One of the largest wobbegongs
The Spotted wobbegong (Orectolobus maculatus) is a shark belonging to the family Orectolobidae, endemic to Australia. It is a large, robust species, typically reaching 4.9-5.9 feet in length, but there have been reports of them reaching longer.
Family: Orectolobidae – Wobbegongs
Common Name– Carpet Sharks
Common Name– Wobbegongs
Status: IUCN Red List LEAST CONCERN
Average Size and Length: They are born around 8.3 inches. Mature males are around 1.9 feet on average. The maximum recorded has been 10.5 feet.
Current Rare Mythical Sightings: The species was described by Pierre Joseph Bonnaterre in 1778. He classified it in the genus Squalus, with the full scientific name of Squalus maculatus. Bonnaterre re-described the species in 1788 in Orectolobus, its current genus, making its full scientific name Orectolobus maculatus, with Squalus maculatus now a synonym of it.
Teeth and Jaw: Like all wobbegongs, it has a short mouth and broad pharynx, which allow it to suck up prey more easily. The teeth of the Spotted wobbegong are described as enlarged fangs; they are long, slender, and sharp. There are two lateral rows in the upper jaw and three lateral rows in the lower jaw. They can extend their mouth by as much as 30% of the nasal distance from its anterior most point to the anterior edge of the pectoral fin, to capture prey. This is equivalent to the combined length of the head and branchial arches.
Head: It has a tubercle above its eye. There are large barbels extending from the nostrils, and large spiracles just behind the small eyes.
Denticles: There are 6-10 dermal lobes below and in front of the eyes and long branched nasal barbels. There are dermal flaps surrounding the rim of its mouth.
Tail: The caudal fin is short and stout.
Demographic, Distribution, Habitat, Environment and Range: The Spotted wobbegong can be found in southern Australia. Sightings have been reported in Queensland, Victoria, South Australia, and Western Australia, in the western Pacific Ocean and eastern Indian Ocean (20°S – 40°S, 113°E – 154°E). They can be found on coral and rocky reefs, bays, estuaries, seagrass, tidepools, under piers, or on sand in temperate seas. The Intertidal zone to greater than 361 feet. Some 38 specimens caught from 1882 to 1995 were found in waters 66–577 feet deep. Adults most commonly occurs on algae-covered rocky reefs and meadows of sea grass or sand, while juveniles are mostly found in estuaries. Their color pattern is ideal to remain camouflaged perfectly in their environment.
Diet: They preferably eat bottom invertebrates, bony fish, sharks and rays. The species’ prey has been known to wander right up to it, including near its mouth, sometimes nibbling its tentacles.
Ram-Suction Index: They are high on the RSI, sucking in and impaling prey on their large teeth.
Aesthetic Identification: The Spotted wobbegong has a dark back; they are a golden sandy to light-green to yellow, or brown color, and broad darker dorsal saddles with white “O-shaped” spots and blotches and corrugated edges that are separated by lighter areas with dark, broad reticular lines. It is a large, and robust species with a wide, flattened, stalky body. The body starts to thin out beyond the pelvic fins. Its body lacks ridges or caudal keels. The fins are wide-lobed. The first spineless dorsal fin starts over the pelvic base, and the anal fin initiates behind the second dorsal fin origin. The pectoral and pelvic fins are broad.
Biology and Reproduction: The Spotted wobbegong is ovoviviparous with large litters up to 37 pups. Females give birth in the spring, after a gestation period of almost a year (Bray, D. J. “Orectolobus maculatus“. Fishes of Australia. Archived from the original on 29 January 2019. Retrieved 28 January 2019). Males are thought to be attracted to the female’s pheromones during mating season.
The Spotted wobbegong has a more complex electrosensory system than the Australian angelshark, and the Spotted wobbegong has a pore cluster inside its snout that is not present in the Australian angelshark. For both species, these electroreceptors are an important mechanism in feeding (Egeberg, Channing A.; Kempster, Ryan M.; Theiss, Susan M.; Hart, Nathan S.; Collin, Shaun P. (2014). “The distribution and abundance of electrosensory pores in two benthic sharks: a comparison of the wobbegong shark, Orectolobus maculatus, and the angel shark, Squatina australis“. Marine and Freshwater Research. 65 (11): 1003–1008).
The Onchobothriid tetraphyllidean cestode is one known parasite of the Spotted wobbegong. Thirty-three species of this cestode are parasitic to the spiral intestine of this shark; they are of the genus Acanthobothrium. The nematode Echinocephalus overstreeti is also a known parasite of the Spotted wobbegong.
Behavioral Traits, Sensing and Intelligence: They are more than likely nocturnal. They are sluggish and inactive by day, spending the day in caves, under overhangs and in channels. They can be found singularly or in aggregations.
The selection of specimens in a group was previously thought to be at random or due to food advantages, but a study led by Macquarie University concluded that Spotted wobbegongs associate with preferred partners for “social” purposes, and some specimens do not associate at all. The study occurred in a small marine reserve over a 15-month period. Out of the 15 tagged and observed specimens, 14 associated with more than one individual, and sex, size, or familiarity did not affect the association of groups. Rob Harcourt (2017), a researcher, stated “What we found was that sharks were interacting in a much more complex way than we predicted”. (Harcort, R. 2017, April 31. “Spotted wobbegong sharks demonstrate social clique behaviour“. Macquarie University.)
They may return to resting sites. They can even make short trips well above the seabed and climb with its back above the water in between tidepools.
Males fight in captivity during the breeding season, which is July in New South Wales.
Speed: More than likely slow like its family members. They probably use their large pectoral and pelvic fins to crawl across the bottom.
Spotted Wobbegong Future and Conservation: The flesh of the Spotted wobbegong is edible and has consequently caused it to be a target of fishing. Their skin is also valued, for its beautiful pattern makes a desirable leather. In Queensland, it is sometimes caught as a bycatch but is not fished for intentionally. They are listed as least concern currently. They are caught in many fisheries, but not worry-some. Multiple conservation actions have taken place for this species, particularly since 2006. It is unknown if its population is decreasing or increasing, but it is not severely fragmented as of 2015. It is listed as a species of least concern on the red list of the International Union for Conservation of Nature as of 23 March 2015, after having been assessed as near threatened in 2003 and 2009. They are known to be displayed in aquaria.
Spotted Wobbegong Recorded Attacks on Humans: They could be potentially dangerous due to their powerful bite if they are provoked. Their bite force is extremely strong, and they tend to latch on and not let go. They are typically docile towards humans, but again if they are provoked, they will defend themselves. Reports are known of it attacking people if they step on it or put a limb near its mouth, due to its thinking that the limb is prey. Divers sometimes pull it by the tail during its daytime resting period, which often provokes it enough to bite. The species can attack if caught with a fishing line or net, or if speared.
The International Shark Attack File lists 4 unprovoked attacks, known to be by the Spotted wobbegong, none of which were fatal. In total, the Australian Shark Attack File has recorded 51 instances where the unprovoked attack, on a human was confirmed to be by any species of wobbegong shark in the years 1900 to 2009, none of which were fatal.