collins English Dictionary
WebThe peristome is also reduced and elliptical, with limited mouth notches. The ambulacrum are polygeminate, with between 9 and 14 pairs of pores per plate, arranged in more or less regular arcs, sometimes almost in bands. All ambulacral plates bear a single, large primary tubercle, occupying almost the entire surface of the plate. WebJul 7, 2024 · The peristome is a fringe of teeth-like projections found at the mouth of the capsule. How do the peristome teeth affect spore dispersal? Dry Epiphragm taut, teeth stretched, gaps develop between teeth, allowing spores to sift out. Peristome teeth long and hair-like. Wet Teeth elongate and are tightly wrapped around each other. WebThe peristome is the opening in the test associated with the mouth. In life it is covered in a flexible connective tissue membrane with embedded platelets. In cidaroids (above left) … flowers in the attic grandmother