genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...
of fish known commonly as
tigerfish
Tigerfish can refer to fish from various families, and derives from official and colloquial associations of these with the tiger (''Panthera tigris''). However, the primary species designated by the name "tigerfish" are African and belong to the ...
, tiger perch or freshwater tripletails, but all of these common names are also used for other families. It is the only genus in the family Datnioididae. These fish are found in fresh and brackish waters of rivers,
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 environme ...
and coastal areas in
South
South is one of the cardinal directions or compass points. The direction is the opposite of north and is perpendicular to both east and west.
Etymology
The word ''south'' comes from Old English ''sūþ'', from earlier Proto-Germanic ''*sunþa ...
and
Southeast Asia
Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia, South-eastern Asia or SEA, is the geographical United Nations geoscheme for Asia#South-eastern Asia, south-eastern region of Asia, consistin ...
, and
New Guinea
New Guinea (; Hiri Motu: ''Niu Gini''; id, Papua, or , historically ) is the world's second-largest island with an area of . Located in Oceania in the southwestern Pacific Ocean, the island is separated from Australia by the wide Torr ...
.
Some researchers suggest that this family is related to the tripletails, family Lobotidae, while others do not find enough evidence to make the suggestion. The two families share an apparently unique mode of tooth replacement, a trait which might be a
synapomorphy
In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to hav ...
Datnioides have a total of 24 vertebrae. The dorsal fin has a hard-rayed portion with 12 fin rays, and a soft-rayed portion with 15 to 16 fin rays. Along with the anal fin, which sits towards the rear of the fish, and the round caudal fin, these fins give the appearance of three caudal fins. The ploughshare bone and palatine bone in Datnioides fish are toothless. There are five species of Datnioides that can grow to be 30 to 45 centimeters in length. These fish are predatory and feed on small fish.
Systematics
The Dutch ichthyologist Pieter Bleeker first introduced the genus Datnioides in 1853. In most classifications, these fish are placed in their own family, called Datnioididae. The genera Lobotes and Hapalogenys, which was formerly often placed in the family Haemulidae, are closely related to Datnioides. In the standard work on fish systematics, "Fishes of the World" by Joseph S. Nelson, Datnioides and Lobotes are placed in the family Lobotidae, which was introduced by U.S. ichthyologist Theodore Nicholas Gill in 1861. Gill also introduced the genus Datnioides in 1861.
Species
The currently recognized
species
In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of ...