The Centropomidae are a single genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 of freshwater

Freshwater

Fresh water is naturally occurring water on the Earth's surface in ice sheets, ice caps, glaciers, bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams. Fresh water is generally characterized by having low concentrations of dissolved salts and...

 and marine

Seawater

Seawater is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5% . This means that every kilogram of seawater has approximately of dissolved salts . The average density of seawater at the ocean surface is 1.025 g/ml...

 fish

Fish

Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...

es in Order

Order (biology)

In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...

 Perciformes

Perciformes

The Perciformes, also called the Percomorphi or Acanthopteri, is one of the largest orders of vertebrates, containing about 40% of all bony fish. Perciformes means perch-like. They belong to the class of ray-finned fish and comprise over 7,000 species found in almost all aquatic environments...

, including the common snook

Common snook

The common snook is a species of marine fish in the family Centropomidae of the order Perciformes. This species is native to the coastal waters of the western Atlantic Ocean and Caribbean Sea, from southern Florida and Texas...

 or róbalo, Centropomus undecimalis. Prior to 2004, three other genera were placed in Centropomidae in subfamily Latinae, which has since been raised to the family level and renamed Latidae

Latidae

The Latidae are a family of perch-like fishes found in Africa and the Indian and Pacific Oceans. The family, previously classified subfamily Latinae in family Centropomidae, was raised to family status in 2004 after a cladistic analysis showed the original Centropomidae was paraphyletic.Many...

 because a cladistic analysis

Cladistics

Cladistics is a method of classifying species of organisms into groups called clades, which consist of an ancestor organism and all its descendants . For example, birds, dinosaurs, crocodiles, and all descendants of their most recent common ancestor form a clade...

 showed the old Centropomidae to be paraphyletic

Paraphyly

A group of taxa is said to be paraphyletic if the group consists of all the descendants of a hypothetical closest common ancestor minus one or more monophyletic groups of descendants...

. Each of the four species (fat, swordspine, common, and tarpon) can be easily identified by their lateral black line. They are good tablefare, and are a sought after gamefish but tricky to catch.

Dating from the upper Cretaceous

Cretaceous

The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...

, the centropomids are of typical percoid

Percoidei

Percoidei is one of eighteen suborders of bony fish in the order Perciformes. Many commercially harvested fish species are contained in this suborder, including the snappers, jacks, whitings, groupers, bass, perches and porgies.-Divisions:...

 shape, distinguished by having two-part dorsal fin

Dorsal fin

A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...

s, a lateral line

Lateral line

The lateral line is a sense organ in aquatic organisms , used to detect movement and vibration in the surrounding water. Lateral lines are usually visible as faint lines running lengthwise down each side, from the vicinity of the gill covers to the base of the tail...

that extends onto the tail, and, frequently, a concave shape to the head. They range from 35 centimetres (13.8 in) to 120 centimetres (47.2 in) in length and are found in tropical and subtropical waters.