Populations of common snook have declined over the last 50 years due to commercial and recreational overfishing as well as habitat degradation and destruction. In 1957, a bill was passed in the Florida legislature which prohibited commercial fishing and the sale of common snook. Passage of this bill helped alleviate commercial fishing pressures on native populations, but habitat loss and water quality degradation may have a continued effect on populations of common snook. In January 1999, the Florida Fish and Wildlife Conservation Commission implemented a slot limit for recreational fisherman in order to protect larger breeding females. Florida fisherman can only harvest common snook between 26 and 34 in (66 to 86 cm) in length. Furthermore, there is a bag limit of 1 or 2 fish per person per day depending on the area. Fishing for common snook is closed between December 15 and January 31 statewide in Florida.
US Federal List: no special status
CITES: no special status
Common snook are considered top predators in their habitat, and adults do not have any natural predators other than humans. Juveniles are preyed upon by dolphins (Delphinidae and Phocidae), fish-eating birds such as osprey and herons, and larger species of fish.
Known Predators:
Common snook are easily recognized by their elongate body, distinct sloping forehead, concave snout, and protruding lower jaw. They are further characterized by their prominent black lateral line, which is formed by 67 to 72 pored scales, that extends into the caudal fin. Common snook range from 0.14 to 140 cm in length (average 50 cm) and can weigh as much as 23.3 kg. Females are generally larger than males.
Coloration ranges from dark brown to dull gray with a yellow to green tint on the dorsal surface. The lateral surface tends to be silvery, and the ventral surface is generally white. The pectoral fins, pelvic fins, second dorsal fin, and the dorsal lobe of the caudal fin are all bright yellow in color, however, some specimens are considerably darker.
Unlike in other species within the genus Centropomus, the tips of their pelvic fins do not overlap or reach the anus. Common snook have 2 dorsal fins that are well-separated, each with 8 to 9 dorsal spines and 10 dorsal soft rays. The anal fin has 3 spines and 6 soft rays, and the second anal spine does not reach vertical from the caudal base. The pectoral fins have 15 to 16 rays and do not reach vertical from the tip of the pelvic fins.
Range mass: 23.3 (high) kg.
Range length: 0.14 to 140 cm.
Average length: 50.0 cm.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry
Sexual Dimorphism: female larger
It is estimated that common snook can live about 20 years. The oldest captured common snook on the Atlantic coast was an 18-year-old female, while on the Gulf coast the oldest was a 15-year-old female.
Range lifespan
Status: wild: 18 (high) years.
Typical lifespan
Status: wild: 20 (high) years.
Common snook are amphidromous fish, moving between fresh and salt water during their life, but not for the purpose of breeding. They can be found in freshwater, brackish, or marine environments at depths up to 22 m. They commonly associate with underwater structures such as pilings, reefs, or sea grass beds, but they most often prefer mangrove-fringed estuarine habitats. As adults, common snook are generally non-migratory, but often assemble in high salinity regions in order to spawn. Most live in waters of temperatures between 25 and 31°C.
Range depth: 22 (high) m.
Habitat Regions: temperate ; tropical ; saltwater or marine ; freshwater
Aquatic Biomes: reef ; lakes and ponds; rivers and streams; coastal ; brackish water
Other Habitat Features: estuarine
Common snook, Centropomus undecimalis, range from the coastal mid-Atlantic regions of the United States through the Gulf of Mexico and Caribbean to parts of Central and South America. Common snook have been documented as far north as Pamlico Sound, North Carolina and as far south as Rio de Janeiro, Brazil. They are particularly abundant around coastal Florida.
