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Vol. 48 No. 1, 2009
Development and Growth of Larvae of the Dog Conch, Strombus canarium (Mollusca:
Gastropoda), in the Laboratory
Zaidi
Che Cob1,*, Aziz Arshad2, Mazlan Abd. Ghaffar1,
Japar Sidik Bujang2, and Wan Lotfi Wan Muda1
1Marine
Ecosystem Research Centre (EKOMAR), Faculty of Science and Technology,
Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
2Department of Biology, Faculty of Science, Universiti
Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia
Zaidi
Che Cob, Aziz Arshad, Mazlan Abd. Ghaffar, Japar Sidik Bujang, and Wan
Lotfi Wan Muda (2009) Strombus
canarium egg masses used in this study were collected while
still underneath spawning females, and embryonic and post-hatching
larval development was observed in the laboratory. Strombus canarium larvae were
reared at 200 larvae/L in 2-L containers with 0.22 μm filtered seawater
medium at a salinity of 30 ± 1 PSU, and fed a single algal species, Isochrysis galbana, at 1000
cells/ml. Fecundity was estimated at 48,745 ± 877 to 93,643
± 1685 (n = 10) eggs/egg
mass. The incubation time was between 110.4 and 134.4 h (mean
122.43 ± 3.07 h, n = 7) at 29
± 1°C, with a high hatching rate (mean 93.34% ± 1.68% hatched, n = 3). The larvae have 2
velar lobes and 1.5 shell whorls at the time of hatching, with an
average shell length of 216.77 ± 5.72 μm (n = 10). Based on prominent
larval characters and visible morphological features, S. canarium larvae can be assigned
to 4 different development stages, i.e. stages I, II, III, and IV,
which are described in this paper. The larvae reached metamorphic
competence at 17-23 d posthatching, and only metamorphosed when
settlement cues (sediments from its natural habitat and 15 mM KCl) were
introduced. They showed a short period of metamorphic competence,
and no spontaneous metamorphosis was observed. Morphological
changes and larval behaviors at the onset and during metamorphosis are
also described.
Key words: Veliger,
Development, Metamorphosis, Malaysia.
*Correspondence: Tel: 603-89215238. Fax:
603-89253357. E-mail:zdcc@ukm.my
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