2005 Vol. 1, No. 6
The mode of segregation of random amplified polymorphic DNA (RAPD) markers in 27 F1 full siblings of Pinctada fucata from a single pair of parents was studied using eight 10-mer primers screened from 21. Of the total 49 loci amplified, 47 loci are normal, accounting for 95.9%, and two loci are unexpectedly amplified in F1 but not in parents. There are 44 loci segregating in the F1 individuals, accounting for 93.6%. Chi square tests indicate that the segregation of 12 loci are deviated significantly from Mendelian fashion, while the segregation of 32 loci are in line with Mendelian fashion, among which 1:1 segregating loci account for 43.8% and 3:1 segregating loci 56.2%. Among the 32 Mendelian segregation loci, paternal specific, maternal specific and biparental loci account for 28.2%，15.6%和56.2%, respectively, indicating that the number of male specific markers is slightly larger than that of female specific markers. The high percentage of 1:1 segregating loci revealed in this study indicates that RAPD markers are useful in construction of linkage map of P.fucata using F1 family materials based on double pseudo-testcross configuration.
The early morphological development of the temperate fish Miichthys miiuy were described including the observations on the embryo, larval and juvenile fish stages. The fertilized eggs are transparent and buoyant. At the temperature of 25~27℃ and salinity of 32.9, the fertilized eggs developed into larval fish in 19 h. Based on the morphological development, we have established the definition of different stages as the follows: (1) larval fish stage: 1~17 d postfertilization, development of all fins was completed; (2) juvenile fish stage: 18~32 d postfertilization, occipital bone spine appeared and the whole body was covered by scales; (3) young fish stage: 33 d postfertilization. The optimal growing temperature was 25.8~32.2℃ and the salinity was 32.5. The morphological characteristics of the egg size (0.91 mm), oil balls (0.33 mm) and occipital bone spine were found to be different from other species in Sciaenis.
The effect of pH on digestive enzyme activity (protease, amylase, lipase) of alimentary organs (hepatopancreas，stomach，gut ) in yellowfin black porgy (Sparus latus) was studied in this paper. The specific activity of protease at different pH shows that the optimum pH for protease in yellowfin black porgy were 2.8，7.0 and 7.4 in stomach, hepatopancreas and intestinal canal, respectively. The optimum pH for lipase in yellowfin black porgy were 7.6，7.2 and 7.6 in stomach, hepatopancreas and intestinal canal, respectively. The optimum pH for amylase in yellowfin black porgy were were 5.2，4.8 and 6.8 in stomach, hepatopancreas and intestinal canal, respectively.
43 main fish species were collected and 940 stomach contents be got altogether in the adjacent waters of Nansha Islands and reefs. Based on the food habits of those fish analyzed and their food organism ecological groups as well as their digestive organ characteristic, as a general, they may be divided into such five kinds of feeding habits as plankton feeding habit, benthos feeding habit, swimming animals feeding habit, both plankton and benthos feeding habit, both benthos and swimming animals feeding habits. Based on the relationship among each nutrient class in food web, they may primarily be divided into four nutrient classes, i.e., primary producer (marine plants), phytophage animals and miscellaneous feeding habit animals, low and middle carnivorous animals, high class carnivorous animals. And according to the nutrient class divided, 43 species may be devided into low class carnivorous fish, middle class carnivorous and high class carnivorous fish with ratio being 28:10:5 in the adjacent water area of Nansha Islands and reefs. Gymnocranius griseus (Tenminck et Schlegelel ) was the decisive fishing target by trammel net in the adjacent water area of Nansha Islands and reefs. From the view point of food web, it should be strengthened for fishing the enemy fish and competitor of G.griseus, in order to remove the enemies of low class carnivorous commercial fish, thus the biomass of G.griseus may increase.
According to zooplankton 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 226 species of zooplankton were identified with 114 species of copepods occupying 50.4%, and the great majority of species are subtropical and tropical species. The total biomass of zooplankton in summer is more than that in spring with average 90.3 mgm-3 and 150.8 mgm-3. The total biomass in spring is more in the north than in the south as Mindong fishing ground is the first, Minzhong fishing ground is second and Minnan-Taiwan bank fishing ground is the lowest, and the density area is unobvious.It is 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 is highest as the density area is obvious. The dominant species are Undinula vulgaris, Temora turbinate, Acrocalanus gracilis and Eucalanus subcrassus, their density area is the main fishing ground. Compared with historical data or adjacent waters, Undinula vulgaris and Eucalanus subcrassus, are always dominant, the density area is similar.
