Mugil cephalusBlack mullet(Also: Callifaver mullet; Common mullet; Gray mullet; Sea mullet)

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Geographic Range

Mugil cephalus occurs in the coastal waters of the tropical and subtropical zones of all seas. Striped mullet are found in the western Atlantic Ocean, from Nova Scotia, Canada south to Brazil, including the Gulf of Mexico. They are absent in the Bahamas and the Caribbean Sea (Robins and Ray 1986). In the eastern Atlantic Ocean, striped mullet occur from the Bay of Biscay (France) to South Africa, including the Mediterranean Sea and the Black Sea (Thomson 1951). The eastern Pacific Ocean range includes southern California south to Chile (Eschmeyer et al. 1983). (Eschmeyer, et al., 1983; Robins and Ray, 1986; Thomson, 1951)

Habitat

Mugil cephalus are found in highly salty to fresh waters that are warm or temperate from 8 to 24 C. They spend a great deal of time close to shore around the mouths of streams and rivers or in brackish bays, inlets, and lagoons with sand or mud bottoms (Texas Parks 2005). They often enter estuaries and freshwater environments. Adult mullet have been found in waters ranging from 0 ppt to 75 ppt salinity. Adults form huge schools near the surface over sandy or muddy bottoms and dense vegetation (Bester 2004). ("Texas Parks and Wildlife Department", 2005; Bester, 2004)

  • Range depth
    0 to 120 m
    0.00 to 393.70 ft

Physical Description

The maximum length of striped mullet is 120 cm, with a maximum weight of 8 kg. The body of striped mullet is subcylindrical and anteriorly compressed. They have a small, terminal mouth with inconspicuous teeth and a blunt nose. The lips are thin, with a bump at the tip of the lower lip. The adipose eyelid is prominent with only a narrow slit over the pupil. The body is elongate and the head is slightly wider than deep. Pectoral fins are short, not reaching the first dorsal fin. The origin of the second dorsal fin is posterior to the origin of the anal fin. The lateral line is not visible. This mullet is often confused with white mullet, Mugil curema. However, white mullet have scales extending onto the soft dorsal and anal fins while striped mullet do not. They may also be identified based on the anal ray fin counts of 8 for striped mullet and 9 for white mullet. The body is grayish olive to grayish brown, with olive-green or bluish tints and sides fading to silvery white towards the belly. Dark longitudinal lines, formed by dark spots at the center of each scale on the upper half of the body, run the length of the body. Young fish smaller than 15 cm in length lack stripes. There is a large dark blotch at the base of the pectoral fin. The pigmentation in the iris is dispersed and brown, a character that also helps to distinguish it from M. curema. The mouth is triangular in shape when viewed from above, with small, close-set teeth arranged in several rows on the jaws (Bester 2004). (Bester, 2004)

  • Sexual Dimorphism
  • sexes alike
  • Range mass
    8 (high) kg
    17.62 (high) lb
  • Range length
    120 (high) cm
    47.24 (high) in

Development

The eggs are transparent and pale yellow, non-adhesive, and spherical with an average diameter of 0.72 mm. Each egg contains an oil globule, making it positively buoyant. Hatching occurs about 48 hours after fertilization, releasing larvae approximately 2.4 mm in length. These larvae have no mouth or paired fins. At 5 days of age, they are approximately 2.8 mm long. The jaws become well-defined and the fin buds begin to develop. At 16 to 20 mm in length, the larvae migrate to inshore waters and estuaries. At 35 to 45 mm, the adipose eyelid is obvious, and by 50 mm it covers most of the eye. At this time the mullet is considered to be a juvenile. These juveniles are capable of osmoregulation, being able to tolerate salinities of 0 to 35 ppt. They spend the remainder of their first year in coastal waters, salt marshes, and estuaries. In autumn, they often move to deeper water while the adults migrate offshore to spawn. However, some young mullet overwinter in estuaries. After this first year of life, mullet inhabit a variety of habitats including the ocean, salt marshes, estuaries, and fresh water rivers and creeks (Bester 2004). (Bester, 2004)

Reproduction

Striped mullet are catadromous, that is, they spawn in saltwater yet spend most of their lives in freshwater. During the autumn and winter months, adult mullet migrate far offshore in large aggregations to spawn. In the Gulf of Mexico, mullet have been observed spawning 65 to 80 km offshore in water over 1,000 m deep. In other locations, spawning has been reported along beaches as well as offshore. (Bester, 2004; Hill, 2004)

