The Spotted wobbegong (Orectolobus maculatus) is a species of Wobbegong sharks in the family Orectolobidae. This species belongs to the genus Orectolobus which is one of the three genera in the family. There are 10 extant species of wobbegongs in the genus Orectolobus.
This shark is a carpet shark with a flattened body that enables it to plaster itself against the seafloor. Of course, just like other wobbegongs, the spotted wobbegong tends to rest most of the time on the seafloor. The unique trait of this species distinguishing it from other wobbegongs is the coloration. They have a typical light green, golden yellow, or brown coloration with white rings irregularly surrounding its body..
The spotted wobbegong is large compared to most other wobbegong species. Their body is somewhat stocky and their fins wide. This shark species has many interesting characteristics ranging from its mystic appearance to the lethargic behavior.
Origin of the Name
When looking at the spotted wobbegong, it would not be a surprise why it is called so. This shark has unique spots around its body, hence the name. Even the scientific name Orectolobus maculatus is a derivation from this shark’s appearance.
The genus name Orectolobus originates from the Greek words orektos and lobos which in rough translations represents “stretched-out lobe”. While the species name maculatus is a Latin name meaning “spotted”, still from its body pattern.
Scientific Classification
Upon discovery of this species, it was classified into the genus Squalus. This was in a 1778 description by Abbe Pierre Joseph Bonnaterre a French naturalist. As a result, the scientific name of the spotted wobbegong was Squalus maculatus.
Ten years later, Pierre re-described this species classifying it this time to its current genus Orectolobus. Hence, the current scientific name Orectolobus maculatus. The Squalus genus is now synonymous with Orectolobus.
Relationship with Other Wobbegong Sharks
Many times the spotted wobbegong has been mistaken as other species of wobbegong such as the dwarf spotted wobbegong (Orectolobus parvimaculatus). But, due to noticeable physical differences, they are identified as two separate species. The dwarf spotted wobbegong has larger, denser dorsal fins with black spots which the spotted wobbegong lacks. This is a typical difference between the two species.
On the other hand, this shark species has been mistaken in the past with the Gulf wobbegong (Orectolobus halei). However, the two are clearly different as the spotted wobbegong has distinctive white spots on its body, more so, it has a greater number of dermal lobes than the Gulf wobbegong.
Another wobbegong species confused as the spotted wobbegong is the ornate wobbegong (Orectolobus ornatus). But, the two species differ in appearance and identified separately.
Where to Find Spotted Wobbegongs
Habitat
The spotted wobbegong mostly occurs over the continental shelves. They are likely to be found from the intertidal zone (foreshore) to the depth of about 715 feet (218 m). This shark species prefer to choose a home in reefs, sandy bottoms, and inside caves. In addition to these places, the spotted wobbegong is also a common sight in very shallow sea waters that may not even cover their body.
Most of the time this shark species chooses to rest on the seafloor without moving. They are typically sluggish and inactive just like other wobbegong species.
Distribution Range
The spotted wobbegong is an indigenous species to the waters around Australia. This particularly points to the western Pacific Ocean. There are also reports of this species in the eastern Indian Ocean. Thus, there are records of the spotted wobbegong in South and Western Australia, Victoria, and Queensland.
On another note are records of this species occurring in Tasmania and the Northern Territory of Australia. However, these records do not have a strong backup, hence, considered erroneous.
Identifying a Spotted Wobbegong
As a typical wobbegong shark, the spotted wobbegong has a robust body with large fins that spreads while it is resting. This shark is among the largest species in the family of wobbegongs. There are many features to look out for while trying to identify a spotted wobbegong.
Particular to spotted wobbegongs are about 8 to 10 dermal lobes that go around its mouth and also toward the head sides. There are also the barbels extending from the nasal openings of this species. Protruding above the eyes are small lumps known as tubercles. These characteristics serve to differentiate the spotted wobbegong from other species with a similar appearance.
Coloration
This shark species has a dull yellow or greenish-brown color. The dorsal side is dark with even darker saddles at the center. On this backside also are circular spots that form irregular patterns that distinguish this species from other wobbegong species. This pattern generally serves as a camouflage when this shark is resting on the seafloor.
Dentition
The spotted wobbegong has unique, long, slender, and sharp teeth. This shark has two lateral teeth rows on the upper jaw while on the lower jaw there are three rows. Sometimes, the teeth of the spotted wobbegong are referred to as enlarged fangs. They can inflict severe and painful injuries if they bite.
Fins
This shark species has two dorsal fins. The first dorsal fin, lacking spine has its origin just above the base of the pelvic fin. While the end of the second dorsal fin marks the origin of the anal fin which is on the ventral side of the shark.
The spotted wobbegong has a quite short caudal fin while the pectoral fins are very broad. This makes Orectolobus maculatus appear flattened while lying on the floor of the ocean.
Growth Size
Normally the spotted wobbegong would grow to the length of about 5 to 6 feet (1.52 to 1.83 m). However, larger individuals tend to grow up to 10 feet (3.2 m) in length. *Orectolobus maculatus* reaches maturity at the length of 4 feet (1.2 m).
