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浙江乐清湾泥蚶的繁殖习性和生长特性 总被引:3,自引:0,他引:3
乐清湾泥蚶雌雄异体,在外形上难以区别,成熟时性腺包被整个内脏团,雌性性腺呈红色或桔黄色,雄性性腺呈乳白色,无性变现象。一般2龄性成熟,但在条件较好的蓄水塘中养殖的泥蚶也有1龄性成熟的现象。自然繁殖期为6月上旬至8月下旬。卵生,体外受精。产卵量大,一颗壳长为2~3em的亲蚶可产卵200—300万颗。乐清湾泥蚶终身生长,但生长速度较慢,且受水温、饵料、潮区、底质和养殖密度等因素影响,一般2年或3年方能达到商品规格。壳长生长前期快,后期慢;体重生长前期慢,后期快。壳长L(mm)与体重W(g)符合W=0.0004L^2.9949(R^2=0.9964)关系。 相似文献
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J. Suwanjarat 《Helgoland Marine Research》1999,53(2):85-91
In this paper spermatogenesis and sperm ultrastructure of the cockle Anadara granosa are studied using transmission electron microscopy. The spermatocyte presents electron-dense vesicles and the arising axoneme
that begins to form the flagellum. During spermatid differentiation, proacrosomal vesicles appear to migrate towards the presumptive
anterior pole of the nucleus; eventually these vesicles become acrosome. The spermatozoon of Anadara granosa is of the primitive type. The acrosome, situated at the apex of the nucleus, is cap-shaped and deeply invaginated at the inner
side. The spherical nucleus of the spermatozoon contains dense granular chromatin and shows invagination at the posterior
poles. The centriole shows the classic nine triplets of microtubules. The middle piece consists of the centriolar complex
surrounded by five giant mitochondria. It is shown that the ultrastructure of spermatozoa and spermiogenesis of Anadara granosa reveals a number of features that are common among bivalves.
Received: 29 September 1998 / Received in revised form: 20 May 1999 / Accepted: 14 June 1999 相似文献
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本文以泥蚶(Tegillarca granosa)为实验对象,研究不同大小个体在不同pH(6.5 ~ 9.5)静水水体中的清滤率、滤食率和吸收率。泥蚶共3组,分别为小规格、中规格和大规格,其壳长分别为9.12 mm、22.38 mm、32.35 mm。结果表明,在pH为8.5时,泥蚶清滤率由高到低依次为大规格、中规格、小规格;滤食率由高到低为中规格、大规格、小规格;吸收率由高到低为中规格、小规格、大规格。虽然大规格泥蚶有最高的清滤率,但结合吸收率和滤食率,中规格泥蚶具有更高的摄食和吸收能力。双因素方差分析显示,在清滤率、滤食率和吸收率的实验中,泥蚶受pH快速变化的影响程度均与其规格有关(P < 0.05)。随pH变化,清滤率受影响程度由小到大为小规格(P < 0.05)、中规格(参照)、大规格(P > 0.05);滤食率受影响程度由小到大为大规格(P > 0.05)、小规格(参照)、中规格(P < 0.05);吸收率受影响程度由小到大为小规格(P > 0.05)、中规格(参照)、大规格(P < 0.05)。中规格泥蚶的滤食水平受pH变化的影响较大,大规格泥蚶的吸收率受pH变化的影响较大。 相似文献