Estimated fecundity of striped mullet is 0.5 to 2.0 million eggs per female, depending upon the size of the individual (Bester 2004). Female mullet reach sexual maturity in their fourth year, when they are between 40 to 42 cm. Males mature in their third year, once they reach a size of 33 to 38 cm. The minimum spawning size of females is between 31 to 34 cm. Striped mullet are oviparous fish (Hill 2004). Beginning in the early fall, large schools of mullet aggregate in the lower reaches of estuaries and at river mouths in preparation for offshore migration to spawning grounds. Environmental cues such as falling water temperatures, passage of cold fronts and falling barometric pressure are thought to trigger aggregation and subsequent migration. Spawning occurs in deep, offshore waters from mid-October through late January, with peak spawning occurring in November and December. Larvae and prejuveniles then migrate to inshore estuaries where they inhabit shallow, warm water in the intertidal zone. Mugil cephalus are isochronal spawners, with all oocytes reaching maturity at the same time. However, based on the size of the female body cavity, it is unlikely that a female's entire store of eggs is hydrated at the same time in preparation for spawning. Rather, females are likely to hydrate eggs in batches and spawn on successive evenings until their supply of yolked eggs is depleted (Hill 2004). (Bester, 2004; Hill, 2004)

  • Breeding interval
    Striped mullets breed once yearly.
  • Breeding season
    Spawning occurs in autumn and winter months.
  • Range number of offspring
    500,000 to 2,000,000
  • Average time to hatching
    48 hours
  • Range time to independence
    0 to 0 minutes
  • Average age at sexual or reproductive maturity (female)
    3 years
  • Average age at sexual or reproductive maturity (female)
    Sex: female
    730 days
    AnAge
  • Average age at sexual or reproductive maturity (male)
    3 years
  • Average age at sexual or reproductive maturity (male)
    Sex: male
    730 days
    AnAge

Once eggs are laid, adult striped mullet do not provide any further parental care (Texas Parks 2005). ("Texas Parks and Wildlife Department", 2005)

  • Parental Investment
  • no parental involvement
  • pre-fertilization
    • provisioning
    • protecting
      • female

Lifespan/Longevity

The lifespan of striped mullet is seven years for males and eight years for females, with a probable average lifespan of five years. The oldest striped mullet on record is one that lived 13 years (Texas Parks 2005). ("Texas Parks and Wildlife Department", 2005)

Behavior

Striped mullet tend to school for protection from predators in the daylight hours, although they feed around the clock (Texas Parks 2005). Striped mullet leap out of the water frequently. Biologists aren't sure why these fish leap so often, but it could be to avoid predators. Another possibility is that the fish spend much of their time in areas that are low in dissolved oxygen. They may quickly exit the water in order to clear their gills and be exposed to higher levels of oxygen (Bester 2004). ("Texas Parks and Wildlife Department", 2005; Bester, 2004)

Home Range

Home ranges of these animals in the wild have not been reported.

Communication and Perception

The communication and perception of striped mullet has not been reported. They are likely to use chemical and visual cues.

Food Habits

Mullet are diurnal feeders, consuming mainly zooplankton, dead plant matter, and detritus. Mullet have thick-walled gizzard-like segments in their stomach along with a long gastrointestinal tract that enables them to feed on detritus.

They are an ecologically important link in the energy flow within estuarine communities. Feeding by sucking up the top layer of sediments, striped mullet remove detritus and microalgae. They also pick up some sediments which function to grind food in the gizzard-like portion of the stomach. Mullet also graze on epiphytes and epifauna from seagrasses as well as ingest surface scum containing microalgae at the air-water interface. Larval striped mullet feed primarily on microcrustaceans. One study found copepods, mosquito larvae, and plant debris in the stomach contents of larvae under 35 mm in length. The amount of sand and detritus in the stomach contents increases with length indicating that more food is ingested from the bottom substrate as these fish mature (Bester 2004). (Bester, 2004)

  • Plant Foods
  • algae

Predation

Major predators of striped mullet include larger fish, birds, and marine mammals. Spotted seatrout, Cynoscion nebulosus, feed on mullet up to 13.8 to 35 cm long. Off the coast of Florida, sharks often feed on large mullet. Pelicans and other aquatic birds as well as dolphins also prey on striped mullet. Humans are also significant predators of striped mullet (Bester 2004). (Bester, 2004)

Ecosystem Roles

Striped mullet are an ecologically important link in the energy flow within marine communities. They serve as prey for their predators. Striped mullet are hosts for many parasites including flagellates, ciliates, myxosporidians, monogenean and digenean trematodes, nematodes, acanthocephalans, leeches, argulids, copepods, and isopods (Bester 2004). (Bester, 2004)