Some reports in the past hold that this shark species reaches maturity at about 2 feet (60 cm) length. But, later discoveries stated otherwise assuming that this report may be a case of misidentification with the Dwarf Spotted Wobbegong (Orectolobus parvimaculatus). This dwarf spotted wobbegong also occurs in Western Australia.
Behaviors of the Spotted Wobbegong
The spotted wobbegong is a slow and sluggish shark species that prefers to spend most of its day time resting on sandy bottoms, inside caves, coastal bays, and coral reefs. They are nocturnal species that becomes more active at night, swimming slowly in search of prey. This shark species is not an active swimmer, as a result, even during its active night time, it still moves slowly.
As a preference, adult spotted wobbegongs would most likely stay on rocky reefs with algae growths, sandy flats, or areas covered by seagrasses. Meanwhile the juvenile sharks tend to prefer water estuaries.
It is suspected that this shark exhibits a preference for the favored resting site. That is to say, they always return to their favorite resting position throughout their life. This behavior is still being studied on this species, thus, yet to be confirmed.
Feeding Behavior
The spotted wobbegong is a typical ambush predator. It lies motionless on the seafloor most of the time making unsuspecting swimming very close to it. They even get too close to its mouth and sometimes nibble on its tentacles. The end result of all these being used as a meal.
The color pattern of the spotted wobbegong helps it to camouflage against its resting site on the bottom of the ocean. Hence, prey could hardly detect the shark’s presence and swim close to it.
When feeding, this shark just like other wobbegongs uses its wide pharynx and short snout to suck prey in. They would typically wait for their prey to come really close before attacking.
Food Components
The diet make-up of the spotted wobbegong includes fish such as basses, luderick, rays, and scorpionfish. This shark also feeds on invertebrates such as lobsters, octopuses, and crabs. Other food sources of the spotted wobbegong may include unfortunate smaller shark species that come close to it.
Social Behavior
Spotted wobbegongs have been found gathering in groups. This group association was thought to occur through random selection or food advantage. A later study proved that this species only group together with choice partners specifically for social reasons. Also, some individuals choose to stay on their own, hence, they do not relate in groups like others.
The social behavior of spotted wobbegongs involves a more complex interaction among individuals. These sharks relate to more than one individual. Sex, size, and familiarity do not in any way affect the social grouping of Orectolobus maculatus.
Predators of the Spotted Wobbegong
Larger shark species pose a threat to the spotted wobbegong as they prey on them. Other potential predators of this species large marine mammals.
Spotted Wobbegong Parasites
The common parasite of the spotted wobbegong shark is the cestode Onchobothriid tetraphyllidean. The cestode has 33 species identified to attach to the spiral intestine of this shark species. These parasites are of the genus Acanthobothrium. Another common parasite of this shark is the nematode Echinocephalus overstreeti.
These parasites may not really be harmful to this shark as it lives with them without a change in activities.
Mating and Reproduction
For mating to occur in this species, female sharks release chemical pheromones which attract several males following her for mating. Observations show that these males struggle with each other during the breeding season. Mating involves the male biting the female spotted wobbegong close to the gill while holding her still for copulation to occur.
The spotted wobbegong is an ovoviviparous species. Their eggs develop and hatch within the body of the female before giving birth to the young ones alive. They can birth up to 37 pups in a litter.
Gestation lasts for about 11 months, with parturition taking place between September and October. At birth, the spotted wobbegong would typically measure 9 inches (23 cm) in length.
It takes the spotted wobbegong a cycle of 3 years to reproduce. The follicles take generally about 2 years to mature before ovulation occurs. Spotted wobbegongs mature sexually at the length of 4 feet (1.20 m).
Spotted Wobbegong and Humans
The spotted wobbegong is a bottom-dweller and may rarely encounter humans. But, for the times and events this shark encountered humans, it is worth knowing what the interaction was like. Thus:
Danger to Humans
Spotted wobbegongs can be potentially dangerous to humans that may approach it. They have long, slender teeth that can inflict severe injury on humans. This shark hardly releases once it successfully bites, hence, severing the injury caused.
There are reports of this shark species attacking humans who mistakenly step on it or even come close to it. They do not need to be provoked to attack. Once they perceive anyone present as a threat or prey, they are likely to attack. They use their bite as a defense mechanism.
Attacks on Humans
The International Shark Attack File (ISAF) has 4 records of unprovoked attacks attributed to the spotted wobbegong. None of these attacks were fatal. In addition to this are 51 unprovoked attacks attributed to any of the wobbegong species in which the spotted wobbegong has slots.
The spotted wobbegong would not actively attack people who enter the water where it dwells. However, getting too close to it even while it is resting is a risky approach. Divers would at times drag this shark by its tail provoking it. This activity would definitely lead to the shark attacking the culprit.
Another instance where this shark would attempt to bite humans is when it is caught on a fishing line or net. Divers and fishermen are more exposed to attacks from this species.
Economic Value
The spotted wobbegong does not have much economic value to humans. However, humans target it for their flesh and skin. The flesh of this shark species serves as food, while the skin can be processed into a finely patterned leather.
