Ostraciidae or Ostraciontidae is a family of squared, Actinopterygii belonging to the order Tetraodontiformes, closely related to the and . Fish in the family are known variously as boxfishes, cofferfishes, cowfishes and trunkfishes. It contains about 23 extant species in 6 extant genera.
Taxonomy
Ostraciidae was first proposed as a family in 1810 by the French
polymath Constantine Samuel Rafinesque.
In the past this grouping was regarded as a
subfamily, the Ostraciinae, along with the subfamily Aracaninae, of a wider Ostraciidae. However, recent
Phylogenetics studies have concluded that the families
Aracanidae and Ostraciidae are valid families but that they are part of the same clade, the suborder
Ostracioidei.
The 5th edition of
Fishes of the World classifies this clade as the suborder Ostracioidea within the order Tetraodontiformes.
Etymology
Ostraciidae takes its name from its
type genus,
Ostracion, a name which means "little box" and is an allusion to the shape of the body of its
type species,
O. cubicus.
Description
Ostraciidae boxfishes occur in a variety of different colors, and are notable for the
or "honeycomb" patterns on their skin. They swim in a rowing manner. Their hexagonal plate-like scales are fused together into a solid, triangular or box-like
carapace, from which the fins, tail, eyes and mouth protrude. Because of these heavy armoured scales, Ostraciidae are limited to slow movements, but few other fish are able to eat the adults. Ostraciid boxfish of the genus
Lactophrys also secrete poisons from their skin into the surrounding water, further protecting them from
predation.
Although the adults are in general quite square in shape, young Ostraciidae are more rounded. The young often exhibit brighter colors than the adults. The
scrawled cowfish,
Acanthostracion quadricornis, can grow up to in length, but is generally smaller at higher latitudes.
Range
Ostraciids occur in the
Atlantic Ocean,
Indian Ocean, and
Pacific Ocean oceans,
generally at middle latitudes, although the common or buffalo trunkfish (
Lactophrys trigonus) which lives mainly in
Florida waters may be found as far north as
Cape Cod.
Toxic defences
The various members of this family are able to secrete cationic
surfactants through their skin which can act as a chemical defense mechanism.
[Abdulhaqq, A.J. & Shier, W.T. (1991): Icthyocrinotoxins and their potential use as shark repellents. Journal of Toxicology-Toxin Reviews, 10 (3): 289–320.] An example of this is
pahutoxin, a water-soluble, crystalline chemical
toxin that is contained in mucus secreted from the skin of
Ostracion lentiginosus and other members of the trunkfish family when they are under stress.
Pahutoxin is a
choline chloride ester of 3-acetoxypalmitic acid
that behaves similarly to steroidal
saponins found in
echinoderms.
When this toxic mucus is released from the fish, it quickly dissolves in the environment and negatively affects any fish in the surrounding area. It is possible since this toxin resembles certain detergents so closely, that adding these detergents as pollutants to seawater has potential to interfere with receptor-mediated processes in marine life.
Classification
The author Keiichi Matsuura lists the following genera and species:
[
]
Extant taxa
There are about 25 recognized extant species in six genera:| +
!Genus
!Species
!Image |
| Acanthostracion Pieter Bleeker, 1865 | | Scrawled cowfish |
| Lactophrys William Swainson, 1839 | | Smooth trunkfish |
| Lactoria D. S. Jordan & Fowler, 1902 | | Lactoria cornuta |
| Ostracion Carl Linnaeus, 1758 |
-
O. cubicum Linnaeus, 1758 (Yellow boxfish)
-
O. cyanurus Rüppell, 1828 (Bluetail trunkfish)
-
O. immaculatum Temminck & Hermann Schlegel, 1850 (Bluespotted boxfish)
-
O. meleagris G. Shaw, 1796 (White-spotted boxfish)
-
Ostracion nasus Bloch, 1785 (Shortnose boxfish)
-
O. rhinorhynchos Pieter Bleeker, 1851 (Horn-nosed boxfish)
-
O. solorense Bleeker, 1853 (Reticulate boxfish)
-
O. trachys J. E. Randall, 1975 (Roughskin trunkfish)
-
O. whitleyi Fowler, 1931 (Whitley's boxfish)
| O. meleagris |
| Paracanthostracion Whitley, 1933 |
-
P. lindsayi (Phillipps, 1932)
|
| Tetrosomus Swainson, 1839 |
-
T. concatenatus (Bloch, 1785) (Triangular boxfish)
-
T. gibbosus (Carl Linnaeus, 1758) (Camel cowfish)
-
T. reipublicae (Whitley, 1930) (Smallspine turretfish)
-
T. stellifer (Bloch & Schneider, 1801)
| T. gibbosus |
Fossil taxa
