scholarly journals Multiple transgressions and slow evolution shape the phylogeographic pattern of the blind cave-dwelling shrimp Typhlocaris

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5268 ◽  
Author(s):  
Tamar Guy-Haim ◽  
Noa Simon-Blecher ◽  
Amos Frumkin ◽  
Israel Naaman ◽  
Yair Achituv
Keyword(s):  
Molecular Evolution ◽  
Mediterranean Sea ◽  
Divergence Time ◽  
Evolutionary Rates ◽  
Radiometric Dating ◽  
Small Range ◽  
Biogeographic Patterns ◽  
Blind Cave ◽  
The Mediterranean ◽  
Slow Evolution

Background Aquatic subterranean species often exhibit disjunct distributions, with high level of endemism and small range, shaped by vicariance, limited dispersal, and evolutionary rates. We studied the disjunct biogeographic patterns of an endangered blind cave shrimp, Typhlocaris, and identified the geological and evolutionary processes that have shaped its divergence pattern. Methods We collected Typlocaris specimens of three species (T. galilea, T. ayyaloni, and T. salentina), originating from subterranean groundwater caves by the Mediterranean Sea, and used three mitochondrial genes (12S, 16S, cytochrome oxygnese subunit 1 (COI)) and four nuclear genes (18S, 28S, internal transcribed spacer, Histon 3) to infer their phylogenetic relationships. Using the radiometric dating of a geological formation (Bira) as a calibration node, we estimated the divergence times of the Typhlocaris species and the molecular evolution rates. Results The multi-locus ML/Bayesian trees of the concatenated seven gene sequences showed that T. salentina (Italy) and T. ayyaloni (Israel) are sister species, both sister to T. galilea (Israel). The divergence time of T. ayyaloni and T. salentina from T. galilea was 7.0 Ma based on Bira calibration. The divergence time of T. ayyaloni from T. salentina was 5.7 (4.4–6.9) Ma according to COI, and 5.8 (3.5–7.2) Ma according to 16S. The computed interspecific evolutionary rates were 0.0077 substitutions/Myr for COI, and 0.0046 substitutions/Myr for 16S. Discussion Two consecutive vicariant events have shaped the phylogeographic patterns of Typhlocaris species. First, T. galilea was tectonically isolated from its siblings in the Mediterranean Sea by the arching uplift of the central mountain range of Israel ca. seven Ma. Secondly, T. ayyaloni and T. salentina were stranded and separated by a marine transgression ca. six Ma, occurring just before the Messinian Salinity Crisis. Our estimated molecular evolution rates were in one order of magnitude lower than the rates of closely related crustaceans, as well as of other stygobiont species. We suggest that this slow evolution reflects the ecological conditions prevailing in the highly isolated subterranean water bodies inhabited by Typhlocaris.

scholarly journals Multiple transgressions and slow evolution shape the phylogeographic pattern of the blind cave-dwelling shrimp Typhlocaris

2018 ◽  
Author(s):  
Tamar Guy-Haim ◽  
Noa Simon-Blecher ◽  
Amos Frumkin ◽  
Israel Naaman ◽  
Yair Achituv
Keyword(s):  
Molecular Evolution ◽  
Mediterranean Sea ◽  
Evolutionary Rates ◽  
Radiometric Dating ◽  
Small Range ◽  
Mountain Range ◽  
Biogeographic Patterns ◽  
Blind Cave ◽  
The Mediterranean ◽  
Slow Evolution

