Cynoscion regalis

Super Group: 
Opisthokonta
Phylum: 
Chordata
Sub-Phylum: 
Vertebrata
Class: 
Actinopteri
Order: 
Perciformes
Sub-Order: 
Percoidei
Family: 
Sciaenidae
Genus: 
Cynoscion
Species: 
regalis
Authority: 
Bloch & Schneider 1801
Synonym(s): 
Johnius regalis (Bloch & Schneider 1801)
Cestreus carolinensis (Gronow 1854)
Labrus squeteague (Mitchill 1815)
Otolithus obliquatus (Cuvier & Valenciennes 1879)
Roccus comes (Mitchill 1814)

Diagnosis

Diagnosis_Genus: Cynoscion Gill. Body elongated and nearly fusiform. Caudal peduncle of moderate size. Head oblong-conical, with a scarcely convex snout. Eyes wholly in the anterior half of the head. Mouth oblique; the supramaxillars cease nearly under or little before the posterior borders of the orbits. Lower jaw protuberant. Preoperculum with its margin membranous and crenulated. Teeth distant and recurved, nearly uniserial in the lower jaw, in front preceded by an additional row ; nearly biserial in the upper jaw, and normally with a canine tooth on each side of the symphysis; one is generally deciduous. Anterior dorsal fin with generally nine or ten spines; posterior of normal size. Anal fin trapezoidal, with only one very slender spine apparent externally. Caudal fin subtruncated. Ventrals in the same relative position as those of Sciaena. Lateral line with a sigmoid flexure, tubular, in scales formed like those of the rest of the body. The pharyngeal bones are armed with acute teeth; those of the upper are considerably curved. The setae of the first ceratobranchials are slender; their teeth are rarely in more than one or two irregular rows, and are but slightly curved. The internal sides of the first and both sides of the remaining branchial arches have a row of appressed semioval plates, armed with curved teeth, increasing in size towards the margin; besides the row of marginal plates, the sides have also many smaller ones. This genus is somewhat allied to Sciaena, but differs especially in the protrusion of the lower jaw, the presence of symphyseal canine teeth in the upper, the character of the preoperculum, and the single slender spine of the anal fin. It is also nearly allied to the typical Otolithi, differing from them by the absence of canine teeth on the lower jaw, the condition of the margin of the preoperculum, the presence of only one anal spine, the character of the lateral line, and especially in the position of the ventral fins. Type. Cynoscion regalis Gill. Syn. Otolithus regalis Cuv. et Val.

Diagnosis_Species: Johnius regalis Bloch & Schneider 1801. Caput totum fquamatum, fquamae-laeves, pinnae dorfale vicinae. Regalis. J. unica ferie dentium minimorum, 2 caninis in fuperiore maxilla, linea laterali recta, ventre albo, pinnis rubris, caudali fquamata, lata, lunata. P. I5. V. 7. A. I2. C. I7. D. 9/9. 50. Habitat in America feptentrionali, in provinciea New-York, King or White-Fifh dictus.

The period of incubation at water temperatures of from 20 to 21°C is 36 to 40 hours (Welsh & Breder, 1924).

Body_adults_length: 50-98 cm
Body_juveniles_length: 14-22.5 cm
Body_egg_length: 0.74-1.10 mm (Welsh & Breder, 1924)
Body_larvae_newly_hatched_length: 1.75 mm (Welsh & Breder, 1924)
Body_larvae_24hPH_length: 2.2 mm (Welsh & Breder, 1924)
Weight_max: 8.9 kg (Fishbase)
Weight: 5 kg (ADW)
 

Etymology

Cynoscion: Greek, kyon = dog + Greek, odous = teeth + Greek, skion, skiaina = barbel, red mullet

Type species

The type species of the genus Cynoscion is Johnius regalis (Bloch and Schneider 1801).

Ecology

Cynoscion regalis lives in Western Atlantic: Nova Scotia, Canada to northern Florida, USA (Fishbase).
Cynoscion regalis are found along the Atlantic coast. They migrate seasonally in the relatively shallow coastal water of sandy mud bottoms, and then to the brackish water of river estuaries for reproduction and feeding in the summer, finally returning offshore in the fall (ADW). During the spawning season, the most important habitat for the weakfish is the brackish waters of the Chesapeake Bay (Lowerre-Barbiere, 1996).

Migratory: diadromous_migration (anadromous)
Causality_of_migration: sexual_migration
Temporality_of_migration: seasonal
Substrate: water
Salinity: marine
Salinity: brackish (for reproduction and feeding in the summer)
Temperature_spawning: 15.5-21°C (Welsh & Breder, 1924)
Salinity: 28.01-30.9 (Welsh & Breder, 1924)
Depth_eggs: pelagic (Welsh & Breder, 1924)
Depth: 10-26 m (Fishbase)
Temperature: 17-27°C (Fishbase)
Habitat: coastal
Habitat: estuarine
 

Life cycle

They may live as long as 17 years; however, 12 years is a more reasonable expected lifespan (http://www.dec.ny.gov/animals/29042.html).
Cynoscion regalis is found in abundance along the Atlantic coast, from Cape Cod to eastern Florida (Welsh & Breder, 1924).
No sexual dimorphism (Fishbase).
The first spawning occurs at an age of 3 to 4 years for the females and 2 to 3 years for the males. Subsequent spawning occurs annually throughout life. In the sample of fish from the Cape May spawning grounds the majority were from 4 to 6 years old and the 5-year-old fish were the most numerous. (Welsh & Breder, 1924).
Generation_time: more than 3 years
Longevity: more than 3 years
Reproduction_mode: sexual (oviparous)
Fertility_period: seasonal (during spring and summer) (from early May to September, Welsh & Breder, 1924)
Spawning_method: external fertilization in the water column

Feeding behaviour

Carnivorous

Mode of locomotion

Motility: motile_swimming

Observation site(s)

SYMBIONTS

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Amyloodinium ocellatum New York Aquarium