scholarly journals Gyraulus marocana sp. nov., a new freshwater snail species (Mollusca, Gastropoda, Planorbidae) from Morocco

2022 ◽  
Vol 7 (1) ◽  
Author(s):  
Youness Mabrouki ◽  
◽  
Peter Glöer ◽  
Abdelkhaleq F. Taybi ◽  
◽  
...  
Keyword(s):  
Protected Area ◽  
Prostate Gland ◽  
Freshwater Snail ◽  
Snail Species ◽  
Gastropod Species ◽  
Biological Interest ◽  
Geographical Barrier ◽  
Middle Atlas ◽  
Deep Suture ◽  
A Site

A new planorbid gastropod species is described: Gyraulus marocana sp. nov. It can be distinguished from other known species by its regularly striated ivory shell, with four whorls separated by a deep suture, prostate gland with 20 diverticula, phallotheca twice as long as the preputium and its orange stylet. The new species was found in the northern part of Morocco, in Lake Zerrouka, a Protected Area, being also a site of ecological and biological interest (known as SIBE). It is located in the Middle Atlas massif, which is a geographical barrier known for its other endemic molluscs.

scholarly journals Cadmium Pathways in Snails Follow a Complementary Strategy between Metallothionein Detoxification and Auxiliary Inactivation by Phytochelatins

2019 ◽  
Vol 21 (1) ◽  
pp. 7 ◽  
Author(s):  
Martin Dvorak ◽  
Raimund Schnegg ◽  
Michael Niederwanger ◽  
Veronika Pedrini-Martha ◽  
Peter Ladurner ◽  
...  
Keyword(s):  
Specific Binding ◽  
Freshwater Snail ◽  
Snail Species ◽  
Loading Capacity ◽  
Gastropod Species ◽  
Invertebrate Species ◽  
Specific Manner ◽  
Arion Vulgaris ◽  
Species Specific ◽  
Complementary Strategy

Metal detoxification is crucial for animals to cope with environmental exposure. In snails, a pivotal role in protection against cadmium (Cd) is attributed to metallothioneins (MTs). Some gastropod species express, in a lineage-specific manner, Cd-selective MTs devoted exclusively to the binding and detoxification of this single metal, whereas other species of snails possess non-selective MTs, but still show a high tolerance against Cd. An explanation for this may be that invertebrates and in particular snails may also synthetize phytochelatins (PCs), originally known to be produced by plants, to provide protection against metal or metalloid toxicity. Here we demonstrate that despite the fact that similar mechanisms for Cd inactivation exist in snail species through binding of the metal to MTs, the actual detoxification pathways for this metal may follow different traits in a species-specific manner. In particular, this depends on the detoxification capacity of MTs due to their Cd-selective or non-specific binding features. In the terrestrial slug Arion vulgaris, for example, Cd is solely detoxified by a Cd-selective MT isoform (AvMT1). In contrast, the freshwater snail Biomphalaria glabrata activates an additional pathway for metal inactivation by synthesizing phytochelatins, which compensate for the insufficient capacity of its non-selective MT system to detoxify Cd. We hypothesize that in other snails and invertebrate species, too, an alternative inactivation of the metal by PCs may occur, if their MT system is not Cd-selective enough, or its Cd loading capacity is exhausted.

scholarly journals Premating barriers in young sympatric snail species

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Arina L. Maltseva ◽  
Marina A. Varfolomeeva ◽  
Arseniy A. Lobov ◽  
Polina O. Tikanova ◽  
Egor A. Repkin ◽  
...  
Keyword(s):  
Gene Flow ◽  
Snail Species ◽  
Sympatric Populations ◽  
Gastropod Species ◽  
Shell Size ◽  
Closely Related Species ◽  
Partial Canonical Correspondence Analysis ◽  
In The Wild ◽  
Isolation Index

AbstractSympatric coexistence of recently diverged species raises the question of barriers restricting the gene flow between them. Reproductive isolation may be implemented at several levels, and the weakening of some, e.g. premating, barriers may require the strengthening of the others, e.g. postcopulatory ones. We analysed mating patterns and shell size of mates in recently diverged closely related species of the subgenus Littorina Neritrema (Littorinidae, Caenogastropoda) in order to assess the role of premating reproductive barriers between them. We compared mating frequencies observed in the wild with those expected based on relative densities using partial canonical correspondence analysis. We introduced the fidelity index (FI) to estimate the relative accuracy of mating with conspecific females and precopulatory isolation index (IPC) to characterize the strength of premating barriers. The species under study, with the exception of L. arcana, clearly demonstrated preferential mating with conspecifics. According to FI and IPC, L. fabalis and L. compressa appeared reliably isolated from their closest relatives within Neritrema. Individuals of these two species tend to be smaller than those of the others, highlighting the importance of shell size changes in gastropod species divergence. L. arcana males were often found in pairs with L. saxatilis females, and no interspecific size differences were revealed in this sibling species pair. We discuss the lack of discriminative mate choice in the sympatric populations of L. arcana and L. saxatilis, and possible additional mechanisms restricting gene flow between them.

