230 research outputs found
Successful transportation of wild stock of endangered "Thooli" (Labeo dussumieri) spawners without anaesthetics
Several problems are encountered during transportation of fishes from wild to
captivity. The note describes successful transportation of wild caught endangered
Labeo dussumieri spawners over distances below 100 km without anesthesia or
sophisticated transporting devices which is of immense help in the gene banking
programme of endangered species
Variabilities in the community structure of phytoplankton in the upwelled and non-upwelled waters of southeastern Arabian Sea during the early summer monsoon
542-549The community structure of microphytoplankton was assessed along the southeastern Arabian Sea during the early phase of the summer monsoon. The study records an intense coastal upwelling along the southernmost region (off Thiruvananthapuram), which decreased further north. High chlorophyll-a (10.8 mg m-3) and nutrient concentration was recorded in the coastal waters of Thiruvananthapuram. Even though off Mangalore (12° N) and off Goa (15° N) where upwelling was confined to narrow coastal zone, also showed high chlorophyll-a concentration, 3.98 mg m-3 and 6.31 mg m-3, respectively. The upwelled waters were dominated by centric diatoms (Thalassiosira sp.) and the non-upwelled waters (12° N and 15° N) were dominated by dinoflagellates. Microphytoplankton cell density was the highest along off Thiruvananthapuram (4.8×104 cells L-1), with maximum cell density along the coastal waters (1.4×104 cells L-1). Phytoplankton community of upwelled and non-upwelled waters showed significant variations with 60 % similarity between phytoplankton communities of upwelled waters
Ecosystem Responses in the Distribution of Black Clam (Villorita cyprinoides) Beds in Vembanad Estuary during Environmental Changes Using GIS and RS
The biomass and distribution of black clam (Villorita cyprinoides) in Vembanad,
a tropical estuary located along the southwest coast of India varied significantly.
Sampling was done in freshwater-dominated zone in the south
(distal) and brackish water zone in the north (proximal), during pre and post
monsoon seasons. Clam biomass was estimated from samples, collected from
different stations during the study period. Water transparency and temperature
were measured at the sample sites. Water samples were collected and
analysed for salinity, dissolved oxygen (DO), pH and hardness. There was a
significant difference in the clam biomass during the two seasons in the distal
zone, and those collected from the distal and proximal zones during premonsoon
season. The data were further analysed to determine the factors affecting
the clam biomass distribution in the two zones and seasons. Factor
analyses, comparing the distal zone during two seasons and zonal variations
were similar to earlier observations. Step wise regression analyses found that
dissolved oxygen (adjusted R2 = 0.3) is the only variable affecting clam survival
during pre-monsoon period in the distal and proximal zones. A geographic
map of the region obtained from the Indian satellite sensor LISS
(Linear Image Self Scanner) was used along with in situ data to map the results
using inverse distance weightage model
Understanding the dietary relationship between extensive Noctiluca bloom outbreaks and Jellyfish swarms along the eastern Arabian Sea (West coast of India)
1389-1394The paper attempts to understand the interrelationship between recurring blooms of dinoflagellate, Noctiluca scintillans as well as increasing jellyfish swarms along the coastal waters of eastern Arabian Sea. The grazing of N. scintillans on diatoms in the productive waters with reduced competition pressure due to the opportunistic feeding of jellyfishes on zooplankton are described here. With the development of N. scintillans in the favourable environmental conditions, jellyfishes utilize this dinoflagellate as their food source and thrive in the coastal waters. Hence, trophic interaction between Noctiluca and jellyfishes leading to their proliferation in the coastal waters are delineated
- …