Iso (genus)

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Iso
Iso flosmaris

Iso flosmaris

Systematics
Perch relatives (Percomorphaceae)
Ovalentaria
Superordinate : Earfish relatives (Atherinomorphae)
Order : Earfish (Atheriniformes)
Family : Isonidae
Genre : Iso
Scientific name of the  family
Isonidae
Rosen , 1964
Scientific name of the  genus
Iso
Jordan & Starks , 1901

Iso is a genus of the ear fish-like (Atheriniformes), which occurs with five species in the surf zone mainly on rocky coasts of the tropical Indo-Pacific .

features

Iso species are small fish and are only four to eight centimeters long. Your body is strongly flattened laterally, reaches its greatest height at the base of the pelvic fin and then becomes increasingly flat up to the tail fin stalk. The edge of the abdomen is keel-like. The head is small, the "snout" (region between the eyes and the tip of the mouth) is rounded, the mouth is slanted. The premaxillary is not protractile (cannot be pushed forward) and is connected to the skull by a central frenulum . The maxillary is slightly concave in front. The jaw teeth on the premaxillary and lower jaw are small but well developed and curved backwards. The ploughshare is also dentate in some species, and there are always no palatal teeth. The gill openings are large, the gill trap rays well developed on the first gill arch.

Iso species are colored silvery, a dark longitudinal band extends from the base of the pectoral fin to the stalk of the caudal fin. The scales are oval, the head is scaly. The pectoral fins stand high, the pelvic fins low.

Systematics

The first species of the genus, Iso rhothophilus , in 1901 by the Irish naturalist James Douglas Ogilby as Tropidostethus rhothopilus described . Since the genus name Tropidostethus had already been assigned to a genus of jumping horror , Iso was established as a new genus in 1901 by the American ichthyologists Jordan & Starks and initially assigned to the New World earfish (Atherinopsidae). In 1964, the American ichthyologist Donn Rosen then established the monotypical family Isonidae for the genus. Dyer and Chernoff assigned Iso to the family Notocheiridae in 1996 because they considered Iso and Notocheirus to be sister genera. For the family Notocheiridae, however, they only gave three autapomorphies . In 2006 the Isonidae family was revalidated again by Saeed, Ivantsoff & Aarn, as Notocheirus and Iso differ by at least 20 characteristics.

species

literature

  • Basim Saeed, Walter Ivantsoff & Aarn: Descriptive anatomy of Iso rhothophilus (Ogilby), with a phylogenetic analysis of Iso and a redefinition of Isonidae (Atheriniformes). Aqua, Journal of Ichthyology and Aquatic Biology, pages 25-43 online

Web links