Effects of land use on intermediate snail host fauna, abundance, distribution and cercariae infection rate in Omo-Gibe river basin, Ethiopia

2020 ◽  
Author(s):  
Ketema Deribew ◽  
Etana Jaleta ◽  
Belayhun Mandefro ◽  
Zeleke Mekonnen ◽  
Delenasaw Yewhalaw ◽  
...  
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Fresh Water ◽  
River Basin ◽  
Anthropogenic Activities ◽  
Freshwater Snail ◽  
Snail Host ◽  
Snail Species ◽  
Intermediate Hosts ◽  
Biomphalaria Pfeifferi

Abstract Background: Land use and land cover change significantly affects biodiversity, abundance and distribution of intermediate snail host fauna. In Omo-Gibe river basin the extent of land-use change is high due to anthropogenic activities leading to habitat change of freshwater snail intermediate hosts. Most intermediate snail hosts of human Schistosome parasites belong to two genera, Biomphalaria and Bulinus. In Addition, Lymnea spp. is another important host of Fasciola which causes fasciolasis in domestic animals and human. This study aims to assess the effects of land-use on the distribution and abundance of freshwater snail intermediate hosts and cercariae infection rates of fresh water intermediate snail hosts in Omo-Gibe River basin, Ethiopia.Methods: This study was conducted in Omo-Gibe river basin in 130 sampling sites which include rivers, lakes, dams, stream, wetlands and irrigation ditches. At each site data on land use, anthropogenic activities, freshwater snail abundance and species diversity, and water samples were collected. Snails were collected from each sampling sites using a scoop (20cm x 30cm) with a mesh size of 300µm. Snails were sorted by genus on Enamel pan using forceps and preserved in labeled vials containing 75% ethanol. Live snails collected from the same habitat were sorted carefully and put in clean plastic buckets half filled with water. Afterwards, snails were provided with fresh lettuce leaves and maintained in the laboratory. Snails were then identified morphologically to family, genus and to species level. Each snail was examined for cercaria shedding by placing in a petri dish containing water and exposed to the sun for 2 hours. Cercariae were morphologically identified by microscopy. ArcGIS software of version 10.3.1 was used to map snail distribution and data were analysed using SPSS version-20.Results: The results obtained in this study shows clearly that land use change affect the distribution and abundance of fresh water snails in Omo-Gibe river basin. Fresh water snails were more abundant in farmland and settlement areas. Of the total 2,559 freshwater snails collected from 130 surveyed sites in Omo-Gibe river basin, 1749 (68.34%) belongs to medically important snail species. Biomphalaria spp.914 (35.7%),, Lymnea spp.439 (17.1%),, Physa spp. 343(13.4%) and Bulinus spp 53 (2%)). Sphaeriidae group accounted for 810 (31.6%) of the collected specimens. Biomphalaria pfeifferi was the predominant species of the total snail sampled from lakes, wetlands, rivers and irrigation ditches. Biomphalaria pfeifferi was the most infected snail species by different cercariae. Bulinus globosus and L.natalensis were infected by more than one and same type of cercariae. However, none of B. sudanica and P. acuta specimens was infected by trematode.Conclusions: The results of this study revealed that land use change altered the abundance, distribution and diversity of medically important fresh water snails in the study area. In general medically important freshwater snails which include: Biomphalaria spp, Bulinus spp and Lymnaea spp were collected from lakes, rivers, wetlands, irrigation ditches.. The medically important snail species found infected by cercaria are L. natalensis, B. pfeifferi and B. globosus. Biomphalaria pfefferi was the predominant species and highly infected by cercariae. Higher infection rate was observed in snails collected in Farmland (16.59%) and Grassland (36.6%).

scholarly journals New record of Insuetophrynus acarpicus Barrio, 1970 (Anura: Rhinodermatidae) in Chile: implications for its conservation

Check List ◽  
2017 ◽  
Vol 13 (1) ◽  
pp. 2046
Author(s):  
Bernardo Segura Silva
Keyword(s):  
Protected Area ◽  
New Record ◽  
Altitudinal Range ◽  
The World ◽  
First Occurrence ◽  
A Site

A new record of the Critically frog Insuetophrynus acarpicus was discovered in Chile from a site lying 66 km southwest from the southernmost locality reported for the species. This new population is the first occurrence of the species in a protected area, and considerably extends the geographical and altitudinal range of I. acarpicus, one of the most endangered frogs in the world.

scholarly journals Seven species of land­snails (Gastropoda) new to the Faroe Islands

2015 ◽  
pp. 191
Author(s):  
Jens-Kjeld Jensen ◽  
Jógvan Fróði Hansen ◽  
Ámundur Nolsø
Keyword(s):  
New Species ◽  
Land Snails ◽  
Snail Species ◽  
Faroe Islands ◽  
Intermediate Hosts ◽  
Gastropod Species ◽  
Additional Species ◽  
Commercial Purpose

<p>Since the investigation performed by Solhøy between 1977 and 1979 (Solhøy, 1981) no organized investigation has been performed on the distribution of land snails in the Faroes. Intense importation of building and gardening materials has since increased the risk of introducing new snail species to the islands. This article is based on material and observations from observers around the islands over several years, who have contacted the first author. This has resulted in the discovery of seven new species to the islands in addition to Solhøy’s twenty species. Four of the new species are snails, while two are slugs. An additional species was introduced for commercial purpose but does not seem to have survived well in the Faroese climate.</p>It is difficult to predict the consequences of the settlement of these new Faroese gastropod species, but they may act as intermediate hosts for parasites, having cats and dogs as final hosts.

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