scholarly journals Inter-island local adaptation in the Galápagos Archipelago: genomics of the Galápagos blue-banded goby, Lythrypnus gilberti

Coral Reefs ◽  
2021 ◽  
Author(s):  
Giacomo Bernardi
Keyword(s):  
Local Adaptation ◽  
Marine Species ◽  
Directional Selection ◽  
Rad Sequencing ◽  
The Past ◽  
Galapagos Archipelago ◽  
Adaptive Radiations ◽  
Shallow Subtidal ◽  
Rocky Habitats ◽  
Neutral Markers

AbstractThe Galápagos Archipelago is a place where terrestrial adaptive radiations of finches, mockingbirds, and tortoises have been studied extensively. In contrast, little is known about the potential for marine species to diverge among islands. The overall degradation of coral reefs in the Galápagos makes understanding the mechanisms and factors of speciation, the engine of biodiversity, important, and timely. While speciation in marine archipelagos has been described in the past, such as for cone snails in Cabo Verde Archipelago and limpets in Hawaii, adaptive radiations in the marine environment are still rare and poorly understood. In this study, we focused on the Galápagos blue-banded goby, Lythrypnus gilberti, a small endemic fish that is found in shallow subtidal rocky habitats. Using RAD sequencing, we analyzed 19,504 loci that were either neutral, or potentially under directional selection. As expected, considering the small geographic range, population structure based on neutral markers was weak. For loci under directional selection, however, marked differences between islands suggested potential for local adaptation. Our data suggest that for marine species, where dispersal barriers are less apparent, mechanisms of local adaptation may also be at play in the Galápagos Archipelago.

scholarly journals Transcriptome Expression of Biomineralization Genes in Littoraria flava Gastropod in Brazilian Rocky Shore Reveals Evidence of Local Adaptation

2021 ◽  
Vol 13 (4) ◽  
Author(s):  
Camilla A Santos ◽  
Gabriel G Sonoda ◽  
Thainá Cortez ◽  
Luiz L Coutinho ◽  
Sónia C S Andrade
Keyword(s):  
Local Adaptation ◽  
Differentially Expressed Genes ◽  
Evolutionary Biology ◽  
Rocky Shore ◽  
Expression Patterns ◽  
Purifying Selection ◽  
Marine Species ◽  
Differentially Expressed ◽  
Planktonic Larva ◽  
Structure Changes

Abstract Understanding how selection shapes population differentiation and local adaptation in marine species remains one of the greatest challenges in the field of evolutionary biology. The selection of genes in response to environment-specific factors and microenvironmental variation often results in chaotic genetic patchiness, which is commonly observed in rocky shore organisms. To identify these genes, the expression profile of the marine gastropod Littoraria flava collected from four Southeast Brazilian locations in ten rocky shore sites was analyzed. In this first L. flava transcriptome, 250,641 unigenes were generated, and 24% returned hits after functional annotation. Independent paired comparisons between 1) transects, 2) sites within transects, and 3) sites from different transects were performed for differential expression, detecting 8,622 unique differentially expressed genes. Araçá (AR) and São João (SJ) transect comparisons showed the most divergent gene products. For local adaptation, fitness-related differentially expressed genes were chosen for selection tests. Nine and 24 genes under adaptative and purifying selection, respectively, were most related to biomineralization in AR and chaperones in SJ. The biomineralization-genes perlucin and gigasin-6 were positively selected exclusively in the site toward the open ocean in AR, with sequence variants leading to pronounced protein structure changes. Despite an intense gene flow among L. flava populations due to its planktonic larva, gene expression patterns within transects may be the result of selective pressures. Our findings represent the first step in understanding how microenvironmental genetic variation is maintained in rocky shore populations and the mechanisms underlying local adaptation in marine species.

scholarly journals Diet and feeding strategy of the dusky grouper Mycteroperca marginata (Actinopterygii: Epinephelidae) in a man-made rocky habitat in southern Brazil

2011 ◽  
Vol 9 (1) ◽  
pp. 161-168 ◽  
Author(s):  
Mario V. Condini ◽  
Elisa Seyboth ◽  
João P. Vieira ◽  
Alexandre M. Garcia
Keyword(s):  
Feeding Strategy ◽  
Marine Species ◽  
Southern Brazil ◽  
Patos Lagoon ◽  
Additional Tool ◽  
Rocky Habitat ◽  
Dusky Grouper ◽  
Dietary Shifts ◽  
Rocky Habitats ◽  
Rocky Bottoms

