2006  Vol. 2  No. 5

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Research Paper
Abstract:

In this paper, the growth characteristics of Babylonia areolata in outdoor tank-culture was studied. The body height and body weight of 1 400 samples at different growth stages in one year old age were measured. The results indicated that: (1)The relationship between body height and body weight growth equations of artificial tank-culture B.areolata could be described by the power function, W=0.2349H2.89(R2=0.9822, P < 0.01);(2)The body height and weight growth curve of B.areolata in one year old age was rising gradually. The velocity of growth was 0.11 mm·d-1 in terms of body height, and 0.03 g·d-1 in terms of body weight. The instantaneous growth rate was 0.69% in terms of body height (IGRH), and 1.96% in terms of body weight (IGRW).It showed that they grew very quickly in one year old age, and without growth turning point.At the same time, the growth of B.areolata was significantly affected by water temperature. When the water temperature decreased to 20.2℃, the velocity of growth of body height and weight were decreased to 0.09 mm·d-1 and 0.01 g·d-1, respectively, and the IGRH and IGRW were decreased to 0.42% and 0.64%, respectively.

Abstract:

Under laboratory conditions, shrimp aquaculture effluent was treated with six densities of Gracilarla tenuistipitata var.liui (0, 10, 20, 25, 30 and 35 g·L-1) respectively for comparing the efficiency of the degradation of NH4+, NO2-, NO3-, PO43- in 24 h. The obtained results showed that all of the five densities used had obvious positive effects on the degradation of NH4+ and PO43-(P < 0.05). The optimal density of Gracilarla tenuistipitata var.liui for degradation was 30 g·L-1, which can result in 69.69% and 92.62% of relative rates of degradation for NH4- and PO43-, respectively.

Abstract:

The morphology and histology of digestive tract of Carcinoscorpius rotundicauda have been studied. The digestive tract of C. rotundicauda was divided into three parts: fore-gut(cavum buccale, oesophagus, craw and gizzard), mid-gut and hind-gut(rectum and anus). The fore-gut and hind-gut were lined with cuticle, which was lacking in the mid-gut. The circular muscle of cavum baccale belong in striated muscle, and there were a number of glands in the cavum baccale. The circular muscle of oesophageal was not continutive, and there were few longitudinal fibers in it. The gizzard was enclosed by a layer of circular muscle, and the longitudinal fibers were arranged in discrete bundles, and there were some radial muscles in the gizzard. There were a number of glands in the intestine wall, and two pairs of hepatopancreas tubes. The circular muscle of retum was continutive, and there were amount of glandular tubes in the layer of cuticle of anus. The connective tissue under the epithelium of anus was packed with glandula integumentaria.

Abstract:

The study was conducted to examine the expression of GH mRNA in different tissues of mud carp by semi-quantitative RT-PCR and the effects of recombinant mud carp insulin-like growth factor-Ⅰ(rmcIGF-Ⅰ) on expression of GH in mud carp. GH mRNA detection result of brain of mud carp was positive, and the other tissues detections results were negative, including liver, kidney, spleen, muscle, intestine, gill, gonad, heart and skin. GH mRNA levels increased a little in brain in response to rmcIGF-Ⅰ, but the treated fish exhibited no obvious change in sera GH concentration following rmcIGF-Ⅰ injection.

Abstract:

