Ornate WobbegongOrectolobus ornatus
This type of carpet shark has a flat head, stocky body, a stout tail, and wide, lobed fins. It has nasal barbels and dermal lobes forming a fringe along the front of its face, both as camouflage and as bait for the small bony fish and invertebrates it likes to ambush. It is usually a golden brown with dark rectangular saddles and rounded groupings of white dots. This nocturnal hunter prefers bays and shallow reefs, and because of its markings and its daytime sluggishness, it is easy for unexpected human encounters to result in bites.
English language common names are ornate wobbegong, banded wobbegong, carpet shark, and gulf wobbegong. Other common names include brokig wobbegong (Swedish), karakusa-ôse (Japanese), korupartahai (Finnish), requin-tapis paste (French), sierlijke bakerhaai (Dutch), stribet wobbegong (Danish), and tapicero ornamentado (Spanish).
Importance to HumansThere is limited interest in the ornate wobbegong by both commercial and recreational fisheries. It is sometimes taken as bycatch by commercial shark fisheries off Western Australia and by line off New South Wales. The flesh of this wobbegong is sometimes marketed but it is of very little value. However, the skin is used for making leather due to its toughness and attractive coloration.
Danger to Humans
The ornate wobbegong can inflict shallow but painful wounds with its sharp anterior teeth if harassed or attacked. It has also been known to swim towards nearby divers in a possibly antagonistic response. Ornate wobbegongs have also been known to bit waders and fishers in tidepools. Humans should take care when present in areas where this wobbegong lives as its camouflage coloration can hide this fish quite well from the unwary. According to the International Shark Attack File, there have been 39 attacks attributed to wobbegongs. It is sometimes difficult to identify wobbegongs during an attack, however one of the attack incidents was due to an ornate wobbegong.
This wobbegong is considered "Near Threatened" by the World Conservation Union (IUCN). There is a lack of information on the population structure, life history and ecology of the ornate wobbegong needed to develop a management plan and for re-assessment of its conservation status. 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.
In areas outside of Australian waters, there is some concern for the ornate wobbegong due to habitat degradation and unregulated fisheries.
Geographical DistributionThe distribution range of the ornate wobbegong is limited to the western Pacific Ocean. This range includes Indonesia, Papua New Guinea, and all coastlines of Australia
It is a tropical species and associated with bays, algal-covered rocky bottoms, and coral reefs of inshore waters from depths of 0-328 feet (0-100 m). The ornate wobbegong actively seeks prey and is active at night while during the day it is often observed resting on the bottom. It prefers clearer water than does its close relative, the spotted wobbegong (Orectolobus maculatus).
The ornate wobbegong has a broad, flattened head with small oval eyes and well-developed spiracles. There are skin flaps (nasal barbels) with a few branches located around the margins of the snout and a symphysial groove on the chin. Five dermal lobes are present below and in front of each eye. It has two large dorsal fins that are nearly equal in sized and triangular. The first dorsal fin is located over the insertion of the pectoral fins and the insertion of the second dorsal fin is above the origin of the anal fin. The anal fin is rounded and located so far posteriorly, that it looks similar to the lower caudal fin lobe. The caudal fin has a long upper lobe that is hardly elevated above the axis of the body. There is a strong terminal lobe and subterminal notch. Sometimes confused with the ornate wobbegong, the spotted wobbegong O.maculatus can be distinguished by the dark saddles and indistinct circles formed by groupings of small white dots.
Typically golden-brown in color, the ornate wobbegong has conspicuous dark rectangular saddles. The lighter spaces between these saddles have dark, light-centered spots but not ocellate in appearance. This ventral surface is pale in color. The fin margins often have dark spots.
The ornate wobbegong is an ambush predator that possesses long teeth lacking lateral cusplets. There are two long and sharply pointed teeth in the upper jaw and three in the lower jaw.
There are nasal barbels along with a few branches located near the snout of the ornate wobbegong. Five dermal lobes are present below and anterior to each eye as well as dermal lobes located behind the spiracles that are either unbranched or weakly branched and broad. Dermal tubercles and ridges are absent on the back of this wobbegong.
The maximum reported size of the ornate wobbegong is 9.5 feet (2.90 m) total length, however the average size is typically 6.6-8.2 feet (2.0-2.5 m) total length. The ornate wobbegong reaches maturity at approximately 5.7 feet (1.8 m) total length and size at birth is about 7.9 inches (20 cm) in length.
Although the diet of this wobbegong has not been reported, it is believe to opportunistically feed on benthic invertebrates and fishes. The ornate wobbegong uses a sit-and-wait ambush strategy that relies on its camouflage coloration pattern to trick potential prey into its range. It is known to prop itself up on the pectoral fins, tempting prey with its barbels. When a prey item does come within range, the wobbegong ambushes it with a quick snap of its jaws. The prey is then swallowed whole. However, larger prey items may be held in the jaws of the ornate wobbegong for days until death occurs at which time the wobbegong is able to swallow its victim without any struggle.
The ornate wobbegong is an ovoviviparous species meaning that the embryos feeding initially on yolk and eventually receiving additional nourishment from the mother through absorption of uterine fluid. This fluid is enriched with mucus, fat or protein and is secreted by specialized structures within the uterine wall. The ornate wobbegong gives live birth to at least 12 pups per litter with each measuring approximately 7.9 inches (20 cm) in total length.
Any large fish or marine mammals are potential predators of the ornate wobbegong.
A newly described species of cestode, Stragulorhynchus orectologi n. g., n. sp., has been documented as a parasite of the ornate wobbegong.
The ornate wobbegong was originally described as Crossorhinus ornatus by De Vis in 1883. This name was later changed to the currently valid Orectolobus ornatus (De Vis 1883). The genus name, Orectolobus, is derived from Greek 'orektos' meaning stretch out and 'lobos' meaning lobe. Synonyms referring to this species in past scientific literature include Orectolobus devisi Ogilby 1916.
A subspecies, Orectolobus ornatus halei, from South Australia was proposed by Whitley (1940). It can be distinguished from the ornate wobbegong by differences in coloration patterns, smaller adult size, and fewer dermal lobes on the head. O. ornatus halei also has a longer pelvic fin to anal fin interspace, smaller pectoral fins and relatively smaller claspers in mature specimens. However it remains to be determined at what level these apparent differences can be recognized and if this is truly a subspecies of the ornate wobbegong.
Prepared by: Cathleen Bester