The dusky grouper (Mycteroperca marginata) is a marine species usually associated with rocky bottoms and reefs. The present work investigated the diet and feeding strategy of a dusky grouper population inhabiting a 4.5 km long pair of rocky jetties located in the mouth of Patos Lagoon estuary. No prior research has been conducted in such man-made habitat and the current study provides a basis for comparative studies on the diet of the dusky grouper populations inhabiting natural vs. man-made rocky habitats. Similarly with previous studies on natural substrates, crabs and fishes were the main food categories consumed (%IRI = 85.1 and %IRI = 12.6, respectively), whereas shrimps and mollusks had lower importance in the diet (%IRI = 1.9 and 0.4, respectively). As previously reported for dusky grouper populations inhabiting reefs and rocky bottoms, the present work revealed conspicuous size related dietary shifts. Blue crabs and fishes become increasingly important food items in the diet of larger individuals (> 500 mm, TL). Finally, it was found that the studied dusky population has a generalist feeding strategy with a high between-individual variation in prey consumption. Such strategy remained similar across the size increment of the species. Our findings suggest that man-made rocky substrates provide suitable feeding grounds for the dusky grouper in southern Brazil and could be used as an additional tool in the conservation efforts of this endangered species.

scholarly journals Marine and freshwater taxa: some numerical trends

2019 ◽  
Vol 6 (2) ◽  
Author(s):  
Semyon Ya. Tsalolikhin ◽  
Aldo Zullini
Keyword(s):  
Sea Level ◽  
Benthic Fauna ◽  
Marine Species ◽  
Inland Waters ◽  
Sea Level Fluctuations ◽  
The Past ◽  
Freshwater Fauna

Most of the freshwater fauna originates from ancient or recent marine ancestors. In this study, we considered only completely aquatic non-parasitic animals, counting 25 phyla, 77 classes, 363 orders for a total that should include 236,070 species. We divided these taxa into three categories: exclusively marine, marine and freshwater, and exclusively freshwater. By doing so, we obtained three distribution curves which could reflect the marine species’ mode of invasion into continental waters. The lack of planktonic stages in the benthic fauna of inland waters, in addition to what we know about the effects of the impoundment of epicontinental seas following marine regressions, lead us to think that the main invasion mode into inland waters is more linked to the sea level fluctuations of the past than to slow and “voluntary” ascents of rivers by marine elements.

scholarly journals Circumstantial evidence for the presence of monk seals in the West Indies

Oryx ◽  
1998 ◽  
Vol 32 (4) ◽  
pp. 310-316 ◽  
Author(s):  
I. L. Boyd ◽  
M. P. Stanfield
Keyword(s):  
West Indies ◽  
Marine Species ◽  
Circumstantial Evidence ◽  
Harbour Seal ◽  
Sea Lion ◽  
The West ◽  
The Past ◽  
The Caribbean ◽  
Monk Seals

Based on interviews with 93 fishermen in northern Haiti and Jamaica during 1997 an assessment was made of the likelihood that monk seals survive in this region of the West Indies. Fishermen were asked to select marine species known to them from randomly arranged pictures: 22.6 per cent (n = 21) selected monk seals. This number was significantly (P < 0.001) greater than the number who selected control species (walrus, harbour seal, and sea-lion) that they were unlikely to have observed. However, it was not significantly different (n = 19, P > 0.1) from the number who selected manatees, which are known to occur in the region in small numbers. More than 95 per cent of respondents also identified species that are known to occur commonly in the region. Further questioning of the 21 respondents who selected monk seals suggested that 16 (78 per cent) of them had seen at least one in the past 1–2 years. Those fishermen that were able to provide further descriptions gave information about size and colour that was consistent with many of these seals being monk seals. It is possible that the Caribbean monk seal is not extinct.

scholarly journals CHANGES IN THE DOMINANT SPECIES AND SIZE STRUCTURE OF DIATOMS FROM THE SURFACE BOTTOM SEDIMENTS OF THE SEA OF AZOV OVER THE PAST 20 YEARS

2021 ◽  
Vol 1 (6) ◽  
pp. 96-103
Author(s):  
G.V. Kovaleva ◽  
◽  
I.Yu. Gavrilova
Keyword(s):  
Bottom Sediments ◽  
Size Structure ◽  
Sharp Decrease ◽  
Marine Species ◽  
Sea Of Azov ◽  
Diatom Analysis ◽  
The Sea Of Azov ◽  
The Past ◽  
The Stability ◽  
Radical Transformation

