Spotted WobbegongOrectolobus maculatus
This flat, wide carpet shark has a stocky body and stout tail, with wide, lobed fins. There are dermal lobes along its mouth and sides of its face like a mustache that act as camouflage as well as bait for prey. It is a sluggish, nocturnal shark that likes to live at the bottom of reefs and ambush small bony fish and invertebrates. This wobbegong can be visually identified from other wobbegongs because it is usually a golden sandy to light green color with a dark saddle across its body and a white irregular ring pattern.
O. maculatus is commonly known as the wobbegon or spotted wobbegon in the English language. Other common names include gevlekte bakerhaai (Dutch), kumohada-ôse (Japanese), rengaspartahai (Finnish), requin-tapis tacheté (French), tapicero manchado (Spanish), and wobbegong (German).
Importance to HumansSpotted wobbegong flesh is often considered excellent for eating. Furthermore, the skin of the shark is very tough and makes very beautifully patterned leather. Nevertheless, the shark is of limited commercial value. It is a pest to many lobster fishers as it is known to trap itself in their lobster pots.
Danger to Humans
The spotted wobbegong is generally not an aggressive creature but is known to attack when provoked. It will bite people when stepped on and even when limbs are put near its mouth, mistaking them for prey. Its bite can cause severe lacerations, and this shark is often reluctant to let go once the bite has been delivered. According the the International Shark Attack File, there have been 23 confirmed attacks on humans by spotted wobbegongs.
The spotted wobbegong is currently assessed as "Near Threatened" in waters off New South Wales due to serious declines in population numbers in that region and "Near Threatened" throughout the remainder of its range by the World Conservation Union (IUCN) Red List. The IUCN consists of a global union of state, governmental agencies, and non-governmental organizations in partnership whos goal is to assess the conservation status of different species.
Geographical DistributionThe spotted wobbegong is native to the western Pacific Ocean, particularly in Japanese and Australian waters and in the South China Sea.
Occurring on continental shelves, from the intertidal zone down to 360 feet (110 m), the spotted wobbegong is commonly found on or around reefs, under piers, and on sandy bottoms. There have been many sightings of this shark in water barely deep enough to cover its entire body. It is considered sluggish and inactive and is often found resting on the ocean floor.
The body and head of the spotted wobbegong is flattened. The mouth is located in front of the eyes and has a protruding jaw that aids in the capture of prey. It has nasal barbels and 8 to 10 dermal lobes around the mouth and on the sides of the head. The first spineless dorsal fin starts over the pelvic base, and the anal fin originates behind the second dorsal fin origin. The caudal fin is much shorter than the rest of the body, and the pectoral and pelvic fins are broad. Spotted wobbegong sharks are also characterized by the presense of large spiracles, nasoral and circumnarial grooves, and the absence of caudal keels and ridges on the body. While other species of wobbegong are similar in appearance, the pattern of coloration is distinctive for the spotted wobbegong.
The spotted wobbegong is generally pale yellow or greenish brown with large, dark saddles down the center of its back and many small, white O-shaped markings over its entire back. The pattern serves as camouflage.
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.
Size, Age, and Growth
The average size of the spotted wobbegong at birth is 8.3 inches (21 cm) total length. Most adult males mature at 23.6 inches (60 cm) and may reach a maximum length of 126 inches (320 cm) total length. However, the average size of an adult male is 59 to 71 inches (150-180 cm) total length.
Favorite foods of the spotted wobbegong include invertebrates such as crabs, lobsters, and octopi as well as bony fish such as sea bass and luderick. This shark is nocturnal, hunting at night and resting during the day. O. maculatus can extend its reach during prey capture by as much as 30% of the nasal distance from its anteriormost point to the anterior edge of the pectoral fin. This is equivalent to the combined length of the head and branchial arches. The spotted wobbegong often sits at the bottom and waits for prey to wander near its mouth. Prey have even been known to nibble on this shark's tentacles before being eaten. Other times this shark has been observed to slowly sneak up on its prey from a long distance.
The spotted wobbegong is an ovoviviparous species, giving birth to a large number of full term embryos. One female was reported to give birth to a record of 37 young. The young measure 8.3 inches (21 cm) total length at birth. During breeding season, the male is attracted to the female by chemical pheromones that she releases into the water. In the mating process, the male often bites the female in the region of the gills and inserts one clasper into the cloaca to deliver sperm.
Any large fish or marine mammals are potential predators of the spotted wobbegong.
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 genusAcanthobothrium. The nematode Echinocephalus overstreeti is also a known parasite of this shark.
This shark was named Orectolobus maculatus by Bonnaterre, 1778. Orectolobus is derived from the Greek word orektos, which means, "stretch out," and the Greek word lobos, which means, "lobe." The genus name maculatusis derived from the Latin word maculosus, which means, "spotted." This shark has also been referred to asSqualus maculatus Bonnaterre 1778, Squalus barbatus Gmelin 1789, Squalus lobatus Bloch and Schneider 1801,Squalus appendiculatus Shaw & Nodder 1806, and Squalus labiatus Bleeker 1857.
Prepared by: Dane Eagle