Animal Diversity Web

Geographic Range

Lemon sharks inhabit the Nearctic region of the Atlantic Ocean, from the coast of New Jersey, USA to southern Brazil, the Caribbean, and the Gulf of Mexico. There have also been sightings of lemon sharks along the coasts of Senegal and the Ivory Coast in Africa. This species is also found in the eastern Pacific Ocean, from Baja California to Ecuador. Lemon sharks are migratory and are found in oceanic waters during migration, but tend to be found in coastal areas otherwise. Efforts are underway to learn more specifics of lemon shark migration through tagging and tracking. (Carpenter, 2010; Compagno, et al., 2005; Gruber, 2004; Morgan, 2011; Sundstrom, 2011)

• Biogeographic Regions
• nearctic
  • native
• neotropical
  • native
• atlantic ocean
  • native
• pacific ocean
  • native

Habitat

Lemon shark are most commonly found in shallow ocean waters (to depths of 90 m), in habitats including mangroves, coral reefs and enclosed bays. They have also been known to congregate around docks. These sharks may be found in brackish and freshwater as well, most typically in river mouths and sounds, though they do not typically venture deep into these areas. They can be found in the open ocean during migrations. Lemon sharks can adapt to low oxygen and shallow water environments and may be found resting on ocean bottoms. (Compagno, et al., 2005; Morgan, 2011; Sundstrom, 2011)

• Habitat Regions
• tropical
• saltwater or marine

• Aquatic Biomes
• pelagic
• benthic
• reef
• coastal
• brackish water

• Range depth

  0 to 90 m

  0.00 to 295.28 ft

Physical Description

The coloration of lemon sharks varies from dark olive to yellowish brown dorsally, with a lighter yellow underside; they have no conspicuous markings. These sharks are large and stocky, with blunt snouts that are shorter than the width of their mouths. The bottom teeth are triangular and narrow with smooth-edged cusps, while the upper teeth are more broad and have smooth cusps and serrated bases. Teeth become more oblique as they near the corners of the mouth. They have two dorsal fins, with the posterior fin being shorter than the anterior, and paired pectoral and pelvic fins. This species is sexually dimorphic, with females being larger than males (averaging 240 cm vs 225 cm, respectively, though larger individuals have been found). (Carpenter, 2010; Sundstrom, 2011)

• Other Physical Features
• ectothermic
• bilateral symmetry

• Sexual Dimorphism
• female larger

• Range mass

  183.7 (high) kg

  404.63 (high) lb

• Range length

  240 to 368 cm

  94.49 to 144.88 in

Development

Following mating, female lemon sharks gestate developing young for 10-12 months, after which they give birth to a litter of 4-17 live pups. Young are typically 60-65 cm long at birth and these sharks grow throughout their lifetimes, at an average rate of 0.54 cm/year. (Morgan, 2011)

• Development - Life Cycle
• indeterminate growth

Reproduction

Mating occurs during the spring months, and is followed by a period of gestation for 10-12 months. It is likely that females store sperm from multiple mates to allow sperm competition, as a recent study showed that many lemon shark litters exhibit multiple paternity, indicating that this species is polyandrous. Mating is generally accomplished by a male biting a female on the pectoral fin and inserting his clasper (sexual organ) into her cloaca; recently mated females exhibit "mating wounds" from this behavior. (Feldheim, et al., 2002; Feldheim, et al., 2004; Morgan, 2011)

• Mating System
• polyandrous

Lemon sharks breed seasonally, typically during the spring and summer months. These sharks are viviparous and give birth to litters of 4-17 pups. Gestation period is 10-12 months and there is some evidence that, after producing a litter, females take a year off before mating again. Each time they give birth, female lemon sharks return to the same nursery areas. Juveniles remain in shallow waters of the nursery area, likely to avoid predators and have easy access to shore-line prey, for 2-3 years. They do not typically leave these safe areas until they have reached at least 90 cm in length and are less vulnerable. There is not much known beyond this regarding how and when juveniles leave for open waters and adult habitats, although there is evidence that they remain nearby their nursery areas for a number of years. (Chapman, et al., 2009; Feldheim, et al., 2002; Feldheim, et al., 2004; Morgan, 2011)

• Key Reproductive Features
• iteroparous
• seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• fertilization
  • internal
• viviparous
• sperm-storing

• Breeding interval

  Lemon sharks breed once yearly.

• Breeding season

  Lemon sharks breed during spring and summer months.

