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Surface interval:919 mins
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Temp: Surf 30°C Bottom 26°C
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Dive type : Recreational, Deep dive, Drift, Reef
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Visibility: Good
Water: Salt
Specific gear used
- BCD: Cressi Sub - Ultralight
- Fins: Atomic Aquatics - Split Fins
- Weights: 4 kg
Recent Divers in Brother Island
Dive Profile
- 1. Nitrox 27
- 15L Steel
200 → 51 bar
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- Average depth: 14.4m
Data provided by EOL.org
Species Identified
Alopias vulpinus (Bonnaterre, 1788) (Common thresher shark)
The thresher shark is an active strong-swimming fish that is occasionally seen leaping out of the water . It feeds primarily on small, schooling fish, but also fish that dwell on the ocean bottom, squids, octopi and, very...
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The thresher shark is an active strong-swimming fish that is occasionally seen leaping out of the water . It feeds primarily on small, schooling fish, but also fish that dwell on the ocean bottom, squids, octopi and, very rarely, seabirds . It uses its unique tail fin to herd fish together in tight shoals, and then stuns them with powerful swipes of the tail. Sometimes two threshers may cooperate in their attack, swimming round the school of fish in ever decreasing circles, then striking the shoal with their tails before turning to swallow their stunned or dead victims . Thresher sharks possess some remarkable physiological adaptations which explain their strength and endurance in a wide range of latitudes and depths. Along each of their flanks runs a strip of red muscle, which can contract powerfully for long periods, enabling the thresher shark to swim for long periods without fatigue . In addition, this red muscle contains a meshwork of tiny blood vessels which transfer heat back towards the body core. Retaining body heat enables the shark to remain active and react quickly even in cold water , and also results in much faster digestion, enabling it to feed again rapidly, should the opportunity arise . Thresher sharks are ovoviviparous, meaning that the young develop inside a weakly formed shell within the female. The gestation period is reported to be nine months, with litters of two to seven pups born during the spring . Thresher sharks reach maturity at between three and eight years old, and are estimated to live for 45 to 50 years .
Carcharhinus longimanus (Poey, 1861) (Oceanic white-tip shark)
The diet of the oceanic whitetip shark primarily consists of bony fishes such as tuna and mackerel, but also includes stingrays, sea turtles, sea birds, squid, crustaceans, mammalian carrion , and occasionally even rubbish...
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The diet of the oceanic whitetip shark primarily consists of bony fishes such as tuna and mackerel, but also includes stingrays, sea turtles, sea birds, squid, crustaceans, mammalian carrion , and occasionally even rubbish that is disposed in the sea . The species is usually solitary, but will occasionally congregate in groups during 'feeding frenzies' where food is plentiful , such as around whale carcasses . However, if other shark species are encountered competing for the same food source, the oceanic whitetip shark usually dominates over them, and may become aggressive . This shark is often accompanied by remoras, dolphin fishes and pilot fishes, and reportedly demonstrates an unusual association with the shortfin pilot whale (Globicephala macrorhynchus) in Hawaiian waters . Although the exact reason for this shark swimming along with pods of pilot whales is unknown, it is suspected that oceanic whitetip sharks are following them to sources of squid, which the pilot whales are extremely efficient at locating . This species mates during the early summer in the north-western Atlantic and the south-western Indian Ocean, and females give birth to 1 to 15 live young approximately a year later . Reproduction is viviparous, with live young being born after being nourished by a placental yolk-sac that is attached to the uterine wall by umbilical cords . Sexual maturity is attained at an age of six to seven years for both sexes .
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 returni...
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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) .
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David 'dibs' Bishop
Egypt
Date: 2017-10-30 - 07:06
Max Depth: 35m Duration: 60mins
Dive with Chrissie Bone from Blue O Two M/Y Red Sea Adventurer
Oceanic Whitetips up close and personal
Thresher Sharks bit deeper
Oceanic had hook & line in mouth
Napoleon wrasse