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Title:	Physiological energetics of the dog conch Laevistrombus turturella röding 1798, from Merambong Shoal, Johore, Malaysia
Authors:	Wan Nurul Husna Wan Hassan (P70779)
Supervisor:	Zaidi Che Cob, Prof. Dr.
Keywords:	Aquaculture Laevistrombus turturella Universiti Kebangsaan Malaysia -- Dissertations Dissertations, Academic -- Malaysia
Issue Date:	5-Apr-2021
Description:	Laevistrombus turturella or commonly known as dog conch is one of the marine mollusc which has important ecological role, as well as high economical values, particularly in the Southeast Asian region. The objective of the present study was to determine the physiological energetics (food consumption (C), food absorption efficiency (AE), respiration (R), excretion (U), mucus (M) and fecal (F) productions) and scope for growth (SFG) of L. turturella from Merambong shoals, Johore, Malaysia. In order to provide the basis for the aquaculture development and/or population management of this herbivores gastropod, the relationships among its life stages (juveniles and adults) and different temperature regimes (22, 26, 30 and 34°C) with the SFG were assessed. After transportation to the laboratory, the conchs were acclimatized for one week in stocking aquarium with well-aerated seawater at 30 PSU salinity and ambient temperature of 26°C. Prior to laboratory experimentations, the gastric emptying levels of the conchs were standardized by allowing them to feed on pellets to satiation, and then starving them for 24h. In the experiment, similar sized aquaria were used with three replicates containing ten juvenile and adult conchs respectively. Result showed that the food consumption was significantly different (p<0.05) between different temperature regimes and life stages. The highest food consumption was observed at 26°C, while adult conch consumed more than juveniles. The food absorption efficiency ranged between 50.14 - 74.75% and no significant different was detected between the juveniles and adults of L. turturella (p>0.05). Nevertheless, the food absorption efficiency was affected by different temperature regimes (p<0.05). The respiration rates increased from 0.03 to 0.14 mlh-1 with increasing temperature and the differences were significant effects (p<0.05). In addition, the juvenile conchs showed significantly higher rates of respiration than the adult conchs (p<0.01). Meanwhile, increased temperature significantly (p<0.05) increased excretion rates from 23.92 to 160.78 μgh-1 and differed between the life stages. Mucus production was significantly differed at different temperature, with no significant different between the juvenile and adult conchs (p>0.05). Fecal production was significantly (p<0.05) decreased with increasing temperature from 1.30 to 2.67 mg/l and significant effects (p<0.05) among two life stages of the conch. In this study, it was demonstrated that the greatest SFG values at 26 and 30°C, while the low and high temperature (22 and 34°C) strongly affected the physiological energetics and the adult conch has significantly higher SFG as compared to the juveniles. However, under these conditions, L. turturella show a positive SFG values from 11.59 to 42.38 Jh-1 with enough to be allocated to growth and to reproductive processes.,Ph.D
Pages:	141
Call Number:	SH20.3.W336 2021 tesis
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Science and Technology / Fakulti Sains dan Teknologi

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