Khalid Abbas

First record of the natural occurrence of hexaploid loach Misgurnus anguillicaudatus in Hubei Province, China

Natural occurrence of hexaploid loach Misgurnus anguillicaudatus detected in central China is reported here for the first time. The evidences from karyotyping, DNA content analysis and nuclear volume measurements were described to confirm the hexaploid nature of the identified individual.

Comparative and evolutionary analysis in natural diploid and tetraploid weather loach Misgurnus anguillicaudatus based on cytochrome b sequence data in central China

To obtain the phylogenetic relationship between diploid and tetraploid Misgurnus anguillicaudatus, the mitochondrial cyt b gene in the diploid and tetraploid weather loach were isolated and sequenced. The DNA sequences were analyzed using MEGA 3.0 software to determine the phylogenetic relationship. Forty-five variable sites among cyt b gene sequences and 18 amino acid substitutions occurred within the diploid and tetraploid loaches as deduced from the nucleotide sequences analysis of the cyt b gene. The nucleotide pairwise distance between diploid and tetraploid loach ranged from 0.001 to 0.025. Phylogenetic analysis revealed evolutionary relationships between diploid and tetraploid loach. Our results indicated a significant difference between diploid and tetraploid loach about the cyt b gene. AMOVA analysis indicated that there were no significant genetic variations within diploid loaches (Fst = 0.2529, P > 0.05) and within tetraploid loaches (Fst = 0.0564, P > 0.05), neither. However, significant genetic differences were found between diploid and tetraploid loaches (Fst = 0.7634, P < 0.05). Thus, it is concluded that no reproductive isolation was found within the same cytotypes of different localities, but there was reproductive isolation between these two cytotypes. The diploid loach existed before the tetraploid loach in nature. The present study is the first to describe the phylogenetic relationships of natural polyploidy weather loach using mtDNA cyt b gene.

Analysis of genetic diversity in Glyptosternum maculatum (Sisoridae, Siluriformes) populations with AFLP markers

We determined the genetic diversity of geographic populations from three spawning grounds (Nyang River, Lhasa River, Shetongmon Reach of Yarlung Zangbo River) of Glyptosternum maculatum with amplified fragment length polymorphism (AFLP) markers. Five primer combinations detected 332 products, 51 of them (15.4%) were polymorphic in at least one population. The Shetongmon population was found to be the richest in genetic diversity as was indicated by the percentage of polymorphic loci and heterozygosity, followed by the Nyang population and the Lhasa population. The pair-wise genetic distance between populations were all very close, ranging from 0.0015 to 0.0042 with an average of 0.0024. The genetic distance was not proportional to the geographic distance. The analysis of molecular variance demonstrated that all variation occurred within populations. The average estimated fixation index (Fst) of three populations across all polymorphic loci was −0.0184, indicating the absence of genetic differences among the three sampled populations. The differentiation among populations was not significant, and population structure was weak. Our observations will help identify the genetic relationship among populations as the first approach to understand the genetic diversity of Glyptosternum maculatum.

Embryonic development of Pelteobagrus fulvidraco (Richardson, 1846)

For production enhancement and procedure upgrade, the developmental phases of laboratory-reared eggs of catfishPelteobagrus fulvidraco were investigated. Twenty mature females and 10 males were collected from Dadongmen wholesale fisheries market in Wuhan City on May 8, 2003. Zygotes were stripped from mature fish after hormone-induced ovulation, fertilized, and incubated through whole embryonic development. The fertilized eggs were stocked in density of 100 eggs/L in white square tanks of 10 L. Incubation water was dechlorinated tap water with continuous aeration. The tanks were lit directly with 60 W fluorescent bulbs with a 12 light: 12 dark photoperiod. Water temperature, dissolved oxygen and pH were 29.0±0.5°C, 6.7±0.4 mg/L and 7.4±2, respectively. The results showed that the eggs ofP. fulvidraco were yellow, sticky and contained much yolk. The mean diameter of fertilized eggs was 2.03 mm. At the water temperature of 29.0±0.5°C, the ontogenesis spent about 33 h after fertilization. From fertilization to hatching, the embryonic development can be divided into 30–40 phases, which varies in the emphasis and direction of development. The detailed embryonic movement was also described.

