A Renewed Understanding of Shell-shape Diversity among Marine Gastropod Species: Invariance and Covariance between Geometrical Parameters in Conispirally Coiled Shells
Journal Title: Annual Research & Review in Biology - Year 2017, Vol 13, Issue 2
Abstract
Approximately conispirally coiled shells make the bulk of shell structure among marine gastropod species, apart from those shells with strongly overlapping whorls (typical, in particular, of Cones, Cowries and the like). By selecting appropriately the set of geometrical parameters appropriate to describe the interspecific variations of shell-shape, an original pattern of covariances and independences was unveiled between these parameters, providing, in turn, a partly renewed understanding of the interspecific diversification of shell-shapes among conispirally coiled marine gastropods. This novel approach should be considered as complementary, rather than alternative, to the traditional and well established models by RAUP and others. Among the four selected descriptive parameters (the whorl expansion ratio, the degree of whorl compression, the number of whorls of fully blown shell and the shell apical angle), four strong covariances and two mutual independences are empirically documented and analysed theoretically. Two covariances (apical angle covarying positively with the whorl expansion ratio and negatively with the degree of whorl compression) are imposed by geometrical constraints exclusively; one covariance (negative between the number of whorls and the whorl expansion ratio) is likely attributable to purely biological causes, tentatively associated to either developmental or functional constraints; while the last covariance (negative between apical angle and number of whorls) involves both geometrical and biological determinisms. Thus, the conispiral coiling mode, in marine gastropods, involves quite an intricate interplay of covariances among the parameters describing shell-shape. While limiting thereby the range of occupation of the potential morphospace, this pattern of covariances introduces enhanced shell shape complexity. Highlighting this underlying complexity may, in turn, contribute to a more thorough and fundamental understanding of the ontogenetic aspects involved in the profuse diversity of shell-shapes among marine gastropods.
Authors and Affiliations
Jean Béguinot
Keywords
Related Articles
- EP ID EP313358
- DOI 10.9734/ARRB/2017/33935
- Views 112
- Downloads 0
Protective Potential of Grape Seed Proanthocyandins Extract against Glivec (Imatinib Mesylate) Induced Liver Toxicity and Oxidative Stress in Male Rats
Objectives: Glivec (Imatinib mesylate) an antineoplastic chemotherapeutic agent used in the treatment of many types of cancer. The current study examines the hepatoprotective potential of grape seed proanthocyandins extr...
Feeding Preferences and Control of a Pakistani Termite Odontotermes obesus (Rambur) (Isoptera, Rhinotermitidae)
Background: Feeding preferences of Odontotermes obesus on five different commercial wood species were studied under choice and no choice trials both in laboratory and field conditions. Feeding preferences as a quantitati...
Association of Delta-Aminolevulinic Acid Dehydratase Polymorphism with Blood Lead and Hemoglobin Level in Lead Exposed Workers
Introduction: Despite decades of intensive research, lead toxicity still remains one of the most health concerns. Hence, risks posed by lead are more likely to be determined by individual susceptibility as delta-aminolev...
Agro-morphological Characterization of Corchorus olitorius Cultivars of Benin
Aim: Corchorus olitorius is indubitably one of the most important vegetables in Benin. It is grown in most regions of the country and also in the tropical and sub-tropical regions of the world, particularly in Asia, Afri...
Population Dynamic of Citrus Blackfly, Aleurocanthus woglumi (Hemiptera: Aleyrodidae), in Tahiti Lime in the eastern of the State of São Paulo, Brazil
Citrus blackfly, Aleurocanthus woglumi is a serious citrus insect pest. The objective of this study was to determine the population dynamic of the CBF in a commercial citrus orchard in the State of São Paulo, Brazil. The...