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 87
- Downloads 0
Molecular Typing of Campylobacter Species Isolated from Healthy Indigenous Chickens in Grenada
Aim: To identify the sequence types (STs) of Campylobacter from indigenous chickens in Grenada and compare the results to other animals in Grenada and other countries from previous published studies. Study Design: Therm...
Antimicrobial Activity of Potato Rhizospheric Pseudomonas chlororaphis subsp. aureofaciens from Sétif Algeria
Aims: This study was assessed to demonstrate the antimicrobial activity in vitro of an identified fluorescent Pseudomonas strain characterized for its capacity to produce phenazine compounds. Methodology: First Pseudomon...
Oryctes owariensis Larvae as Good Alternative Protein Source: Nutritional and Functional Properties
In Côte d’Ivoire, the larvae of Oryctes owariensis are prized and widely consumed as alternative protein source. The present study was aimed at evaluating the nutritional and functional properties of the larva flour for...
Antimicrobial Activities of Phragmanthera incana (schum.) Balle, a Mistletoe Species Harvested from Two Host Plants against Selected Pathogenic Microbes
Aims: Phragmanthera incana, African mistletoe popularly called “bird lime”, devil’s fuge, “all heal, Iscador”, “mystyldene”, “golden bough” etc a hemi-parasitic plant was screened for its antimicrobial properties due to...
Stimulation of Hepatocytes Repair by Fruit Juice of Opuntia ficus indica in Anti Cancer Drug Cyclophosphamide (CP)-Induced Liver Toxicity in Mice
Cyclophosphamide (CP) is a cytotoxic alkylating agent that has been used extensively in medicine as anti neoplastic agent for the treatment of different cancers worldwide. Chemotherapy with CP is associated with signific...