According to production statistics and resources monitoring data of light seine fishery on Minnan-Taiwan bank fishing ground（11600～11930E，2200～2430N）during 1987 to 2003 in Fujian, this paper studied and analyzed the status, developmental evolvement and utilization status of resources. The results showed that the light seiner had decreased continually with the station in marine fishery declining constantly due to development of single trawlers and drift gill net; fishing vessels became large and fishing ground was pushed to deep water,significant development had been achieved in light-source fittings technology; Decapterus maruadsi was dominant in the catch, the percent of Pneumatophorus japonicus increased and Sardinella aurita fluctuated obviously. This paper also put forward a series of management suggestion of optimizing fishing structure and reasonable utilizing the fisheries resources such as to improve and enhance the fishing technology and competitive ability of light seine fishery etc.
In order to increase bacteria production and ratio of spore formation, experiments were conducted to obtain the best fermentation condition and media, and to determine the growth curve under the most favourable culture. The most favourable fermantation for strain D-1 was 30℃ in temperature, 6.5~6.8 in initial of media pH, 5% inoculum size, and 100 mL media per 500 mL flask in volume. Suitable culture medium was obtained through testing the single effect of medium elements on growth of D-1, including carbon sources, nitrogen sources, inorganic salt and growth factor. The optimal prescription for D-1 fermentation, as determined by orthogonal testing, was composed of 2% maize starch, 2.5% peptone, 0.8% NaH2PO4,1.5% maize syrup, 0.05% MgSO47H2O and 0.1%MnSO4(3.08%). To obtain the best inoculate and culture time, the growth curve of D-1 was determined under the most favourable medium and culture conditions. As determined from the growth curve, the best inoculate time should be 18~20 h, and culture time should be 26 h.
Four species of aquatic products as Tilapia niloticus, Decapterus maruadsi, Litopenaeus vannamei and Crassostrea rivularis were pretreated by perchloric acid（HClO4）solution to extract the total volatile basic nitrogen（TVBN）,which was determined by nitrogen auto analyzer. The influence of different concentration of HClO4 solution, extracting time and keeping time of the extract before distillation on determination was studied. The results showed that the recovery was between 98.42% and 101.18%, RSD was below 1.40%,by determinating the TVBN in aquatic products after the samples had been homogenized for 2 minutes at 0.6 molL-1 HClO4 solution. The result of this method had no significant difference compared with the distillation in GB/T 5009.44,and the operation was easy and rapid.
Based on marine fishery statistics data in Liaoning province, an analysis of marine fishery yield structure was made, the surplus yield model was used to calculate the maximum sustainable yield, and the forecasted yield of marine culture, pelagic fishing and each domestic fishing sea over the period from 2004 to 2010 was calculated by using autoregressive integrated moving average model ［ARIMA(p,d,q)］ and grey model theory［GM(1,1)］. The result indicated that offshore fishing yield in Liaoning province, which had overrun maximum sustainable yield,would increase on the certain degree over the period from 2004 to 2010 if some effective measures wasn't be adopted. Compared with the number of 2003 in Bohai Sea and Yellow Sea, the marine fishing yield would increase by 234.0 thousand tons and 237.9 thousand tons. Furthermore, compared with the number of 2003 in mariculture and pelagic fishing, the yield would increase by 85.9 thousand tons and 2 424.0 thousand tons. And a discussion about the structure regulation of marine fishery yield was made.
five diets added feed additive Stafac-500（Stafac）0，20, 40, 60 or 80 mgkg-1 diet were conducted to determine the weight gain (WG, %), survival, feed conversion ratio (FCR) for Litopenaeus vannamei juvenile (weight 0.22 g) at indoor concrete pools（0.90 m0.60 m1.0 m）for 8 weeks. Groupers of 60 animals were used in each pool, in triplicate WG of the shrimp fed five diets contained feed additive Stafac-500 were 1 10543，1 11533，1 15022，1 19253 and 1 27233, respectively；and FCR were 1.560.11, 1.510.02, 1.450.01, 1.420.10 and 1.490.02, respectively. The result showed that shrimp fed trial diets contained feed additive Stafac-500 40, 60 and 80 mgkg-1 diet superior to the control. However, dietary Stafac-500 (Stafac）did not affect the whole-body composition among shrimp fed with the various diets.
The research of planktonic Ostracoda has attracted much attentions. This paper makes a review on the shape and classification, geographic distribution and diversities of species, and the ecological groups of planktonic Ostracoda since 1980s. Furthermore, the diurnal vertical migration of planktonic Ostracoda and its relations with the marine environment are also discussed.
The most important bacterial diseases such as vibriosis, winter ulcer, photobacteriosis, furunculosis, marine flexibacteriosis, pseudomonadiasis, streptococciosis, bacterial kidney disease(BKD), mycobacteriosis and edwardsiellosis, yersiniaosis encountered in the rapidly developing mariculture industry are described, including the pathogenic bacteria and diagnosis of these diseases. To reduce the outbreaking of fish diseases, vaccination of cultured fish for control of specific bacterial disease is now a common practice. So the studies of vaccines for fish is also described in this review. These assessments will benefit for marine fish aquaculture and bacterial diseases prevention.