Late-glacial to Holocene transition in northern Spain deduced from land-snail shelly accumulations

2012 ◽  
Vol 78 (2) ◽  
pp. 373-385 ◽  
Author(s):  
Yurena Yanes ◽  
Igor Gutiérrez-Zugasti ◽  
Antonio Delgado
Keyword(s):  
Shell Growth ◽  
Late Glacial ◽  
Land Snail ◽  
Balance Model ◽  
Adult Size ◽  
Northern Spain ◽  
Shell Size ◽  
Juvenile Stages ◽  
Climate Fluctuation ◽  
Extreme Seasonality

AbstractShells of the helicid Cepaea nemoralis were studied using taphonomic, isotopic and morphometric measurements to estimate late glacial–Holocene (~ 12.1–6.3 cal ka BP) environmental conditions in northern Spain. Higher taphonomic alteration among Holocene shells suggests lower sedimentation rates or higher shell-destruction rates than during glacial conditions. Shells preserved the aragonitic composition despite differing degree of skeleton damage. Shell δ13C values were − 10.3 ± 1.1‰, − 8.2 ± 2.3‰, and − 7.3 ± 1.6‰ for modern, Holocene and late-glacial individuals, respectively. Higher δ13C values during the late-glacial and some Holocene periods imply higher water stress of C3 plants and/or higher limestone contribution than today. Intrashell δ13C values were higher during juvenile stages suggesting higher limestone ingestion to promote shell growth. Shell δ18O values were − 1.1 ± 0.7‰, − 0.9 ± 0.8‰ and − 0.1 ± 0.7‰ for modern, Holocene and late-glacial specimens, respectively. A snail flux-balance model suggests that during ~ 12.1 − 10.9 cal ka BP conditions were drier and became wetter at ~ 8.4 − 6.3 cal ka BP and today. Intrashell δ18O profiles reveal that glacial individuals experienced more extreme seasonality than interglacial shells, despite possible larger hibernation periods. Shell size correlated positively with δ18O values, suggesting that growth rates and ultimate adult size of C. nemoralis may respond to climate fluctuation in northern Spain.

Paleoenvironmental implications of carbon stable isotope composition of land snail tissues

2013 ◽  
Vol 80 (3) ◽  
pp. 596-605 ◽  
Author(s):  
Yurena Yanes ◽  
María P. Asta ◽  
Miguel Ibáñez ◽  
María R. Alonso ◽  
Christopher S. Romanek
Keyword(s):  
Isotope Composition ◽  
Isotope Analysis ◽  
Land Snail ◽  
Balance Model ◽  
Metabolic Rates ◽  
Stable Isotope Composition ◽  
Cam Plants ◽  
Shell Size ◽  
Flux Balance ◽  
C Value

Land snail shell δ13C value is often used as a paleovegetation proxy assuming that snails ingest all plants in relation to their abundance, and that plants are the only source of carbon. However, carbonate ingestion and variable metabolic rates complicate these relationships. We evaluate if live-collected snails from Lanzarote (Canary Islands) reflect the abundance of C3 and CAM plants. Snails were collected on either CAM or C3 plants for isotope analysis of shell and body, and shell size. Respective shell and body δ13C values of snails collected on CAM plants averaged − 8.5 ± 1.7‰ and − 22.8 ± 1.6‰, whereas specimens from C3 plants averaged − 10.1 ± 0.7‰ and − 24.9 ± 1.1‰. A flux balance model suggests snails experienced comparable metabolic rates. A two-source mass balance equation implies that snails consumed ~ 10% of CAM, which agrees with their abundance in the landscape. Snails collected on CAM plant were smaller than those on C3 plants. Conclusively: 1) snails consume CAM plants when they are available; 2) migration of snails among C3 and CAM plants is a common phenomenon; and 3) C3 plants may be a more energetic food for growth than CAM plants. This study shows that shell δ13C values offer approximate estimates of plants in C3–CAM mixed environments.

scholarly journals Cost of autotomy drives ontogenetic switching of anti-predator mechanisms under developmental constraints in a land snail

2012 ◽  
Vol 279 (1748) ◽  
pp. 4811-4816 ◽  
Author(s):  
Masaki Hoso
Keyword(s):  
High Efficiency ◽  
Shell Growth ◽  
Land Snail ◽  
Life History Strategies ◽  
Body Parts ◽  
Developmental Constraint ◽  
Developmental Constraints ◽  
Evolution Of Life ◽  
Snake Range ◽  
In The Wild

