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Temp: Surf 28°C Bottom 27°C
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Dive type : Recreational
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Visibility: Excellent
Water: Salt
Specific gear used
- Computer: Suunto - Zoop
- Weights: 4 kg
Recent Pictures in Moorea
Dive Profile
- 1. Air
- 12L Aluminium
220 → 60 bar
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- Average depth: 15m
Data provided by EOL.org
Species Identified
Negaprion brevirostris (Poey, 1868) (Lemon shark)
The lemon shark has been the subject of one of the most long-term and intensive studies on a shark species. Much of what is known about this shark is due to the work of Dr Samuel Gruber and his colleagues. This predator ...
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The lemon shark has been the subject of one of the most long-term and intensive studies on a shark species. Much of what is known about this shark is due to the work of Dr Samuel Gruber and his colleagues. This predator is most active at dawn and dusk, and occurs singly or in loose aggregations of up to 20 individuals. It feeds primarily on fishes, including sea catfishes, mullet, stingrays and eagle rays, but also on crustaceans and molluscs. During the day they often lie quietly on the seabed, apparently resting, but in reality this behaviour uses up more energy than when swimming, due to the extra effort required to pump water over the gills . Therefore, they may be lying motionless waiting for wrasses or other small reef fishes to clean them of any parasites . The lemon shark is viviparous; the embryos develop inside the mother and receive nutrients via a yolk sac placenta. After a gestation period of 10 to 12 months, pregnant females enter shallow nursery areas in spring and summer to give birth to litters of 4 to 17 pups. The pups have a very slow growth rate and remain within nursery grounds for a considerable length of time, where they are less vulnerable to predation by larger sharks . The mangroves that the young frequently inhabit are highly productive waters, creating a marvellous site for feeding, but also an area of very low oxygen content. Luckily, the lemon shark has numerous adaptations that enhance oxygen uptake, such as blood with an unusually high affinity for oxygen, and thus the pups can lie feeding in the rich waters, protected from any large potential predators by the mangrove's tangled roots . As they grow, their range expands dramatically, from six to eight kilometres up to around 300 kilometres. Maturity is reached at about six and a half years of age, and it is believed that the lemon shark lives for up to 27 years .
Carcharhinus melanopterus (Quoy and Gaimard, 1824) (blacktip reef shark)
This powerful swimmer is well known for its tendency to enter incredibly shallow water, and is often found in water only 30 centimetres deep or less, with its distinctive dorsal fin protruding from the surface of the water...
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This powerful swimmer is well known for its tendency to enter incredibly shallow water, and is often found in water only 30 centimetres deep or less, with its distinctive dorsal fin protruding from the surface of the water. It is also found near the bottom or in mid-water in deeper water, singly or in small groups . It feeds on a wide variety of small fish and invertebrates, including mullet, groupers, wrasses, cuttlefish, squid, shrimp . Blacktip reef sharks are viviparous, and therefore the embryos develop inside the mother, for about 16 months. Females generally give birth between late winter and early summer, to between two and four pups . However, reproductive cycles appear to vary throughout the blacktip reef shark's range, with reports of annual, biannual and biennial reproductive cycles . The blacktip reef shark is not an extremely dangerous species, although it is responsible for several provoked and unprovoked attacks on humans. Many are on people that are swimming or wading on reefs, presumably because they were mistaken for small prey. These sharks are more cautious when encountering divers and can usually be driven off .
Eretmochelys imbricata (LINNAEUS) 1766 (Hawksbill Turtle)
Hawksbills may take decades to mature and it could be between 20 to 40 years before they are ready to breed . Upon reaching sexual maturity, a female will typically lay up to five clutches of around 100 to 140 eggs in one ...
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Hawksbills may take decades to mature and it could be between 20 to 40 years before they are ready to breed . Upon reaching sexual maturity, a female will typically lay up to five clutches of around 100 to 140 eggs in one breeding season, and then wait a few years before nesting again . Nesting is much more dispersed than in other marine turtles, but individuals do tend to return to a particular beach season after season . Having survived the dash to the sea, hatchlings are believed to spend their first few years in the open ocean before returning to more sheltered coastal waters. Recent studies indicate that the oceanic phase may be shorter for hawksbills, or even omitted in certain regions, as hatchlings swim less vigorously than those of other species . Probably less than one out of 1000 eggs will survive and reach adulthood . Adults are opportunistic predators, using their sharp beak to prize invertebrate prey from crevices within the reef. Unusually amongst marine animals , sponges make up the majority of the hawksbill's diet .
Triaenodon obesus (Rüppell, 1837) (Whitetip reef shark)
Despite its docile nature during the day this nocturnal shark can become aggressive when hunting at night, thrashing through coral reefs looking for potential prey. The whitetip reef shark usually hunts alone, but is non-t...
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Despite its docile nature during the day this nocturnal shark can become aggressive when hunting at night, thrashing through coral reefs looking for potential prey. The whitetip reef shark usually hunts alone, but is non-territorial and will occasionally work in cooperation with others in the pursuit of prey . Feeding primarily on bottom-dwelling octopus, lobsters, crabs and bony fish, it often chases its prey into a crevice before jamming its body in after it, sealing the exit . The extremely posterior location of the first dorsal fin compared to those of other sharks is an adaptation to this feeding habit, which allows them to get their heads and mouths much further into the gaps and holes in the coral . The whitetip reef shark's mating season varies with location . Reproduction is viviparous and after a gestation period of around a year the female will give birth to one to five live pups, which are completely independent at birth . Both sexes reach sexual maturity at approximately 5 years old, and it is estimated that this species can live to an age of 25 years .
Sphyraena putnamae Jordan & Seale, 1905 (Barracuda)
Found near prominent current-swept lagoons or seaward reefs . Also in bays and inner turbid lagoons . Nocturnally active, but occurring in relatively large schools during the day . Sold fresh or processed into fish cakes .
Found near prominent current-swept lagoons or seaward reefs . Also in bays and inner turbid lagoons . Nocturnally active, but occurring in relatively large schools during the day . Sold fresh or processed into fish cakes .
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David Hsl
French Polynesia
Date: 2017-07-04 - 10:53
Max Depth: 25.3m Duration: 47mins
Dive with Christian Vandoren from Moorea Fun Dive
