Bacterial quality and depuration of the green mussel Perna viridis from natural beds

Green mussel (Perna viridis) and sea water from their natural beds on the coastal areas of Porto Novo were studied between April and August 1996 for their bacterial quality. Water samples from the beds were also analysed for their physico-chemical parameters. The total bacterial count of mussels from natural beds as well as bed waters ranged 10³ organisms per gram of mussel meat suspension and per milliliter of sea water. The faecal coliforms were found to be within the permissible limits. Pathogenic bacteria such as Salmonella spp., Streptococcus spp. and Staphylococcus spp. were absent. The variations in pH, temperature, salinity and dissolved oxygen of the seawater samples were insignificant. The mussels were subjected to depuration by different methods among which chlorination was found to be most effective.

Systematic study of the blue green algae of Ceylon kept at the herbarium of the Royal Botanical Gardens, Peradeniya

The collection of blue green algae kept at the herbarium of the Royal Botanical Gardens, Peradeniya, was collected by Ferguson more than 70 years ago. Since then many changes have taken place in the taxonomy of the blue green algae. West (1902), Lemmermann (1907), Wine (1915), Crow (1923), Bharadwaja (1934) and Holsinger (1935) had described some of the blue green algae of Ceylon. While examining the collections of blue green algae kept at the herbarium, the authors found that most of the identifications were incorrect and required revision. In the present paper 20 blue green algae are described. The classification and key to the species are based on the characters given by Desikachary (1959). Blue green algae are important to fisheries since Chanos larvae feed on them.

Red-Green-Blue 2D tuneable liquid crystal laser devices

In this paper, we review our recent experimental work on coherent and blue phase liquid crystal lasers.We will present results on thin-film photonic band edge lasing devices using dye-doped low molar mass liquid crystals in self-organised chiral nematic and blue phases. We show that high Q-factor lasers can be achieved in these materials and demonstrate that a single mode output with a very narrow line width can be readily achievable in well-aligned mono-domain samples. Further, we have found that the performance of the laser, i.e. the slope efficiency and the excitation threshold, are dependent upon the physical parameters of the low molar mass chiral nematic liquid crystals. Specifically, slope efficiencies greater than 60% could be achieved depending upon the materials used and the device geometry employed. We will discuss the important parameters of the liquid crystal host/dye guest materials and device configuration that are needed to achieve such high slope efficiencies. Further we demonstrate how the wavelength of the laser can be tuned using an in-plane electric field in a direction perpendicular to the helix axis via a flexoelectric mechanism as well as thermally using thermochromic effects. We will then briefly outline data on room temperature blue phase lasers and further show how liquid crystal/lenslet arrays have been used to demonstrate 2D laser emission of any desired wavelength. Finally, we present preliminary data on LED/incoherent pumping of RG liquid crystal lasers leading to a continuous wave output. © 2009 SPIE.

Growth of the green mussel, Perna viridis (Linn. 1758), from Moheshkhali Channel of the Bay of Bengai, Bangladesh

Growth of Perna viridis L. inhabiting Moheshkhali jetty of the channel was studied for one year from November, 1990 to October, 1991. The mussel attained 88.12mm±14.69 in length within 12 months with a mean growth rate of 7.34mrnlmonth. Employing von Bertalanffy's growth equation it was found that P. viridis can be 88.43mm, 114.69mm and 121.9lmm at the age of 1, 2 and 3 year respectively. The highest growth rate was recorded during November-April, coinciding with the maximum abundance of phytoplankton and the greatest salinity. The maximum growth rate (99.38%) was recorded at an early stage and was followed by a sharp decline to 4.47%. The growth pattern of P. viridis fitted well with the von Bertalanffy's growth equation.

