Textural and compositional variations in beach sands along Karachi coast

The texture of clastic sediments is a fairly reliable index of the erosional history and energy conditions of the depositional environment, while its mineralogy reflects the composition of the source rocks. The beach sands of Clifton, Sandspit, Hawkesbay and Paradise Point were studied to determine their erosional history, depositional environment and their source

Ecophysiological response of Nerita oryzarum (Recluz), a gastropod, to variations in temperature, pH and salinity

During ecophysiological investigations on an intertidal gastropod, Nerita oryzarum (Recluz), of Mumbai shore, various biochemical changes could be recorded. Glycogen and lipid contents of N. oryzarum were found to decrease, whereas, water content increased with decreasing salinity. The rate of oxygen consumption declined with the decrease in salinity and also in highly acidic (pH 2) as well as highly alkaline (pH 10) sea water. The observed variations in the rate of oxygen consumption and changes in biochemical composition in the animal with changes in salinity, pH and temperature are probably the process of physiological and biochemical adjustments to the fluctuating environmental conditions in the intertidal region.

Salinity and temperature variations of the surface waters in the Jaffna Lagoon

Salinity and temperature in the sea surface of the Jaffna Lagoon were observed from August 1967 to July 1968. Peak surface temperatures were recorded during April and the lowest temperature recorded was in December. The seasonal variations of surface temperature closely followed a similar pattern in all locations of the lagoon. Salinity values in the lagoon surface were very high during the period from May to August and were relatively low during the period from October to December. Monsoon, rainfall, exchange of water between the lagoon and the sea and within the lagoon, and the currents in the Palk Bay might have been the factors which influenced the salinity structure of the surface waters of the lagoon during this period.

Hydrobiology of Colombo (Beira) Lake, 1. Diurnal variations in temperature, hydrochemical factors and zooplankton

An extensive study of the hydrobiology of the Colombo Lake was initiated by the authors in May 1969 as a contribution to the International Biological Program (Productivity of freshwater communities) by the Department of Zoology, Vidyalankara University of Ceylon, Kelaniya. The Colombo Lake often referred to as the Beira Lake covers an area of approximately 160 acres. The water is usually very turbid with a greenish blue appearance due to the presence of large quantities of blue green algae.

Genetic diversity and population history of the red panda (Ailurus fulgens) as inferred from mitochondrial DNA sequence variations

The red panda (Ailurus fulgens) is one of the flagship species in worldwide conservation and is of special interest in evolutionary studies due to its taxonomic uniqueness. We sequenced a 236-bp fragment of the mitochondrial D-loop region in a sample of 5

Rapid evolution, genetic variations, and functional association of the human spermatogenesis-related gene NYD-SP12

NYD-SP12 is a recently identified spermatogenesis-related gene with a pivotal role in human testis development. In this study, we analyzed between-species divergence and within-species variation of NYD-SP12 in seven representative primate species, four wo

Growth performance and morphological variations of local and Thai climbing perch (Anabas testudineus, Bloch)

Climbing perch locally known as koi (Anabas testudineus) is a popular food fish in our country. Thai climbing perch was introduced in Bangladesh from Thailand. To explore the variation in growth performance and orphological features of local and Thai climbing perch a study was undertaken. The highest gain in length, weight and SGR were found in Thai koi 12.23±0.38 cm, 55.83±0.53 g and 7.92±0.11 %/day respectively. Fourteen morphometric characters were studied where eleven (TL, SL, HL, HBD, LBD, DFL, PECFL, PELFL, AFL, UJL and LJL) showed significant difference (p<0.01) in Thai koi from the local ones. Of the meristic characters no. of dorsal fin rays (hard), anal fin rays (hard), caudal fin rays and scale along lateral line (upper and lower) as recorded from the Thai koi were significantly higher (p<0.01) than that of the local koi. The no. of dorsal fin rays (soft) in Thai koi were also significantly higher (p<0.05) from that of local koi. The number of vertebra were also variable in local and Thai climbing perch (25 in case of local koi and 26 in case of Thai koi). Hence, the results obtained form the present study satisfy the characteristics of A. testudineus which reveals that both the local and Thai koi belongs to the same species. Growth performance of Thai koi was better compared to local koi reared in same conditions.

Seasonal and sex related haematological variations of the freshwater spiny eel, Mastacembelus armatus reared in the cemented cisterns

The seasonal and sex related haematological vanatlons in the freshwater spiny eel Mastacembelus armatuswere studied during summer from April to June 2001 and winter from November 2001 to January 2002. In total 60 fish (30 males and 30 females) ranging from 30- 55.6 cm in total length and from 55-95.5 g in weight were collected from the culture stock maintained in the cemented cisterns. It was observed that the values of the total erythrocyte count (TEC), haemoglobin concentration (Hb ), haematocrit values, packed cell volume (PCV) and neutrophil count were significantly higher (P< 0.05) in males than the females during summer (April to June- on-set of breeding season). Females were observed to have remarkably higher values (P< 0.01) of erythrocyte sedimentation rate (ESR), total leucocyte count (TLC) and thrombocyte count during summer. On the other hand, insignificant variations in the various haematological parameters were noticed during winter (November to January) between the two sexes of M. armatus.

