Macroalgae and seagrass contribution to gastropods in sub-tropical and temperate tidal flats

2008 ◽  
Vol 89 (2) ◽  
pp. 399-404 ◽  
Author(s):  
Hideyuki Doi ◽  
Masatoshi Matsumasa ◽  
Mamoru Fujikawa ◽  
Keiichi Kanou ◽  
Takao Suzuki ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Benthic Communities ◽  
Tidal Flats ◽  
Food Sources ◽  
Snail Species ◽  
Terrestrial Plants ◽  
Gastropod Species ◽  
High Productivity ◽  
Intertidal Flats ◽  
Waves And Currents

Macroalgal and seagrass communities are widely distributed in marine and brackish shallow water and have high productivity. The primary production in marine costal areas is often transported to intertidal flats by waves and currents and beached on the flats. Thus, we hypothesized that the macroalgae and seagrasses are food sources for benthic communities on intertidal flats where some gastropod species often dominate. We performed comparisons of food sources among different gastropod species on sub-tropical and temperate tidal flats (26° and 38°N, respectively), and used isotope mixing models using carbon and nitrogen stable isotopes. A mixing model for stable isotopes, IsoSource, revealed that main food sources for three snails were macroalgae (50–56%) and seagrass (39–45%) at the temperate site. The contributions of terrestrial plants, sediment organic matter and benthic microalgae were weaker than those of macroalgae and seagrasses. At the sub-tropical site, snails fed mainly on macroalgae. The differences in food sources between snail species were not remarkable, although the nitrogen values were slightly different. It would thus appear that macroalgae and seagrass play an important role in the food webs not only in their own habitats but also on the adjacent tidal flats.

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.

Determination of food sources and trophic position in Malaysian tropical highland streams using carbon and nitrogen stable isotopes

2017 ◽  
Vol 37 (2) ◽  
pp. 97-104 ◽  
Author(s):  
Dhiya Shafiqah Ridzuan ◽  
Che Salmah Md. Rawi ◽  
Suhaila Abdul Hamid ◽  
Salman Abdo Al-Shami
Keyword(s):  
Stable Isotopes ◽  
Trophic Position ◽  
Food Sources ◽  
Nitrogen Stable Isotopes ◽  
Carbon And Nitrogen ◽  
Highland Streams

Investigating food assimilation in a carnivorous teleost by stable isotopes analysis: the case of ribbonfish off south-east Brazil

2020 ◽  
Vol 100 (3) ◽  
pp. 445-451
Author(s):  
Ana Paula Madeira Di Beneditto ◽  
Pedro Viana Gatts ◽  
Vanessa Trindade Bittar
Keyword(s):  
Stable Isotopes ◽  
Coastal Waters ◽  
Food Sources ◽  
Commercial Fisheries ◽  
Target Species ◽  
Main Food ◽  
Adult Females ◽  
Trichiurus Lepturus ◽  
Credible Intervals ◽  
Food Assimilation

AbstractThis study verifies the food assimilation of a carnivorous teleost in different timescales (weeks vs months) and evaluates how it uses the food sources. The target species is the adult ribbonfish, Trichiurus lepturus, a voracious teleost caught in commercial fisheries off south-east Brazil (21°S–22°S). The isotope models indicated Chirocentrodon bleekerianus as the main food in the ribbonfish diet in the last weeks (liver: 38.5%; 95% credible intervals: 3.4–73.9%) and last months (muscle: 36.2%; 95% credible intervals: 3.4–68.7%). The contribution of other food sources ranges from 10–16% (liver) and from 10–20% (muscle). Food assimilation remains similar at different timescales. The isotope models suggested a strong and long-lasting association of the adult females of ribbonfish with coastal waters along the study area.

Feeding ecology and basal food sources that sustain the Paradoxal frog Pseudis minuta: a multiple approach combining stomach content, prey availability, and stable isotopes

Hydrobiologia ◽  
2014 ◽  
Vol 740 (1) ◽  
pp. 253-264 ◽  
Author(s):  
Sonia Huckembeck ◽  
Daniel Loebmann ◽  
Edelti F. Albertoni ◽  
Sonia M. Hefler ◽  
Mauro C. L. M. Oliveira ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Stomach Content ◽  
Feeding Ecology ◽  
Prey Availability ◽  
Food Sources ◽  
Multiple Approach ◽  
Pseudis Minuta

The monogenean Paradiplozoon ichthyoxanthon behaves like a micropredator on two of its hosts, as indicated by stable isotopes

2018 ◽  
Vol 93 (1) ◽  
pp. 71-75 ◽  
Author(s):  
B. Sures ◽  
M. Nachev ◽  
B.M. Gilbert ◽  
Q.M. Dos Santos ◽  
M.A. Jochmann ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Trophic Level ◽  
Trophic Interactions ◽  
Carbon Sources ◽  
Food Sources ◽  
Carbon And Nitrogen ◽  
Blood Sucking ◽  
Vaal Dam ◽  
Living Organisms ◽  
Host Fishes

