Height-depth (breadth) relationship of shells in the backwater oyster Crassostrea madrasensin (Preston) of the Cochin harbour

A study of the height-depth relation in the Indian backwater oyster Crassostrea madrasensis (Preston) was carried out. The plot of height against depth showed an exponential trend and a relationship of the form H = ADB. Plot of height against depth also showed larger deviations in height for oysters with greater depth. Analysis showed that variations in height do not result in corresponding variations in depth, particularly in oysters with increased height.

Height-length relation of shells in the Indian backwater oyster Crassostrea madrasensis (Preston) of the Cochin harbour

Height-length relationship in Crassostrea madrasensis (Preston) showed an exponential trend and relation in the form, H=ALᴮ. Deviations of actual values from the mean values consequent to the increase in size were noticed. Height and length approximated in oysters of less than 3.5cm in height resulting in orbicular shape. In oyster of shell height 3.5cm to 8cm, increase in height is faster leading to an oval shape. Above 8cm in height, the oysters become further elongated. Height-length relation is non-linear with an index (B value) of 1.1156. A linear relationship also holds good as the B value is not very much different from unity (H=-2.5424+2.0036L).

Condition index and percentage edibility of Crassostrea madrasensis (Preston) inhabiting the Cochin Harbour

Monthly variations in condition index and percentage edibility of the population of oysters, namely, Crassostrea madrasensis (Preston) is reported for males, females and indeterminates for the period October 1981 to September 1982. Condition index and percentage edibility showed more or less similar trend for the total population and also for males, females and indeterminates. The condition index and percentage edibility were maximum during October 1981 which declined progressively and reached the lowest in February-March, 1982. From April it showed steady increase and reached the maximum again in October 1982 and this coincided with the gonadal cycle in oysters.

Hydrography of the Cochin harbour

The hydrography of the Cochin harbour is studied with reference to air temperature, dissolved oxygen, salinity and pH. The analysis of the data shows unique hydrographical characteristics which are influenced by the monsoon rains. The uniqueness lies mainly in the fluctuations of salinity which registers as low as 0.6‰ during monsoon period to near sea conditions (29.4‰) during the summer period. The dissolved oxygen, temperature and pH also showed fluctuations corresponding to seasons.

A survey for paralytic shellfish poisoning (PSP) in Vancouver Harbour

Shellfish samples were collected from seven inter-tidal and two sub-tidal sites between 23 May and 8 June 1999 in Vancouver Harbour and were analysed for paralytic shellfish poisoning (PSP) using a mouse bioassay. PSP was detected in mussels collected at four sampling sites in English Bay and Burrard Inlet, at a concentration below 20 mug saxitoxin equivalents (STXeq)/100 g wet weight. (C) 2003 Elsevier Ltd. All rights reserved.

Liberal Christianity : its origin, nature, and mission / by Jean Râeville ; translated and edited by Victor Leuliette.

http://www.archive.org/details/liberalchristian00rvuoft

Polychaete burrows harbour distinct microbial communities in oil-contaminated coastal sediments

Previous studies have shown that the bioturbating polychaete Hediste (Nereis) diversicolor can affect the composition of bacterial communities in oil-contaminated sediments, but have not considered diversity specifically within bioturbator burrows or the impact on microbial eukaryotes. We tested the hypothesis that H. diversicolor burrows harbour different eukaryotic and bacterial communities compared with un-bioturbated sediment, and that bioturbation stimulates oil degradation. Oil-contaminated sediment was incubated with or without H. diversicolor for 30 days, after which sediment un-affected by H. diversicolor and burrow DNA/RNA samples were analysed using quantitative reverse transcription PCR (Q-RT-PCR) and high-throughput sequencing. Fungi dominated both burrow and un-bioturbated sediment sequence libraries; however, there was significant enrichment of bacterivorous protists and nematodes in the burrows. There were also significant differences between the bacterial communities in burrows compared with un-bioturbated sediment. Increased activity and relative abundance of aerobic hydrocarbon-degrading bacteria in the burrows coincided with the significant reduction in hydrocarbon concentration in the bioturbated sediment. This study represents the first detailed assessment of the effect of bioturbation on total microbial communities in oil-contaminated sediments. In addition, it further shows that bioturbation is a significant factor in determining microbial diversity within polluted sediments and plays an important role in stimulating bioremediation.

Plymouth — A World Harbour through the ages

Plymouth Sound and adjacent estuaries, UK has been used as a working harbour throughout the ages and has a place in maritime history as the port from where the Pilgrim Fathers left for North America in 1620 on the Mayflower and Charles Darwin departed from on the HMS Beagle on his trip to Galapagos in 1831. Today, it remains a working harbour, home to the largest naval base in Western Europe, the host of numerous cruise ships and recreational boats, yet its complex of estuaries (Tamar, Plym, Lynher) and creeks is nationally and internationally recognised as of conservation importance due to its physical characteristics and flora and fauna. Here, we briefly recount the history and importance of Plymouth through the ages in terms of its historic use as a harbour, its marine science heritage and importance on the international stage. We also briefly describe its ecology.

Molluscan assemblages on an intertidal sandflat in Princess Royal Harbour, Westren Austrailia

The molluscan fauna of an intertidal sand beach in Princess Royal Harbour, W.A.. is divided into two associations. The upper association, located between +0.10 and +0.59 m relative to tidal datum, is characterized by Hydrococcus graniformis and Batillariella estuarina. The lower assemblage, between +0.09 and -0.29 m is dominated numerically by Zeacumantus diemenensis and Katelysia scalarina. The assemblages are equivalent to the midlittoral- and sublittoral-fringe groupings described on both sandy and rocky shores by other authors. There is no supralittoral-fringe component in the molluscan fauna ofprincess Royal Harbour. The break between the two assemblages occurs at + 0.1 m, just below the minimum tide level in the area. Possible reasons for the zonation patterns are discussed and compared with other studies of intertidal zonation on sandy shores.

A COMPARATIVE STUDY OF LASAEA AUSTRALIS, VULSELLA SPONGIARUM, PINNA BICOLOR AND DONACILLA CUNEATA (MOLLUSCA; BIVALVIA) FROM PRINCESS ROYAL HARBOUR, WESTERN AUSTRALIA

Monthly samples of L. australis, V. spongiartum, P. bicolor and D. cuneata were collected over a period of 12 months from Princess Royal Harbour, Western Australia. Preliminary information on densities and biomass is given. Gonad histology points to seasonal reproductive cycles with autumn spawning in P. bicolor and D. cuneata and irregular spawning in V. spongiantm and L. australis. However, L. australis did show two peaks of larval brooding in the study period. Length-frequency data are discussed in the light of the proposed reproductive patterns for the four species. Allometric relationships between length and both height and width for all species are described and their value to each species assessed. Populations of L. australis from different habitats show significant differences in shell shape.