Characterization of three fibrinogenolytic enzymes from Chinese green tree viper (Trimeresurus stejnegeri) venom

Rong Gao, Yun Zhang, Qing-Xiong Meng, Wen-Hui Lee, Dong-Sheng Li, Yu-liang Xiong and Wan-Yu Wang. Characterization of three fibrinogenolytic enzymes from Chinese green tree viper (Trimeresurus stejneger ) venom. Toxicon 36, 457-467, 1998.-From the venom of Chinese green tree viper (Trimeresurus stejnegeri), three distinct fibrinogenolytic enzymes: stejnefibrase-l, stejnefibrase-2 and stejnefibrase-3, were purified by gel filtration, ion-exchange chromatography and reverse-phase high-performance chromatograghy (HPLC). SDS-PAGE analysis of those three enzymes showed that they consisted of a single polypeptide chain with mel. wt of -50 000, 31 000 and 32 000, respectively. Like TSV-PA (a specific plasminogen activator) and stejnobin (a fibrinogen-clotting enzyme) purified from the same venom, stejnfibrase-1, -2 and -3 were able to hydrolyze several chromogenic substrate. On the other hand, different from TSV-PA. and stejnobin, stejnefibrase-l, -2 and -3 did not activate plasminogen and did not possess fibrinogen-clotting activity. The three purified enzymes directly degraded fibrinogen to small fragments and rendered it unclottable by thrombin. Stejnefibrase-2 degraded preferentially BE-chain while stejnefibrase-l and -3 cleaved concomitantly Ax and B beta-chains of fibrinogen. None of these proteases degraded the gamma-chain of fibrinogen. When correlated with the loss of clottability of fibrinogen, the most active enzyme was stejnefibrase-l. The activities of the three enzymes were inhibited by phenylmethylsulfonyl fluoride (PMSF) and p-nitrophenyl-p-guanidinobenzoate (NPGB), indicating that like TSV-PA and stejnobin, they are venom serine proteases. (C) 1998 Elsevier Science Ltd. All rights reserved.

Characterisation of neurons in the pedal ganglia of the green-lipped mussel, Perna canaliculus, using antibodies raised against neuropeptides and neurotransmitters involved in gastropod egg-laying behaviour and bivalve reproduction and spawning

To characterise central neurons in the pedal ganglia of both male and female green lipped mussel, Perna canaliculus immunohistochemical techniques were used. Mollusc antibodies were used against neuropeptides and neurotansmitters known to control reproduction and spawning. Anti-ELH and anti-APGWamide showed very strong immunoreactivity in small type of neurons. Anti-5-HT and anti-DA immunoreactivity was mostly in large type of neurons. The labelled neurons are consistent with descriptions of neurosecretory cells implicated in the control of reproduction and spawning on the basis of earlier histological staining techniques used in this species. The use of selective immunological markers for peptides and amines appears to be a, promising tool for further characterisation of neurosecretory cells, and to isolate an'tl characterise neuropeptides and other biologically active materials involved in the control of reproduction in Perna canaliculus.

Taxonomic study of coenocytic green algae commonly growing on the coast of Karachi

Twelve commonly occurring coenocytic and siphonaceous species of marine benthic algae, i.e., Bryopsis pennatta Lamouroux, Caulerpa chemnitzia (Esper) Lamouroux, Ca. faridii Nizamuddin, Ca. manorensis Nizamuddin, Ca. racemosa (Forsskal) J. Agardh, Ca. taxifolia. (Vahl) C. Agardh, Chaetomorpha antennina (Bory de Saint-Vincent) Kutzing, Cladophora uncinella Harvey, Codium decorticatum (Woodward) Howe, Co. flabellatum Nizamuddin, Co. iyengarii Borgesen, and Valoniopsis pachynema (Martens) Borgesen, belonging to four different orders of the class Bryopsidophyceae, division Chlorophyta, were collected from the intertidal region of different coastal areas near Karachi (Pakistan) and investigated taxonomically. Codium decorticatum is a new report from this region and Co. decorticatum, Co. flabellatum and Co. iyengarii are described for the first time from the coast of Pakistan.

