THE INDUCTION AND EXTRACTION OF METALLOTHIONEINS IN ARTEMIA

A small amount of heavy metal binding protein,identified by BioRad Protein Assay,has been iso-lated from the adult brine shrimp,Artemia franciscanus.This protein has an apparent molecular weight be-tween 6000 to 9000 dalton.a UV absorption peak at 260 instead of 280 nm like most proteins;andhas high affinity towards binding with radioactive labeled ~(109)Cd.These characteristics are similarto that of metallothioneins reported for many vertebrate and invertebrate,marine and terrestrialanimals.After the brine shrimp is exposed to a small amount of Cd~(2+)for 24 h,a large amount ofmetallothionein can be isolated,showing the inducibility of this detoxifying protein in the adult Artemiain a short period of time.     

RADIOCARBON DATING OF A PEAT DEPOSIT IN THE CUCAMONGA FAULT ZONE,CALIFORNIA*

A sequence of peat beds was deposited in a small sag pond along the Cucamonga fault zone during late Holocene. The stratigraphic section of this deposit is described; several beds have been radiocarbon dated. Comparison of radiometric and stratigraphic chronologies allows reconstruction of the geomorphic history of the sag pond, which extends back 3000 years, and establishes evidence that the fault has been active within the very recent geologic past.     

Late Quaternary paleolimnology of Walker Lake,Nevada

Diatoms, crustaceans, and pollen from sediment cores, in conjunction with dated shoreline tufas provide evidence for lake level and environmental fluctuations of Walker Lake in the late Quaternary. Large and rapid changes of lake chemistry and level apparently resulted from variations in the course and discharge of the Walker River. Paleolimnological evidence suggests that the basin contained a relatively deep and slightly saline to freshwater lake before ca. 30 000 years B.P. During the subsequent drawdown, the Walker River apparently shifted its course and flowed northward into the Carson Sink. As a result, Walker Lake shallowed and became saline. During the full glacial, cooler climates with more effective moisture supported a shallow brine lake in the basin even without the Walker River. As glacial climates waned after 15 000 years ago, Walker Lake became a playa. The Walker River returned to its basin 4700 years ago, filling it with fresh water in a few decades. Thereafter, salinity and depth increased as evaporation concentrated inflowing water, until by 3000 years ago Walker Lake was nearly 90 m deep, according to dated shoreline tufas. Lake levels fluctuated throughout this interval in response to variations in Sierra Nevada precipitation and local evaporation. A drought in the Sierras between 2400 and 2000 years ago reduced Walker Lake to a shallow, brine lake. Climate-controlled refilling of the lake beginning 2000 years ago required about one millennium to bring Walker lake near its historic level.Through time, lake basins in the complex Lake Lahontan system, fill and desiccate in response to climatic, tectonic and geomorphic events. Detailed, multidisciplinary paleolimnologic records from related subbasins are required to separate these processes before lake level history can be reliably used to interpret paleoclimatology.This is the fifth of a series of papers to be published by this journal that was presented in the paleolimnology sessions organized by R. B. Davis and H. Löffler for the XIIth Congress of the International Union for Quaternary Research (INQUA), which took place in Ottawa, Canada in August 1987. Drs. Davis and Löffler are serving as guest editors of this series.     

Comparative studies on the larval development of the penaeid shrimps,Penaeus Chinensis,P. merguiensis andP. penicillatus