• Range number of offspring

  4 to 17

• Range gestation period

  10 to 12 months

• Range age at sexual or reproductive maturity (female)

  6 to 7 years

• Range age at sexual or reproductive maturity (male)

  6 to 7 years

Following mating, there is parental involvement by male lemon sharks. Females gestate young for 10-12 months. (Morgan, 2011)

• Parental Investment
• female parental care
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • female

Lifespan/Longevity

The longest recorded lifespan for the lemon shark in captivity is 25 years. Using size and growth rate information, individuals caught in the wild have been estimated at over 30 years old. (Carpenter, 2010; Sundstrom, 2011)

• Range lifespan
  Status: wild

  30 (high) years

• Range lifespan
  Status: captivity

  25 (high) years

Behavior

Lemon sharks are usually solitary, but they been found in groups of up to 20 individuals based on sex and size, often around fishing docks. They are active throughout the day, but are most active at dusk and dawn. (Carpenter, 2010; Compagno, et al., 2005; Morgan, 2011)

• Key Behaviors
• natatorial
• diurnal
• nocturnal
• crepuscular
• motile
• migratory
• solitary

Home Range

Juvenile lemon sharks stay in the nursery areas in which they were birthed until they are large enough to be able to survive in deeper waters. Their activity areas are typically just a few square kilometers, whereas adults may range within several hundred square kilometers. This species is also migratory, though not much is currently known about their habits during migration periods. (Morgan, 2011; Sundstrom, 2011)

Communication and Perception

Lemon sharks use a number of sensory channels. Their retinas have specialized horizontal bands known as "visual streaks" that are extremely rich in cones, which discern color and visual detail. Their vision is very important in prey capture, as evidenced by an experiment conducted at the Lerner Marine Laboratory, which found that temporarily blinded lemon sharks were not able to detect a 113 kg chunk of blue marlin (Makaira nigricans), while unimpaired lemons sharks found the blue marlin with ease. Lemon sharks do, however, have an acute sense of smell; another experiment at the same laboratory found that individuals of this species were able to detect one part of tuna juice in 25 million parts of sea water. As with all sharks, lemon sharks have ampullary receptors (Ampullae of Lorenzini) concentrated on their heads, which sense electric charges and serve to help them hone in on prey items. These sharks also have a homing sense, enabling females to return to the same areas each time they give birth and juveniles to return to safe nursery waters. (Feldheim, et al., 2002; Gruber, 2007; O'Connell, 2008; Reader's Digest Association, 1987)

• Communication Channels
• visual
• tactile

• Perception Channels
• visual
• acoustic
• chemical
• electric

Food Habits

Lemon sharks feed on molluscs, crustaceans, and bony fish. Some examples of prey items include cowfish (Acanthostracion quadricornis), flathead mullets (Mugil cephalus), spot-fin porcupinefish (Diodon hystrix), Atlantic guitarfish (Rhinobatos lentiginosus), spotted eagle rays (Aetobatus narinari), brown crabs (Cancer pagurus), red swamp crayfish (Procambarus clarkii), and southern stingrays (Dasyatis americana). Juveniles are known to feed on giant tiger prawns (Penaeus monodon) and shore crabs (Carcinus maenas). (Carpenter, 2010; Morgan, 2011; Sundstrom, 2011)

• Primary Diet
• carnivore
  • piscivore
  • eats non-insect arthropods
  • molluscivore

• Animal Foods
• fish
• mollusks
• aquatic crustaceans

Predation

While adult lemon sharks may occasionally eat juveniles, there are no known predators of adult lemon sharks. (Morgan, 2011)

• Known Predators

  • Lemon shark (Negaprion brevirostris)

Ecosystem Roles

Lemon sharks are hosts to a variety of ectoparasitic copepod species, as well as several endoparasitic fluke and tapeworm species. It has also been found with attached remoras (Echeneis naucrates), or sharksuckers, which feed on scraps from feeding lemon sharks and can also help to keep infestations of dermal parasites in check. (Bailly, 2012; "Negaprion brevirostris (POEY, 1868)", 2013; Mustard, 2013)

Economic Importance for Humans: Positive

Lemon shark meat has been marketed fresh, salted or frozen and their fins, in particular, are prized among Asian cultures for use in shark-fin soup. Liver oil from lemon sharks has been used for its vitamin content and its hide has been used as leather. (Carpenter, 2010)

• Positive Impacts
• food
• body parts are source of valuable material
• source of medicine or drug
• research and education

