Vol. 47 No. 3, 2008
Sexual Polymorphism in a Population of Strombus canarium
Linnaeus, 1758 (Mollusca: Gastropoda) at Merambong Shoal, Malaysia
Che Cob1,*, Aziz Arshad2, Mohd Hanafi Idris2, Japar Sidik Bujang2, and
Mazlan Abd Ghaffar1
of Environmental and Natural Resource Science, Faculty of Science and
Technology, National University of Malaysia, 43600 Bangi, Selangor,
2Department of Biology, Faculty of Science, Universiti
Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia
Che Cob, Aziz Arshad, Mohd Hanafi Idris, Japar Sidik Bujang, and Mazlan
Abd Ghaffar (2008) Various morphometric parameters of Strombus
canarium Linnaeus, 1758 from Merambong Shoal, Malaysia, were measured
and analyzed. The parameters include shell length, body whorl length,
shell width, shell depth, shell lip thickness, aperture length, animal
weight and shell weight. The population showed sexual polymorphism, and
in addition to normal males and females, a 3rd morph composed of
abnormal females with imposex characters were present. The latter
(imposex females) accounted for 35.71% of the total adult female
sub-population. Comparisons between males and normal females showed
that the former had a significantly larger, heavier, and more-elongate
shell than the latter. The male shells also had a significantly thicker
lip with a higher degree of posterior and lateral lip flaring.
Conversely, females allocated more energy into tissue production than
shell deposition relative to males. The 3rd imposex morph had a
significantly larger and heavier shell, and a higher degree of
thickening and flaring of the lip compared with both male and normal
female shells. Imposex females also allocated less energy to gonad
production relative to tissue production compared to normal females.
Key words: Dog
conch, Allometric analysis, Polymorphism, Imposex.
*Correspondence: Tel: 60-3-89215238. Fax: 60-3-89253357.