Photos
Aucune photo sur cette plongée
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Temp: Fond 29°C
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Type de plongée : Loisir, Profonde
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Visibilité : Excellente
Type d'eau Salée
Equipement particulier utilisé
Photos récentes sur Marsa Alam
Centre de plongée & Palanquée
Palanquée :
Alan Kingshott
Profil de plongée
- 1. Air
- 12L Steel
210 → 50 bar
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- Profondeur moyenne: 24.5m
Données fournies par EOL.org
Espèces identifiées
Chelonia mydas Linnaeus 1758 (Green Turtle)
Green turtles are long-lived and may take up to 59 years to reach sexual maturity Undertaking tremendous feats of navigation, adults return to the same beach to breed each season, part of the population in Brazil asto...
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Green turtles are long-lived and may take up to 59 years to reach sexual maturity Undertaking tremendous feats of navigation, adults return to the same beach to breed each season, part of the population in Brazil astonishingly migrates around 2,250 kilometres across the open ocean to breed on the Ascension Islands . Mating tends to occur just offshore of the nesting beaches; using a curved claw on each front flipper and a flat nail at the end of the tail, males are able to grip their mates . Females haul out onto the beach at night and dig large nests with their back flippers beyond the high tide mark, they typically lay between 100 and 150 eggs in one nest and then proceed to cover the eggs with sand; the whole process takes around two hours . A single female returns to breed only once every two to five years but will lay up to nine nests in that one season . Incubation takes between 45 and 70 days, and temperature has been shown to determine of the sex of hatchlings; with females being produced at warmer temperatures . Breaking open their eggs with a special hooked 'egg tooth' that will subsequently be lost; hatchlings use their powerful front flippers to reach the surface, and then proceed to the sea . The soft-bodied juveniles are particularly vulnerable at this time from a variety of predators, such as ghost crabs and gulls on the beach to sharks and dolphins in the water . Unlike other marine turtles, adult green turtles are almost exclusively herbivorous, grazing on seagrasses and algae ; it is assumed that juveniles are more omnivorous although the exact composition of their diet is unknown
Sphyrna lewini (Griffith and Smith, 1834) (scalloped hammerhead)
Forming impressively large schools, female scalloped hammerheads gather in the Gulf of California during the day, around underwater mountains known as seamounts, where they perform a wide range of poorly-understood beh...
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Forming impressively large schools, female scalloped hammerheads gather in the Gulf of California during the day, around underwater mountains known as seamounts, where they perform a wide range of poorly-understood behaviours . These aggregations are thought to be a result of many sharks, particularly younger females, seeking refuge in a safe place near a rich food supply, although many alternative theories have been put forward . Young scalloped hammerheads also tend to live in large schools, whereas adults usually occur singly, in pairs, or in small groups . These sharks feed on fish, cephalopods, lobsters, shrimps, crabs, other sharks, and rays. They are thought to be potentially dangerous to humans although few attacks have been recorded . The teeth of the scalloped hammerhead are best suited to seizing prey that can be swallowed whole, rather than ripping into larger prey. The hammer-shaped head is thought to be a mechanism to spread out the ampullae of Lorenzini – sensory organs that detect electric currents, chemicals in the water, and temperature changes . Larger shark species may attack young scalloped hammerheads, but adults have no natural enemies. Adults visit cleaning stations where fish known as cleaner wrasse remove parasites from their skin and mouths . During the 9 to 10 month gestation, the eggs of the scalloped hammerhead hatch inside the body of the female. After hatching, but before birth, they are nourished by a yolk sac placenta. The female moves to shallow waters during the summer where she will give birth to between 15 and 31 live young .
Cheilinus undulatus Rüppell, 1835 (Humphead wrasse)
Humphead wrasses are extremely long-lived, known to survive for at least 30 years, and taking around five to seven years to reach sexual maturity . Adults are usually solitary, spending the day roaming the reef and ret...
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Humphead wrasses are extremely long-lived, known to survive for at least 30 years, and taking around five to seven years to reach sexual maturity . Adults are usually solitary, spending the day roaming the reef and returning to particular caves or ledges to rest at night . Very little is known about these fish; adult females are able to change sex but the triggers for this development are not known . Pairs spawn together as part of a larger mating group that may consist of over 100 individuals. The planktonic eggs are released into the water and once the larvae have hatched they will settle out on the substrate . Using their tough teeth, these fish are able to consume hard-shelled species such as molluscs, echinoderms and crustaceans . They are one of the few predators of species that destroy coral reefs, such as the infamous crown of thorns starfish (Acanthaster planci) .
Pterois volitans (Linnaeus, 1758) (Red lionfish)
Doryrhamphus excisus Kaup, 1856 (Bluestripe pipefish)
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Égypte
Date : 2004-08-11 - 10:00
Profondeur Max: 36.8m Durée : 51mins
Plongée avec Flowers Of Sinai
Saw a hammerhead in the distance, then a gentle swim back up the reef.