Background. Aquatic subterranean species often exhibit disjunct distributions, with high level of endemism and small range, shaped by vicariance, limited dispersal, and evolutionary rates. We studied the disjunct biogeographic patterns of an endangered blind cave shrimp, Typhlocaris, and identified the geological and evolutionary processes that have shaped its divergence pattern. Methods. We collected Typlocaris specimens of three species (T. galilea, T. ayyaloni, and T. salentina), originating from subterranean groundwater caves by the Mediterranean Sea, and used three mitochondrial genes (12S, 16S, COI) and four nuclear genes (18S, 28S, ITS, H3) to infer their phylogenetic relationships. Using the radiometric dating of a geological formation (Bira) as a calibration node, we estimated the divergence times of the Typhlocaris species and the molecular evolution rates. Results. The multi-locus ML/Bayesian trees of the concatenated seven gene sequences showed that T. salentina (Italy) and T. ayyaloni (Israel) are more closely related than T. galilea (Israel). The divergence time of T. ayyaloni and T. salentina from T. galilea was according to COI – 6.0 [4.5-7.2] Ma and according to 16S – 5.9 [3.6-7.4] Ma. The computed interspecific evolutionary rates for COI – 0.0074 substitutions/Myr and for 16S – 0.0041 substitutions/Myr. Discussion. Two consecutive vicariant events have shaped the phylogeographic patterns of Typhlocaris species. First, T. galilea was tectonically isolated from its siblings in the Mediterranean Sea by the arching uplift of the central mountain range of Israel ca. 7 Ma. Secondly, T. ayyaloni and T. salentina were stranded and separated by a marine transgression ca. 6 Ma, occurring just before the Messinian Salinity Crisis. Our estimated molecular evolution rates were in one order of magnitude lower than the rates of closely related crustaceans, as well as of other stygobiont species. We suggest that this slow evolution reflects the ecological conditions prevailing in the highly isolated subterranean enclosures inhabited by Typhlocaris.

scholarly journals Multiple transgressions and slow evolution shape the phylogeographic pattern of the blind cave-dwelling shrimp Typhlocaris

2018 ◽  
Author(s):  
Tamar Guy-Haim ◽  
Noa Simon-Blecher ◽  
Amos Frumkin ◽  
Israel Naaman ◽  
Yair Achituv
Keyword(s):  
Molecular Evolution ◽  
Mediterranean Sea ◽  
Evolutionary Rates ◽  
Radiometric Dating ◽  
Small Range ◽  
Mountain Range ◽  
Biogeographic Patterns ◽  
Blind Cave ◽  
The Mediterranean ◽  
Slow Evolution

Background. Aquatic subterranean species often exhibit disjunct distributions, with high level of endemism and small range, shaped by vicariance, limited dispersal, and evolutionary rates. We studied the disjunct biogeographic patterns of an endangered blind cave shrimp, Typhlocaris, and identified the geological and evolutionary processes that have shaped its divergence pattern. Methods. We collected Typlocaris specimens of three species (T. galilea, T. ayyaloni, and T. salentina), originating from subterranean groundwater caves by the Mediterranean Sea, and used three mitochondrial genes (12S, 16S, COI) and four nuclear genes (18S, 28S, ITS, H3) to infer their phylogenetic relationships. Using the radiometric dating of a geological formation (Bira) as a calibration node, we estimated the divergence times of the Typhlocaris species and the molecular evolution rates. Results. The multi-locus ML/Bayesian trees of the concatenated seven gene sequences showed that T. salentina (Italy) and T. ayyaloni (Israel) are more closely related than T. galilea (Israel). The divergence time of T. ayyaloni and T. salentina from T. galilea was according to COI – 6.0 [4.5-7.2] Ma and according to 16S – 5.9 [3.6-7.4] Ma. The computed interspecific evolutionary rates for COI – 0.0074 substitutions/Myr and for 16S – 0.0041 substitutions/Myr. Discussion. Two consecutive vicariant events have shaped the phylogeographic patterns of Typhlocaris species. First, T. galilea was tectonically isolated from its siblings in the Mediterranean Sea by the arching uplift of the central mountain range of Israel ca. 7 Ma. Secondly, T. ayyaloni and T. salentina were stranded and separated by a marine transgression ca. 6 Ma, occurring just before the Messinian Salinity Crisis. Our estimated molecular evolution rates were in one order of magnitude lower than the rates of closely related crustaceans, as well as of other stygobiont species. We suggest that this slow evolution reflects the ecological conditions prevailing in the highly isolated subterranean enclosures inhabited by Typhlocaris.

