BUKU ABSTRAK - Universiti Putra Malaysia

Population Parameters of Planktonic Shrimp, Lucifer intermedius (Decapoda:
Sergestidae) from Sungai Pulai Seagrass Beds, Johor, Peninsular Malaysia
Assoc. Prof. Dr. Aziz Arshad
Norhafizah Osman, S. M. Nurul Amin and Zaidi Che Cob
Institute of Bioscience, University Putra Malaysia,
43400 UPM Serdang, Selangor, Malaysia.
+603-8946 4118; aziz.upm@gmail.com
Keywords: Growth, mortality, recruitment, exploitation, lucifer intermedius, Malaysia
First Hatching Success and Larval Development of Dog Conch, Strombus canarium
(Mollusca: Gastropoda) in a Laboratory Condition
Assoc. Prof. Dr. Aziz Arshad
Zaidi Che Cob, Japar Sidik Bujang, S.M.Nurul Amin and Mazlan Abd. Ghaffar
Faculty of Agriculture, University Putra Malaysia,
43400 UPM Serdang, Selangor, Malaysia.
+603-8946 4118; azizarshad@putra.upm.edu.my
Keywords: Hatching, larval development, strombus canarium, Malaysia
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Agriculture
Growth, mortality and recruitment of sergestid shrimp, Lucifer intermedius was investigated using length
frequency data between April 2007 and December 2007 in the Sungai Pulai seagrass beds, Johor strait, Peninsular
Malaysia. The von Bertalanffy growth parameters, Asymptotic length and growth co-efficient (K) were estimated
at 11.10 mm and 1.40/year. The growth performance index was calculated at 2.237. Total mortality was estimated
at 5.32/year. The natural and fishing mortality was 2.99/year and 2.33/year, respectively. The recruitment pattern
of Lucifer intermedius was continuous throughout the year with two major peasks. The exploitation rate was
estimated at 0.44. This indicates that fishery status of Lucifer intermedius in the Sungai Pulai seagrass area was
below the optimum level of exploitation.
The dog conch, Strombus canarium Linnaeus, 1758 or locally known as ‘siput gonggong’ is a commercially
important shallow water gastropod in the Johor Strait that is highly associated with dense seagrass habitat. The
objectives of this study is to know the hatching process and describe the early development stages of the species.
Strombus canarium females can reproduce as year round but showed peaks in spawning activity during the period
from October to early March. They produced long gelatinous tube of an egg strand that coiled and intertwined to
form an egg mass. The egg strand can reach up to 30 m in length. In this study, the conch embrynic development
was described and its evolution in time was recorded. The incubation time (time from eggs deposition to completed
hatching) ranged from 106 to 135 h in seawater at 30 PSU and 29 0 c. The conch larvae emerged as swimming
veliger and feeds on the plankton before metamorphosed and assuming a benthic life. Potassium chloride was
applied as metamorphosis inducers, which is very important as otherwise the competent larvae were unable to
metamorphose and will ultimately die of exhaustion. The planktonic stage lasted between 18 to 25 days. The
metamorphosis competent period is relatively short, started from day 17 to day 23 post hatch. Description of each
of the parval stages and its development time were presented in this paper.