Mugil cephalus, commonly known as the striped mullet, is a widely distributed fish species found in coastal temperate, tropical, and subtropical waters worldwide. This versatile fish is a familiar sight in various marine and estuarine environments. Its presence is significant for its abundance, its multifaceted role in aquatic ecosystems, and its long-standing relationship with human societies.
Physical Traits and Appearance
The striped mullet exhibits a robust, cylindrical body that is elongated and tapers slightly towards the tail. Its coloration typically features a dark olive-green or grayish-brown back, gradually lightening to silvery sides and a white belly. Distinct dark longitudinal stripes often run along its flanks, which contribute to its common name.
The head of Mugil cephalus is broad and somewhat flattened, featuring a small, triangular mouth with thin lips. This mouth contains small, closely-set teeth, often arranged in multiple rows on the upper jaw. The fish possesses two dorsal fins; the first is spiny with four spines, while the second is composed of soft rays.
Natural Habitat and Diet
Mugil cephalus is a highly adaptable species, thriving in a range of aquatic environments including coastal marine waters, estuaries, and even freshwater rivers. Its euryhaline nature, the ability to tolerate varying salinities, allows it to move between different water types. Adults often form large schools over sandy or muddy bottoms in shallow coastal areas, though they can inhabit depths up to 120 meters.
The striped mullet’s feeding behavior is diurnal. It functions as a detritivore and herbivore, sifting through sediments to consume a diet composed of zooplankton, dead plant matter, microalgae, and detritus. Its stomach contains thick-walled, gizzard-like segments and a long gastrointestinal tract, which aid in processing these food sources.
Reproduction and Development
The reproductive cycle of Mugil cephalus involves migration to offshore spawning grounds in large aggregations during the autumn and winter months. These fish are broadcast spawners, releasing millions of eggs and sperm directly into the open ocean, where fertilization occurs. Females can produce between 0.5 to 2.6 million eggs per season, with larger individuals producing more.
After fertilization, the transparent, pale yellow eggs, containing an oil globule for buoyancy, hatch within 30 to 64 hours, depending on water temperature and salinity. The newly hatched larvae, measuring about 2.4 mm, then move towards inshore nursery areas such as estuaries and coastal lagoons. These shallow waters provide protection from predators and abundant feeding grounds. Juveniles reach about 5 cm in length before transitioning to deeper waters, with sexual maturity attained around three to four years of age.
Role in Ecosystems and Human Value
Mugil cephalus plays a significant role in coastal ecosystems, acting as a link in the energy flow within estuarine communities. By consuming detritus, microalgae, and other organic matter from sediments, they contribute to nutrient cycling and the overall health of these environments. Their position at the base of the food web also makes them an important forage fish, providing a food source for larger predators such as various bird species, marine mammals, and other fish.
Beyond its ecological contributions, the striped mullet holds considerable economic value globally. It is a highly valued species in commercial fisheries and aquaculture across many regions, including the Mediterranean Sea and Taiwan, where it is sometimes referred to as “Gray Gold.” The fish is marketed in various forms, including fresh, dried, salted, and frozen, and its roe is particularly prized as a delicacy in several cultures, notably in Taiwan and Japan.