Tropical intertidal gastropods: insights on diversity, abundance, distribution and shell morphometrics of Pulau Bidong, Malaysia
Baharuddin, N.; Basir, N.H.M.; Zainuddin, S.N.H. (2019). Tropical intertidal gastropods: insights on diversity, abundance, distribution and shell morphometrics of Pulau Bidong, Malaysia. AACL Bioflux 12(4): 1375-1387
In: Aquaculture, Aquarium, Conservation & Legislation - International Journal of the Bioflux Society. Bioflux: Romania. ISSN 1844-8143; e-ISSN 1844-9166, more
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| Keywords |
Gastropoda [WoRMS]
Marine/Coastal |
| Author keywords |
shallow, waves, Gastropoda, diversity t-test, SHE analysis |
| Authors | | Top |
- Baharuddin, N.
- Basir, N.H.M.
- Zainuddin, S.N.H.
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| Abstract |
The intertidal zone or littoral zone is the part of the ocean that is underwater during high tide and exposed during low tide. The intertidal ecosystem is continually under pressure from both humans and the natural elements of waves and tidal shifts. The organisms that reside here must be able to tolerate extreme changes to physicochemical factors such as light, temperature, water movement, salinity and oxygen. Gastropods from phylum Mollusca are highly resistant and adaptable to extreme changes in the environment. This study investigates the diversity, abundance, and distribution of tropical intertidal gastropods in different areas. Also, it examines how shell morphometrics and biomass affect these factors. Sampling was done in Pantai Pasir Cina (PPC) and Pantai Pasir Pengkalan (PPP) at Pulau Bidong, Malaysia in August 2018. Transect lines of 60 m × 10 m were laid out perpendicular to the shore. Six quadrats of 1 m2 were placed at three tidal zonation’s: high, mid, and low tide. A total of 1326 individual gastropods represented by eight families (Littorinidae, Muricidae, Planaxidae, Siphonariidae, Neritidae, Nacillidae, Patellidae and Trochidae) were recorded, along with five subclasses namely Ceanogastropoda, Heterobranchia, Neritimorpha, Patellogastropoda and Vetigastropoda. A total number of 19 species were recorded from both study sites. The Shannon diversity index, H’ showed that at the intertidal zones at both locations the diversity was less than two, indicating low diversity. In contrast, Simpson’s index, D at all intertidal zones at both sites had values of almost one, indicating a high level of dominance. This pattern is also seen for evenness indices such as J’ and Ep’ where all values are close to one, which indicates complete evenness for all tidal zones. The diversity t-test revealed significant differences between the sites of PPC and PPP, t (1192.5) = -4.9652, p < 0.05. The SHE analysis of the two sites showed a lognormal pattern. Community structures of intertidal zones at PPC and PPP are between ‘more equally’ and ‘very equally’ and fall under the ‘good’ or the ‘very good’ categories. Although it is the baseline, a future study on spatial heterogeneity and temporal variability are needed to provide more comprehensive knowledge of malacofauna communities and their ecological importance. |
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