The paper presents the results of diatom analysis of surface bottom sediments selected with a range of 20 years. Samples of surface sediments of the Sea of Azov collected in 1998 (before the salinization period) and in 2019 were studied. The results of the diatom analysis of the bottom sediments showed that the sediments were dominated by spores of diatoms from the genus Chaetoceros and stomatocysts of golden algae. In addition to spores and stomatocysts, diatoms from the genus Thalassiosira sp., Coscinodiscus sp., Ditylum brightwellii, Pseudosolenia calcar-avis and Thalassionema nitzschioides were often found in the surface soils of 1998. In the sediments selected in 2019, medium – and large-sized taxa (Actinoptychus senarius, Actinocyclus octonarius, Thalassiosira sp., Coscinodiscus sp.) began to predominate in frequency of occurrence and abundance. The appearance of these species can be associated with an increase in the average salinity of the waters of the Sea of Azov, since most of the representatives of the above taxa belong to marine and brackish-water-marine species. A decrease in freshwater runoff and an increase in salinity in the Sea of Azov can lead not only to a radical transformation of the native microalgae community, but also increases the risk of alien marine species of plankton and benthos. Large-sized diatoms are less attractive as a food base for zooplankton, which can also lead to changes in the native biota of the Sea of Azov. In general, these dangerous transformations can lead to a sharp decrease in the stability of the ecosystem of the Sea of Azov and irreversible consequences.

scholarly journals Evidence for divergent selection and spatial differentiation in a putative zona pellucida gene is indicative of local adaptation in Pacific cod

2021 ◽  
Author(s):  
Ingrid Spies ◽  
Daniel Drinan ◽  
Eleni Petrou ◽  
Rory Spurr ◽  
Theodore Hartinger ◽  
...  
Keyword(s):  
Local Adaptation ◽  
Zona Pellucida ◽  
Atlantic Cod ◽  
Spatial Differentiation ◽  
Marine Species ◽  
Genomic Region ◽  
Divergent Selection ◽  
Pacific Cod ◽  
Sperm Binding ◽  
Outlier Loci

Genetic differentiation has been observed in marine species even when no obvious barriers to gene flow exist. The study of highly differentiated outlier loci can provide information on how genetic variation might contribute to local adaptation. A locus which aligned to a predicted zona pellucida sperm-binding protein 3 gene (ZP3) in Atlantic cod was previously identified in Pacific cod populations as a high differentiation outlier. In other marine species, ZP3 is involved in reproductive isolation, local adaptation, and has neofunctionalized as an antifreeze gene, but the function of this genomic region is not understood in Pacific cod. We sequenced a 544 bp region of ZP3 in 230 Pacific cod collected from throughout their geographic range. Here we show that ZP3 haplotypes exhibit strong spatial structure and there is evidence for divergent selection at this locus in samples collected from the Bering Sea region. The potential for adaptation to different thermal regimes is particularly relevant given that Pacific cod have demonstrated high natural mortality during recent ocean warming events.

scholarly journals The Pleistocene-Holocene aquatic molluscs as indicators of the past ecosystem changes in Transbaikalia (Eastern Siberia, Russia)

2020 ◽  
Author(s):  
Olga K. Klishko ◽  
Evgeniy V. Kovychev ◽  
Maxim V. Vinarski ◽  
Arthur E. Bogan ◽  
Georgiy. A. Jurgenson
Keyword(s):  
Regional Climate ◽  
Far East ◽  
Marine Species ◽  
Drill Hole ◽  
Historical Change ◽  
Neolithic Period ◽  
Eastern Siberia ◽  
Alluvial Deposits ◽  
Fossil Species ◽  
The Past

ABSTRACTData on historical change of the Transbaikalian malacofauna in the Neopleistocene and Holocene is presented. Fossil shells from archeological excavations of the ancient settlements dating from the Neolithic period to Medieval and also from a drill hole of the Neopleistocene alluvial deposits were collected. In total nine species of bivalve molluscs from the families Margaritiferidae, Unionidae, Limnocardiidae, Glycymerididae, including one marine species, and two gastropod species from families Viviparidae and Planorbidae were identified. The time of the existence of each fossil species was determined by radiocarbon dating. It was found that the species ranged in age from more 50,000 and 2,080–1,210 years ago. Five species inhabited the Transbaikal region and are locally extirpated in the present. Their disjunctive ranges in the past included southern Europe and Western and Eastern Siberia to Transbaikalia and in the east to Far East and Primorye of Russia. The time of existence and extirpation of the thermophilic species of genera Adacna, Planorbis, Lanceolaria and Amuropaludina corresponds to cycles of the warming and cooling in Pleistocene and Holocene according to regional climate chronological scales. It was possible to separate these species as indicators of paleoclimate. Change of the species composition of the malacofauna of region connected with natural cycles of climatochrons in the Pleistocene and Holocene is the appearance of the climatogenic succession. In the course of this succession the disappearance of the stenothermal species occurred on a regional level and decreasing their global ranges.

