Shell shape variation in the Nassariid Buccinanops globulosus in northern Patagonia

Abstract

Morphological variation among natural populations is a phenomenon commonly observed in marine invertebrates and well studied, particularly, in shelled gastropods. The nassariid Buccinanops globulosus is interesting to study shell shape variation because it exhibits strong interpopulation differences in life history features, including maximum size, fecundity and growth rate. In this study, we examined the pattern of variation in size and shell shape among populations and between sexes of B. globulosus (Bahía San Antonio 40°29 0 S 63°01 0 W, Playa Villarino 40°45 0 S 64°40 0 W and Bahía Nueva 42°46 0 S 65°02 0 W). In particular, we used geometric morphometric techniques to test: (1) whether the two components of shell morphology (size and shape) are independent and (2) whether shape differences between sexes are consistently found among populations, regardless of their body sizes. Our results show shell shape variation between the populations of B. globulosus of northern Patagonia. Intraspecific shell shape variation is affected by body size, indicating allometry. Regardless of the size differences, individuals from Playa Villarino have high-spired shells, and shorter apertures and wider columellar area than individuals from the other populations. Also, sex-related shape differences were consistently found at each population, thus suggesting a common sexual dimorphism in shell morphology for this species. The functional significance of the variability found is discussed in terms of the flexibility of developmental programmes for morphology as well as the evolution of phenotypic plasticity.

Quantifying the Geometric Shell Shape between Populations of True Limpets Lottia Mesoleuca (Mollusca: Lottidae) in Colombia

“…This is the reason why studies have been conducted to identify species in other marine organisms, including some limpets, such as the case of Cellana strigilis, which has phenotypic plasticity [66][67][68]. Such phenotypic plasticity may be due to the natural selection during evolution or during the life cycle, the environment, predation [30,[69][70][71][72][73] or by means of ontogenetic changes [74][75][76] associated with environmental conditions, such as temperature [28,77,78].…”

Species density and shell morphology of gold ring cowry (Monetaria annulus, Linnaeus, 1758) (Mollusca: Gastropoda: Cypraeidae) in the coastal waters of Ambon Island, Indonesia

“…The same environmental conditions and geographical locations made the shells of gastropods have the same structure and shape (Trussell 1997;Tissot 1984;Cazenave and Zanatta 2016;Zhao et al 2019). In addition, variations of the shapes of gastropods shells are influenced by the body size and the sex differences (Avaca et al 2013). The results of the One-Way-ANOVA analysis on the length and the width of the blotch of M. annulus (Table 3) is shown the significance value was 0.000, lower than the α value of 0.05 (p<0.05).…”

Shell alterations in limpets as putative biomarkers for multi-impacted coastal areas

“…Environmental parameters such as hydrodynamics (e.g., wave action), temperature, sun exposure (e.g., desiccation), type of substrate and salinity can lead to inter-and intraspecific changes in the shape, thickness, composition and sculpture of mollusc shells (Underwood, 1979;Vermeij, 1973). Studies using gastropods (Avaca et al, 2013;Laitano et al, 2013;M arquez et al, 2011;Nuñez et al, 2012) and bivalves (Alzieu, 2000;Alzieu et al, 1986) have shown that morphological and chemical composition changes in shells can also be induced by the exposure to hazardous chemicals in laboratory assays and along pollution gradients in the environment.…”