NISCAIR Online Periodicals Repository Community: Indian Journal of Geo-Marine Sciences (IJMS)

Effect of stocking density on the hatching rate, larval and early juvenile rearing of edible sea cucumber Holothuria scabra (Jaeger, 1883)

Title: Effect of stocking density on the hatching rate, larval and early juvenile rearing of edible sea cucumber Holothuria scabra (Jaeger, 1883)

Authors: Asha, P.S.; Diwakar, K.

Abstract: Fertilized eggs, auricularia larvae and three month old juveniles of H. scabra, obtained from induced spawning were used for various experiments to assess the effect of stocking density on hatching rate, larval and early juvenile rearing of commercially important sea cucumber H. scabra. Experiments were conducted for two days on hatching rate of fertilized eggs, for ten days on larval survival, growth and development and for 120 days on juvenile’s growth rate. An inverse relationship was observed between stocking density and hatching rate. Hatching rate varied between 15.1% at 8 eggs mL^-1 to a maximum of 66.4% at 0.5 eggs mL^-1. High survival, growth rate and fastest development of auricularia at stocking density 1 larvae mL^-1 indicated the optimum larval rearing conditions. Maximum growth rate in length and weight, suggested the stocking density 4.2 Nos. m^-2 is good for juvenile rearing. One way ANOVA on the differences in the hatching rate, larval growth and survival rate, juvenile growth rate both in length as well as in weight at different stocking densities indicated high level of significances (P<0.001).

Page(s): 191-195

Comparative length-weight relationship of two species of catfishes, Arius caelatus (Valenciennes, 1840) and Arius tenuispinis (Day, 1877) from Mumbai waters⁺

Title: Comparative length-weight relationship of two species of catfishes, Arius caelatus (Valenciennes, 1840) and Arius tenuispinis (Day, 1877) from Mumbai waters⁺

Authors: Sawant, Bhawesh T.; Chakraborty, S. K.; Jaiswar, A. K.; Bhagabati, Sarada K.; Kumar, Tarkeshwar; Sawant, Paramita B.

Abstract: Based on the length weight data collected from New Ferry Wharf (NFW), Sasoon Docks (S.D) & Versova landing centres, the length-weight relationship for two important catfishes, Arius caelatus and A. tenuispinis from Mumbai waters has been reported in the present communication. There is no significant difference in growth between sexes for both the species, based on the ANACOVA test. Length-weight relationship derived were W = 0.00419 * L ^3.263 (R²= 0.899) and W = 0.0306 * L ^2.720 (R² = 0.953), for A. caelatus and A. tenuispinis respectively. Growth pattern study showed isometric growth for A. caelatus and A. tenuispinis.

Page(s): 266-269

Ambience of physico-chemical characteristics to actinobacterial density in the Chennai coast of the Bay of Bengal, India

Title: Ambience of physico-chemical characteristics to actinobacterial density in the Chennai coast of the Bay of Bengal, India

Authors: Gnanam, S.; Sivakumar, K.; Vijayalakshmi, S.; Balasubramaniyan, T.

Abstract: Present study consists seasonal abundance and relationship of actinobacteria with the important chemical characteristics of the marine environment in both water and sediments. Actinobacterial density exhibited clear seasonal variations, being highest (38 × 10⁴ CFU/gdry wt) in monsoon and lowest (13 × 10⁴ CFU/gdry wt) in summer, 2009. Seasonal variations of actinobaterial diversity showed is positive correlation with water nutrients such as phosphate , nitrite, nitrate and silicates and with sediment nutrients such as clay soil, total organic carbon, total nitrogen and total phosphorus. Negative correlation was observed with water temperature, salinity and pH. Monsoon and summer seasons exhibited the major influence on the actinobacterial population in the marine environment of Chennai coast.

Page(s): 254-265

Developmental biology of brackishwater copepod Oithona rigida Giesbrecht: A laboratory investigation

Title: Developmental biology of brackishwater copepod Oithona rigida Giesbrecht: A laboratory investigation

Authors: Santhanam, P; Perumal, P.

Abstract: In the present study ,attempt was made on larval metamorphosis of cyclopoid copepod Oithona rigida under laboratory condition. In the larval development, O. rigida has six naupliar and six copepodite stages precede the adult and it reached adulthood early. Duration of development from egg to adult was 12 days at 28°C. Copepodite stages lasted longer than naupliar stages.

Page(s): 236-243

NISCAIR Online Periodicals Repository Community: Indian Journal of Geo-Marine Sciences (IJMS)

Effect of stocking density on the hatching rate, larval and early juvenile rearing of edible sea cucumber Holothuria scabra (Jaeger, 1883)

Comparative length-weight relationship of two species of catfishes, Arius caelatus (Valenciennes, 1840) and Arius tenuispinis (Day, 1877) from Mumbai waters+

Ambience of physico-chemical characteristics to actinobacterial density in the Chennai coast of the Bay of Bengal, India

Developmental biology of brackishwater copepod Oithona rigida Giesbrecht: A laboratory investigation

Comparative length-weight relationship of two species of catfishes, Arius caelatus (Valenciennes, 1840) and Arius tenuispinis (Day, 1877) from Mumbai waters⁺