A description of Ucides occidentalis Ortmann, 1897 (Crustacea : Decapoda : Ocypodidae) zoea I.

ABSTRACT

In order to facilitate the ecological study of the economically important red mangrove crab Ucides occidentalis, we describe the zoea I phase using samples hatched from gravid females taken from the Guayas River Estuary of Ecuador. No other phases of this species’ larval development have been described. The morphological differences between this developmental phase in U. occidentalis and its single congener U. cordatus that may be diagnostic include the number of segments in the pleon, the setation pattern of the basial endopodite of the maxillule, and, in maxillipeds I and II, the segmentation of the terminal plumose natatory setae.     

锯缘青蟹抱卵蟹孵化的初步研究

选择性腺发育好的雌蟹 ,经催产后大部分个体在 2～ 14d内即可抱卵 ,抱卵率通常在 6 5 %左右 .抱卵的青蟹在水温 2 3～ 2 9℃ ,盐度 2 5～ 30下 ,经过 10～ 19d即可孵出幼体 .水温高 ,孵化时间短 ;水温低 ,孵化时间长     

饥饿对锯缘青蟹幼体生化组成的影响

对锯缘青蟹（scylla serrata)刚孵化幼体在饥饿状态下生化组成的变化进行分析测定，为合理投饵和提高青蟹早期幼体的成活率提供理论依据。研究发现：1）饥饿幼体同时动用蛋白质和脂类作为能量来源，且以脂类为主，当幼体饥饿超过1．5d，脂类储存就已接近匮乏；2）饥饿的幼体明显地保留高度不饱和脂肪酸20：4n-6和20:5n-3（EPA），而2：6n-3(DHA)的保留程度很低，饱和脂肪酸16：0，单不饱和脂肪酸16：1和18：1是主要的供能脂肪酸；3）在饥饿状态下，幼体蛋氨酸和亮氨酸的比例略为升高，脯氨酸的比例有所降低，其他氨基酸的比例基本不变。上述结果表明，应尽早投喂富含22：6n-3(DHA)的高脂食物，以保证早期幼体的生长发育，提高幼体成活率。     

The first zoeal stage of Harrovia albolineata Adams and White, 1848 (Crustacea: Brachyura: Pilumnidae), with a note on Eumedonine systematics

The first zoeal stage of Harrovia albolineata Adams and White, 1848 (subfamily Eumedoninae) is described. The zoea has a preponderance of pilumnid rather than parthenopid characters, and supports recent views that the Eumedoninae should be transferred from the Parthenopidae to the Pilumnidae. This zoeal stage is compared with those of Echinoecus pentagonus, the only other eumedonine whose larval development is known, and differs mainly in the structure of its abdomen and carapace. The status of the subfamily Eumedoninae is also briefly discussed.     

温度对锯缘青蟹状幼体呼吸和排泄的影响

用水瓶法和径流装置测定了锯缘青蟹各期状幼体(Z1～Z5)在不同温度(22、24、26、28、30和32℃)下的耗氧率和氨氮排泄率.实验结果表明,耗氧率和氨氮排泄率随温度的升高而升高,但各期幼体之间存在差异;Q10值表明,最适温度Z1和Z2是24～26℃,Z3和Z4是28～30℃,而Z5是26～28℃;耗氧率和氨氮排泄率与幼体干质量呈幂函数关系,M=aDWb,耗氧率和氨氮排泄率的a值范围分别是119.26～304.64和508.13～942.17,平均值分别为180.23和754.74;b值范围分别是-0.6724～-0.5155和-0.7729～-0.4536,平均值分别为-0.5865和-0 6131;不同温度下各期幼体的O/N平均值为15.6,青蟹幼体主要以蛋白质代谢物质;耗氧率和氨氮排泄率与温度和体重的二元回归方程分别为R=14.83+0.526T-0.090DW(r2=0.8211,n=26)和E=6.09+4.47T-0 376DW(r2=0.7796,n=26),F检验表明相关性极显著(F相似文献   

The larval development of the mud shrimp Upogebia yokoyai Makarov, 1938 (Decapoda: Gebiidea: Upogebiidae) reared under laboratory conditions

Larval development of the mud shrimp Upogebia yokoyai Makarov, 1938 Makarov, VV. 1938. Crustacea Anomura. Fauna USSR. 10;3, Moscow, Leningrad: AN SSSR.  [Google Scholar] (Decapoda: Gebiidea: Upogebiidae) is described and illustrated for the first time from material reared in the laboratory. The development includes four zoeal stages and a megalopa. At 20–22°C the megalopa was attained 16 days after hatching. The zoeae of U. yokoyai are distinguishable from those of the sympatric species Upogebia major and Upogebia issaeffi, inhabiting Russian waters of the Sea of Japan, by the presence of two pairs of spines (posterolateral and posterodorsal), each on the fourth and fifth pleonal somites. The megalopa of U. yokoyai differs in the length of the rostral spine, shape of telson and number of antennular aesthetascs.     

Larval development and emigration behaviour during sea-to-land transition of the land hermit crab Coenobita brevimanus Dana, 1852 (Crustacea: Decapoda: Anomura: Coenobitidae) under laboratory conditions

To determine the early life history of the land hermit crab Coenobita brevimanus Dana, 1852, larvae were cultured individually in the laboratory. The zoeal and the megalopal stages are described and illustrated. The larvae developed through four planktonic zoeal stages to the megalopal stage. The major differences in the zoeal characters between C. brevimanus and other described Coenobita species were found in the armature of the pleomeres, whereas the character of pleomeres of C. brevimanus zoeae is the same as that of the coconut crab Birgus latro, a different genus in the same family. Morphological similarity was also found in segmentations of antennules and antennae in megalopae between C. brevimanus and the coconut crab. Megalopae of C. brevimanus were cultured in containers holding seawater and a hard substrate. These crabs migrate from the sea to land after developing a habit of acquiring gastropod shells.     

梅尼小环藻(Cyclotella meneghiniana Kiits)的培养与利用

通过正交试验研究了梅尼小环藻在人工半海水培养中与水体主要因子（ｐＨ、ＥＤＴＡ钠盐、营养盐）之间的关系．摸索出了梅尼小环藻种群生长繁殖的最适ｐＨ值、ＥＤＴＡ钠盐浓度和营养盐的最优组合．经过生化测定，梅尼小环藻体内维生素Ｃ湿重含量为１７６μｇ／ｇ．梅尼小环藻作为中华绒螯蟹一期状幼体的饵料，状一期幼体到二期幼体的变态率为７０％．