Message in a bottle: the Mediterranean Sea currents acted as protagonists in shaping the distribution of the sea daffodil (Pancratium maritimum, Amaryllidaceae)

2020 ◽  
Vol 194 (2) ◽  
pp. 207-220
Author(s):  
Olga De Castro ◽  
Michele Innangi ◽  
Bruno Menale
Keyword(s):  
Mediterranean Sea ◽  
Eastern Mediterranean ◽  
Divergence Time ◽  
Time Estimation ◽  
Wide Distribution ◽  
Central Mediterranean ◽  
Divergence Time Estimation ◽  
Sea Currents ◽  
The Mediterranean ◽  
Pancratium Maritimum

Abstract The Mediterranean Basin can be considered as a natural laboratory with which to study the effects of sea currents in the dispersal of coastal plant species that use hydrochory. Pancratium maritimum is a perennial geophyte, with a wide distribution along Mediterranean coasts. We aim to provide a timeframe for the origin of the diversification of this plant, to clarify its phylogeographical structure and to investigate the role of currents in the Mediterranean Sea in influencing spatial patterns of its genetic distribution. The phylogeographic history was analysed using 50 populations. A genetic structure analysis and divergence time estimation was performed using plastid sequences. Five haplotypes were detected, of which two were the most abundant; a third was observed in the central Mediterranean, and two rare haplotypes were present in the eastern Mediterranean. The genetic breaks were concordant with the direction of the major Mediterranean currents. The divergence time estimation for the origin of P. maritimum was located at the end of the Neogene (mid Pliocene to mid Pleistocene). We showed the importance of sea currents in the Mediterranean in acting both as a means of dispersal and as a barrier to the distribution and evolution of P. maritimum due to the special adaptations of its seeds.

scholarly journals Relationships between phytoplankton light absorption, pigment composition and size structure in offshore areas of the Mediterranean Sea

2011 ◽  
Vol 2 (2) ◽  
pp. 107 ◽  
Author(s):  
Emanuele Organelli ◽  
Caterina Nuccio ◽  
Chiara Melillo ◽  
Luca Massi
Keyword(s):  
Mediterranean Sea ◽  
Cell Size ◽  
Size Structure ◽  
Taxonomic Composition ◽  
Small Range ◽  
Pigment Composition ◽  
Absorption Coefficients ◽  
Phytoplankton Assemblages ◽  
Phytoplankton Absorption ◽  
The Mediterranean

Phytoplankton absorption is mainly determined by pigment composition and packaging into the cell, in turn affected by pigment concentration and cell size and shape. The variations of the chlorophyll-specific absorption coefficients at two selected wavelengths (443 nm and 675 nm) were analysed for offshore areas of the Mediterranean Sea (Alboran, Algerian, Tyrrhenian, Ionian Basins and Sardinia Channel) investigated in autumn 2006, 2007 and 2008. The spatial distribution of Tchl a, accessory pigments, size structure and taxonomic composition of phytoplankton assemblages was diversified among the areas, characterized by higher contribution of photoprotective pigments in oligotrophic surface waters, while accessory chlorophylls increased in deeper layers and where microphytoplankton dominated. (443) values decreased from the oligotrophic waters to the more mesotrophic ones where microphytoplankton prevailed, while for (675) a small range of variation was observed. The differentiation of (443) was explained by the variations in the phytoplankton assemblage mean cell size, that consequently can be assumed as the main factor determining package effect. Comparison with previous parameterizations supported the existence of a Mediterranean differentiation for which the use of global models might determine inaccuracy for predicting phytoplankton absorption coefficients and thus refining ecological models.

Aeromonas dhakensis pneumonia and sepsis in a neonate Risso’s dolphin Grampus griseus from the Mediterranean Sea

2015 ◽  
Vol 116 (1) ◽  
pp. 69-74 ◽  
Author(s):  
L Pérez ◽  
ML Abarca ◽  
F Latif-Eugenín ◽  
R Beaz-Hidalgo ◽  
MJ Figueras ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Grampus Griseus ◽  
The Mediterranean ◽  
Risso's Dolphin

Dolphin Morbillivirus in the Mediterranean Sea

2008 ◽  
Vol 34 (4) ◽  
pp. 514-515 ◽  
Author(s):  
Giovanni Di Guardo
Keyword(s):  
Mediterranean Sea ◽  
Dolphin Morbillivirus ◽  
The Mediterranean
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