Progress in the discovery of extant and fossil bryozoans

2020 ◽  
Vol 635 ◽  
pp. 71-79 ◽  
Author(s):  
M Pagès-Escolà ◽  
PE Bock ◽  
DP Gordon ◽  
S Wilson ◽  
C Linares ◽  
...  
Keyword(s):  
New Species ◽  
Marine Invertebrates ◽  
Marine Species ◽  
Past Century ◽  
Fossil Species ◽  
The Past ◽  
Extant Species ◽  
Technological Developments ◽  
Relative Productivity ◽  
Species Descriptions

The number of species that exist on Earth has been an intriguing question in ecology and evolution. For marine species, previous works have analysed trends in the discovery of extant species, without comparison to the fossil record. Here, we compared the rate of description between extant and fossil species of the same group of marine invertebrates, Bryozoa. There are nearly 3 times as many described fossil species as there are extant species. This indicates that current biodiversity represents only a small proportion of Earth’s past biodiversity, at least for Bryozoa. Despite these differences, our results showed similar trends in the description of new species between extant and fossil groups. There has been an increase in taxonomic effort during the past century, characterized by an increase in the number of taxonomists, but no change in their relative productivity (i.e. similar proportions of authors described most species). The 20th century had the most species described per author, reflecting increased effort in exploration and technological developments. Despite this progress, future projections in the discovery of bryozoan species predict that around 10 and 20% more fossil and extant species than named species, respectively, will be discovered by 2100, representing 2430 and 1350 more fossil and extant species, respectively. This highlights the continued need for both new species descriptions and taxonomic revisions, as well as ecological and biogeographical research, to better understand the biodiversity of Bryozoa.

Paracentrotus lividus (Echinodermata: Echinoidea) attachment force and burrowing behavior in rocky shores of SW Portugal*

Zoosymposia ◽  
2012 ◽  
Vol 7 (1) ◽  
pp. 231-240 ◽  
Author(s):  
DAVID JACINTO ◽  
TERESA CRUZ
Keyword(s):  
Sea Urchins ◽  
Paracentrotus Lividus ◽  
Wave Exposure ◽  
Rocky Shores ◽  
Rock Pools ◽  
Test Diameter ◽  
Test Size ◽  
Shallow Subtidal ◽  
Rocky Habitats ◽  
Intertidal Pools

The rock burrowing sea urchin Paracentrotus lividus is a common wave-swept organism that inhabits intertidal rock pools and shallow subtidal temperate shores. Here we present field data on P. lividus attachment force, burrow shape and test diameter measured in different rocky habitats (intertidal pools, low shore intertidal channels and shallow subtidal shores) and in two study sites with different wave-exposure conditions. These data were then analyzed to look for a pos­sible relationship between the size of sea urchins and their attachment force and burrow shape as well as the influence of wave-exposure and habitat in the measured variables. P. lividus test diameter varied among habitats: urchins were smaller in mid-shore intertidal pools and bigger in shallow subtidal shores. We observed in all studied habitats that attachment force was not correlated with test size, while burrow shape index (BSI) was negatively correlated with test size. Results suggest that the attachment force of large and small urchins was similar, but smaller animals occurred in relatively deeper burrows (higher BSI values). Attachment force was positively correlated with BSI, which indicates that burrows may enhance attachment force of P. lividus living in rocky shores by allowing the use of spines as anchorage points and reducing the urchin area exposed to drag forces. Our results partially support the hypothesis that attachment force and BSI might be influenced by local variation in wave-exposure. Higher values for both attachment strength and BSI were measured in intertidal rock pools, the most wave-exposed habitat considered in this study, suggesting that urchins living in such habitat are more able to resist dislodgment by wave-induced forces since they occupy relatively deeper burrows and thusattach more firmly to the substrate. However, neither attachment force nor BSI were higher in the more exposed shore.

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