Florfenicol, the latest generation chloramphenicols, has been specifically developed for veterinary use. Tilapia is a very important cultured fish species in China. Therefore the studies on pharmacokinetics of florfenicol in tilapia will be very helpful to guide the use of the drug. The pharmacokinetics of florfenicol was studied in plasma of tilapia (Oreochromis niloticus × O. aureus) in freshwater at 22℃. The fish weighing about 98 g were forced-fed with medicated feed containing a single dose of 10 mg·kg-1 bodyweight of florfenicol. The pharmacokinetic data derived from the experiment were analyzed by non-compartmental methods based on statistical moment theory. The peak drug concentrations (Cmax) in plasma and muscle were estimated to be 4.46 μg·mL-1 and 6.88 μg·g-1, respectively, and the time to the peak drug concentration (Tmax) in both plasma and muscle was 12 h. And correspondingly the elimination half-lives during elimination phase (T1/2β) were 10.03 h in plasma and 10.97 h in muscle. The drug concentrations in both plasma and muscle maintained above the effective concentrations (MIC≤0.8 μg·mL-1) beyond 40 h following a single oral dose of 10 mg florfenicol·kg-1, and at 168 h after administration, the drug level, was 0.04 μg·mL-1 in plasma and was below detection limit (0.03 μg·g-1) in muscle, which indicated florfenicol was effective against pathogens and rapidly eliminated, resulted in low residue in tilapia, so it was safe to be used. Therefore, florfenicol was of great value for the control of bacterial diseases in fish.

Abstract:

With dilution technique, this paper studied the microzooplankton grazing rate (μ) and the phytoplanton growth rate (g) of Daya Bay in March, 2005. Grazing experiments were conducted at 5 stations within the Bay. The phytoplankton growth rate and microzooplankton grazing rate is about 0.16~1.14 per day, 0.33~1.74 per day, respectively. The percentage of microzooplankton grazing pressure on the phytoplankton standing crop is 47%~258% per day. And the percentage of potential primary production ingested by microzooplankton per day is about 70%~330%. The results showed that Daya Bay water is the typical subtropical water with high μ and g, and the herbivory of microzooplankton and growth of phytoplankton are also influenced by the currents and other factors. Compared with the similar studies in other bays around the world, the grazing pressure of microzooplankton in Daya Bay is at the higher levels.

Abstract:

Species status for Chinese Pinctada fucata, Japanese P. fucata martensii and Australian P. imbricata was investigated using ITSs and AFLP. The results indicated that genetic differentiation among populations of the three nominal species is low, and intraspecific and interspecific genetic distances are overlapping, as revealed by ITSs and AFLP markers. Based on AFLP data, phylogenetic analysis showed that most individuals from P. imbricata population are clustered together, consistent with the result from principal component analysis. It was found that the three nominal species are genetically isolated by geographic distance. AMOVA indicated that no more than 6% of the total variation is attributed to interspecific differences. These observations support the hypothesis that the three species are conspecific. According to the priority rule of nomination, the correct name of the species should be P. fucata because Atlantic P. imbricata is reported to be genetically different from Australian P. imbricata.

Abstract:

According to phytoplankton investigation data in spring and summer in Fujian sea area during 2003 to 2004, this paper analyzed and studied the species composition and quantity distribution characteristics in the area. The results showed that 111 species of phytoplankton were identified with 81 species of diatoms occupying 73.0%; the total biomass of phytoplankton in summer was more than that in spring with average 30.9×104 ind·m-3 and 2 645.6×104 ind·m-3, respectively.The total biomass of Mindong fishing ground in spring was highest, Minzhong fishing ground was lowest; but it was contrarily in summer.The total biomass in Minzhong and Minnan-Taiwan bank fishing ground obviously increased with boosting up by warm current, and Minnan-Taiwan bank fishing ground was highest and Minzhong fishing ground was followed with the obvious density area, the biomass was over 40 000×104 ind·m-3. The dominant species were tropical near-oceanic group and tropical oceanic high-salinity group as Chaetoceros lorenzianus, Stephanopyxis palmerana, Rhizosolenia stolterfothii, Trichodesmium thiebautii, Trichodesmium hildebrandtii and Dactylioselen mediterraneus. The species diversity index was low, but the quantity of dominant species was high. The dense areas of phytoplankton were the main fishing ground of trawler and light seine. Compared with the data of historical and adjacent waters, the fluctuation of majority index was large in years; the biomass of phytoplankton increased obviously but the dense area was changed slighly.

