NISCAIR Online Periodicals Repository Collection: IJMS Vol.32(1) [March 2003]

Effects of industrial wastes on the growth and reproductive stages of macroalgae of Visakhapatnam coastline, east coast of India

Title: Effects of industrial wastes on the growth and reproductive stages of macroalgae of Visakhapatnam coastline, east coast of India

Authors: Murthy, S. B. K.; Rao, M. Umamaheswara

Abstract: Experiments were conducted to understand the effects of effluents and sediment extracts of Hindustan Zinc Smelter and Alum factory, on the growth and reproductive stages of 9 macroalgae of the Visakhapatnam coast. In fully grown algae, growth inhibition was minimum at 0.001 or 0.01 % concentrations of HZE-I and II, HZR-I and II and AFE and AFR and maximum at intermediate concentrations (2.5-25 % HZE and R-I and 0.25-8.0 % HZE and R – II and AFE and AFR). Stationary growth and death of algae was observed at highest concentrations tested. The toxic effects were more in HZE- II and HZR – II, than in AFE, AFR, HZE-I and HZR-II. Tetraspore production from one brown and 4 red algae and spore germination decreased from 2.0-10.5 % HZE-1 and HZR-I and from 0.1-1.8 % of other wastes. Sporeling growth and survival were affected at concentration 4-150 times less than those observed for the fully grown algae. Among the 3 classes of algae tested, green algae were more tolerant to the industrial wastes, than the brown and red algae. These culture experiments indicated the damage caused by industrial wastes to macroalgal communities.

Page(s): 57-66

Stock assessment of small head hair tail Eupleurogrammus muticus (Gray) (Pisces/ Trichiuridae) from Mumbai coast

Title: Stock assessment of small head hair tail Eupleurogrammus muticus (Gray) (Pisces/ Trichiuridae) from Mumbai coast

Authors: Rizvi, Anees Fatma; Chakraborty, Sushant K.; Deshmukh, Vinay D.

Abstract: Based on the data collected from New Ferry Wharf, Versova and Vasai in the years 1997-99, the age, growth, mortality and stock assessment of small head hair tail, Eupleurogrammus muticus (Gray) is reported in the present communication. The growth parameters - asymptotic length (L∞ and growth coefficient (K) were estimated as 811 mm and 0.78 per year respectively. The average total, natural and fishing mortality coefficients were estimated as 4.36, 1.15 and 3.21 respectively. The yield isopleth diagram shows that eumetric fishing could be achieved at exploitation rate (E) of 0.68 and Lc / L∞ ∞value of 0.68. The present E of 0.73 is well beyond the optimum E of 0.50. Thus some management measures should be taken to prevent depletion of this resource.

Page(s): 85-88

Protozoa associated with leaf litter degradation in Coringa mangrove forest, Kakinada Bay, east coast of India

Title: Protozoa associated with leaf litter degradation in Coringa mangrove forest, Kakinada Bay, east coast of India

Authors: Dorothy, K. Padma; Satyanarayana, B.; Kalavati, C.; Raman, A. V.

Abstract: Observations (1995-’96) on mangrove leaf litter revealed a variety of microorganisms dominated by bacteria (5 types), 12 species of flagellates, 2 sarcodines, 17 ciliates, 2 suctorids and 2 sessile ciliates besides several diatoms, nematodes and nauplii. Overall, bacteria outnumbered (4.59 x 10⁵ no. g^-1 dry weight) all others constituting 80-90% of the population followed by flagellates (4.8%), ciliates (4.4%) and, sessile ciliates (0.2%). Chromulina sp., Spumella socialis and Euglena acus (flagellates), Cyclidium sp., Prorodon sp., Euplotoides aediculatus and Zoothamnium sp. (ciliates) were relatively dominant (mean density 4,331 individuals l^–1) in the litter collected from Avicennia plot. Flagellates, Astasia sp., Heteronema sp. and Paranema sp. and, ciliates, Prorodon sp., Holosticha sp. and E. aediculatus were, however, more common in Excoecaria (mean density 3719 individuals l^–1). In situ experiments on leaf decay showed that the entire process lasted 12-18 days in summer and 26-32 days during monsoon. Bacteria were the first to settle, followed by nanoflagellates (2-20 m), microciliates (20-100 m), macrociliates (100-200 m) and sessile ciliates. Nematodes indicated culmination. Bacterial (mean) biomass registered highest value (6.43x10^-3 mgC g^-1) within 24 hours but decreased (3.1x10^-6 mgC g^-1)by day-3 to 5. Mean flagellate biomass peaked (32.6 mgC g^-1) by day-2 and microciliates (92 mgC g^-1) by day-5 in summer and (47mgC g^-1) by day-24 during monsoon. Macrociliates registered highest biomass (168.4mgC g ^–1) by day-6 in summer but lagged behind until day-26 to day-30 (154mgC g ^–1) during monsoon. A distinct prey predator relationship, direct dependence of ciliate species on nanoflagellate and bacterial populations as well as, a well marked microbial community succession were evident.

Page(s): 45-51

Antibiotic susceptibility of Bacillus spp. isolated from shrimp (Penaeus monodon) culture ponds

Title: Antibiotic susceptibility of Bacillus spp. isolated from shrimp (Penaeus monodon) culture ponds

Authors: Balakrishnan, S.; John, K. R.; George, M. R.

Abstract: About 30 Bacillus isolates from various sources like shrimp intestine, pond water and pond sediment were assayed for susceptibility to 16 antibiotics, which included cell wall synthesis inhibitors, protein synthesis inhibitors and nucleic acid synthesis inhibitors. Most of the isolates were more sensitive against protein synthesis inhibitors than nucleic acid synthesis inhibitors. Present study showed that all the Bacillus isolates were sensitive to tetracycline and chloramphenicol, two commonly used antibiotics in shrimp hatcheries and culture systems. This indicates that use of certain antibiotics would adversely affect these types of beneficial bacteria in shrimp aquaculture systems.

Page(s): 81-84