科研之友
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摘要
Some of the gastropods of the Baja California peninsula are of commercial value, but the majority are not. Among the less commercially valuable species are members of the genus Tegula, which are ecologically important because of their abundance and the trophic level they occupy. Mature specimens of T. eiseni, T. funebralis, T. aureotincta, T. gallina, and T. regina were collected from two rocky reefs close to Bah赤a Tortugas, B.C.S. and were processed using a paraffin-embedding technique. All of these species are dioecious, without external sexual dimorphism; in adults, the female gonads are green moss colored while male gonads are cream colored. The gonadal tissue is limited externally by a single ciliated cylindrical epithelium with plentiful granular glandular cells and is located on a connective tissue and muscular fiber layer. This layer is invaginated towards the gonad core, creating radially distributed trabeculae where the germinal tissue is found. The size of the oogonia fluctuates between 10 and 30 米m, and that of the developing oocytes ranges between 30 and 140 米m. In this stage, the cells are pyriform with a peduncle linked to the trabeculae. Mature oocytes have an average size of 165 米m and present a well-defined chorion and a large quantity of vitelline platelets that occupy the whole cytoplasm. In the five species, the development in males is similar until the spermatid stage. In general, the average size of the spermatic cell nucleus is 2.5 米m, while the flagellum length varies from 35 to 45 米m. The species differ in the shape of the acrosome. La costa oriental de la Pen赤nsula de Baja California se caracteriza por ser una zona de alta productividad biol車gica en la que coexiste un elevado n迆mero de gastr車podos, algunos de alto valor comercial y otros, la gran mayor赤a, no. Tal es el caso de diversas especies del G谷nero Tegula, las cuales, ya sea por su abundancia y/o por el nivel tr車fico que ocupan dentro de la comunidad, resultan relevantes. Ejemplares adultos de Tegula eiseni, T. funebralis, T. aureotincta, T. gallina y T. regina, fueron colectados en dos arrecifes rocosos pr車ximos a Bah赤a Tortugas, B.C.S. y procesados mediante la t谷cnica de inclusi車n en parafina. Las especies estudiadas son dioicas sin dimorfismo sexual externo; la g車nada de las hembras adultas es color verde musgo, mientras que la de los machos es color crema. La g車nada se encuentra limitada externamente por un epitelio cil赤ndrico simple ciliado con abundantes c谷lulas glandulares granulares, que se asienta sobre una capa de tejido conjuntivo y fibras musculares. Esta ca
