This is a euryhaline, pelagic nearshore species, it sometimes forages in lagoons, estuaries and lower courses of rivers and can tolerate freshwater. It inhabits inshore marine waters, estuaries, lagoons and rivers where it can tolerate wide ranges of temperature and salinity. Adults are found in waters that range in temperature and salinity from 8 to 24°C, and 0 ppt to 75 ppt respectively. Juveniles are able to tolerate salinities from 0 ppt to 35 ppt (Bester 2004). It is capable of surviving temperatures ranging from 12-25°C (Harrison and Senou 1999). It is a benthopelagic, catadromous species that is usually found at a depth of zero to 10 m, but can be found as deep as 120 m (Moreira 1992, Harrison 1995, Riede 2004). It often enters estuaries and rivers and forms schools over sand or mud bottoms (Eschmeyer et al. 1983, Thompson 1986, Allen 1991, Yamada et al. 1995, Allen et al. 2002). Adults filter out organic detritus, microscopic algae, and small particulate materials by gulping sediment. It is mainly diurnal, feeding on zooplankton as larvae and detritus, micro-algae and benthic organisms as juvenile and adult fish (Blaber 1976, Tung 1981, Cardona 2000). Juveniles feed on zooplankton, larger individuals filter algae, detritus, sediment and small invertebrates. This species is also known for its leaping capabilities. It is an important prey item for sharks, dolphin, seals and birds (Heemstra and Heemstra 2004).
Eggs are released in batches from May to September near estuaries where juveniles remain for up to three years (Bianchi et al. 1999). It is known to breed in its third year of life: adults school in estuaries then move out to sea to spawn in coastal surface water, before returning to estuaries and freshwater (Harrison and Senou 1999). Offspring are spawned offshore by schooling adults and fry eventually migrate inshore while feeding on zooplankton. Tag returns along the U.S. Gulf of Mexico coast indicate that M. cephalus do not make extensive migrations in this region, but instead remain in a relatively small area and return to their original bay system after spawning (Hill 2004). Species of Mugilidae are typically hardy and capable of rapid growth. Fricke et al. (2009) describes M. cephalus as a keystone species.
Spawning occurs in large groups and in deep waters far offshore (McEachran and Fechhelm 1998, Saleh 2013). It spawns in offshore waters of the Gulf of Mexico at depths of 40–1,650 m beyond the continental shelf 50–100 km off the coast (Ibáñez et al. 2012). It has an oviparous life cycle and practices a polyandrous mating system. Fecundity ranges from 270,000-1.6 million eggs per individual per season; absolute fecundity is between 2.9-16 million eggs. In Florida, M. cephalus spawns offshore from October through mid-January, with spawning completed by late February. Larvae become abundant in the waters of the northern Gulf of Mexico between November and December in water temperatures between 23-25°C.
The lifespan of
M. cephalus is estimated to be seven years for males and eight years for females, with an average of five years (Texas Parks and Wildlife Department 2005). Individuals become sexually mature at around 32-50 cm in length and around two years in age (Saleh 2013). An African study indicates that this species reaches maturity at 39 cm for males and 42 cm for females, and likely begins reproduction in December (Ndour
et al. 2013). Maximum standard length for this species is 120 cm male/unsexed (Thompson 1990), maximum reported weight for this species is 12 kg (Fadeev 2005), and maximum reported age for this species is 16 years (Thompson 1963).
