Opsanus beta

Super Group: 
Goode & Bean 1880
Batrachus tau beta (Goode & Bean 1880)
Opsanus vandeuseni (Fowler 1939)


Diagnosis_Genus: Opsuanus Rafinesque.Holobranchial Jugular.Body oblong thick attenuated behind, without scales, abdomen convex, no lateral line. Head large, broad, depressed above; eyes approximated on the top, separated by a furrow, and with an appendage behind: mouth large, lips thick, without barbs, lower jaw the longest, two rows of obtuse teeth to each jaw: Gill cover large, soft, spinescent above, branchial membrane with nine rays. All the fins with soft rays covered by a thick skin,two dorsal fins, the second very long, the first short, and with few hard thick obtuse rays,anal short, vent nearer to the tail than to the head.
Diagnosis_Species: Batrachus tau beta George & Bean. A specimen (N° 23541), 22 centimeters long was collected by Dr. Velie at Punta Russa, the most southern locality on record for this species. This fish, like all other Gulf of Mexico specimens inspected by us, agrees closely with var. β, as defined by Giinther in the tendency to expansion of the dark areas; the presence of small whitish spots upon the body; the greater average number of bands on the anal, approximating in number those of the dorsal, and the marking of the pectorals and caudal in white spots upon dark ground, lather than in brown upon white. The coloration of the southern specimens appears to be due to a tendency toward melanism, the dark areas being intensified as well as expanded. In the Punta Russa specimen (No. 23511) the main color is nearly black, the lines and marblings being of light shades of brown and brownish white, sharply and beautifully defined against the dark body-color. In the Pensacola specmien, No. 21477, the melanistic tendency is less evident. We consider the Gulf specimens as, for the present, constituting a distinct subspecies, founded entirely upon color. Radial formula of No. 23541, D. Ill, 24. A. II, 10. The first and second dorsal fins are continuous in 23541, but this is evidently' accidental. That the number of bands on the finsandtheir tendency to confluence is a character of little importance is shown in the following color notes: No. 4637 a. Beesley's Point. S. F. Baird. Light brown, finely marbled with darker, and not white spotted (a and b). Dorsal with eight bands. Anal w^ith seven bauds. Caudal with six bands. Pectorals irregularly brown spotted. 4637 b. Beesley's Point. S. F. Bakd. Light brown, coarsely marbled with darker. Dorsal with six bands, anal with six bauds, caudal with four bands, pectorals with the brown spots arranged in four bands. 4637 c. Beesley's Point. S. F. Baird. Dorsal mth eight, anal with seven, caudal with five, pectoral with five bands. 4637 d. Beesley's Point. S. F. Baird. Dorsal with eight, anal with six, caudal with four, pectoral with spots arranged in irregular, almost complete, bands. 4637 e. Dorsal with nine bands, the second and third and sixth and seventh confluent. Anal with nine bands. Pectoral with irregularly arranged quadrangular spots of brown and white, in a sort of checkerboard arrangement. 3441. Norfolk, Va. Dr. Jeffries. Body as usual. Dorsal with seven, anal with eight, caudal with four bands. Pectorals irregularly spotted with brown, arranged approximately in five bands. 23541. Punta Eussa, Fla. Dr. J. W. Velie. Body brown, marbled with very dark brown, and spotted with whitish. Dorsal with nine very regular blackish bands of uniform width, sharply separated by white. Anal with nine regular bands. Caudal with five. Pectoral brownish black dotted with white. 20632. Wood's Holl, Mass. U. S. F. C. Young specimen. White, with sides coarsely reticulated with brown. Dorsal with seven irregular confluent bands. Anal with nine irregular bands. Caudal irregularly marbled with broad penciling of brown. Pectoral with three or four very irregular lines of brown blotches. D 26. A 21. Others in the same bottle correspond in markings and radial formulae. 746. Indianola, Texas. J. H. Clark. Faded alcoholic specimens show a general agreement with the other Gulf specimens in the presence of seven to nine bands in both dorsal and anal, and in the white spots on pectoral and caudal. D. III. 25; A. 20 (in two specimens). 21477. Pensacola, Fla. Silas Stearns. Body nearly black, but agreeing in general with the descriptions, and with tendency to white maculation on body, pectoral, and caudal. Three bands on dorsal, eight on anal, not clearly separated as in the Key West specimen.
Body_adults_length: 10-36 cm
Body_length_sexual_maturity: 9.5 cm (U.S.A. off west-central Florida)
Body_adults_weigh: 0,110-1.360 Kg
Body_eggs_length: 4.1 mm
Toxicity: Yes_Ciguatera (https://www.flmnh.ufl.edu/fish/discover/species-profiles/opsanus-beta/) (Gulf toadfish have a slimy coating on their scales that can cause physical irritation)
Sequence_beta urea transporter: AF165893 (Rodela et al. 2011)
Sequence_beta glucocorticoid receptor: HQ424878 (Rodela et al. 2011)


beta: Named for its type locality, Brazil.

Type species

The type species for the genus Opasanus is Opsanus cerapalus (Rafinesque, 1818).

Type illustration / Type locality / Type specimen

Type locality: Off Institute of Marine Science dock, Aransas Pass, Port Aransas, Aransas County, Texas, U.S.A.
Type specimen: UMMZ 167103


Habitat: Demersal
Habitat: Western Atlantic: Florida (USA), Little Bahama Bank (Bahamas) and the entire Gulf of Mexico to Campeche, Mexico. Range extended to Brazil. Commonly found in seagrass beds and rocky cuts in coastal bays and lagoons, and in shallows along open coast.
Substrate: water
Salinity: marine
Migratory: Yes. Diadromous migration
Causality_of_migration: Sexual reproduction
Temporality of migration: Seasonal (February-March)
pH: 7.48 - 9.14
Temperature: 13.4 - 34.4°C
Temperature_spawning: 19.5°C
Oxygen_level: Oxic
Depth: Epipelagic (1-9 m)

Life cycle

Longevity_male: more than 3 years (19.4 years)
Longevity_female: more than 3 years (14.2 years)
Generation_time_female: 1 to 3 years (3 years)
Generation_time_male: 1 to 3 years (2 years)
Reproduction_mode: sexual
Fecundity_number_of_eggs_per_spawning: 12
Fertility_period: Seasonal (February-March, Western cost of Florida)
Spawning_method: External fertilization in the water column. (After spawning occurs, the male guards and aerates the large eggs until they hatch.
Sexual_diphormism_male: Bladders larger (8 gm)

Feeding behaviour


Mode of locomotion

Motility: motile_swimming


Observation site(s)


Displaying 1 - 2 of 2
Association with... Region origin Name of site In reference...
Amyloodinium ocellatum Gulf Coast Research Laboratory
Amyloodinium ocellatum Gulf Coast Research Laboratory

ASQME static network (beta)

ASQME dynamic network (beta)

ASQME map (beta)