Autotomy of body parts offers various prey animals immediate benefits of survival in compensation for considerable costs. I found that a land snail Satsuma caliginosa of populations coexisting with a snail-eating snake Pareas iwasakii survived the snake predation by autotomizing its foot, whereas those out of the snake range rarely survived. Regeneration of a lost foot completed in a few weeks but imposed a delay of shell growth. Imprints of autotomy were found in greater than 10 per cent of S. caliginosa in the snake range but in only less than 1 per cent out of it, simultaneously demonstrating intense predation by the snakes and high efficiency of autotomy for surviving snake predation in the wild. However, in experiments, mature S. caliginosa performed autotomy less frequently. Instead of the costly autotomy, they can use defensive denticles on the inside of their shell apertures. Owing to the constraints from the additive growth of shells, most pulmonate snails can produce these denticles only when they have fully grown up. Thus, this developmental constraint limits the availability of the modified aperture, resulting in ontogenetic switching of the alternative defences. This study illustrates how costs of adaptation operate in the evolution of life-history strategies under developmental constraints

scholarly journals Sensitivity of groundwater recharge using climatic analogues and HYDRUS-1D

2012 ◽  
Vol 16 (8) ◽  
pp. 2485-2497 ◽  
Author(s):  
B. Leterme ◽  
D. Mallants ◽  
D. Jacques
Keyword(s):  
Water Balance ◽  
Groundwater Recharge ◽  
Potential Evapotranspiration ◽  
Future Climate ◽  
Annual Precipitation ◽  
Balance Model ◽  
Subtropical Climate ◽  
Northern Spain ◽  
Near Surface ◽  
Hydrus 1D

Abstract. The sensitivity of groundwater recharge to different climate conditions was simulated using the approach of climatic analogue stations, i.e. stations presently experiencing climatic conditions corresponding to a possible future climate state. The study was conducted in the context of a safety assessment of a future near-surface disposal facility for low and intermediate level short-lived radioactive waste in Belgium; this includes estimation of groundwater recharge for the next millennia. Groundwater recharge was simulated using the Richards based soil water balance model HYDRUS-1D and meteorological time series from analogue stations. This study used four analogue stations for a warmer subtropical climate with changes of average annual precipitation and potential evapotranspiration from −42% to +5% and from +8% to +82%, respectively, compared to the present-day climate. Resulting water balance calculations yielded a change in groundwater recharge ranging from a decrease of 72% to an increase of 3% for the four different analogue stations. The Gijon analogue station (Northern Spain), considered as the most representative for the near future climate state in the study area, shows an increase of 3% of groundwater recharge for a 5% increase of annual precipitation. Calculations for a colder (tundra) climate showed a change in groundwater recharge ranging from a decrease of 97% to an increase of 32% for four different analogue stations, with an annual precipitation change from −69% to −14% compared to the present-day climate.

Ecophenotypic plasticity in shell growth direction of asari clam Ruditapes philippinarum

2021 ◽  
pp. 1-6
Author(s):  
Takeshi Tomiyama
Keyword(s):  
Growth Rate ◽  
Shell Growth ◽  
Shell Height ◽  
Growth Direction ◽  
Ruditapes Philippinarum ◽  
Shell Morphology ◽  
Individual Growth ◽  
Shell Size ◽  
Internal Factors ◽  
Suitable Habitats

Abstract Asari clam (or Manila clam) Ruditapes philippinarum is an important bivalve for local fisheries. This species exhibits a large variation in shell morphology, and the shell roundness tends to be greater in more unsuitable habitats. To test whether the increments in shell size parameters (length, height and width) were affected solely by environmental conditions or by internal factors such as initial shell shapes or growth rate, a field caging experiment was conducted at two different sites of unsuitable and suitable habitats in Matsukawaura Lagoon, Japan, where shell shapes of wild clams were significantly different between the habitats. In the experiment, clams were released from the two sites to the same site or to the other site and were re-collected after 3, 6 and 12 months of caging. Caged clams originating from unsuitable habitats and released to suitable habitats showed a reduction in shell height relative to shell length, while clams from suitable habitats introduced to unsuitable habitats showed marked increases in both shell height and width. Generalized linear mixed models suggested that the increase in shell height was affected largely by the release habitat (environment) whereas the increase in shell width was affected largely by the individual growth rate. These results suggest that marginal growths in shell height and width respond differently to external and internal factors of clams, resulting in plasticity in their shell shapes according to the environments to which they are translocated.

