Lemon Shark, Common Lemon Shark.
A large bodied shark with a short, rounded snout. Second dorsal fin almost as large as first dorsal. Dorsal coloration yellowish-brown, or olive-brown. Ventral coloration usually cream or yellow. Juveniles tend to have bluer hues and whiter ventrums. Some adults are quite dark. Fins may have dusky tips and posterior margins.
Maximum length 368cm (Hueter and Gruber 1982) but rarely exceeds 250cm. Size at birth 60-65cm.
Tropical and warm-temperate. Lemon sharks inhabit shallow coral reefs, mangroves, sandy and muddy bays, and river mouths. From the intertidal zone to at least 92m.
The lemon shark is most abundant in the western Atlantic. It is seasonally present from New Jersey to Brazil. It was once relatively abundant in the Eastern Pacific too, but overfishing has caused great declines. Officially it occurs from the Sea of Cortez to Ecuador.
There are also records from West Africa but there is uncertainty whether this is the same species (Campagno 1984). More research needs to be conducted but sightings are rare.
Lemon Sharks are caught commercially on longlines and the meat is dried, salted, or smoked. The fins fetch a very high price. The Lemon Shark is consumed in the United States and in Central and South America (Rose 1996). The rough and heavy skin has made the lemon shark preferable among tanneries for the production of leather. However, it is not included in TRAFFIC Network’s list of species frequently appearing in available information on worldwide shark fisheries (Rose 1996). It is a target species in Belize, Mexico and USA and reported as bycatch in St Lucia (Oliver 1996, Anon. 1997). Lemon Sharks were seen at a fish market in Cameroon in 1991, but not since then (C. Grist pers. comm.). The species is also caught in recreational fishing and was reported as the 13th most common shark species in the US recreational fishery (Casey and Hoey 1985). A decrease in the number of juvenile Lemon Sharks between 1986-1989 in the lower Florida Keys may have been caused by several years of shark fishing tournaments and 20 years of targeting with gillnets affecting the return of females to bear new litters (Manire and Gruber 1990). The Lemon Shark is a popular aquarium species and it is also used extensively for research purposes. Lemon Sharks used to be common in the western Atlantic, from New Jersey, USA to Brazil, but lately their numbers have been depleted, especially around Florida.
Citations and References
Sundström, L.F. 2015. Negaprion brevirostris. The IUCN Red List of Threatened Species 2015: e.T39380A81769233. https://dx.doi.org/10.2305/IUCN.UK.2015.RLTS.T39380A81769233.en. Downloaded on 05 October 2020.
A viviparous species with yolk-sac placenta. In Florida, mating occurss from late April to mid May. Up to 21 pups per litter, usually around 12. Gestation is approximately 12 months. Mating takes place biennially.
Lemon sharks mostly eat bony fishes i.e. reef fishes, eels, etc. Larger sharks also eat sharks and rays including small lemon sharks. Juveniles often consume crustaceans i.e. shrimps and amphipods.
Adult lemon sharks are generally solitary but occasionally form large aggregations, sometimes resting together on the substrate. The reason for these gatherings are unknown.
Reaction to divers
Usually quite tolerant of divers unless approached very closely. Can become quite aggressive in baited situations.
In South Florida and the Bahamas, lemon sharks are occasionally encountered on un-baited reef dives but sightings are unreliable. Fortunately, there are a few areas where baited dives attract numerous lemons.
Tiger Beach in the Bahamas remains the best site in the Western Atlantic to encounter lemon sharks. There are a variety of spots within the general area that attract lemons but the highest ratio that I have seen is at the old anchor chain in the middle of a shallow sand flat known as Tiger Wreck. This tends to be the first spot that we (Big Fish Expeditions) dive at because it is a good check-out dive site at only around 7m deep. Although you can also see all the other species that TB is famous for at Tiger Wreck, this particular spot mostly attracts lemon sharks.
At Fish Tales (less than a km away) there are also plenty of lemon sharks but they are mixed in with the tigers, reef sharks, nurse sharks, bulls, and hammerheads, so they tend to get overlooked. However, Fish Tales is a better spot to photograph them with a nice coral backdrop.
Another excellent spot to for close encounters with lemon sharks is during the baited dives off Jupiter Inlet in Florida. The feeds are in significantly deeper water than Tiger Beach so this dive is best for advanced divers.
In Bimini, we sometimes leave the hammerhead spot and snorkel in the mangroves. If you bring a little chum, this can be a good spot to look for neonate lemon sharks swimming around the mangrove roots.
Sharptooth Lemon Shark Extremely similar but this species does not share it’s range with the common lemon shark. It can be distinguished by its more curved, pointed fins, and small black spot on the tip of its snout.
Sandtiger Shark Similar coloration and fin sizes but easily distinguished by its pointed snout and permanently exposed pointed teeth.