Biogeographic Regions: nearctic (Native ); neotropical (Native ); atlantic ocean (Native )
Common snook are pelagic feeders. Daily feeding peaks occurrs 2 hours before sunrise and 2 to 3 hours after sunset. Their feeding behavior is affected by the tidal cycle, and feeding activity noticeably increases with an increase in water flow following a period of standing flood or ebb tides
Common snook are voracious predators and opportunistic carnivores. They primarily feed on other pelagic fish, though diet varies with habitat type. Juveniles generally inhabit freshwater habitats, and their diet primarily consists of palaemonid shrimp, microcrustaceans, copepods and mosquitofish. In saltwater environments, common snook have a similiar diet, but they may also prey upon other species of fish such as sheepshead minnows, bay anchovies, and pinfish. In saltwater environments, common snook also consume zooplankton and larger crustaceans.
Animal Foods: fish; aquatic crustaceans; zooplankton
Primary Diet: carnivore (Piscivore , Eats non-insect arthropods)
Adult common snook are top predators in their environment, preying on many species of pelagic fish, crustaceans, and copepods. Juveniles are preyed upon by dolphins, birds, and larger fish. In Florida, common snook are often parasitized by myxosporeans: Myxobolus centropomi, Fabespora sp., and Ceratomyxa choleospora.
Commensal/Parasitic Species:
While commercial fishing of common snook is illegal throughout Texas and Florida, they are prized game fish throughout their known geographic range. They are known as strong fighters when hooked. In 1986, Florida's fisheries and sport fishing enterprises of all game fish were estimated to be worth 5 to 7 billion USD annually. Common snook is prized for its culinary value.
Positive Impacts: food ; ecotourism
There are no known adverse effects of common snook on humans.
The oocytes in follicles of common snook mature in a manner typical of most teleost fishes. The yolk averages 91% of egg mass. Eggs average 0.6 – 0.8 mm in diameter (0.27 mm^3 volume).
Hatchlings measure 1.4 to 1.5 mm in length. Common snook grow slowly in the first month following hatching, but growth rates nearly triple thereafter until the end of the first year. Juveniles can grow as much as 1 mm per day, but this rate slows to about 0.15 mm per day once they reach 2.4 mm in length. Juvenile common snook typically have absorbed their yolk sac by the time they reach 2.2 mm in length (in about 4 days). At 4.0 mm in length, melanophores become visible, and, by 7.0 mm in length, adult pigmentation becomes apparent. Bone ossification begins when juveniles reach roughly 5.0 mm in length, and by 8.6 mm the jaws are completely ossified and lined with teeth.
Common snook, like most fish, uses their lateral line system to detect movement and vibrations in the surrounding water. This sense organ allows a fish to orient itself in the water column, avoid collisions with other fish or submerged objects, and sense the presence of other organisms such as predators or potential prey. Common snook are sight-feeders, using their sense of vision in concert with their olfaction and gustatory senses to find prey. They attempt to capture any moving particle in their mouth, where the potential food item is then either ingested or rejected depending on taste and texture. Marine fishes, including common snook, can distinguish amino acids solutions at concentrations to the order of 10^-9 M using their sense of olfaction. Common snook, with their acute senses of vision and olfaction in combination with their lateral line system, are some of the top predators in their habitat.
Perception Channels: visual ; tactile ; acoustic ; vibrations ; chemical ; electric
Although common snook can occupy both freshwater and marine environments, they must spawn in saltwater, as sperm can only become active in saline conditions. Common snook are often observed congregating at the mouths of rivers, inlets, and canals during times of spawning. Several males often follow a single female during these mass spawning congregations. Common snook spawn in the evening over a period of several days. In Florida, two reproductive peaks are often observed, the first from June to July and the second from August to October. Reproductive peaks often occur during times of increased rainfall, which may be the result of increased phytoplanktonic primary production during rainy periods. If so, spawning activity may related to food availability.
Common snook are protandric hermaphrodites, meaning they change from male to female after maturation. The gonads of common snook contain both male and female sex cells. Female gonads mature directly from mature male gonads shortly after a male has concluded spawning. This transition takes place between the ages of 1 and 7 years. As a result of this process, the majority of small common snook are male and the majority of large individuals are female. In Florida, the ratio of males to females between the ages of 0 and 2 years differs significantly between the east and west coasts of the state. This variation is attributed to protrandry and differences in growth and mortality rates.
