白暨豚的舌

在现代生存的四类淡水豚中,恒河豚(Platanista gangetica)和拉河豚(Pontoporia blain-villei)的舌已有详文报道(Arvy和Pilleri,1970;Yamasaki等,1976a)。亚河豚(Iniageoffrend)的舌也在Yamasaki的文章中作为和上述二种淡水豚舌的比较而述及。白暨豚(Liptes vexillifer)的舌除陈宜瑜等(1975)曾提及外,迄今未有其他报道。鉴此,作者对白暨豚的舌作了解剖学和组织学的观察,现将研究结果报告如下: 白暨豚舌的标本取自幼体、亚成体、成体和老年个体等七头个体。为了比较,还收集了亚河豚、其它海豚类和陆生哺乳类的舌。用10％甲醛固定保存,各项量度根据固定标本测量。白暨豚舌的外形描述以NNC 7909号标本为主,以其它个体的观察为辅。其组

THE TONGUE OF THE BAIJI, LIPOTES VEXILLIFER

Seven specimens of the tongue of Baiji (Lipotes vexillifer) were studied. There are rwo pits on the dorsum of the tongue, which is divided into two parts, the front and the rear, by a connecting line between the two pits. The former consists of the apex linguae and corpus linguae; and the latter, radix linguae. These two pits correspond to the pits of the V-shaped row of the marine dolphins. There are two or three warty projections protruding from the bottom of the pit. Taste buds are found in the epithelium of the warty projections and the lateral wall of the pit. But the taste buds in the young adult (NNC 8003) are less in number than those in the calf (NNC 8005). No. taste bud was found in the old individual (NNC 7405). There are many papillaty projections along the anterolateral margins of the tongue. They are numerous in the calf, but much less in the adult (NNC 7909). In the old individual the projections became atrophied (table 2). Lingual glands, sero-mucous in nature, are well developed in adults. They open on the dorsal surface from the middle region of the posterior part of the tongue to the vicinity of the epiglottis and on the wall of the oropharynx. No sulcus terminalis and foramen caecum as well as the lingual papillae (filiform, fungiform, foliate and circumvallate papillae) can be found. For comparison, tongues of the Inia boliviensis, marine dolphins and terrestrial animals were observed. Measurements of the tongue of the dolphins are shown in table 3. The tongue of Inia also has a V-shaped row of pits, which are seven in number on each side of its posterior dorsum. There is a distinct difference in the ratio between the length of the two parts of the tongue of Lipotes and Inia. The posterior part of the tongue of Lipotes is twice as long as that of the anterior part, but the former is only 18.2% of the latter in Inia. This finding is in agreement with the results obtained by Zhou et al. (1979a, 1979b, 1981a).