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.
- Biogeographic Regions
- nearctic
- neotropical
- atlantic ocean
- pacific ocean
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.
- Habitat Regions
- tropical
- saltwater or marine
- Aquatic Biomes
- pelagic
- benthic
- reef
- coastal
- brackish water
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).
- Other Physical Features
- ectothermic
- bilateral symmetry
- Sexual Dimorphism
- female larger
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.
- 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.
- 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.
- Key Reproductive Features
- iteroparous
- seasonal breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- fertilization
- viviparous
- sperm-storing
Following mating, there is parental involvement by male lemon sharks. Females gestate
young for 10-12 months.
- Parental Investment
- female parental care
-
pre-fertilization
- provisioning
-
protecting
- female
-
pre-hatching/birth
-
provisioning
- female
-
provisioning
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.
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.
- 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.
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.
Food Habits
Lemon sharks feed on molluscs, crustaceans, and bony fish. Some examples of prey items
include cowfish (
Lactophrys 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
).
- 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.
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.
- Echeneis naucrates (Order Perciformes, Class Actinopterygii)
- Alebion carchariae (Order Siphonostomatoida, Subclass Copepoda)
- Alebion elegans (Order Siphonostomatoida, Subclass Copepoda)
- Kroyeria spatulata (Order Siphonostomatoida, Subclass Copepoda)
- Nemesis pilosus (Order Siphonostomatoida, Subclass Copepoda)
- Nemesis robusta (Order Siphonostomatoida, Subclass Copepoda)
- Nesippus orientalis (Order Siphonostomatoida, Subclass Copepoda)
- Pandarus sinuatus (Order Siphonostomatoida, Subclass Copepoda)
- Paralebion elongatus (Order Siphonostomatoida, Subclass Copepoda)
- Perissopus dentatus (Order Siphonostomatoida, Subclass Copepoda)
- Dermophthirius nigrelli (Class Monogenea, Phylum Platyhelminthes)
- Heteronchocotyle hypoprioni (Class Monogenea, Phylum Platyhelminthes)
- Neodermophthirius harkemai (Class Monogenea, Phylum Platyhelminthes)
- Anthobothrium laciniatum (Class Cestoda, Phylum Platyhelminthes)
- Callitetrarhynchus gracilis (Class Cestoda, Phylum Platyhelminthes)
- Callitetrarhynchus speciosus (Class Cestoda, Phylum Platyhelminthes)
- Dasyrhynchus giganteus (Class Cestoda, Phylum Platyhelminthes)
- Dasyrhynchus variouncinatus (Class Cestoda, Phylum Platyhelminthes)
- Floriceps saccatus (Class Cestoda, Phylum Platyhelminthes)
- Otobothrium penetrans (Class Cestoda, Phylum Platyhelminthes)
- Paraorygmatobothrium roberti (Class Cestoda, Phylum Platyhelminthes)
- Phoreiobothrium anticaporum (Class Cestoda, Phylum Platyhelminthes)
- Phyllobothrium dasybati (Class Cestoda, Phylum Platyhelminthes)
- Platybothrium harpago (Class Cestoda, Phylum Platyhelminthes)
- Platybothrium hypoprioni (Class Cestoda, Phylum Platyhelminthes)
- Phoreiobothrium lasium (Class Cestoda, Phylum Platyhelminthes)
- Phyllobothrium lactuca (Class Cestoda, Phylum Platyhelminthes)
- Poecilancistrium caryophyllum (Class Cestoda, Phylum Platyhelminthes)
- Pseudogrillotia perelica (Class Cestoda, Phylum Platyhelminthes)
- Tentacularia insignis (Class Cestoda, Phylum Platyhelminthes)
- Tentacularia perelica (Class Cestoda, Phylum Platyhelminthes)
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.
- 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.
- 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.
Additional Links
Contributors
Alexander Lister (author), Sierra College, Jennifer Skillen (editor), Sierra College, Jeremy Wright (editor), University of Michigan-Ann Arbor.
- Nearctic
-
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- Neotropical
-
living in the southern part of the New World. In other words, Central and South America.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- 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.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- 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.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- tropical
-
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
- saltwater or marine
-
mainly lives in oceans, seas, or other bodies of salt water.
- pelagic
-
An aquatic biome consisting of the open ocean, far from land, does not include sea bottom (benthic zone).
- 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.
- reef
-
structure produced by the calcium carbonate skeletons of coral polyps (Class Anthozoa). Coral reefs are found in warm, shallow oceans with low nutrient availability. They form the basis for rich communities of other invertebrates, plants, fish, and protists. The polyps live only on the reef surface. Because they depend on symbiotic photosynthetic algae, zooxanthellae, they cannot live where light does not penetrate.
- coastal
-
the nearshore aquatic habitats near a coast, or shoreline.
- brackish water
-
areas with salty water, usually in coastal marshes and estuaries.
- ectothermic
-
animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature
- 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.
- indeterminate growth
-
Animals with indeterminate growth continue to grow throughout their lives.
- polyandrous
-
Referring to a mating system in which a female mates with several males during one breeding season (compare polygynous).
- 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).
- 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
- fertilization
-
union of egg and spermatozoan
- internal fertilization
-
fertilization takes place within the female's body
- viviparous
-
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
- sperm-storing
-
mature spermatozoa are stored by females following copulation. Male sperm storage also occurs, as sperm are retained in the male epididymes (in mammals) for a period that can, in some cases, extend over several weeks or more, but here we use the term to refer only to sperm storage by females.
- female parental care
-
parental care is carried out by females
- natatorial
-
specialized for swimming
- diurnal
-
- active during the day, 2. lasting for one day.
- nocturnal
-
active during the night
- crepuscular
-
active at dawn and dusk
- motile
-
having the capacity to move from one place to another.
- migratory
-
makes seasonal movements between breeding and wintering grounds
- solitary
-
lives alone
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- visual
-
uses sight to communicate
- acoustic
-
uses sound to communicate
- chemical
-
uses smells or other chemicals to communicate
- electric
-
uses electric signals to communicate
- food
-
A substance that provides both nutrients and energy to a living thing.
- drug
-
a substance used for the diagnosis, cure, mitigation, treatment, or prevention of disease
- carnivore
-
an animal that mainly eats meat
- piscivore
-
an animal that mainly eats fish
- molluscivore
-
eats mollusks, members of Phylum Mollusca
References
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 .
Jürgen Pollerspöck. 2013. "Negaprion brevirostris (POEY, 1868)" (On-line). Shark References. Accessed January 25, 2013 at http://shark-references.com/species/view/Negaprion-brevirostris .