Common snook breed seasonally and are often observed congregating at the mouths of rivers, inlets, and canals during times of spawning. In Florida, two reproductive peaks are often observed, the first from June to July and the second from August to October. Spawning often peaks during times of increased rainfall. Common snook practice broadcast spawning.
Breeding interval: Common snook generally breed twice each year.
Breeding season: In Florida, reproduction of common snook peaks in June and July and again from August to October.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sequential hermaphrodite (Protandrous ); sexual ; fertilization (External ); broadcast (group) spawning
Little information is known regarding the parental investment of common snook in their offspring. As broadcast spawners, however, members of this species are unlikely to provide parental care to hatchlings or juveniles.
Parental Investment: no parental involvement; pre-fertilization (Provisioning)
The common snook (Centropomus undecimalis) is a species of marine fish in the family Centropomidae of the order Perciformes. The common snook is also known as the sergeant fish or robalo. It was originally assigned to the sciaenid genus Sciaena; Sciaena undecimradiatus and Centropomus undecimradiatus are obsolete synonyms for the species.
One of the largest snooks, C. undecimalis grows to a maximum overall length of 140 cm (4.6 ft), but the common length is 50 cm (1.6 ft). The IGFA world record is 24.32 kg (53 lb 10 oz) caught in Parismina Ranch, Costa Rica, by Rafael Montalvo.[3][2] Of typical centropomid form, it possesses drab coloration except for a distinctive black lateral line. It can also have bright yellow pelvic and caudal fins, especially during spawn.[4]
The common snook is a protandric hermaphrodite fish species.[5] Its spawning season appears to span from April to October, with the peak spawning occurring during July and August.[6] Spawning typically occurs in near-shore waters with high salinities.[7] Following the spawning period, the juveniles then migrate to the brackish waters of the nearby estuarine environments.[7] When these juveniles mature, they return to the higher-salinity waters of the open ocean to join the breeding population.[7]
The common snook is an estuarine and freshwater-dependent fish species.[8] Within estuaries, juvenile common snook are most often found inhabiting areas such as coastal wetland ponds, island networks, and creeks.[9] Despite being a euryhaline species of fish, the common snook does show a tendency to gravitate towards lower-salinity conditions in the early stages of its life.[10] By being able to adapt and thrive in both high- and low-salinity conditions through osmoregulation, common snook display a high level of habitat plasticity.[11] Common snook are opportunistic predators whose feeding habits indicate a positive relationship between their size and the size of their prey, meaning that as the snook grows, it feeds on larger and larger prey.[12] Common snook have been found to occasionally engage in cannibalism.[13] This usually occurs during the winter when adults and juveniles are in close proximity to one another within their estuarine habitats.[13] This form of cannibalism where the juveniles are fed on by the adults is referred to as intercohort cannibalism.[13] The adult common snook that do cannibalize juveniles most likely target them because the juveniles may be the largest of the available prey, so are nutritionally efficient to prey upon.[13]
Common snook, like many species of fish, are very in tune with their environments; even a slight change in their surroundings can have a significant impact on their behavior. For example, common snook are able to determine when to start and stop spawning based on the temperature and salinity of the water they inhabit, the amount of rainfall in the area, and whether or not the moon is full.[14][15] However, in some cases, disturbances in their environment can have very negative effects on the snook population. One example is the devastating results of a cold snap. Snook are very susceptible to cold temperatures, with the effects ranging from the complete halt of all feeding at a water temperature of 14.2 °C (57.6 °F), to the loss of equilibrium at 12.7 °C (54.9 °F), to death at a temperature of 12.5 °C (54.5 °F).[16] Recently, a cold snap in January 2010 resulted in a 41.88% decline in nominal abundance of the common snook population in southwest Florida from the previous year and a 96-97% decrease in apparent survival estimates.[17]