Culture of green algae Chlorella ellipsoidea in inexpensive media

The culture of the of green alga Chlorella ellipsoidea was conducted under natural conditions at the same place simultaneously in five different media, viz., medium-I (inorganic medium), medium-II (powdered whole-pulse medium), medium-III (medium of pulse bran), medium-IV (mixed medium = 50% inorganic medium + 50% whole-pulse powder medium), medium-V (mixed medium = 50% inorganic medium + 50% pulse bran medium). The culture was done in 500 ml conical flask. Growth rates of C. ellipsoidea in five different media were different and reached maximum cell densities of 0.63 x 10^6 cells per ml in 8 days in medium-I, 4.02 x 10^6 cells per ml in 10 days in medium-II, 3.62 x 10^6 cells per ml in 9 days in medium-III, 4.38 x 10^6 cells per ml in 11 days in medium-IV and 4.36 x 10^6 cells per ml in 11 days in medium-V. The range of air temperature was 20 to 33°C and that of culture media was 24 to 32°C and light intensity was 2000 to 7000 lux during the culture period. The inexpensive culture media were found to be significantly useful for algal culture.

A new method for venom extraction from venomous fish, green scat

Scatophagus argus argus (Green Scat) is a pretty aquarium fish. Its hard spines are venomous and can cause painful injury. In this study 60 specimens of Green Scat were collected periodically from coastal waters of Boushehr (south of Iran) from May 2011 to April 2012. Anatomical features of venomous spines were investigated. Scat venom was extracted from the spines in a new manner for keeping the specimens alive. The nature of venom was tested by SDS-PAGE. Ethical issues and animal welfare principles such as rapid and instantaneous anesthetizing, post operation disinfection and fast recovery of the specimens was practiced in order to minimize the complications. This method enhanced the purity and quantity of venom as demonstrated by 12 separated proteins in electrophoresis. New ethical issues were developed to surviving the specimens and prolong viability as well.

Pickled products from green mussel

Methods of preparing different types of delicious ready to serve pickled products from green mussel (Perna viridis) and a comparative study of their storage characteristics are reported. Of the three types of products, namely, dried and pickled, fried and pickled and light smoked and pickled, the last one had the best shelf life. The optimum conditions of drying and smoking for preparing such type of pickles are also reported.

Biology and farming of the green mussel Mytilus smaragdinus

Biological investigations were carried out in Sapian Bay, Capiz from November 1975 to December 1976 with samplings conducted fortnightly. Histological studies on the gonad reveal a high percentage of ripe and spent females during the month of April and May, and ripe to near ripe during November to December. However, larval counts were highest on February 25, 1976 with 253 mytilid larvae per haul compared to 0-79 per haul during all other months. The high larval count was followed by the highest spat settlement during the next sampling period two weeks later, with the spat collector set in the water during the February 25 sampling. The four materials tested, blue polypropylene fiber rope, black polypropylene fiber, and coir rope, all had their highest spat counts during this period with an average of 471 spats per standard 10 cm rope piece. The range during the other time periods is 2-283 spats. Of the 4 materials tested, the black fibrillated polypropylene film had the highest larval counts in 15 out of a total of 25 sampling periods. The blue rope was the poorest spat collector. Coconut husk was tested later on and it proved to have a very high catchability, with spats completely enveloping the husk surface. Growth monitored from one cohort in Sapian Bay averaged 10 mm per month. 50-60 mm is considered marketable size. Trial growth experiments with transplanted mussels were also conducted at Igang Bay in Guimaras Island, Makato River in Aklan, and a milkfish pond in Leganes, Iloilo. Survival in Igang was less than 50% after the second week, and the condition of the surviving mussels can be described only as 'watery' with the mantle completely transparent. Mortality was minimal in Makato but the growth rate was only 30% that of Sapian Bay. The pond experiments were terminated due to severe crab predation.

Toxicity of malachite green to the larvae of Penaeus monodon Fabricius

A study was undertaken examining the effect of malachite green on the development and survival of the zoeae, mysis and post-larvae of Penaeus monodon. Sensitivity varied with the different larval stages; the zoeae appeared to be the least tolerant. The prophylactic potentials of malachite green in the control of Lagenidiumand Zoothamnium infesting P. monodon larvae are considered briefly. Toxicity risks may be reduced by application between ecdyses or by the removal of the dye by filtration through activated carbon.