The common snook (''Centropomus undecimalis'') is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of marine

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Centropomidae ''Centropomus'' is a genus of predominantly marine fish comprising the family Centropomidae. The type species is '' Centropomus undecimalis'', the common snook. Commonly known as snooks or ''róbalos'', the ''Centropomus'' species are native to ...

of the

order Order, ORDER or Orders may refer to: * A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica * Categorization, the process in which ideas and objects are recognized, differentiated, and understood ...

Perciformes Perciformes (), also called the Acanthopteri, is an order or superorder of ray-finned fish in the clade Percomorpha. ''Perciformes'' means " perch-like". Among the well-known members of this group are perches and darters ( Percidae), and als ...

. The common snook is also known as the sergeant fish or robalo. It was originally assigned to the sciaenid genus ''

Sciaena ''Sciaena'' is a genus of marine ray-finned fishes belonging to the family Sciaenidae, the drums and croakers. These fishes are found in the Eastern Pacific Ocean and the Eastern Atlantic Ocean. Taxonomy ''Sciaena'' was first proposed as a gen ...

;'' ''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 . The common length is . The IGFA world record is caught in Parismina Ranch, Costa Rica, by Rafael Montalvo. Of typical centropomid form, it possesses drab coloration except for a distinctive black

lateral line The lateral line, also called the lateral line organ (LLO), is a system of sensory organs found in fish, used to detect movement, vibration, and pressure gradients in the surrounding water. The sensory ability is achieved via modified epithelia ...

. It can also have bright yellow pelvic and

caudal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only ...

s, especially during spawn.

General ecology

Reproductive ecology

The common snook is a

protandric Sequential hermaphroditism (called dichogamy in botany) is one of the two types of hermaphroditism, the other type being simultaneous hermaphroditism. It occurs when the organism's sex changes at some point in its life. A sequential hermaphrodite ...

hermaphrodite fish species. Its spawning season spans from April to October. The peak spawning occurs during July and August. Spawning typically occurs in near-shore waters with high

salinities Salinity () is the saltiness or amount of salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensionless and equal to ...

. Following the spawning period, the juveniles then migrate to the

brackish water Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuary ...

s of the nearby

estuarine An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environm ...

environments. When these juveniles mature, they return to the higher-salinity waters of the open ocean to join the breeding population.

Habitat ecology

The common snook is an estuarine and freshwater-dependent fish species. Within estuaries, juvenile common snook are most often found inhabiting areas such as coastal wetland ponds, island networks, and creeks. Despite being a

euryhaline Euryhaline organisms are able to adapt to a wide range of salinities. An example of a euryhaline fish is the short-finned molly, '' Poecilia sphenops'', which can live in fresh water, brackish water, or salt water. The green crab ('' Carcinus m ...

species of fish, the common snook shows a tendency to gravitate towards lower-salinity conditions in the early stages of its life. By being able to adapt and thrive in both high- and low-salinity conditions through

osmoregulation Osmoregulation is the active regulation of the osmotic pressure of an organism's body fluids, detected by osmoreceptors, to maintain the homeostasis of the organism's water content; that is, it maintains the fluid balance and the concentration ...

, common snook display a high level of habitat

plasticity Plasticity may refer to: Science * Plasticity (physics), in engineering and physics, the propensity of a solid material to undergo permanent deformation under load * Behavioral plasticity, change in an organism's behavior in response to exposur ...

. 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. Common snook occasionally engage in

cannibalism Cannibalism is the act of consuming another individual of the same species as food. Cannibalism is a common ecological interaction in the animal kingdom and has been recorded in more than 1,500 species. Human cannibalism is also well document ...

. This usually occurs during the winter when adults and juveniles are in close proximity to one another within their estuarine habitats. This form of cannibalism where the juveniles are fed on by the adults is referred to as intercohort cannibalism. The adult common snook that cannibalize juveniles most likely target them because the juveniles may be the largest of the available prey, so are nutritionally efficient to prey upon.

Physiological ecology

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. 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 A cold wave (known in some regions as a cold snap, cold spell or Arctic Snap) is a weather phenomenon that is distinguished by a cooling of the air. Specifically, as used by the U.S. National Weather Service, a cold wave is a rapid fall in temp ...