Economic Importance for Humans: Negative

This animal poses only a minor threat to humans; there are only 10 recorded unprovoked lemon shark attacks (none fatal) on record in the International Shark Attack File. (Carpenter, 2010; Morgan, 2011)

• Negative Impacts
• injures humans
  • bites or stings

Conservation Status

Although lemon sharks are classified as "Near-Threatened" by the International Union for Conservation of Nature (IUCN), there are no management plans currently in place for this species. (IUCN, 2012; Sundstrom, 2011)

• IUCN Red List

  Near Threatened

• US Federal List

  No special status

• CITES

  No special status

• State of Michigan List

  No special status

Contributors

Alexander Lister (author), Sierra College, Jennifer Skillen (editor), Sierra College, Jeremy Wright (editor), University of Michigan-Ann Arbor.

References

Jürgen Pollerspöck. 2013. "Negaprion brevirostris (POEY, 1868)" (On-line). Shark References. Accessed January 25, 2013 at http://shark-references.com/species/view/Negaprion-brevirostris.

Bailly, N. 2012. "Negaprion brevirostris (Poey, 1868)" (On-line). FishBase: World Register of Marine Species. Accessed January 25, 2013 at http://www.marinespecies.org/aphia.php?p=taxdetails&id=105800.

Carpenter, K. 2010. "Negaprion brevirostris" (On-line). FishBase. Accessed October 05, 2011 at http://www.fishbase.org/summary/speciessummary.php?id=897.

Chapman, D., E. Babcock, S. Gruber, J. Dibattista, B. Franks, S. Kessel, T. Guttridge, E. Pikitch, K. Feldheim. 2009. Long-term natal site-fidelity by immature lemon sharks (Negaprion brevirostris) at a subtropical island. Molecular Ecology, 18: 3500-3507. Accessed January 25, 2013 at http://www.oceanconservationscience.org/press/files/lemonsharkpaper0809.pdf.

Compagno, L., M. Dando, S. Fowler. 2005. Sharks of the World. Princeton, NJ: Princeton University Press.

Feldheim, K., S. Gruber, M. Ashley. 2004. Reconstruction of parental microsatellite genotypes reveals female polyandry and philopatry in the lemon shark, Negaprion Brevirostris. Evolution, 58/10: 2332-2342.

Feldheim, K., S. Gruber, M. Ashley. 2002. The breeding biology of lemon sharks at a tropical nursery lagoon. Proceedings of the Royal Society B, 269/1501: 1655-1661. Accessed January 25, 2013 at http://rspb.royalsocietypublishing.org/content/269/1501/1655.full.pdf+html.

Gruber, S. 2007. "Lemon shark fact file" (On-line). ARKive. Accessed January 25, 2013 at http://www.arkive.org/lemon-shark/negaprion-brevirostris/.

Gruber, S. 2004. "Research: Early Life History" (On-line). Bimini Biological Research Station. Accessed January 25, 2013 at http://www6.miami.edu/sharklab/research_earlylife.html.

IUCN, 2012. "The IUCN Red List of Threatened Species" (On-line). Accessed January 26, 2013 at www.iucnredlist.org.

Morgan, A. 2011. "Lemon Shark" (On-line). Ichthyology. Accessed October 10, 2011 at http://www.flmnh.ufl.edu/fish/gallery/descript/lemonshark/lemonshark.html.

Mustard, A. 2013. "Lemon shark (Negaprion brevirostris) accompanied by Remoras (Echeneis naucrates) at night. Little Bahama Bank. Bahamas. Tropical West Atlantic Ocean." (On-line image). Animals and Earth. Accessed January 25, 2013 at http://www.animalsandearth.com/en/photo/view/id/137022-lemon-shark-negaprion-brevirostris-accompanied-by-remoras-echeneis-naucrates-at-night-little-bahama-bank-bahamas-tropical-west-atlantic-ocean#/1/tag/Negaprion%20Brevirostris/undefined/.

O'Connell, C. 2008. "Evaluation of a Three-Dimensional Magnetic Barrier on Juvenile Negaprion brevirostris" (On-line). Ocean Magnetics. Accessed January 25, 2013 at http://www.sharkdefense.com/om/Fencing/Lemon_Sharks/lemon_sharks.html.

Reader's Digest Association, 1987. Sharks: Silent Hunters of the Deep. New York, CA: Reader's Digest Services Pty Ltd..

Sundstrom, L. 2011. "Negaprion brevirostris" (On-line). Accessed October 05, 2011 at http://www.iucnredlist.org/apps/redlist/details/39380/0.