Pleistocene–Holocene environmental change in the Canary Archipelago as inferred from the stable isotope composition of land snail shells

2011 ◽  
Vol 75 (3) ◽  
pp. 658-669 ◽  
Author(s):  
Yurena Yanes ◽  
Crayton J. Yapp ◽  
Miguel Ibáñez ◽  
María R. Alonso ◽  
Julio De-la-Nuez ◽  
...  
Keyword(s):  
Environmental Change ◽  
Canary Islands ◽  
Environmental Changes ◽  
Isotope Composition ◽  
Moving Average ◽  
Land Snail ◽  
Balance Model ◽  
Low Latitude ◽  
The Times

AbstractThe isotopic composition of land snail shells was analyzed to investigate environmental changes in the eastern Canary Islands (28–29°N) over the last ~ 50 ka. Shell δ13C values range from −8.9‰ to 3.8‰. At various times during the glacial interval (~ 15 to ~ 50 ka), moving average shell δ13C values were 3‰ higher than today, suggesting a larger proportion of C4 plants at those periods. Shell δ18O values range from −1.9‰ to 4.5‰, with moving average δ18O values exhibiting a noisy but long-term increase from 0.1‰ at ~ 50 ka to 1.6–1.8‰ during the LGM (~ 15–22 ka). Subsequently, the moving average δ18O values range from 0.0‰ at ~ 12 ka to 0.9‰ at present. Calculations using a published snail flux balance model for δ18O, constrained by regional temperatures and ocean δ18O values, suggest that relative humidity at the times of snail activity fluctuated but exhibited a long-term decline over the last ~ 50 ka, eventually resulting in the current semiarid conditions of the eastern Canary Islands (consistent with the aridification process in the nearby Sahara). Thus, low-latitude oceanic island land snail shells may be isotopic archives of glacial to interglacial and tropical/subtropical environmental change.

scholarly journals Some Morphological Variations in The Land Snail Monacha cantiana (Montagu,1803) within Baghdad Province

2013 ◽  
Vol 10 (1) ◽  
pp. 1-12
Author(s):  
Baghdad Science Journal
Keyword(s):  
Population Density ◽  
Shell Height ◽  
Calcium Content ◽  
Land Snail ◽  
Shell Morphology ◽  
Shell Size ◽  
Aperture Diameter ◽  
Morphological Variations ◽  
Shell Diameter ◽  
Soil Calcium

The present work includes investigation of some features of shell morphology; shell size, shell thickness, shell colour of the land snail Monacha cantiana, in addition to the correlation between height and diameter of shell and between shell aperture diameter and shell diameter at four sites within Baghdad Province, Iraq. Also, measurements of three environmental variables were made; soil temperature, soil moisture and soil calcium content in adition to population density. Shell Aperture Index (Ia) and Shell Index (SI) for individuals from size class ranged between (9-12)mm were measured. The results showed that the deference in shell size by using (Ia) within population related to temperature, moisture and population density but, the value of Shell Index decreased in AL-Kadhimiya site (0.81-0.97) due to increase in population density. The species was characterized by shell colour variation (creamy white, white ,creamy). Also, The results showed strong and positive correlation between shell height and diameter and between shell aperture diameter and shell diameter for all size classes.

Notodiscus (Charopidae) on South Georgia: some implications of shell size, shell shape, and site isolation in a singular sub-Antarctic land snail

2011 ◽  
Vol 23 (5) ◽  
pp. 442-448 ◽  
Author(s):  
P.J.A. Pugh ◽  
R.I. Lewis Smith
Keyword(s):  
East Coast ◽  
Land Snail ◽  
Shell Shape ◽  
Shell Size ◽  
Site Isolation ◽  
South Georgia ◽  
North East ◽  
Larus Dominicanus ◽  
Close Proximity ◽  
Georgia Population

AbstractMultivariate analysis shows that shells of Notodiscus sp. (Charopidae: Pulmonata) reported from South Georgia are smaller and proportionately taller than, but otherwise similar to, populations of Notodiscus hookeri (Reeve) from Iles Crozet and Iles Kerguelen. The origin of this solitary, and spatially limited, South Georgia population is enigmatic. It is confined to a remarkably small coastal lowland site which was glaciated at Last Glacial Maximum, precluding a Tertiary relict origin, and on the leeward north-east coast, ruling out post-glacial ocean rafting. The site is close to the King Edward Point settlement, yet the absence of any logistics connections with the Iles Crozet or Iles Kerguelen mitigates against anthropogenic introduction. The close proximity of the population to nests of blue-eyed shag (Phalacrocorax atriceps), Dominican gull (Larus dominicanus) and light-mantled sooty albatross (Phoebetria palpebrata) could imply the snail was originally introduced to South Georgia via these ocean transiting seabirds.

Land snails on Porto Santo: adaptive and non-adaptive radiation

1996 ◽  
Vol 351 (1337) ◽  
pp. 309-327 ◽  
Keyword(s):  
Distribution Patterns ◽  
Land Snail ◽  
Land Snails ◽  
Regional Differentiation ◽  
Similar Species ◽  
Adaptive Responses ◽  
Shell Size ◽  
A Value ◽  
Allopatric Divergence ◽  
Evolution Proceeds