Most fishermen do not intentionally fish the spotted wobbegong, instead, they occur as bycatch on traps set for other fish.
Conservation
Currently, the International Union for Conservation of Nature (IUCN) listed the spotted wobbegong as “Least Concern (LC)”. This assessment follows the fact that this species is not a major target of most fisheries. Besides, there is control in the fishing of marine species in regions where they occur.
Apart from bycatch capture and fishing for food, there is no significant threat currently on this species. As of 2006, there are several conservation actions for the protection of the population of this species.
12 Interesting Facts About the Spotted Wobbegong
1. Its Common Name “Spotted Wobbegong” Comes from the Shark’s Body Pattern
The body pattern of this shark species mostly visible from the dorsal side shows unique circular spots which led to the name “Spotted wobbegong”. Even the specific epithet maculatus is a Latin word translated as “Spotted”. Hence, this shark’s predominant body pattern led to the name it is being called.
2. The Spotted Wobbegong is Often Mistaken for the Dwarf Spotted Wobbegong (Orectolobus parvimaculatus)
The dwarf spotted wobbegong is similar in appearance to the spotted wobbegong. However, with noticeable differences, they are both classified as separate species. The dwarf spotted wobbegong has larger, denser dorsal fins with black spots that are not in the spotted.
3. The Spotted Wobbegong is a Lazy Shark
This shark species spends most of its day time resting on the floor of the ocean. They do not move until it is dark when they emerge to hunt. They are sluggish and slow, thus mostly clambering on the seafloor instead of swimming. This behavior is typical of wobbegong species.
4. This Shark Has 8 – 10 Dermal Flaps Edging Its Snout
The distinctive trait of the spotted wobbegong includes the 8 – 10 flaps of skin that surrounds its mouth. In some other wobbegong species such as the Tasselled wobbegong (Eucrossorhinus dasypogon), the dermal lobes are many and branching.
5. It Has a Pale Yellow or Greenish Brown Coloration
The color of spotted wobbegongs is dominantly pale yellow or greenish-brown. There are darker saddles on the dorsal side and also whitish spots that form a pattern.
6. The Spotted Wobbegong Is Among the Largest Species of Wobbegong
This shark typically grows to a length of 5 to 6 inches (1.52 to 1.83 m). However, the larger ones can reach 10 feet (3.2 m) in length. This makes the spotted wobbegong one of the largest wobbegong species.
7. This Shark Is Not Suitable for Home Aquaria
Due to the large size of the spotted wobbegong it is not recommended for a home aquarium. Although, it can survive in captivity where there is enough space. This shark is not active, hence, it does not require so much swimming space. Just enough space to accommodate its size and local movements. The wobbegong species most suitable for home aquaria is the Tasselled wobbegong (Eucrossorhinus dasypogon), and Ward’s wobbegong (Orectolobus wardi).
8. Spotted Wobbegongs Exhibit Social Grouping
Spotted Wobbegongs comes together in social groups. This association according to researchers is especially for social purposes. Therefore, individual spotted wobbegongs associate with partners they choose. This is irrespective of age, sex, and activities.
9. The Spotted Wobbegong Can “Walk”
This shark species instead of swimming prefers to use its fins as limbs “walking” along the seafloor. Well, this is more like clambering while moving along sands and rocks. This movement is most common at night when they emerge in search of prey. The muscles of the fins help to push their body.
10. Their Reproduction Takes About Three Years to Complete
With a triennial reproduction cycle, the spotted wobbegong would reproduce once in three years. It takes them about two years to grow follicles which after ovulation would take place. Gestation lasts for a period of 10 to 11 months.
11. The Spotted Wobbegong is Potentially Dangerous to Humans
This shark has long sharp teeth that can cause a painful wound to human beings. To add to it, once they bite, their jaws lock making them bite for longer severing the pain. There are several unprovoked shark attacks on humans attributed to the spotted wobbegong.
12. They Do Not Have Significant Economic Value
Apart from this shark’s flesh used for food and the tough skin used for leather, there are no other tangible economic benefits of the spotted wobbegong. As a result, fisheries do not always target this species.
13. This Shark Mostly Attack Divers
Divers who swim to the bottom of the ocean might unknowingly get bitten by a camouflaged spotted wobbegong. This may not always be the case as some divers tend to pull this shark by its tail provoking it enough to launch an attack.
14. The Spotted Wobbegong (Orectolobus maculatus) is Currently Assessed As “Least Concern”
The International Union for Conservation of Nature (IUCN) listed this species as “Least Concern (LC)”. They are not a major target of fisheries. Moreover, there is controlled fishing in areas where they occur. This offers some stability to the population of this species.
Further Reading
- “Orectolobus maculatus, Spotted Wobbegong”, FishBase.
- “Spotted Wobbegong, Orectolobus maculatus“, Australian Museum.
- “Discover Fishes: Orectolobus maculatus, Spotted Wobbegong”, Florida Museum of Natural History.
- “Spotted Wobbegong (Orectolobus maculatus)“, IUCN Red List of Threatened Species.
- “Spotted Wobbegong Sharks, Orectolobus maculatus“, The MarineBio Conservation Society.