Response of extract release volume to the variations in pH and microbial load during spoilage of fish at refrigeration temperature

This report briefly describes the microbial status and storage properties of fish raised under composite fish culture in sewage fed ponds.

Mitochondrial Cytochrome b Sequence Variations and Population Structure of Siberian Chipmunk (Tamias sibiricus) in Northeastern Asia and Population Substructure in South Korea

Twenty-five chipmunk species occur in the world, of which only the Siberian chipmunk, Tamias sibiricus, inhabits Asia. To investigate mitochondrial cytochrome b sequence variations and population structure of the Siberian chipmunk in northeastern Asia, we

The zooplankton population structure and their trend of variations in the southern of Caspian Sea (Iranian waters)

Caspian Sea has gone under a lot of changes due to human influences and the unwanted presence of a ctenophora Menomiopsis leidyi which has greatly changed the structure of planktons in the last recent years. Therefore, this study was carried out in order to determine these changes in the zooplankton community. the Sampling was done in 8 transacts in Astara, Anzali, Sefidrood, Tonekaboun, Noushahr, Babolsar, Amirabad and Bandar Torkaman coastal waters at 5 different depths including 5, 10, 20, 50 and 100 m. Sampling was carried out in four seasons of spring, summer, autumn and winter during 2008, 2009 and 2010 on board of R/V Gilan. Altogether, 12 species of zooplankton were identified in 2008, 22 species in 2009 and 14 species in 2010. The zooplankton included four groups: copepoda (4 species), cladocera (8species), rotatoria (10 species) and protozoa (2 species).The increase of diversity in 2009 was due to cladocera and rotatoria groups. The abundance of zooplankton in the spring was 5074 + 7807 ind/m3 more than other season in 2008. The abundance of copepoda in the summer reached the highest value of 3332 ind/m3 and since autumn the abundance gradually decreases and in the winter reached to the lowest value. The most abundance of cladocera was 797 ind/m3 in winter and decreased in summer and autumn. The abundance of rotatoria was 2189 ind/m3 in winter. rotifera and copepoda consisted the main population of Zooplanktons in the winter. The results of 2009 and 2010 showed that the abundance of zooplankton in winter was 2.6 fold of autumn, 1.6 fold of summer and 1.1 fold (1/9 fold in 2010)of spring. After increasing increased of temperature, phytoplankton, and zooplankton in summer, M.leidyi increased too. In the autumn M. leidyi reached to the highest rate and decreased zooplankton. The maximum population of zooplankton was in the layer 0-20 m and in the layer more than 20 meters, the abundance of zooplankton decreased very much. In 216 2008, 2009 and 2010, the abundance of zooplankton was 87, 77 and 77 percent in the layer 0-20 m respectively. In this study, the thermocline was observed in the layer 10 – 20 meters in the spring, that formed a thin layer but in the summer it was in the layer 20 to 50 meters. Temperature decreased between 11 to 15 oC in this layer. The variation of temperature between surfaces to bottom was 10 to 13 oC in spring, 19 to 21 in summer, about 9 oC in autumn and maximum 3 oC in winter. The most biomass of zooplankton was in the west. The biomass of zooplankton in central west and east of Southern of Caspian Sea was 54 %, 22 % and 24 % respectively in 2008, in 2009 was 48%, 33% and 20% respectively and in 2010 was 54 %, 29 % and 16 % respectively .The biomass decreased from west to east. The model of zooplankton designed by principal component analysis (PCA)and linear regression for Southern of Caspian Sea.

The seasonal variations of sea level due to density variations in the Arabian Gulf and Gulf of Oman

From the distribution of oceanographic data (temperature and salinity) in both Arabian Gulf and Gulf of Oman, the steric components (thermal, haline and steric heights) are calculated for the upper 50m layer during different seasons. The analysis reveals relevant evidence, that temperature variations (thermal component) play a role in the fluctuations of sea level within the investigated area. The salinity variations (haline component) is only significant near the entrance. The sea level variations due to density (steric component) is low during winter and spring and high during summer and autumn. The steric height is always lower in the northern and central regions of Arabian Gulf and higher in eastern region of Arabian Gulf and in the Gulf of Oman, i.e. the surface water must flow from the Gulf of Oman to the Arabian Gulf. The steric sea level gradient around the Strait of Hormuz are 0.04 cm/km in winter, 0.04 cm/km in spring, and 0.025 cm/km in summer and 0.014 cm/km in autumn.