The morphology of larval and 1st postlarval stages ofPenaeus penicillatus are described. Results from comparative studies on larval development ofP. penicillatus, P. merguiensis andP. chinensis are as follows: These three species could not be identified during their naupliar stages. In the 1st protozoea, the antennule L1/L2 value is 1.7–2.0 inP. merguiensis, but less than 1.7 inP. chinensis andP. penicillatus; in the 2nd protozoea, the supra-orbital spine inP. chinensis is not bifurcated, while those ofP. merguiensis andP. penicillatus are bifurcated; in the 3rd protozoea, there is a minute (or no) dorso-median spine on the posterior margin of the 1st and 2nd abdominal somite inP. chinensis, but they are prominent inP. merguiensis andP. penicillatus. In the mysis and 1st postlarval stages,P. chinensis differs fromP. merguiensis andP. penicillatus in having 9 (8 in the other 2 species) long setae on the exopod of pereopods 1–3; additionally, one dorsal tooth appears on the rostrum ofP. chinensis in the 2nd mysis and that of the other 2 species in the 3rd mysis;P. chinensis has 2 (mostly) or 1 dorsal tooth on the rostrum in the 3rd mysis and 2–3 in the 1st postlarva, whileP. penicillatus andP. merguiensis have only 1 in the 3rd mysis and 1st postlarva. Comparative studies on larval development showedP. penicillatus has closer affinity withP. merguiensis than withP. chinensis. Contribution No. 2218 from the Institute of Oceanology, Chinese Academy of Sciences     

青海察尔汉盐湖深水盐田光卤石矿物化特性研究总结报告

虽然国家“七五”重点工程一青海钾肥厂已转入生产阶段近九个年头，但对用盐湖卤水通过大面积深水盐田（池内水深1M左右）晒制光卤石在我国至今缺乏成熟的经验。本文就是通过对青海钾肥厂十平方公里盐田的西光卤石池光卤石矿六年的定期取样分析资料，总结出深水盐田光卤石矿的物化特性及其形成机理，以便为其它与将来特别是青钾二期工程更大面积的盐田生产和盐田管理提供基础和指导。本文是目前对深水盐田光卤石矿物化特性进行全面描述的唯一资料。     

Distribution patterns of benthic juvenile gobies in and around seagrass habitats: effectiveness of seagrass shelter against predators

The significance of a sheltering effect of seagrass against predators influencing the distribution patterns of benthic juveniles of the streaked goby Acentrogobius sp. was investigated by field experimentation in and around seagrass habitats at Moroiso and Aburatsubo Bays, Miura Peninsula, Japan. In the former bay, juveniles were always restricted to the seagrass bed, whereas at the latter, they also occurred over the surrounding bare sand substrate. Juveniles never occurred inside predator-exclusion cages over unvegetated sand in Moroiso Bay. Additionally, a tethering experiment resulted in similarly small numbers of juveniles being preyed upon in both the seagrass bed and over bare sand, suggesting that the predation risk for juveniles may not differ between the habitat types and was thus not responsible for their distribution patterns. The availability of symbiotic shrimp burrows, which were scarce in bare sand in Moroiso Bay but abundant in a similar area in Aburatsubo Bay, was also hypothesized as a determinant of distribution pattern. In a manipulative experiment at Aburatsubo Bay, however, juveniles showed no response to alterations in the availability of symbiotic shrimp burrows, indicating that neither the sheltering effect of seagrass against predators nor the availability of symbiotic shrimp burrows was a significant factor in streaked goby juvenile distribution. Food availability may be a determinant, because food abundance patterns were concordant with the juvenile distribution pattern.     

海水养虾池的几种致病弧菌生态

研究了对虾养成期中养殖海水和虾体中弧菌的数量变化、种类组成及其相关因素，初步探讨了弧菌数量与虾病的关系。结果表明，无论养殖水和虾作中弧菌检出率均为100％，养殖水中弧菌测值为2.3×102～4．9×105个／dm3，均值1．78×105个／dm3；虾体中弧菌数是4.4×102～2．9×106个／g，均值为2.9×104个／g。出现于虾体和养殖水中的弧菌有副溶血弧菌（Vibrioparahaemolyticus）、溶藻弧菌（Vibrioalginolyticus）、创伤弧菌（Vibriovulnificus）、河弧菌（Vibriofluvialis）和模拟弧菌（Vibriomimicus）．其中副溶血弧菌和溶藻弧菌是各地的优势种。检测期间，虾池水的生化和理化因素较稳定，对弧菌数量无明显影响。个别虾池出现虾病与弧菌数量较高有关。以分离菌株进行浸染试验的结果表明，副溶血弧菌和溶藻弧菌能使对虾出现与病虾同样的病症。