Biological aspects and exploitation of Plectorhinchus gaterinus (Forsskal, 1839) (F: Haemulidae) from the northern Red Sea, El-Tor, Egypt

Abstract. Laminated sediments in the Shaban Deep, a brine-filled basin in the northern Red Sea, were analyzed with backscattered electron imagery. Here we present possible mechanisms involved in the formation of laminae of various types and homogenous intervals arising from the detailed investigation of multicore GeoB 7805-1 (26 13.9' N and 35 22.6' E; water depth 1447 m) and gravity core GeoB 5836-2 (26 12.61' N, 35 21.56' E; water depth 1475 m). Sediment makeup includes six types: a) a laminated structure with alternating light (mainly coccoliths) and dark (diatom frustules) layers, where the diatom component is indicative of the intra-annual variability between stratification and mixing events; b) a pocket-like structure attributed to the sinking of particles within fecal pellets and aggregates; c) a matrix of tightly packed diatoms that relates to extended stratification/mixing periods of the water column; d) homogenous intervals that result from turbidity deposition; e) silt accumulations which origin may lie in agglutinated foraminifers; and f) pyrite layers with pyrite formation initiated at the seawater-brine interface.

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Transition from continental rifting to oceanic spreading in the northern Red Sea area

10.5194/egusphere-egu21-4185 ◽

2021 ◽

Author(s):

Sami El Khrepy ◽

Ivan Koulakov ◽

Nassir Al-Arifi ◽

Mamdouh S. Alajmi ◽

Ayman N. Qadrouh

Keyword(s):

Red Sea ◽

Plate Tectonics ◽

Continental Rifting ◽

Low Velocity ◽

Lower Velocity ◽

Velocity Anomaly ◽

Oceanic Spreading ◽

Lithospheric Extension ◽

Sea Area ◽

Northern Red Sea

<p><strong>Lithosphere extension, which plays an essential role in plate tectonics, occurs both in continents (as rift systems) and oceans (spreading along mid-oceanic ridges). The northern Red Sea area is a unique natural geodynamic laboratory, where the ongoing transition from continental rifting to oceanic spreading can be observed. Here, we analyze travel time data from a merged catalogue provided by the Egyptian and Saudi Arabian seismic networks to build a three-dimensional model of seismic velocities in the crust and uppermost mantle beneath the northern Red Sea and surroundings. The derived structures clearly reveal a high-velocity anomaly coinciding with the Red Sea basin and a narrow low-velocity anomaly centered along the rift axis. We interpret these structures as a transition of lithospheric extension from continental rifting to oceanic spreading. The transitional lithosphere is manifested by a dominantly positive seismic anomaly indicating the presence of a 50&#8211;70-km-thick and 200&#8211;300-km-wide cold lithosphere. Along the forming oceanic ridge axis, an elongated low-velocity anomaly marks a narrow localized nascent spreading zone that disrupts the transitional lithosphere. Along the eastern margins of the Red Sea, the lithosphere is disturbed by the lower-velocity anomalies coinciding with areas of basaltic magmatism.</strong></p>

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Scorpaena decemradiata new species (Teleostei: Scorpaenidae) from the Gulf of Aqaba, northern Red Sea, a species distinct from Scorpaena porcus

Scientia Marina ◽

10.3989/scimar.04824.17a ◽

2018 ◽

Vol 82 (3) ◽

pp. 169

Author(s):

Ronald Fricke ◽

Daniel Golani ◽

Brenda Appelbaum-Golani ◽

Uwe Zajonz

Keyword(s):

New Species ◽

Red Sea ◽

Gulf Of Aqaba ◽

Pectoral Fin ◽

Dorsal Fin ◽

Lower Jaw ◽

Fin Ray ◽

Fin Rays ◽

Northern Red Sea ◽

Scorpaena Porcus

The scorpionfish Scorpaena decemradiata n. sp. is described from off the coast of Israel in the Gulf of Aqaba, northern Red Sea. The new species is similar to S. porcus Linnaeus, 1758, but is characterized by dorsal fin spines XII, soft dorsal fin rays 10 (the last divided at base); pectoral fin rays 16, uppermost branched pectoral fin ray is the second; lacrimal with 2 spines over maxilla that point at nearly right angle from each other, the posterior pointing ventrally and slightly anteriorly; occipital pit well developed; anteriormost mandibular lateral-line pores small, separated; scales ctenoid; 59-62 scale rows in longitudinal series; scales absent on chest and pectoral fin base; and cirri developed over entire head and body, but no cirri on lower jaw. An updated checklist of the species of the genus Scorpaena Linnaeus, 1758 and a key to the species of the eastern Atlantic, Mediterranean Sea and Red Sea are presented.

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