Original Article

Morphological variation among cowries (Gastropoda: Cypraeidae) using geometric morphometrics and correlation analysis based on distances

Authors
Ma. Lotus Espina-Patiluna¹ and Cesar G. Demayo^2
1College of Fisheries and Aquatic Sciences, Western Philippines University, Puerto Princesa City, Palawan
²Biological Science Department, Mindanao State University-Iligan Institute of Technology Tibanga, Iligan City

ABSTRACT
Cowries (Cypraeidae) are popular among shell collectors because of their beauty and relative availability. Some species of cowry have high collection values among shell markets, however this has led to an increase number of species and unnecessary proliferation of taxonomic names with little information on their morphology. Thus, this study was conducted to describe morphological variations among cowry shells obtained along Sindangan Bay, Philippines. The shell morphological attributes (e.g. shell shape, color, bands, banding pattern), morphometric characters (e.g. shell length, width, height, number of teeth, etc.), and shape were characterized using the relative warp scores generated from the outline and landmark-based geometric morphometric analysis (GM) and correlation analysis based on distances (CORIANDIS). Sixteen (16) morphological and ten (10) meristic characters of 113 samples from the seven Cypraeidae species were examined and analyzed. The variations on color, banding pattern, lateral margins, dorsal/transverse line, spire, teeth, size and shape of the shell were mainly observed. Relative warp analysis showed significant shell shape variation among Cypraeidae species. Correlation analysis based on distances showed morphological, size, and shape differences among Cypraeidae species. As revealed in correlation analysis, the observed variation in size was significantly correlated with shape. The observed differences could be due to many factors including genetic, biotic and abiotic factors; developmental processes and physiology in responses of the organisms to a unique environment. Thus, geometric morphometrics and CORIANDIS helped us understand the nature of diversity in the family Cypraeidae species. Further studies on environmental heterogeneity, species position within the population’s distribution, and the genetic basis of the observed phenotypic diversity are necessary. Such emphasis can lead to additional information in the systematic studies on species of family Cypraeidae.

Keywords: cowry, cluster, dendrogram, disparity, Sindangan, variation

^{Available Online: 26 July 2024}

How to Cite:
Espina-Patiluna MLE and Demayo CG. 2024. Morphological variation among cowries (Gastropoda: Cypraeidae) using geometric morphometrics and correlation analysis based on distances. The Palawan Scientist, 16(2): 95-112. https://doi.org/10.69721/TPS.J.2024.16.2.09

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