Intraspecific variation in the metabolic scaling exponent in ectotherms: Testing the effect of latitudinal cline, ontogeny and transgenerational change in the land snail Cornu aspersum

AbstractThe Metabolic Scaling Theory (MST), hypothesizes limitations of resource-transport networks in organisms and predicts their optimization into fractal-like structures. As a result, the relationship between population growth rate and body size should follow a cross-species universal quarter-power scaling. However, the universality of metabolic scaling has been challenged, particularly across transitions from bacteria to protists to multicellulars. The population growth rate of unicellulars should be constrained by external diffusion, ruling nutrient uptake, and internal diffusion, operating nutrient distribution. Both constraints intensify with increasing size possibly leading to shifting in the scaling exponent. We focused on unicellular algae Micrasterias. Large size and fractal-like morphology make this species a transitional group between unicellular and multicellular organisms in the evolution of allometry. We tested MST predictions using measurements of growth rate, size, and morphology-related traits. We showed that growth scaling of Micrasterias follows MST predictions, reflecting constraints by internal diffusion transport. Cell fractality and density decrease led to a proportional increase in surface area with body mass relaxing external constraints. Complex allometric optimization enables to maintain quarter-power scaling of population growth rate even with a large unicellular plan. Overall, our findings support fractality as a key factor in the evolution of biological scaling.

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Uptake and biological responses in land snail Cornu aspersum exposed to vaporized CdCl2

Ecotoxicology and Environmental Safety ◽

10.1016/j.ecoenv.2017.10.050 ◽

2018 ◽

Vol 148 ◽

pp. 377-383 ◽

Cited By ~ 4

Author(s):

L. Sturba ◽

G. Liberatori ◽

M.L. Vannuccini ◽

S. Ancora ◽

I. Corsi

Keyword(s):

Land Snail ◽

Biological Responses ◽

Cornu Aspersum

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Influence of temperature acclimation and gut content on the supercooling ability of the land snail Cornu aspersum

Comparative Biochemistry and Physiology Part A Molecular & Integrative Physiology ◽

10.1016/j.cbpa.2008.02.013 ◽

2008 ◽

Vol 150 (1) ◽

pp. 14-20 ◽

Cited By ~ 5

Author(s):

Armelle Ansart ◽

Pierre-Aymeric Aulne ◽

Luc Madec ◽

Philippe Vernon

Keyword(s):

Land Snail ◽

Temperature Acclimation ◽

Gut Content ◽

Influence Of Temperature ◽

Cornu Aspersum

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Faecal microbiota dynamics in Cornu aspersum during dietary change and antibiotic challenge

Journal of Molluscan Studies ◽

10.1093/mollus/eyz016 ◽

2019 ◽

Vol 85 (3) ◽

pp. 327-335

Author(s):

Parker N Smith ◽

Sarah M Boomer ◽

Michael J Baltzley

Keyword(s):

Food Source ◽

Population Analysis ◽

Amplicon Sequencing ◽

Land Snail ◽

Faecal Microbiota ◽

16S Rrna Amplicon Sequencing ◽

Significant Difference ◽

Cornu Aspersum ◽

Penicillin Treatment ◽

Pre Treatment

ABSTRACTDespite its widespread geographic distribution and applications, the herbivorous land snail Cornu aspersum represents an understudied animal host. In this study, we used a culture-based approach, in combination with a population analysis based on 16S rRNA amplicon sequencing, to describe changes in the faecal microbiota of wild-caught snails that were fed a nonsterile plant diet over a period of 21 days. At the beginning of the experiment, wild-caught snails harboured diverse populations of Gammaproteobacteria. The two most abundant genera of Gammaproteobacteria were soil-associated Pseudomonas and Buttiauxella; the latter is an understudied genus often reported in snails and slugs. During penicillin treatment, the diversity of Gammaproteobacteria in experimental snails bottlenecked, resulting in Pseudomonas takeover. Following penicillin treatment, experimental snails began to recover, with faecal samples containing pre-treatment Gammaproteobacteria groups by day 21. There was a significant difference in the colony-forming units/g across days and across treatments. Additionally, there was a significant interaction between day and treatment. The food source was not sterile and supported its own population of Gammaproteobacteria, primarily Pseudomonas, which would have been taken up by the snails daily. Given that Buttiauxella was not observed on the food source, we hypothesize that it was present and maintained within the digestive tract of C. aspersum, and this is consistent with the idea that C. aspersum maintains an endogenous gut microbiome.

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Brachylaima spp. (Trematoda) parasitizing Cornu aspersum (Gastropoda) in France with potential risk of human consumption

Parasite ◽

10.1051/parasite/2020012 ◽

2020 ◽

Vol 27 ◽

pp. 15

Author(s):

Claudia Gérard ◽

Armelle Ansart ◽

Nolwenn Decanter ◽

Marie-Claire Martin ◽

Maxime Dahirel

Keyword(s):

North Africa ◽

Intestinal Parasite ◽

Health Hazard ◽

Land Snail ◽

Human Consumption ◽

Geographic Spread ◽

Great Body ◽

Cornu Aspersum ◽

Second Intermediate Host ◽

First Time

The edible land snail Cornu aspersum, native to the Mediterranean coastlines of North Africa, is widely distributed on most continents and often invasive in areas where introduction is recent. This species could contribute to the geographic spread of parasites as demonstrated for Brachylaima spp. These cosmopolitan trematodes may represent a threat to human health, like in Australia where Brachylaima cribbi infects humans. In this study, we demonstrate for the first time the occurrence of Brachylaima spp. in two French populations of C. aspersum, Thorigné-Fouillard (Ille-et-Vilaine), and Arçais (Deux-Sèvres), with an overall prevalence of 10.4% (Thorigné-Fouillard) and 73.3% (Arçais), respectively and a metacercarial intensity on average three times higher in Thorigné-Fouillard (37) than in Arçais (11). Cornu aspersum may act as a first and second intermediate host, as demonstrated in Arçais. The morphometrics of metacercariae, particularly the great body length about 2 mm, discriminate our Brachylaima species from those already described in C. aspersum (B. cribbi in Australia, and B. aspersae, B. llobregatensis and B. mascomai in Europe). Molecular analysis, based on 28S and COI, suggests the occurrence of two species in our study, one of which is probably Brachylaima mesostoma, an intestinal parasite of passeriform birds described in Central Europe. We underline the need for further research to identify species of Brachylaima in France and measure the health hazard of consuming field-collected snails.

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