11 Interesting Facts About Morwong
The morwong is a fish found in the coastal waters of southeastern Australia. Here are 11 fascinating facts about this unique fish species:
Introduction
The morwong (Nemadactylus macropterus) is a large, predatory fish belonging to the Cheilodactylidae family. It is an important commercial and recreational fish in Australia, highly prized for its white, flaky, tasty flesh.
Morwong has a distinctive appearance, with a tapered body shape, large pectoral fins, and a protruding lower jaw lined with sharp teeth. They inhabit rocky reefs and offshore seamounts at depths of 5-200 meters.
These fish display interesting behaviors and adaptations that aid their survival. Read on to uncover more intriguing details about morwong!
1. Impressive Size
Morwong can grow quite large, potentially reaching over 1 meter in length and weighing up to 25 kilograms. However, they are commonly caught at sizes of 30-70 centimeters.
Their considerable size allows them to hunt large prey like octopuses, fish, and crustaceans. It also helps them establish dominance over smaller fish when competing for food and shelter.
2. Varied Coloration
Morwong display a beautiful array of colors and patterns. The upper body is generally red-brown to green-brown. The lower half of the body fades to a pale yellow or white underside.
Rows of azure blue spots run horizontally across their sides. These iridescent markings shine brightly when fishing boats illuminate morwong congregating around reefs at night.
3. Unique Dentition
To effectively capture and consume its prey, the morwong possesses an impressive set of cone-shaped teeth in the front of its jaws. They also have flat, crushing teeth further back in their mouths to break down hard-shelled marine invertebrates like crabs, urchins, and mollusks.
Their varied teeth allow them to handle a wide range of food items. This diet flexibility aids the morwong’s survival during times of prey scarcity.
4. Solitary Behavior
Morwong tend to be loners, inhabiting rocky caves and crevices alone during the day. They venture out at dawn and dusk to actively feed, then return to their sheltered dens.
Their solitary nature makes them more difficult for spearfishermen to locate. It also means morwong may have to cover more territory when foraging compared to schooling fish species.
5. Light Sensitivity
Morwong have well-developed eyes containing a tapetum lucidum – a reflective layer that amplifies incoming light. This helps them spot prey in the dimly lit reef environments they occupy.
Their visual acuity and light sensitivity likely aid nighttime feeding forays away from their shelters. It also causes them to shy away from bright fishing lures and boat lights.
6. Sexual Dimorphism
There are distinct physical differences between male and female morwong. Males possess a more tapered body shape and frequently grow larger than females.
Females have a broader, stockier profile and produce more rounded, buoyant eggs to accommodate internal gestation. Their smaller mouths and teeth are better suited for eating small invertebrates rather than hunting large, mobile prey.
7. Internal Fertilization
Morwong are viviparous – the females internally fertilize their eggs and give birth to live young. This reproductive strategy means morwong produce fewer offspring compared to fish that release eggs into the water column. However, their larvae have higher survival rates since they avoid predation in the plankton-rich open ocean.
8. Slow Maturation
Morwong grow slowly, taking over 6 years to reach sexual maturity. Their longevity helps compensate for slow growth and low fecundity. Some morwong over 20 years old have been caught by fishermen.
9. Valuable Fishery
The morwong’s large size, tasty fillets, and lack of small bones make it a highly desirable catch. It is one of the top 10 commercial fishery species in New South Wales, comprising up to 20% of trap and line catches.
Recreational anglers also prize morwong for their fighting spirit – their broad pectoral fins allow them to put up a lengthy, challenging battle when hooked. Careful management is required to prevent overfishing of slow-growing fish like the morwong.
10. Strong Site Fidelity
Morwong display strong site fidelity – they repeatedly return to the same sheltered habitats, cleaning stations, and feeding grounds. Understanding these movement patterns and key habitat requirements allows fisheries managers to effectively monitor populations and implement spatial protections.
11. Unique Swim Bladder
Morwong possess a divided swim bladder with smaller anterior and larger posterior sections. Both chambers must fill with gas to achieve neutral buoyancy, allowing morwong to hover motionless while hunting. This complex bladder structure also produces loud croaking sounds that may function in communication.
Conclusion
The morwong is an Australian coastal fish shrouded in mystery. Many aspects of its life history like reproduction, larval development, and feeding behaviors are still being uncovered by researchers.
Hopefully, this overview of 11 intriguing morwong traits piqued your interest to learn more about this charismatic fish! Careful ongoing study is needed to properly manage commercial and recreational morwong fisheries while preserving essential habitats for the persistence of this unique species.
