NISCAIR Online Periodicals Repository Collection: IJMS Vol.31(3) [September 2002]

Book Review

Title: Book Review

Abstract: Paleamonid prawns: Biodiversity, taxonomy, biology and management(by K. V. Jayachandran)
C. T. Achuthankutty

Page(s): 254-256

In vivo induction of multiple shoots for scaling up of propagation of tree mangrove Bruguiera gymnorrhiza (Linn.) Sav. (Rhizophoraceae)

Title: In vivo induction of multiple shoots for scaling up of propagation of tree mangrove Bruguiera gymnorrhiza (Linn.) Sav. (Rhizophoraceae)

Authors: Basak, U. C.; Das, P.

Abstract: In vivo shoot induction in hypocotyls and rooting of the regenerated shoots of Bruguiera gymnorrhiza (Linn.) Sav., was standardised as a new method of vegetative propagation. Rooting response of the air-layers made from multiple shoots with the aid of exogenously applied plant growth regulators (IAA+IBA) by pre-girdling is studied. Multiple shoots were induced in 80 % of the hypocotyls treated and the number of regenerated shoots varied from 2-5 with an average value of 3.5 per hypocotyl. Better rooting performance (80 %) was recorded in air-layers treated with IAA+IBA (3000 mg l^-1each). More than 80 % of the rooted air-layers survived in the nursery in polybags. Thus, through this method, 2-3 times more planting materials could be made available for vegetative propagation of B. gymnorrhiza.

Page(s): 249-250

Settlement pattern of ascidians in harbour waters of Mumbai, west coast of India

Title: Settlement pattern of ascidians in harbour waters of Mumbai, west coast of India

Authors: Swami, B. S.; Chhapgar, B. F.

Abstract: The study was carried out in Mumbai (Bombay) harbour during 1995-96 by exposing perspex coupons at two study sites, namely South break waters and Tidal basin . Though the ascidian species, solitary or colonial, settle throughout the year, their prevalence however, varies considerably from month to month. As many as ten species of ascidians were recorded from the two sites. Out of these, seven species, namely Symplegma reptans, Symplegma brakenbielmi, Symplegma viride, Diplosoma macdonaldi, Botrylloides magnicoecum, Botrylloides chevalense and Ecteinascidia sp. are colonial ascidians and Styela bicolor, Ascidia indica and Ascidia sydneiensis are solitary forms. Of these, the species namely A. sydneiensis B. magnicoecum, B. chevalense, S. viride, D. macdonaldi and A. indica are reported for the first time from this region. Amongst these, S. reptans, B. magnicoecum and A. sydneiensis are of common occurrence. The species S. reptans and A. sydneiensis occurred throughout the year. During monsoon (June-September), the settlement of ascidians at cleaner south break waters is notably reduced, whereas, at tidal basin the colonies recorded were around 110/m². At south break waters, during post-monsoon period, when water temperature reduced to 27°C and sea conditions are normal, the ascidians appeared in large number (max.1776/m²). During pre-monsoon period, though the population density varied, the species composition remained high at both the sites. The non-monsoon months of October to May is the favourable period for ascidian settlement in Mumbai harbour.

Page(s): 207-212

Wave forces on a vertical cylinder defenced by a perforated vertical and inclined barriers

Title: Wave forces on a vertical cylinder defenced by a perforated vertical and inclined barriers

Authors: Neelamani, S.; Reddy, M. G. Muni

Abstract: Wave forces on a vertical cylinder defensed by a perforated vertical and inclined barriers with 45° angle of inclination were experimentally investigated. The relative wave height, (H_i/d) varied from 0.114 to 0.429 and the porosity was kept constant with 12%. The force ratios were found reducing with increase of H_i/d. It is estimated that on an average, the reduction of force on the vertical cylinder is about 35% due to perforated vertical barrier and is about 30% due to sloped barrier. Incident wave steepness, (H_i/L) varied from 0.007 to 0. 080 and the force ratios were also found reducing with increase of wave steepness. The force ratios are less sensitive for the scattering parameter (ka).

Page(s): 179-187