Abstract:

Based on twice survey data in the adjacent waters of Zhanjiang port of autumn and winter in 2005, the species composition and stock density of necton were analyzed. The results showed that there were 131 species of necton belonging to 91 genus, 60 families, 16 orders in the waters, among them, fish 89, crustacean 34, cephalopoda 8. The necton mostly belonged to the fauna of Indian-Pacific. The dominant species of fish were warm-water(91.01%), followed by warm-temperate(8.99%), without cold-temperate. The dominant species of crustacean and cephalopoda were warm-water, followed by eurythermal, warm-temperate, without cold-temperate. The catch rates of necton presented seasonal variation obviously, being more in autumn(16.91 kg·h-1) than in winter(10.82 kg·h-1). According to the catch rates, the fish were the most, followed by crustacean and cephalopoda in both seasons. The stock density of necton was 528.44 and 338.13 kg·km-2 in autumn and winter, respectively. In addition, some protective measures for fishery resources were suggested in the paper.

Research Notes
Abstract:

The benzene hexachlorides (BHCs) and dichloradiphenyl trichloroethanes (DDTs) in sediments of some aquaculture ponds in Zhuhai, China were determined in July, 2005. The results showed that the contents of total BHC and total DDT were from 0.36 to 1.67 (arithmetic mean=0.91) μg·kg-1 and 0.95 to 2.59(1.81) μg·kg-1, respectively. The residue levels of ΣBHC, ΣDDT in sediments of the tested area were lower than those of some rivers, lakes and bays, and also under the superior limits of national sediment quality standard for no contamination fishery products. The quality grade of BHCs or DDTs was "basically clean". The ratio of γ-BHC/ΣBHC, (DDE+DDD)/ΣDDT were from 0 to 21.6% and 61.1% to 76.7%, respectively. It may be guessed that BHCs gradually decreased, most residual DDT had decomposed to DDE and DDD, there was little or no BHCs or DDTs distributed into the sediments of Zhuhai aquaculture ponds in recent years. The contents of BHC and DDT were lower than the ERL value of risk evaluation to consumers of bottom feeders.

Abstract:

The PCR technique was used to amplify rDNA-ITS-1 of Lutjanus fulviflamma, then the purified PCR productions were cloned into T-vector and sequenced by M13+/-primers.As a result, 566 bp nucleotide sequences of rDNA-ITS1 were obtained. The average contents of A, T, G and C were 14.1%, 16.1%, 30.2% and 39.6%, respectively, the contents of GC (69.8%) were obviously higher than those of AT. Using these primers, ITS-1 region can be amplified in other four Lutjanus species, but the lengths of ITS-1 were largely different between different species.

Abstract:

This paper uses ActionScript and ASP to accomplish the task of transfer data to flash of dynamic web based on Flash MX 2004 and MS Access 2000. The function of circumgyratetion of scene and specimen is implemented by ActionScript. With the spread of digital earth′s concept, the virtual fisheries specimen museum will become the important branch of fisheries museum.

Review
Abstract:

In this paper, the research progress of the angoitensin converting enzyme inhibitory peptides (ACEIP) from aquatic products at home and abroad was summarized. And the function mechanism of ACEIP, preparation crafts as well as the relationships between structures and effects were discussed.It has the guidable significance for exploiting the ACEIPs from the aquatic materials.

Abstract:

Microsatellite DNAs, or single sequence repeats (SSRs), are small array of one to six tandemly repeated bases that spread throughout the genome. Microsatellite DNAs are highly polymorphic, abundant, co-dominantly inheritant, simple in practice and readily transferable. Thus they have been widely used in many fields and have become one of the most popular molecular markers. Yet microsatellite DNAs need to be isolated de novo from species that are being examined for the first time. There are a number of ways to obtain microsatellite markers from genomic DNA. The aim of the present paper is to review the state-of-the-art methods of microsatellite DNA isolation for reference.