A survey has been made of the land snail fauna of Porto Santo, Madeiran archipelago. Porto Santo is an isolated island about 12 km long by 5 km wide. The fauna is exceptionally species-rich and characterisied by radiations of species in several families, especially the Helicidae. Sixty-five samples from the mainland and five offshore islets yielded 56 species, 84% of them endemic, with a mean of 11.5 species per site, and marked regional differentiation in faunal composition. A given site produces on average only approximately one fifth of the number of species possible, equivalent to a value for Whittaker’s index of diversity of 4.5. Patterns of localization occur on the peaks to the east and west of the island, with numerous cases of replacement by congeneric and morphologically similar species. Local areas have assemblages of species differing in shell size and shape, which probably exploit different niches, the pattern in one area paralleling that in others. The low-lying sandy areas which separate these areas are now unfavourable to many endemic species; those which do occur in them tend to have island-wide distributions. Morphological variation in such species appears to have ecological rather than geographical correlates. We conclude that adaptive responses have occurred, but that much of the species richness can be interpreted as non-adaptive, that is, due to allopatric divergence in isolation by species which retain similar niches. Even on so small a land mass the topography is such that for many land molluscs it represents a cluster of refuges intermittantly connected through impermanent and often unfavourable sandy environments, on each of which evolution proceeds independently. Differences in distribution patterns between families probably arise because they evolved at different times in the island’s history. These results are compared with those from snail faunas in other parts of the world, some of which are similar to them.

Role of ambient wavelength, shell size and pigmentation intensity in the heating of Mediterranean Theba pisana (Eupulmonata: Helicidae)

2020 ◽  
Vol 86 (3) ◽  
pp. 249-253
Author(s):  
Tatjana Tull ◽  
Danina Schmidt ◽  
Heinz-R Köhler
Keyword(s):  
Biological Significance ◽  
Green Light ◽  
Land Snail ◽  
Solar Irradiation ◽  
Mediterranean Population ◽  
Shell Size ◽  
Light Emitting ◽  
Theba Pisana ◽  
Higher Temperature ◽  
Set Up

ABSTRACT Theba pisana is a polymorphic land snail widely used in ecophysiological research on the biological significance of solar irradiation. We investigated whether, taking size into account, differently pigmented morphs of a Mediterranean population of T. pisana influence the snails’ heating under different wavelengths. We used a laboratory set-up comprising light-emitting diodes emitting visible light of defined wavelengths and quantified shell heating using high-resolution thermography. Shell pigmentation was quantified densitometrically. There were significant effects of both shell size and light wavelength, such that small snails heated more than large ones over 15 min, and blue light (470 nm) raised temperature more than green light (525 nm). Pigmentation alone did not show significance, but a trend towards higher temperature with increasing pigmentation was evident. Despite the observed significances and trends, we could only explain at most 4.67% of variation in shell heating by multiple regression modelling. However, the light intensity used in this experiment was low and the pigmentation intensity of the shells varied, at most, by a factor of 2. This suggests the actual temperature of a snail depends not only on the tested variables, but also on the multifactorial action of a number of unknown, perhaps intrinsic physiological parameters.

Oxygen and carbon stable isotopes of Mytilus galloprovincialis Lamarck, 1819 shells as environmental and provenance proxies

The Holocene ◽  
2019 ◽  
Vol 30 (1) ◽  
pp. 65-76 ◽  
Author(s):  
Stefania Milano ◽  
Bernd R Schöne ◽  
Igor Gutiérrez-Zugasti
Keyword(s):  
Stable Isotopes ◽  
Mytilus Galloprovincialis ◽  
Shell Growth ◽  
Geochemical Data ◽  
Carbon Stable Isotopes ◽  
Northern Spain ◽  
Mollusc Shell ◽  
Geochemical Composition ◽  
Mussel Shells ◽  
Geochemical Analyses

Mollusc shell stable isotopes are commonly used to reconstruct past environmental conditions. However, despite being abundant components of natural and anthropogenic fossil accumulations, the geochemical composition of mussel shells ( Mytilus spp.) has rarely received attention in palaeoenvironmental studies. This study tests the suitability of oxygen isotopes (δ18Os) of Mytilus galloprovincialis as palaeothermometer. For 1 year, mussels and water samples were collected twice a month from Berria Beach, in Northern Spain. The geochemical data of the shells indicate that water temperatures can be reconstructed with an average offset of 1.2 ± 0.7°C with respect to the measured values. Furthermore, no prolonged shell growth cessations are observed. These results validate M. galloprovincialis as reliable recorders of seasonal water temperature fluctuations, supporting their use in palaeoenvironmental studies. In addition, further shell and water collections were carried out in the upper and lower areas of a nearby estuary. The geochemical analyses of these shells were aimed to test whether oxygen and carbon stable isotopes (δ13Cs) may be used as novel proxies to identify the shell provenance at local scale. The results show that the δ18Os versus δ13Cs correlation direction varies along the coast–upper estuary geographical gradient, suggesting it to be a potential new proxy to distinguish between marine and estuarine mussel specimens.

Sign in / Sign up

Export Citation Format

Share Document