蚤消化系统的研究：14种蚤前胃的结构

STUDIES ON THE DIGESTIVE SYSTEM OF FLEAS: STRUCTURESOF THE PROVENTRICULI OF FOURTEEN FLEA SPECIES

蚤的前胃结构与其传病机制密切相关。本文应用解剖、组织切片和扫描电镜研究１４种蚤的前胃、前胃的外部形态可分为：球状、椭球状、管状和圆台状。的胃刺内部有原生质。前胃刺的末端形态可分为：钩形、弯叉形、叶形、针形、矛形、喇叭口形、“Ｗ”形、大叉形、小叉形、马刀形、锥形和舌形。前胃刺包括有齿刺和无齿刺两类，有齿刺上齿的分布范围有：１／２、１／３、１／４、２／３和刺全长。未观察到花蠕形蚤Ｖｅｒｍｉｐｓｙｌｌａ ａｌａｋｕｒｔ和缓慢细蚤Ｌｅｐｔｏｐｓｙｌｌａ ｓｅｇｎｉｓ的前胃刺上有齿。前胃刺末端形态和齿的分布呈现出科的相似性。前胃刺基部的形态有：四棱形、正方形、五边形、不规则五边形、六边形、卵形和圆形。致痒蚤Ｐｕｌｅｘｉｒｒｉｔａｎｓ和印鼠客蚤Ｘｅｎｏｐｓｙｌｌａｃｈｅｏｐｉｓ的前胃刺较粗长、骨化强、在刺两侧具较密的齿且多分布于刺的一半以上，这些特征可能适宜于鼠疫杆茵的生存与大量聚集。没有观察到使潜蚤Ｔｕｎｇａｃａｌｌｉｄａ的前胃和前胃刺。

he structure of proventriculus of 14 flea species was studied by means of dissection, histological section and scanning electron microscopy. They include Tungacallida, Pulex irritans, Ctenoccphalides felis felis, Xenopsylla cheopis, Vermipsyllaalakurt, Lentistivalius affinis, Neopsylla specialis specialis, Neopsylla dispar fukienensis, Ctenophthalums eothenomus, Leptoplylla segnis, .Macrostylophora euteles,Noroptyllus wualis bo--seensis, Monopsyllus anisus, Syngenoptyllus calccatus. Theresults are summarized as follows.The external shape of proventriculus could be divided into four types: globular,ellipsoid, tubular and cono truncado. There are altogether twelve types of the apical shape of proventricular spines, i.e., (1 ) hooked, (2) curved and forked, (3)lobular, (4) acicular, (5) spearhead, (6) flaring, (7)W--shaped, (8) big forked,(9) small forked, (10) sabre--shaped, (11) cone and (12) ligulate. There is a seriesof lateral teeth on the spines and the distribution ranges are one half, one-third,one-fourth, two-thirds or throughout the entire length of the spine. The proventricular spines of the vector fleas of plague, Pulex irritans and Xenopsylla chcopis,have similar features: the spines being broad, long and strongly sclerotized; lateralteeth distributed densely and over one half of the spines. It seems that these structures favour the growth and aggregation of bacteria. However, the teeth are lacking in Vermipsylla alakurt and Leplopsylla segnis. The proventriculus is absentin Tunga callida, a characteristic of the species.