Morphology of Buccopharyngeal Cavity of Two Species of Genus Hypophthalmicthys.

Morphological and morphometric data of the buccal cavity, pharyngeal bone and dentition of two species of Hypophthalmicthys (i.e. H. molitrix and H. nobilis) were collected. The structure of the bucccopharyngeal cavity (BC) of Hypophthalmicthys spp. follows a typical pattern of teleost fish. BC in bighead carp is comparatively bigger than that of silver carp measuring 29.01% and 28.12% of standard body length. Mouth gape measures 21.7% of head length in bighead carp and 31.06% of head length in silver carp. In both the species ventral surface of the lateral projection of pharyngeal bone bears pits and openings however, their position differs. This can be a high weight taxonomic character for the identification of the two species. Both species exhibit small teeth bearing area with Dl/Pl ratio <0.5. Pharyngeal bone bears a single row of teeth (0,4-4,0) with their masticating surface steeply inclined towards dorso-mesially.

Study of Plankton Diversity in Recreational Lake Tilyar, Rohtak (Haryana) India.

The plankton diversity of Tilyar Lake (Lat 76°38’ E and 28° 88’ W Long), Rohtak was monitored fortnightly from April 2009 to September 2009. During the study period 55 taxa (33 taxa of phytoplankton and 22 taxa of zooplankton) were recorded. Among phytoplankton maximum phytoplankton taxa were observed for Chlorophyceae (15) followed by Cynophyceae (14) and Bacillariophyceae were represented by 4 taxa only. Zooplankton community comprised of Protozoans (2 taxa), Rotifers (10 taxa), Brachipods (5 taxa), Copepods (4 taxa) and Ostracopods were represented by single taxa.

Zooplankton Diversity in Shallow Lake of Sultanpur National Park, Gurgaon (Haryana).

Abundance, community composition and density of zooplankton were analyzed in the shallow lake of Sultanpur National Park, Gurgaon, Haryana (India) from February, 2011 to January, 2012. A total of 42 species of Zooplanktons (23 species of Rotifers, 15 species of Brachiopods, 3 species of Copepods and 1 species of Ostrachopod) belonging to 19 genera, 12 families, 7 orders and 4 classes were recorded during the study period. Rotifers were the dominant group among zooplankton community, with 23 species and 9 genera, constituting 55 % of the total zooplankton population. High Shannon diversity index (2.5±0.05) was recorded during the season of monsoon indicating high diversity and minimum Simpson’s index (0.13±0.03) was recorded in the same season indicating low species dominance. Pielou’s evenness ranged from 0.64 to 0.97 but average evenness among the different seasons were not significantly variable indicating uniformity in zooplankton community.

Survey and study of phytoplankton ecology in Sukhna Lake, Chandigarh, (India)

Phytoplankton biodiversity and water quality of national wetland, Sukhna Lake, Chandigarh (Lat. 30° 44'14 N, Long. 76° 47' 14 E), India were examined in the present study. During the present study (April 2009 to September 2009), phytoplankton composition and physico-chemical characteristics of water are indicative of mesotrophic condition in three different collection zones (ZA, ZB and ZC) of the lake. The species richness displayed fair variety of algal species (89 taxa). The community was dominated by the members of chlorophyceae and cyanophyceae. Highest phytoplankton density (2082 individual/ L) and species diversity (0.928-2.628) was found during the summer season in the wild area (ZA) where there was no anthropogenic activity. The area with maximum disturbance in water column (ZC) showed minimum phytoplankton density (164/L) and species diversity (0.991-2.319). Phytoplankton densities have significantly positive correlation with TDS(r= 0.669, significant at 0.05 level), chloride(r= 0.717, significant at 0.05 level) and significantly negative correlation with BOD(r= 0.623, significant at 0.05) in ZA and significantly positive correlation with bicarbonate alkalinity(r= 0.728, significant at 0.01 level) and calcium hardness(r= 0.672, significant at 0.05 level) in ZB.