Threatened fishes of the world: Macrura reevesi Richardson 1846 (Clupeidae)

Reeves’shad. Conservation status: Listed as endangered in China red data book of endangered animals and endangered in National Environmental Protection Agency and Endangered Species Scientific Commission PRC (Wang 1989). Identification: An extremely compressed silvery fish with a long-ellipsoidal shape. D III/14–15, A II/16–18, P I/13–15, V 8, vertebrae 44–45, abdominal scutes 29–34, gill rakers 230–290, sharp snout, large mouth with a marked groove in the center of maxilla, wel1-developed sebaceous eyelids (Yang 1987). Lateral line is absent. Caudal fin has minute scales and is deeply forked. It is a handsome fish, with a metallic blue-green back that lightens to silver along the sides. According to the data of the investigation of the Yangtze River, the longest life span can be over 8 years and the largest fish can be 616 mm long and 4.7 kg weight (Wang 1989). Drawing by G. R. Yang. Distribution: It occurs intermittently along the South China coast and far up the Yangtze, Pearl, and Qiantang rivers (Wang 2003). It is also found in Phuket Island, Andaman Sea of eastern Indian Ocean, and the species thus overlaps Tenualosa toli in range (Whitehead 1985). Abundance: Very common and one of most abundant species in the Yangtze River historically (Qiu et al. 1989). Significantly declines since 1970s and possible extinct in the rivers (Liu et al. 2002). Habitat and ecology: It is an anadromous fish and spends most of its life at sea. Immature Macrura reevesi occurs on shallow inshore habitats in estuaries and the adult scatters near the surface in offing (Cao 2004). It only enters the freshwater river in which it was born to spawn. This is a filter feeder fish that feeds on plankton such as Cyclopoids, Rotifer, Copepoda, etc. and large amount of members of Bacillaria and fragmentary organic matters (Wang 1989). Reproduction: The age of sexual maturity is generally over 3 years. Fecundity ranges from 1070,000 to 4280,000 eggs (Qiu et al. 1989). Every year from the last ten days of February to early March in spring, the sexually matured adults of the fish swim in schools upstream from sea into rivers to spawn. This operation continues for about a W. Weimin (&) Æ K. Abbas Æ M. Xufa Fisheries College, Huazhong Agricultural University, Wuhan, Hubei 430070, PR of China e-mail: wangwm@mail.hzau.edu.cn Environ Biol Fish (2006) 77:103–104 DOI 10.1007/s10641-006-9030-7

PURIFICATION AND PARTIAL CHARACTERIZATION OF LIVER CATALASE FROM CONTROL AND Pb+Cd METAL MIXTURE STRESSED Oreochromis niloticus

Water contamination is a severe environmental issue and has worse effects on fish health. Antioxidant system is present in all living organisms that maintain redox homeostasis by neutralizing reactive oxygen species (ROS). Catalase (CAT) is the part of antioxidant system that protect an organism from oxidative stress by detoxifying H2O2 into H2O and O2 molecule. Majority of enzymes are intermingled with other biomolecules when extracted and needed to purify so that biochemical properties can be described clearly. The first purpose of the present research work was to investigate whether tilapia produce more CAT in the chronic metal mixture stressed condition or not. While, the second purpose of the present research work was to purify and partially characterize the liver CAT from control and Pb+Cd metal mixture stressed Oreochromis niloticus. The inferences of present study showed higher liver CAT activity in control O. niloticus as compared to binary metal mixture treated O. niloticus. Significant differences (p<0.05) were observed when compared liver CAT activity among control and stressed fish. Specific activity of purified liver CAT was observed 1027.52 and 946.93 Umg -1 for control and metal stressed fish, respectively. The fold purification of control and metal treated fish liver CAT was recorded 15.27 and 15.44, respectively. Optimum pH and temperature of liver CAT purified from both control and metal stressed fish was found 7 and 25°C. Km value for control and metal stressed O. niloticus liver was measured 6.82 and 1.71mM H2O2mL -1 , respectively. On the basis of present study