云南特有螺类光肋螺蛳主要生物学特征研究

Study on main biological characteristics of an endemic gastropod Margarya mansugi in Yunnan,China

光肋螺蛳(Margarya mansugi)是仅分布于云南省的特有螺类。受过度捕捞、栖息环境破坏等人为因素影响,光肋螺蛳自然种群急剧萎缩,目前已被世界自然保护联盟列为极危物种。由于光肋螺蛳的研究资料匮乏,其生物学特征尚未被完全掌握,制约了光肋螺蛳保护对策的制定。为此,通过室内人工驯养观察,记述了光肋螺蛳的形态、活动习性、食性、生长和繁殖等主要生物学特征。光肋螺蛳壳质厚且坚硬,呈长圆锥形,褐色,角质厣,螺壳一般有5~6个螺层,体螺层有4条环肋,雌螺体型一般比同龄雄螺大;喜栖息在水体底层,夜晚活动频率明显高于白天;主要以藻类为食,成螺经驯化可摄食人工配合饲料;仔螺、幼螺和成螺的生长速度顺次降低;性成熟时间需要两年以上,卵胎生,终年生产,一般在白天交配,交配时间7~10 h,分批产仔,每次产仔1~2只,观察到的一只雌螺分9批产仔,共产仔螺14只。从受精到仔螺产出需85 d以上。本研究可为光肋螺蛳基础生物学研究积累资料,同时也可为高原湖泊特有螺类的人工驯养繁育提供参考。

Margarya mansugi is an endemic gastropod only distributed in Yunnan,China. Due to overfishing and habitat environment damage,the natural population of M. mansugi has shrunk sharply,and has been listed as critically endangered species by IUCN. Due to the lack of research data,the biological characteristics of M. mansugi have not been fully mastered,which restricts the formulation of its protection countermeasures. In this study,the main biological characteristics of M. mansugi,such as morphology,activity habits,feeding habits,growth and reproduction,were observed during indoor artificial domestication experiments. The shell of M. mansugi is thick and hard,brown,long conical,and horny. The shell generally has 5 to 6 layers and the body layer has 4 ring ribs. The females are generally larger than the males of the same age. Margarya mansugi likes to inhabit the bottom of the water body,and its activity frequency at night is significantly higher than that during the daytime. Margarya mansugi mainly feeds on algae,and the adults can feed on artificial feed after domestication. The growth rate of the larval,the young and the adult of M. mansugi decrease in turn. Margarya mansugi was viviparous and can spawn throughout the year. Sexual maturity takes over two years for M. mansugi,and the mating usually takes place in the daytime and lasts for 7 to 10 hours. Margarya mansugi spawn in batches,giving birth to 1 to 2 larval gastropods each time. A female M. mansugi was observed to give birth to 14 offspring in 9 batches. It takes more than 85 days from fertilization to birth. The present results can accumulate data for the basic biological research of M. mansugi and provide reference for the artificial domestication and breeding of endemic snails in plateau lakes.