Commensal/Parasitic Species

Economic Importance for Humans: Positive

Striped mullet are regarded as an excellent food fish. They are also used as bait for a variety of fishes, including billfish, commonly bringing a higher price as bait than as food fish. These fish are prized for their roe. Striped mullet are marketed fresh, dried, salted, and frozen with the roe sold fresh or smoked. This fish is also used in Chinese medicinal practices. It is a very important commercial fish in many other parts of the world (Bester 2004). (Bester, 2004)

Economic Importance for Humans: Negative

No negative effects on humans have been reported for striped mullet.

Conservation Status

Striped mullet are not listed as endangered or vulnerable with the World Conservation Union (IUCN), CITES, or the U.S. Endangered Species Act. These are common and abundant fish.

Contributors

Tanya Dewey (editor), Animal Diversity Web.

Roy Pullukat (author), University of Michigan-Ann Arbor, Kevin Wehrly (editor, instructor), University of Michigan-Ann Arbor.

Glossary

Atlantic Ocean

the body of water between Africa, Europe, the southern ocean (above 60 degrees south latitude), and the western hemisphere. It is the second largest ocean in the world after the Pacific Ocean.

World Map

Pacific Ocean

body of water between the southern ocean (above 60 degrees south latitude), Australia, Asia, and the western hemisphere. This is the world's largest ocean, covering about 28% of the world's surface.

World Map

benthic

Referring to an animal that lives on or near the bottom of a body of water. Also an aquatic biome consisting of the ocean bottom below the pelagic and coastal zones. Bottom habitats in the very deepest oceans (below 9000 m) are sometimes referred to as the abyssal zone. see also oceanic vent.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

brackish water

areas with salty water, usually in coastal marshes and estuaries.

chemical

uses smells or other chemicals to communicate

coastal

the nearshore aquatic habitats near a coast, or shoreline.

cosmopolitan

having a worldwide distribution. Found on all continents (except maybe Antarctica) and in all biogeographic provinces; or in all the major oceans (Atlantic, Indian, and Pacific.

detritivore

an animal that mainly eats decomposed plants and/or animals

detritus

particles of organic material from dead and decomposing organisms. Detritus is the result of the activity of decomposers (organisms that decompose organic material).

diurnal
  1. active during the day, 2. lasting for one day.
drug

a substance used for the diagnosis, cure, mitigation, treatment, or prevention of disease

ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

estuarine

an area where a freshwater river meets the ocean and tidal influences result in fluctuations in salinity.

external fertilization

fertilization takes place outside the female's body

fertilization

union of egg and spermatozoan

food

A substance that provides both nutrients and energy to a living thing.

freshwater

mainly lives in water that is not salty.

heterothermic

having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.

introduced

referring to animal species that have been transported to and established populations in regions outside of their natural range, usually through human action.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

natatorial

specialized for swimming

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

planktivore

an animal that mainly eats plankton

polygynandrous

the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

saltwater or marine

mainly lives in oceans, seas, or other bodies of salt water.

seasonal breeding

breeding is confined to a particular season

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

visual

uses sight to communicate

zooplankton

animal constituent of plankton; mainly small crustaceans and fish larvae. (Compare to phytoplankton.)

References

2005. "Texas Parks and Wildlife Department" (On-line). Accessed December 02, 2005 at http://www.tpwd.state.tx.us/huntwild/wild/species/mullet/.

Bester, C. 2004. "Ichthyology at the Florida Museum of Natural History" (On-line). Accessed October 16, 2005 at http://www.flmnh.ufl.edu/fish/Gallery/Descript/StripedMullet/StripedMullet.html.

Eschmeyer, W., E. Herald, H. Hammann. 1983. A field guide to Pacific coast fishes of North America. Boston: Houghton Mifflin Company.

Hill, K. 2004. "Smithsonian Marine Station at Fort Pierce" (On-line). Accessed October 16, 2005 at http://www.sms.si.edu/irlspec/Mugil_cephal.htm.

Man, S., I. Hodgkiss. 1981. Hong Kong freshwater fishes. Hong Kong: Wishing Printing Company.

Robins, C., G. Ray. 1986. A field guide to Atlantic coast fishes of North America. Boston, U.S.A.: Houghton Mifflin Company.

Thomson, J. 1951. Growth and habits of the sea mullet, Mugil dobula Günther, in Western Australia. Australia: Aust. J. Mar. Freshwat..