scholarly journals Age and Growth of Garra rufa Heckel, 1843 from Merzimen Stream, Euphrates River Basin, Turkey

Author(s):  
Erdogan ÇİÇEK ◽  
Burak SEÇER ◽  
Selda ÖZTÜRK ◽  
Sevil SUNGUR
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mehmet Zülfü Çoban ◽  
Mücahit Eroğlu ◽  
Mustafa Düşükcan

AbstractThis study was carried out to determine some bioecological characteristics of Mastacembelus mastacembelus, which is the only species of Mastacembelidae family living in Turkey. Fish samples were caught between 2014–2018 from Keban Dam Lake, one of the most important reservoirs of the upper Euphrates Basin. In totally, 348 Mastacembelus mastacembelus individuals were examined, including 178 males and 170 females. The age distributions were defined between the I–XV age groups. Total lengths ranged from 14.20 to 81.80 cm in males and from 15.60 to 77.30 cm in females. Total length–weight relationships were calculated as W = 0.0083 × TL2.6516 for males, W = 0.0043 × TL2.8310 for females and W = 0.0063 × TL2.7256 for all population, and the growth type was estimated as “negative allometric”. The von Bertalanffy growth parameters for all individuals were computed as L∞ = 90.99, k = 0.13, t0 = − 0.45. The total (Z), natural (M), fishing (F) mortality rates and exploitation rate (E) were estimated as Z = 0.313, M = 0.270, F = 0.043 and E = 0.137, respectively. The length at first capture (Lc) was found as 50.72. The optimum, maximum and economic yields were calculated as E0.5 = 0.361; Emax = 0.776; E0.1 = 0.664, respectively.


2018 ◽  
Vol 16 (1) ◽  
Author(s):  
Marília Hauser ◽  
Carolina R. C. Doria ◽  
Larissa R. C. Melo ◽  
Ariel R. Santos ◽  
Daiana M. Ayala ◽  
...  

ABSTRACT The goliath catfish Brachyplatystoma rousseauxii has crucial economical and ecological functions in the Amazon basin. Although its life history characteristics have been studied in the Amazon, there is little information in the Madeira River basin, which holds genetically distinct populations and where dams were recently built. Using fish collected in Bolivia, Brazil and Peru, this study provides a validation of growth rings deposition and details the growth patterns of B. rousseauxii in the Madeira before the dams’ construction. Age structure and growth parameters were determined from 497 otolith readings. The species exhibits two growth rings per year and sampled fish were between 0 and 16 years old. In the Brazilian portion of the basin, mainly young individuals below 5 years old were found, whereas older fish (> 5 years) were caught only in the Bolivian and Peruvian stretches, indicating that after migrating upstream to reproduce, adults remain in the headwaters of the Madeira River. Comparing with previous publications, B. rousseauxii had a slower growth and 20 cm lower maximum standard length in the Madeira River than in the Amazon River. This study provides a baseline for future evaluation of changes in population dynamics of the species following dams closure.


2018 ◽  
Vol 26 (8) ◽  
pp. 217-229
Author(s):  
Zeyad Jameel Al- Saedi ◽  
Mustafa Rashead Al-Obaidi

Morphological and morphotectonic analysis have been used to obtain information that influences basis. The study area includes the Euphrates river basin in Iraq. Tectonically this area within a Stable shelf, The Stable Shelf which covers the vast majority of the focal south and west of Iraq reaches out into Syria and Jordan and Southwards into Kuwait and Saudi Arabia. It is separated in Iraq into three considerable structural zones. Discrimination of morphotectonic indices of Euphrates basin by using sevenindices. The Euphrates basin (main basin) was divided into four sub-basin (s.b) Wadi Horan, Wadi Ubaiyidh, Shuab Hwaimy, and Shuab Qusair. Which has been completed for each drainage basin utilizing remote sensing and GIS techniques? So as to identify the tectonic activity, different indices including Drainage density (D), Sinuosity index (S), Hypsometric integral (HI), Drainage basin asymmetry (AF), Basin Shape (BS), Transverse Topographic Symmetry (T) and Active tectonic index (Iat). The study demonstrates that the intensity of tectonic activities in different parts of the basin and sub-basins are different. The values of Drainage density (D) main basin and sub-basins are in high classes which mean that the study area has resultant of slight or impermeable subsurface material, little vegetation as well as a good discharge for water and sediments. The Sinuosity index (S) of all study area are sinuous and its semi-equilibrium. Hypsometric integral (HI) of Horan, Ubaiyidh and shuab Hwaimy sub-basins shows high values of HI which means high rates of geological erosion while the shuab Qusair and main basin shows moderate of erosion rates, HI high values shows that study area is tectonically uplifted. According to the calculation of Drainage basin asymmetry (AF) the study area reflects inactive tectonic activity. The Basin Shape (BS) all of the basins are in third class and it reflects inactive tectonic activity. After computing Transverse Topographic Symmetry (T) index in the area of investigate, the outcome demonstrate that all the subbasins lie in low active tectonics except wadi Horan and the main basin was moderate active tectonics. Based on an Active tectonic index (Iat) all the basins were moderate active tectonics except Horan subbasin is active tectonically. These basins have evolved as a result of plate movements, subsidence, uplift and various erosional processes. The study shows the variable relationship between faulting and valleys but most of the trends of faults are subparallel to the Euphrates River. Faults orientations in the study area are parallel to NE-SW direction and NW-SE direction. And also the type of drainage network in the study area which is varied from dendritic to parallel with SW-NE trending and its indicate that study area may be structurally controlled.


2019 ◽  
Vol 509 ◽  
pp. 73-86 ◽  
Author(s):  
D.V. Ozherelyev ◽  
V.G. Trifonov ◽  
H. Çelik ◽  
Ya.I. Trikhunkov ◽  
P.D. Frolov ◽  
...  

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