. Snook are very susceptible to cold temperatures, with the effects ranging from the complete halt of all feeding at a water temperature of , to the loss of

equilibrium Equilibrium may refer to: Film and television * ''Equilibrium'' (film), a 2002 science fiction film * '' The Story of Three Loves'', also known as ''Equilibrium'', a 1953 romantic anthology film * "Equilibrium" (''seaQuest 2032'') * ''Equilibr ...

at , to death at a temperature of . 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.

Distribution and habitat

''C. undecimalis'' is widespread throughout the

tropical The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...

waters of the western

Atlantic Ocean The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ...

, from the coast of the

North Carolina North Carolina ( ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, South Carolina to the south, Georgia (U.S. stat ...

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

including the

Gulf of Mexico The Gulf of Mexico () is an oceanic basin and a marginal sea of the Atlantic Ocean, mostly surrounded by the North American continent. It is bounded on the northeast, north, and northwest by the Gulf Coast of the United States; on the southw ...

and the

Caribbean Sea The Caribbean Sea is a sea of the Atlantic Ocean, North Atlantic Ocean in the tropics of the Western Hemisphere, located south of the Gulf of Mexico and southwest of the Sargasso Sea. It is bounded by the Greater Antilles to the north from Cuba ...

. 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. Occurring in shallow coastal waters (up to in depth),

estuaries An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environm ...

and

lagoon A lagoon is a shallow body of water separated from a larger body of water by a narrow landform, such as reefs, barrier islands, barrier peninsulas, or isthmuses. Lagoons are commonly divided into ''coastal lagoons'' (or ''barrier lagoons'') an ...

s, the fish often enter

fresh water Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salt (chemistry), salts and other total dissolved solids. The term excludes seawater and brackish water, but it does include ...

. They are

carnivorous A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose nutrition and energy requirements are met by consumption of animal tissues (mainly mu ...

, with a diet dominated by smaller fishes, and

crustacean Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthrop ...

s such as

shrimp A shrimp (: shrimp (American English, US) or shrimps (British English, UK)) is a crustacean with an elongated body and a primarily Aquatic locomotion, swimming mode of locomotion – typically Decapods belonging to the Caridea or Dendrobranchi ...

, and occasionally

crab Crabs are decapod crustaceans of the infraorder Brachyura (meaning "short tailed" in Greek language, Greek), which typically have a very short projecting tail-like abdomen#Arthropoda, abdomen, usually hidden entirely under the Thorax (arthropo ...

s. 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. 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 occurred. Warmer winter temperatures resulting from climate change has been suggested as a likely cause. There may be potential food-web effects, particularly for sea trout (''Cynoscion'' species), related to the snook colonization.

Human interest

Three

United States Navy The United States Navy (USN) is the naval warfare, maritime military branch, service branch of the United States Department of Defense. It is the world's most powerful navy with the largest Displacement (ship), displacement, at 4.5 millio ...

submarine A submarine (often shortened to sub) is a watercraft capable of independent operation underwater. (It differs from a submersible, which has more limited underwater capability.) The term "submarine" is also sometimes used historically or infor ...

s have been named for this species, USS ''Robalo'' (SS-273) and USS ''Snook'' (SS-279) in the

Second World War World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

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. Snook are prized as

game fish Game fish, sport fish or quarry refer to popular fish species pursued by recreational fishing, recreational fishers (typically angling, anglers), and can be freshwater fish, freshwater or saltwater fish. Game fish can be fish as food, eaten aft ...

, being known for their great fighting capabilities. The IGFA all-tackle world record for common snook stands at caught by Gilbert Ponzi near Parismina Ranch, Costa Rica. Previous world records were caught in

Fort Myers, Florida Fort Myers (or Ft. Myers) is a city in and the county seat of Lee County, Florida, United States. As of the 2020 United States census, 2020 census, the population was 86,395; it was estimated to have grown to 95,949 in 2022, making it the List o ...

, and Gatun Spillway Canal Zone, Panama. Anglers regularly use a variety of lures to catch snook. Common lures include jerkbaits, bucktail jigs, topwater lures, spoons, and live bait.

Protection in Florida Gulf Coast

"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." 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.

References

External links

* {{Taxonbar, from=Q1914539

common snook 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 ' ...

Fauna of the Southeastern United States Fish of the Western Atlantic

Fish of Aruba