AbstractThe analysis of stable isotopes of carbon and nitrogen has been used as a fingerprint for understanding the trophic interactions of organisms. Most of these studies have been applied to free-living organisms, while parasites have largely been neglected. Studies dealing with parasites so far have assessed the carbon and nitrogen signatures in endoparasites or ectoparasites of different hosts, without showing general trends concerning the nutritional relationships within host–parasite associations. Moreover, in most cases such systems involved a single host and parasite species. The present study is therefore the first to detail the trophic interactions of a freshwater monogenean–host model using δ13C and δ15N, where a single monogenean species infects two distinctly different hosts. Host fishes, Labeobarbus aeneus and Labeobarbus kimberleyensis from the Vaal Dam, South Africa, were assessed for the monogenean parasite Paradiplozoon ichthyoxanthon, individuals of which were removed from the gills of the hosts. The parasites and host muscle samples were analysed for signatures of δ13C and δ15N using an elemental analyser connected to an isotope ratio mass spectrometer. Host fish appear to use partly different food sources, with L. aeneus having slightly elevated δ13C signatures compared to L. kimberleyensis, and showed only small differences with regard to their nitrogen signatures, suggesting that both species range on the same trophic level. Carbon and nitrogen signatures in P. ichthyoxanthon showed that the parasites mirrored the small differences in dietary carbon sources of the host but, according to δ15N signatures, the parasite ranged on a higher trophic level than the hosts. This relationship resembles predator–prey relationships and therefore suggests that P. ichthyoxanthon might act as a micropredator, similar to blood-sucking arthropods such as mites and fleas.

scholarly journals Benthic communities of shallow-water reefs of Abrolhos, Brazil

1997 ◽  
Vol 45 (1-2) ◽  
pp. 35-43 ◽  
Author(s):  
Roberto Villaça ◽  
Fábio B. Pitombo
Keyword(s):  
Shallow Water ◽  
Coral Species ◽  
Coral Cover ◽  
Benthic Communities ◽  
Algal Species ◽  
Percentage Cover ◽  
High Productivity ◽  
Fringing Reefs ◽  
Cover Ratio ◽  
Line Transects

The benthic communities of fringing and mushroom-shaped shallow-water reefs of the Abrolhos region (southern coast of Bahia) were surveyed. Line transects were used to estimate coral and algal percentage cover. Mussismilia braziliensis is the most conspicuous coral species in the majority of the communities surveyed, but turf algal make up the dominant cover in all but one studied reef. In general, communities on mushroom-shaped reefs have higher diversity and higher coral cover than on fringing reefs. For both reef morphologies, the coral to alga cover ratio does. not show marked differences between annual surveys, despite the high productivity characteristic of the dominant algal species.

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.

scholarly journals Phytoplankton Fuel Fish Food Webs in a Low-Turbidity Temperate Coastal Embayment: A Stable Isotope Approach

2021 ◽  
Vol 8 ◽  
Author(s):  
Goutam Kumar Kundu ◽  
Changseong Kim ◽  
Dongyoung Kim ◽  
Riaz Bibi ◽  
Heeyong Kim ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Food Webs ◽  
Trophic Levels ◽  
Food Sources ◽  
Estuarine Fish ◽  
Multiple Sources ◽  
Terrestrial Organic Matter ◽  
Fish Food ◽  
High Productivity

Trophic contributions of diverse OM sources to estuarine and coastal food webs differ substantially across systems around the world, particularly for nekton (fish, cephalopods, and crustaceans), which utilize basal resources from multiple sources over space and time because of their mobility and feeding behaviors at multiple trophic levels. We investigated the contributions of putative OM sources to fish food webs and assessed the spatiotemporal patterns, structures, and trophic connectivity in fish food webs across four seasons from three closely spaced (10–15 km) sites: an estuarine channel (EC), a deep bay (DB), and an offshore (OS) region in Gwangyang Bay, a high-productivity, low-turbidity estuarine embayment off the Republic of Korea. While nearly all previous studies have focused on few representative species, we examined δ13C and δ15N values of whole nekton communities along with dominant benthic macro-invertebrates, zooplankton, and their putative primary food sources. The δ13C and δ15N values coupled with MixSIAR, a Bayesian mixing model, revealed that these communities utilized multiple primary producers, but phytoplankton comprised the primary trophic contributor (46.6–69.1%). Microphytobenthos (15.8–20.4%) and the seagrass Zostera marina (8.6–19.8%) made substantial contributions, but the role of river-borne terrestrial organic matter was negligible. Spatially different species composition and stable isotope values, but higher utilization of coastal phytoplankton by estuarine fish, indicated disparate food webs structures between the EC and DB/OS coastal areas, with considerable trophic connectivity. Greater overlaps in fish and cephalopod isotopic niches than among other consumers and a higher estimated carbon trophic enrichment factor for EC nekton confirmed feeding migration-mediated biological transport of coastal OM sources to the estuary. Further, the seasonally consistent structures and resource utilization patterns indicate that fish food webs are resilient to changes at lower trophic levels. Our results contrast with those for other highly turbid coastal systems depending highly on diversified basal sources, including exported terrestrial and wetland detritus alongside autochthonous phytoplankton. Finally, this study provides a novel perspective on the role of OM sources in such low turbidity and highly productive coastal embayments and enhances our understanding of marine ecosystems.

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.

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