C. undecimalis is widespread throughout the tropical waters of the western Atlantic Ocean from the coast of the North Carolina to Brazil including the Gulf of Mexico and the Caribbean Sea.[18] Snook likely originated in Central America, and changes in the earth's climate brought the snook to Florida. During a great warming trend after the Ice Age, snook moved northward along the Mexico shoreline. They followed the perimeter of the Gulf of Mexico, along the west and east coasts of Florida. Massive snook are found in Central America, although they seem to look a little different because of the weather and water quality, but they are the same. No restrictions exist in most of Central America on the size or quantity of snook one can keep, consequently many locals have been keeping and killing these large snook for quite a while.[19] Occurring in shallow coastal waters (up to 20 m (66 ft) in depth), estuaries and lagoons, the fish often enter fresh water. They are carnivorous, with a diet dominated by smaller fishes, and crustaceans such as shrimp, and occasionally crabs.[20]
Due to their limited cold tolerance, snook have been physiologically restricted from inhabiting temperate climates. In Florida, northern limits in their geographic range have historically been Tarpon Springs along the Gulf Coast and Cape Canaveral on the east coast.[21] Over the past 15 years, snook have extended their range as far north as the Suwannee River Estuary (~29°N), where an exponential increase in their population has been experienced.[22] Warmer winter temperatures resulting from climate change have been suggested as a likely cause.[23] There may also be potential food-web effects, particularly for sea trout (Cynoscion species), related to the snook colonization.[22]
Three United States Navy submarines have been named for this species, USS Robalo (SS-273) and USS Snook (SS-279) in the Second World War and USS Snook (SSN-592) in the 1950s.
Considered an excellent food fish, the common snook is fished commercially and foreign-caught fish are sold in the US. When cooking snook, the skin must be removed, because it imparts an unpleasant taste, described as soapy, to the fish.[24]
Snook are also prized as game fish, being known for their great fighting capabilities.[25] The IGFA all-tackle world record for common snook stands at 53 lb 10 oz (24.3 kg) caught by Gilbert Ponzi near Parismina Ranch, Costa Rica. Previous world records were caught in Fort Myers, Florida, and Gatun Spillway Canal Zone, Panama.[26]
Anglers regularly use a variety of lures to catch snook. Common lures include jerkbaits, bucktail jigs, topwater lures, spoons, and live bait.
"At the June 2012 Florida Fish and Wildlife Conservation Commission (FWC) meeting, Commissioners voted to keep the recreational harvest of snook in Gulf of Mexico waters closed through Aug. 31, 2013. This closure will offer the species additional protection after a 2010 cold kill detrimentally affected the population. Snook closed to harvest in Gulf of Mexico and Atlantic waters in January 2010 after a severe cold kill affected snook population number."[27]
All snook were "catch-and-release only" in the Gulf of Mexico until August 31, 2013. At that time, the FWC could choose to open or close snook harvest for another season. The commercial harvest or sale of snook is prohibited by the same regulations.
At the June 2013 FWC meeting, commissioners voted to let the recreational harvest of snook reopen in Gulf of Mexico waters from September 1 that year. The next stock assessment for snook was scheduled for 2015, but had not yet occurred as of June 2016, effectively leaving the fish under a protected status.[28]
The common snook (Centropomus undecimalis) is a species of marine fish in the family Centropomidae of the order Perciformes. The common snook is also known as the sergeant fish or robalo. It was originally assigned to the sciaenid genus Sciaena; Sciaena undecimradiatus and Centropomus undecimradiatus are obsolete synonyms for the species.
One of the largest snooks, C. undecimalis grows to a maximum overall length of 140 cm (4.6 ft), but the common length is 50 cm (1.6 ft). The IGFA world record is 24.32 kg (53 lb 10 oz) caught in Parismina Ranch, Costa Rica, by Rafael Montalvo. Of typical centropomid form, it possesses drab coloration except for a distinctive black lateral line. It can also have bright yellow pelvic and caudal fins, especially during spawn.
