Halmahera Epaulette Shark, Halmahera Walking Shark.
Elongated, slender body. Well developed pectoral and pelvic fins on fore-body (used partially for walking). Two equally sized dorsal fins on rear-body. Tail long and straight with upper and lower caudal lobes on underside. Sub-terminal notch present.
Dorsal coloration tan to reddish brown with concentrations of dark spots forming broken bands along the torso and tail. Three large dark spots behind gills; the largest being elongated or U shaped and partially outlined in white on the lower side. Head orange-brown with small dark spots on nose and forehead. Two larger dark spots on lower cheeks. Ventrum pale.
Maximum confirmed length 79cm but probably attains greater length (personal observation).
Shallow tropical coral reefs, rocky outcrops, and seagrass beds. From 0 to 10m.
Endemic to the Maluku Islands in north-central Indonesia. Found near Ternate Island and Halmahera Island.
The Halmahera Epaulette Shark is threatened by fishing, habitat loss and degradation, pollution, and climate change. It is taken by artisanal fishing by gleaning (collecting by hand or hand spear on intertidal reef flats at night), extensive gill netting down to 20 m depths, and hand-lining which is prevalent throughout most of its range at 5–15 m depths. There is habitat degradation of reef flats due to dynamite fishing and open-pit mining in coastal zones throughout its range. The mining in the area also poses a threat of heavy metal pollution. A study of mercury in the Halmahera Epaulette Shark shows exposure of 6.50 μg/g creatinine, which is above the safe threshold of 1 μg/g creatinine (Jutan et al. 2019).
Global climate change has already resulted in large-scale coral bleaching events at increasing frequency causing worldwide reef degradation since 1997. Almost all warm-water coral reefs are projected to suffer significant losses of area and local extinctions, even if global warming is limited to 1.5ºC (IPCC Report, 2019). There are also collections for the aquaria trade where larger individuals (>60 cm TL) are collected for local aquaria and smaller individuals (<60 cm TL) are targeted for export to European aquaria, sometimes up to 60 individuals per shipment.
VanderWright, W.J., Allen, G.R., Derrick, D., Dudgeon, C.L., Erdmann, V & Sianipar, A. 2020. Hemiscyllium halmahera. The IUCN Red List of Threatened Species 2020: e.T176486052A176486116. https://dx.doi.org/10.2305/IUCN.UK.2020-3.RLTS.T176486052A176486116.en. Downloaded on 30 December 2020.
Oviparous. Reproductive cycle poorly known.
Unknown. Probably benthic invertebrates.
Nocturnal. Hides by day under corals venturing out at sunset to feed. Swims or ‘walks’ along on its flexible pectoral and pelvic fins. Wriggles through gaps in coral in search of prey or to seek protection.
Reaction to divers
Seeks cover when caught in a diver’s spotlight. Some animals are more tolerant of diver’s lights than others.
The Halmahera epaulette shark can only be seen at the Maluku Islands. The dive masters at Weda Resort on Halmahera Island have a good track record for finding this species, which they call Walking Sharks.
In May of 2018, we encountered multiple sharks on two out of three night dives. Epaulette sharks do not migrate so they should be reasonably easy to find year round.