xenomorphism n. [Gr. xenos, stranger; morphe, form] (MOLL: Bivalvia) Sculpture in the umbonal region of the unattached valve that resembles the substratum on which the attached valve was fixed. xenomorphic a.
xenoparasite n. [Gr. xenos, guest; para, beside; sitos, sit] An ecosite that becomes pathogenic due to a weakened resistance on the part of its host.
xerarch succession A series of community changes from bare land to climax.
xeric a. [Gr. xeros, dry] Arid; lacking in moisture; adaptation to dryness.
xerophilous a. [Gr. xeros, dry; philos, loving] Living in dry places.
xerophobous a. [Gr. xeros, dry; phobos, fear] Intolerant of arid conditions.
xerosere n. [Gr. xeros, dry; L. serere, to join] A sere arising under dry conditions. see lithosere, hydrosere.
xerothermic fauna Animals found in warm, dry conditions.
xiphidiocercaria n. [Gr. xiphos, sword; kerkos, tail] (PLATY: Trematoda) Cercaria with a long tail and a stylet in the anterior rim of the oral sucker. see microcotylate cercaria, microcercous cercaria.
xiphiform a. [Gr. xiphos, sword; L. forma, shape] Sword-shaped.
x-organ 1. (ARTHRO: Crustacea) In Decapoda, a neuro-secre-tory organ situated in the eye stalk, and the cephalon of sessile-eyed crustaceans; frontal organs in Anostraca. see organ of Bellonci, frontal eye complex, frontal organ. 2. (kinor) In female chaetonotoids that lack an oviduct, a sac-like structure through which the eggs pass to the surface of the body.
xylanase n. [Gr. xylon, wood; -ase, enzyme] (ARTHRO: In-secta) In wood ingesting Cerambycidae, an enzyme that hydrolizes xylosan to xylose.
xyloid a. [Gr. xylon, wood; eidos, like] Like or resembling wood; ligneous.
xylophagous a. [Gr. xylon, wood; phagein, to eat] Wood-eating.
xylotomous a. [Gr. xylotomous, wood-cutting] The ability to cut or bore into wood.
xyphus n. [Gr. xiphos, sword] (ARTHRO: Insecta) In Heterop-tera, a posteriorly directed triangular process of the mesosternum.
Was this article helpful?